Come Rain or Come Shine

Guest Post by Willis Eschenbach [Updated, see end of article]

One of the claimed dangers of a few degrees warming of the Earth is increasing drought. Drought is a very difficult thing to fight, because it is hard to manufacture water. So this is a frightening possibility.

I have long claimed that “a warmer world is a wetter world”. I have said this without any actual data, based solely on the following logic.:

Increased temperature —> increased evaporation —> increased precipitation.

Today I graphed the numbers for the US precipitation. I used the USHCN state-by-state precipitation database, which also includes area-averaged values for regions of the US, and for the US itself.

First, here is the change in precipitation in the US since 1895:

Figure 1. Annual precipitation in the US. PHOTO SOURCE

Since the both the US and the globe have warmed since 1895 it seems that a warmer US is a wetter US. However, precipitation is spotty and unevenly distributed. One area can be very wet while a nearby area is dry, so what about the precipitation in each of the states?

The USHCN database contains state data. Since there are drier states and wetter states, I looked at the percentage increase in precipitation rather than the absolute change in precipitation. Here are the state-by-state results:

Figure 2. State by state changes in precipitation, 1895-2009. Values are change per century divided by average annual rainfall.

One of the things that AGW supporters have been saying would result from warming is that the desert belts would move poleward. These are the great belts that circle the earth at about 30° North and 30° South latitude. The North American belt encompasses the Southwestern US (Southern California, Arizona, New Mexico, and Texas) and Northern Mexico. If these belts were actually moving poleward as the globe warmed over the last century, we should see decreased precipitation in the Southwestern US.

Instead, all of the southwestern states have increased rainfall. The main area with decreased rainfall encompasses the Rocky Mountain states in the central Northwestern US.

My conclusions? Precipitation is indeed spotty. A warmer US is indeed a wetter US. And there is no decrease in the Southwestern US data which would show that the great northern desert belt is moving polewards. So either the desert belt is not moving poleward, or the movement is offset by the overall increase in precipitation.

[UPDATE] Some commenters have correctly pointed out that I have only shown the precipitation, which doesn’t show the change in droughts. This is because droughts are a combination of soil moisture, temperature, rain, and other factors. This is measured by the Palmer Drought Severity Index (PDSI). The PDSI index values have the following meaning:

-4.0 to less (Extreme Drought)

-3.0 to -3.9 (Severe Drought)

-2.0 to -2.9 (Moderate Drought)

-1.9 to +1.9 (Near Normal)

+2.0 to +2.9 (Unusual Moist Spell)

+3.0 to +3.9 (Very Moist Spell)

+4.0 to above (Extremely Moist)

I used the USHCN database cited above to look at the state-by-state trends per century in the PDSI. Note that these are not the average PDSI values by state, which are without exception in the range -1.9 to +1.9 (near normal). Figure 3 is a histogram of the trends per century. A “histogram” shows the number of states (left scale) that have a certain trend range (bottom scale).

Figure 3. Histogram of state trends per century of the PDSI

The trend in most of the states (39 out of 48) is toward less drought (increasing PDSI). However, most of the trends (32 of 48) are between 0 and +2.0, which is not a large change. As a result, most of the trends are not statistically significant. Figure 4 shows the significant state trends:

Figure 4. Significant trends in the PDSI in the US states.

As you can see, despite the warming of the last 115 years shown in the USHCN dataset, while some of the PDSI trends have decreased, almost all of the statistically significant changes in the PDSI are positive (less drought). And few of the changes are statistically significant.

The IPCC models say that increasing warmth will lead to increasing drought, particularly in the mid-latitudes:

In a warmer future climate, most Atmosphere-Ocean General Circulation Models project increased summer dryness and winter wetness in most parts of the northern middle and high latitudes. Summer dryness indicates a greater risk of drought.

Despite these model prediction, we have seen no such increase in drought in the US. For most of the US, there has been so statistically significant change in the PDSI index showing the number and strength of droughts in most US states. And where there has been a statistically significant change, it is in the direction of reduced drought.

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160 thoughts on “Come Rain or Come Shine

  1. Well, here in Australia, we have had recent “100 year wet events”. Lake Eyre for instance, is now flooded.

    Lots of rain in New South Wales, Queesnland and Victoria. While all the time, since last year’s Victorian bush fires, predictions we’d have more dry, more dought and more bush fires.

    Nah! Nature is not cooperating with the computer models.

  2. Would have thought the – minus temp story was important enough to leave number 1 for at least a full 48 hours or related stories anyway so the press can have a look at it/digest etc… When big stories like that are quickly “demoted” or put number 2 etc.. or “lower priority” it detracts from them.. sorry my take on this one…

  3. I think you will find that the warmistas have already changed horses on this one when they had to explain how their prediction of a world where was snow was an increasing rarity was confounded by the reality of the winter of 2009-10. Yes, now CAGW is going to bury us under winter snow and maybe drown us with summer deluges.

  4. Sometimes simple logic works. “Increased temperature —> increased evaporation —> increased precipitation.”

    The real savings of water however is in the growth rate of crops. Cuurently it would take from ten to twenty percent more water to grow the amount of food we currently grow if C02 was still at 280 PPM!

    The monetary cost of increasing our world water supply by this amount would be trillions. The political stress of such a need could lead to wars. Any warming efffect of increased C02 decrease rapidly, the benefits continue on at least a lineal scale, if not greater, to at least 1000 PPM.

  5. The positioning of deserts has little to do with temperature, but mostly with geography: they form around 30deg N & S latitude due to Hadley Cell Circulation, and usually on the leeward side of mountain ranges.

  6. the unstated corollary is that if in fact it is cooling over the oceans where the bulk of the evaporation takes place then we will see dryer conditions overlall.

    The ARGO bouys are showing a slight cooling worldwide over the oceans, but this is an average, some areas have cooled signifigantly, so if the prevailing winds come from a cooler ocean area we might expect dryer conditions over land in the winds path.

  7. Willis,

    This is useful data to counteract overwrought “it’s worse than we thought” predictions. But what if it turns out that once WUWT’s documentation of UHI, poorly sited weather stations, weather station drop-out, and now the Mysterious Missing Em’s means it has actually cooled since 1895?

    Oh, never mind.

  8. It is curious that one of the states that had the largest decrease in rainfall (Wyoming) abuts one that had one of the largest increases (South Dakota). It makes no sense that the rain stops at the border. I wonder if the data is corrupted. Did the measuring techniques change over time (and space?)

  9. Excellent post Willis!

    There is a great many factors that effect precipation movement to be unpredictable. Evaporation and water is the regulator to keeping oceans from boiling and temperatures in check. In the last 100 years, we have changed that landscape and developed mass industrial technology that drinks up great amounts of water.
    I have noticed a trend that the mountains play an important role in directing evaporation formations southward along the west coast then move northeast ward once past the mountain formations.
    Winds are interesting when they are layered and hitting objects like hills or mountains.

  10. Fascinating graph since here in NW Wisconsin in the US we hear how we are below ‘average’ in rainfall and the lakes are well below the ‘ordinary’ high water mark but the graph makes things look a little above ‘normal’. Is there something new (?) showing up here like a several year weather pattern versus climate instead of just today’s weather versus climate?

  11. The fly in the oinment will be Australia. The expert opinion in the AR4 was that the US would generally benefit, but the mountainous western states would have les rain. Between US and Australia looks like their regional projections are a bit off. I think David Stockwell has pointed this out, as did the likelihood of errors by Dr.s Browning and Gravel.

  12. Patrick Davis (03:38:14) :
    Since 1967, the ocean salinity has changed on the surface and become more salty in the equatorial area. This would definately effect evaporation and cause massive draught as it did. Now the salinity is flipping the other way in the northern regions and is less salty.

  13. I’m ignorant. We had some very large hailstones here a few weeks ago, up to a couple of inches in diam. Does a conventional rainfall weather station capture these comprehensively, or is it hit and miss? Do they have any effect on pan evaporimeters, like splashing?

  14. Sometimes simple logic is overly simplistic.

    Increased temperature —> increased evaporation —> increased precipitation

    But the water doesn’t evaporate and then precipitate in the same place, or in a dramatically changed climate in the same places as it used to. In addition, more of that added precipitation will quickly be lost again by evaporation.

    The changes that you see now are not necessarily the changes you will see as the planet continues to heat. The fact is, at the moment the amount of warming that has been seen is minimal, because the planet doesn’t warm instantly, but the CO2 in the atmosphere now has already committed us to at least 1.5C warming, where we’ve only seen 0.5C to date.

    But when the planet warms more, yes, some areas will see much more precipitation, and while you may oversimplify it and say “more water is good for crops,” it can also cause flooding, and continued, previously uncommon flooding can destroy habitats. Ecosystems will change.

    Meanwhile other regions (like the southwest U.S.) will see more evaporation, with that water precipitating elsewhere, like in the northeast U.S. For regions that are already under stress for water, this is very bad news.

  15. “Joe (04:30:08) :

    Since 1967, the ocean salinity has changed on the surface and become more salty in the equatorial area. This would definately effect evaporation and cause massive draught as it did. Now the salinity is flipping the other way in the northern regions and is less salty.”

    So what you are suggesting is there is a “~100 year” cycle which brings about dry, ~100 years later wet, ~100 later dry, ~100 years later wet etc, conditions. And in well mixed sea water around the equater, I didn’t know the surface was saltier than the bottom.

  16. Drought is not simply a change in rainfall. Indeed, drought is a complex attribute to define — and not surprising there are many definitions of drought depending on what sector is being considered. At the least one needs to consider drought as a function of moisture availability for an activity. Hence this means drought is a function of: total rain, average temperature, dry spell duration, rainfall intensity, maximum temperatures, hot spell versus cold spell duration, seasonality, inter-annual variability, etc. One can actually have drought with no change or even counter-intuitive change in rainfall totals! Hypothetically, for example, imagine a shorter rain season of more intense rain events with longer dry spell durations and higher maximum temperatures. The response of, say, agriculture which has significant sensitivity to crossing environmental thresholds and dependencies on timing, would be marked, yet the rainfall totals may actually not change much from climatological baselines. i.e. it’s HOW the rain falls in conjunction other relevant parameters (such as Tmin and Tmax etc) that is important if you want to assess impacts. As usual, the impact of climate change can’t simply be swept under the rug with simple generalized statements on rainfall totals. (Likewise, nearly all of climate change needs far more nuanced assessment that can ever be properly addressed in a blog).

  17. Living in a state that’s surrounded by water, Florida, I know for a fact that if you have a lingering HIGH PRESSURE WEATHER SYSTEM, no clouds form and you get no rain. It has nothing to do with climate.

  18. The key to the exercise is to realize that climate and it’s variation are far more mysterious (in the sense of not being easy to model) than we thought. We must stop making multi-trillion $ policy decisions based upon models that are tweaked according to a political (economic) agenda and that can’t predict next month let alone the next century.

  19. Great post Willis.

    I think an unbiased examination of drought cycles would find correlations to the ENSO, PDO and even the ~1500-yr (Bond/Dansgaard-Oeschger) cycles.

    Lake sediments indicate that drought- and wet-prone conditions of West and East Africa alternate with the 1500-yr cycle. During the Medieval Warm Period (~800 AD to ~ 1300 AD) and the Modern Warming (~1880 to present), East Africa has been more drought-prone than West Africa… During the intervening Little Ice Age (~1300 AD to ~1880 AD), West Africa was more drought-prone than East Africa. (Verschuren, 2001 and Russel et al., 2007)

    Drought conditions of the American Southwest might also have a similar “mega-trend.” On a more local scale, the conditions correlate fairly well with the PDO. The “poster child” of global warming droughts, Lake Powell, has actually been gaining water volume since 2004. The entire Colorado River lake system has grown by 7% since 2004. Only Lake Mead has shown a decline in water volume over that time period…

    Change in Water Volume Since 2004

    Lake Powell +40%
    Lake Mead -21%
    Flaming Gorge +21%
    Lake Navajo +37%
    Lake Havasu +1%
    Blue Mesa +13%

  20. As already pointed out by David Becker, Ph.D. (04:18:08):
    Adjoining WY and SD are at opposite ends of the scale.
    And not only that:
    ”High end” SD is surrounded by states that are all at the lower end of the scale.

    Even though there can indeed be significant divergences from expected standard deviations in the real world, since this data goes back at the way to 1895 it seems more than a little odd that SD should be such a significant ”local outlier”.

  21. Wow awesome 30 second disprove of what thousands of actual scientists are researching! Lets close the CSIRO her in Australia and just pay Mr Eschenbach a cool million for 5 minutes work a week and he can have the rest of the time off.

    Hmm I just realised that comment may not strike many of you as sarcastic. It is.

  22. Interesting.

    Typo correction: “The MAIN area with decreased rainfall encompasses the Rocky Mountain states in the central Northwestern US.”

  23. The real savings of water however is in the growth rate of crops. Currently it would take from ten to twenty percent more water to grow the amount of food we currently grow if C02 was still at 280 PPM!

  24. Does morning dew count? Part of it gets absorbed by plants and soil, part evaporates. What proportions of each? I usually water my garden in the early morning to take advantage of the dew. How about sublimation, in addition to evaporation? Or lag times of water movement thru the ground ( varying porosity ) to replenish aquifers, etc. etc.

    My point is that there are so many unknowns, and chaotic behavior, in the hydrologic cycle that trying to model the granularity of it is impossible. You can drive yourself nuts trying to figure it out.

  25. OT Warning:

    If Piltdown Man was the scientific frauf of the 20th century, then Meltdown Mann must be the scientific fraud of all time.

  26. 30% of the suns rays are reflected by clouds.
    70% of the Earths surface is water, the rest mostly land.
    On a day without clouds, the ‘average’ temperature of land increases proportionately more than the ‘average’ temperature of the air above the seas; compared with cloudy days.
    So, the global ‘average’ temperature will be hotter if 29% of the clouds are over land and much colder if 31% of the clouds are over land.
    Small changes in where clouds actually are will have a huge effect on the reported average global temperature, even though the same amount of energy is entering the system.
    The rainfall pattern, linked to some clouds, is indicative that the ratio of clouds over land:sea’s changes in time, and does so quite quite dynamically +/- 25% per years.

  27. Why don’t people talk about wind, wind patterns and changes and location of high and low pressure? I have done yacht racing for 4 decades and track the same and know how this effects rainfall and weather. If you have some humidity, some low pressure you get lift. I have seen clear skies turn into a thunderhead and deluge in a single hour. Add heat and the lift takes it up to cold air. This surface temp stuff it not complete. Air temps at 50,000 feet have never become hot.

  28. Much of the folklore about drought in the southwest is due to fact that water usage has increased dramatically in the last 50 years.

    When lake levels drop, people assume that it is due to decreased inflows rather than increased outflows. A lot of water in the west is being used to raise biofuels crops, particularly corn. When I see people out here driving cars advertising “green” biodiesel, I immediately question their IQ.

  29. You must remember about these eco-idiots that, in their myopic minds, global warming only produces negative benefits. Positive benefits of global warming cannot be used to control and tax people. That is why such people say global warming means more droughts.

  30. Where is the arbitrary 21 year base line and the corresponding anomaly graph?
    Also, your y-axis scale needs to be much smaller to make the changes look much bigger. :)

  31. “sphaerica (04:44:07) :
    [...]
    The fact is, at the moment the amount of warming that has been seen is minimal, because the planet doesn’t warm instantly, but the CO2 in the atmosphere now has already committed us to at least 1.5C warming, where we’ve only seen 0.5C to date.”

    The fact is that you confuse assumptions with facts.

  32. Do any climatologists read geology? It is pretty well established that in geological time warm eras are wet and cool eras are dry.

  33. Willis,
    One thing I have been studying is density changes in the atmosphere as rotation pulls along the atmosphere which is very elastic. With this volcano blocking sunlight, it is also putting more dust and debris into the atmosphere in the northern hemispherical cycle. Gravity(joke name) as mass has no power of it’s own. The magnetic field will pull on the debris field.
    Expect colder temperatures to come from this in the northern hemisphere.

  34. Here in New Hampshire we have seen an annual increase of about 12% (5.5 inches) over the 114 year period. With the majority of the increase occurring in the months of June, July and October.

    Also interesting is that the months of January, February and September have shown a decrease during this period.

  35. There is a case to be made that we need to be able to move water more efficiently over long distances. But then even looking at California, we’ve really done near to nothing about desalinating sea water for drinking/irrigation use.

    I’m reminded of a great old quote from just after the American civil war. President Grant sent his secretary of the interior out to look at the far west so far as population expansion into that area. That worthy reported “All this land lacks is water and good people.” Grant fired back, “That’s all Hell lacks.”

  36. I grew up on a sand farm in SE Missouri. About 15 miles from the Southernmost part of the hilly, forested area called Crowley Ridge. We had a sand hill that was rich in Bison Skulls, arrow heads, etc.

    It was the driest couple of square miles, probably, in all Missouri, and Arkansas. No joke. My father got ulcers watching the storm clouds come down from the North, and Split, going right around us.

    There was a U.S. Army Air Corps flight school a few miles away. The instructors told (I’m sure of this because our local crop-duster trained there) the trainees that in case of Bad weather to fly over to the area of our farm. They told the recruits that if there was going to be clear skies anywhere in the area it would be there.

    Weather is really complicated. “There is much more, Horatio, than is dreamed of in your philosophee.”

  37. @David A (04:00:00) :

    The real savings of water however is in the growth rate of crops. Cuurently it would take from ten to twenty percent more water to grow the amount of food we currently grow if C02 was still at 280 PPM!

    Yes. I learned this several years ago. It’s not commonly known. Plants use less water per unit of biomass as CO2 concentration rises. If I recall correctly the mechanism whereby this occurs is due to the way stomata regulate gas exchange. Stomata are microscopic pores in leaf surfaces that iris open and closed to regulate gas (CO2 and O2) exchange. Water vapor escapes from the plant (transpiration) during the exchange. When the CO2 concentration is higher in the air less total air volume is required for the gas exchange. The stomata don’t open as much and less water vapor escapes in the process. Pretty cool.

  38. Willis – your post reminded me of an interesting video I saw on YouTube a couple of years ago. It looks at water vapour trends in the US. I don’t know much about the author, and the presentation is a little basic. But the points are well made – I’d encourage you and others here to watch the vids and consider the points raised. The presentation is in two parts:

    On a loosely related matter, disappearing Lake Chad was the poster child of the AGW movement a few years ago. I have looked for more recent trends, but nothing much to find. I recall there were serious floods across North Africa a year or two ago and I wondered how much would have drained into Lake Chad. Is it a case of “no news is good news”? Does anybody have anything on the latest postion of Lake Chad?

  39. Nothing new . Read

    The Past and Future of Climate
    David Archibald
    May, 2007

    Figure 7: The Last Four Ice Ages

    Also interesting is the amount of dust. Colder is drier and warmer is wetter, generally.
    Large areas of Australia are covered by sand dunes that formed in these ice ages and are now stabilised by vegetation.

    http://www.climatepolice.com/Past_Future_climate.pdf

  40. sphaerica (04:44:07) :
    “Increased temperature —> increased evaporation —> increased precipitation
    But the water doesn’t evaporate and then precipitate in the same place, or in a dramatically changed climate in the same places as it used to. In addition, more of that added precipitation will quickly be lost again by evaporation.”

    Global precipitation trends can (are) be folllowed, but it is easy to agree
    that it is more fruitful to look at regional to local climates, because of the
    reasons given by spaherica. Also locally, if you want to say anything
    meaningful about drought, which was Willis opening phrase, you would
    have to plot temperature, precipitation, transpiration over the seasonal
    cycle and identify periods of concern; your local farmer will help you.

    fredb (04:51:05) :

    says the essential about drought in his post, but for some it seems to
    be to analytical a text.

  41. Should there be concern about rain records with respect to how/where they are measured, much like the concerns about the sitings of temperature gauges? Will Anthony begin a ‘rain stations’ project when the surface stations is complete?

  42. Dear Willis
    Thank you very much for your very good posts.
    A way to look at rain fall might be the variation in the amount of dam water reservoir of the region under analysis. In Spain that amount right now is more than 20% of the mean of the last ten years and at 82% of its capacity. See http://www.embalses.net/

  43. Footnote to good observation by David Middleton (04:55:14) :

    I believe only reason Lake Mead is minus 21% is that dam operators are filling Lake Powell first; and for the most part (except for relatively minor ”flushing” operations) are not letting anything in excess of that which is run thru the turbines go thru Glen Canyon Dam; i.e.:
    All spring runoff in excess of power generation needs is being held behind that dam.

    Lake Powell has been WAY down from full capacity. Several of us drove by Glen Canyon Dam on the way to row the Colorado River thru Grand Canyon last year, and the ”bathtub ring” on Lake Powell was striking. And note the Park Service just opened a long road extension to the Pierce Ferry river-runner takeout at the end of the Grand Canyon river run; after that takeout was closed for a number of years due to extreme low water in Lake Powell.

  44. Here is some good data:

    http://www.esd.ornl.gov/projects/qen/nerc130k.html

    The Younger Dryas and Older Dryas do have “dry” in them for good reason.
    Cold climate = dry.

    Short term drops in temperature in Summer time though, cause a jump in rainfall.
    The complete opposite happens in winter, when it takes a temperature uiplift
    to force an increase in precipitation.
    Such that when looking at England and Wales rainfall since 1766, generally the colder years are wetter, and hotter are years dry.
    But some years above 10.0 deg. C., are amongst the wettest. It all depends on when the temperature spikes and notches occur relative to the seasons.

    Longer periods of colder climate regimes do always go dry, and deserts expand.

  45. I consider that what the warmist are thinking is that with increased temperature, there won’t be any precipitation as a result of there being a higher temperature all the time, regardless.

    A Kinda sorta Venus scenario …

    But what they —the warmist— neglect to consider is that the Earth is farther away from the Sun, and therefore is very much less affected over all by solar radiation in the way they would have the rest of us believe.

    By dint of just the changing of the seasons alone, we aren’t so nearly affected as they would think, even by our own influences.

  46. Dear Willis: Common sense prevails though it would not reach the MSM. Your wise, and elementary, reasoning about the WATER CYCLE tell us that something is rotten in the educational area, perhaps because of blindly following UNICEF (binding agreements?) regarding educational curricula, I don´t know but perhaps the “prophet of evil” most malevolous climatic theories are corrupting our kids´minds (actually grand kids) with all that environmental and “save the planet” crap.

  47. BTW Glaciers grow with increasing humidity
    Didn´t you know buddy that Ice, is made out of water?, so:
    No water=No Ice.

  48. I tackled this <a href="http://sonicfrog.net/?p=2841"back in Feb when we had the Global Warming caused blizzards. Remember the lame rational to support that was that we were getting more storms and blizzards because Global Warming = an increase in precipitation. A blogger was using the EPA’s stats to show that North America had become wetter over the last century. OK, but then I decided to follow the link for more info. Low and behold, this was on the next EPA page.

    Precipitation has generally increased over land north of 30°N from 1900-2005, but has mostly declined over the tropics since the 1970s. Globally there has been no statistically significant overall trend in precipitation over the past century, although trends have varied widely by region and over time.

    I’m glad someone else has followed up on this. But Willis, really, you could have just come to me and I would have saved you all the time and research! :-)

    Mike aka Sonicfrog.

  49. not willing to believe there can be such a deviation between South Dakota and Colorado.

    I’m willing to bet there is an element of quality of record keeping that is involved.

    Like the time the attendant goes on vacation and has their relative take the measurements while they are out of town. “Uncle bob” had better things to do.

  50. TWW (04:26:30) :
    willis’s map is based on 1895 to 2009 change. so, you know what the comparisons are with.

    when the TV folks talk and newspaper folks write, there is not even a reference year. it is just based on whatever will make the news interesting to watch/read.

    as for the “professors” announcement, it is based on god knows what reference years…. they are just geared towards trying to get some grant money.

  51. During the last century many areas have changed land uses.

    It wouldn’t surprise me if the increased rainfall in the northeastern US is related to more tree cover. Early in the century this area was largely agricultural. There was appreciable sheep grazing of the hills and hay exports to transport folks in new york city.

    On another note, I wonder if cosmic ray intensity will correlate better with rainfall than temperature trends. The indian monsoon has a perodicity with the 22 year hale cycle

    http://cdaw.gsfc.nasa.gov/publications/ilws_goa2006/178_Hiremath.pdf

  52. @DAVID A
    Great post. An EXTREMELY important point !!

    The science of Botany was well developed long before the politicization of climate science. Science done prior to this politicization cannot be reasonably challenged on the basis of political bias. I quote the abstract of a paper published in 1983 that addresses the question of the direct effects of CO2 concentration on agricultural productivity and water use efficiency.

    “About 430 observations of the yields of 37 plant species grown with CO2 enrichment increased agricultural weight yields by 36%. Additional analysis of 81 experiments which had controlled CO2 concentrations showed that yields will probably increase by 33% with a doubling of CO2 concentration. Another 46 observations of the effects of CO2 enrichment on transpiration were extracted and averaged. These data showed that a doubling of CO2 could reduce transpiration by 34%, which combined with the yield increase, indicates that water use efficiency may double.”(with a doubling of CO@ concentration)

    Kimball,B.A. and Idso, S.B. 1983. “Increasing atmospheric CO2 : effects on crop yield, water use and climate. Agric. Water Manag., 7:55-72

    This link shows time lapse photography of the effect of CO2 concentration on plant growth

    http://www.co2science.org/education/truthalerts/v13/cowpea.php

    Any discussion that attempts to infer a link between increases in CO2 and decreases in the food supply as a result of (computer projections of) drought, that does not take into account the positive externalities of CO2 emissions is simply not science. It is propaganda. If there is one important lesson we should have learned in the twentieth century, it is that policies that are based upon propaganda rather than facts are extremely dangerous.

  53. Look we have the great MattB (05:00:48) : with us, he’s come to defend the indefensible LOL.

  54. Here is a really interesting paper which clearly demonstrates the periodicity of rainfall with the solar cycle in the US. Seems there is a lag with the TSI.

    http://www.greatglobalwarmingswindle.com/pdf/Gamma%20Rays%20and%20Climate%20-%20Perry,%20Charles.pdf

    Even in the chart presented by willis we can see the 22 year hale cycle in the original posting. Landscheidt could predict el ninos and the US midwest droughts by using solar observations. i don’t understand why wattsupwith doesn’t look at his approaches as he is the only person with a track record of successful predictions around appreciable rainfall change trends.

  55. What David said.

    David Becker, Ph.D. (04:18:08) :
    “It is curious that one of the states that had the largest decrease in rainfall (Wyoming) abuts one that had one of the largest increases (South Dakota). It makes no sense that the rain stops at the border. I wonder if the data is corrupted. Did the measuring techniques change over time (and space?)”

  56. Dust in the atmosphere is generally reckoned to be a sign of dryness and desertification. The Vostok ice core record shows that dust tends to be at its highest toward the end of ice ages and at a minimum during the warm inter-glacials. (http://en.wikipedia.org/wiki/Ice_age). In other words, the data shows that warmer periods have less desertification.

  57. If Earth started getting no volcanoes I just bet ya’ the desert would begin spreading towards the poles in a big time hurry. Water vapor that has little dust to cling to produces less clouds/rain. That all changes dramatically with a decent size eruption.

    But if its colossal enough it can also lead to our extinction… those things that protect life on this rock… eruptions.

  58. willis, your main point about the lack of a drying trend in the US is a good one.

    As an exercise, though, I do wonder, though, whether “increased temperature = increased evaporation = increased precipitation” is necessarily correct. Evaporation is a function of temperature and of the humidity of the air into which it evaporates. The humidity of the air is a function of how well the precipitation cycle (mostly the Hadley-Walker aspect) works.

    The precipitation cycle depends on how well each leg works. If the cooling/sinking leg does not work so well with increased CO2 then perhaps the upper troposphere becomes “clogged” with relatively warm air, which inhibits the formation/size of rain clouds.

    Something to ponder.

    David

  59. Adjacent regions/area having diametrically opposing rainfall data comes with the territory. Simply watch a time sequence of intrumental or tree ring data and the reason why is readily apparent. There are places which share common borderline inclusion with more than 1 region. The patterns repeat often enough, and the dry vs wet centers are offset enough to make for regions/states that appear in stark contrast over time.
    That being said, we live in a time where data has not been properly taken, stored or reported.
    Like the missing M in METAR, the reset button is now M as in Mandatory.
    It’s going to be a long time before confidence is restored in climate records.
    Work done prior to the politicisation of climate data is at a premium.

  60. ” sphaerica (04:44:07) :

    Sometimes simple logic is overly simplistic.

    Meanwhile other regions (like the southwest U.S.) will see more evaporation, with that water precipitating elsewhere, like in the northeast U.S. For regions that are already under stress for water, this is very bad news.”

    Your first line is certainly correct.
    Regarding the last para, you might want to consult your local meteorologist.

    I know.. AlGore hasnt actually invented the Jet Stream, yet.
    Still…..

  61. We know from western history that during the Roman warm period north Africa was the bread basket of the empire. We also know that during the Medieval warm period the US southwest supported corn crops that allowed the Anasazi to flourish.

    From this it would appear that warmer climates are wetter in the northern hemisphere desert belts. I suspect that similar patterns could be inferred from palynological records in the southern hemisphere (northern too).

    This begs the question of why the climate models predict otherwise.

  62. Chris Riley (08:49:01) :,

    Very good point. Add to this the possibility that the “heat in the pipeline” is actually the fuel used to increase the biomass fertilized by human CO2 emissions. The net is a small increase in temperatures while feeding millions (if not billions) more humans.

    The perfect negative feedback.

  63. David Becker, Ph.D. (04:18:08)

    It is curious that one of the states that had the largest decrease in rainfall (Wyoming) abuts one that had one of the largest increases (South Dakota). It makes no sense that the rain stops at the border. I wonder if the data is corrupted. Did the measuring techniques change over time (and space?)

    David, the data is aggregated by the USHCN on a state-by-state basis, so the changes will be on a state-line basis. I was curious about this as well. The South Dakota data could be corrupted, as it contains a fairly large single-year jump. I have no independent way to verify it, but it may be bad.

    w.

  64. This is a simple question but has a very complex answer. The distribution of moisture over geographic areas has many factors, few that respect political boundaries. Gross measurements like average rainfall or average temperature may make nice maps but in essence tell us little about what is happening in large geographic areas. Wyoming the Dakotas and Nebraska are good examples. Physiographic regions are a much better way to look at these things. Now the data sets may not exist for a solid physiographic region by region analysis. As others have pointed out form, timing, intensity and so on are all factors that need to be considered. That said, this is a very interesting presentation. I think the take home message is you can’t predict or model forward what you don’t understand.

    Someone asked if climatologists have ever read any geology or something to that effect. It has been clear to his geologist, since I was a small boy growing up in Wisconsin, they do not, have not and even if they did, probably don’t understand it. Another big knowledge gap lay in soil science. From what my pedological associates tell me they are even more ignorant of that science.

    In the early 80′s I planned and excited an extensive drilling program in central Alberta, west of Edmonton. Knowing from local rainfall records (±15 years) that June was by far the wettest month of the year and knowing I was to work mostly on highly bentonitic soils, I choose July to start. That year June was mostly dry and warm. July was very wet. It was quite a scrabble to get things finished on time.

  65. Earth also had less deserts during other periods when earth was warmer. Growing deserts usually tend to coincidence with global cooling. Norwegian weather stations also shows increase in precipitation during modern “global warming” period: http://eklima.met.no/yr/trend/RRA_G0_Year_650_NO.jpg

    During this years unusually cold winter we also had the driest months in over 100 years in some areas of this country.
    The preciptiation trends for winter for all of norway: http://eklima.met.no/yr/trend/RRA_G0_Season_650_NO.jpg

  66. sphaerica (04:44:07)

    Sometimes simple logic is overly simplistic.

    Increased temperature —> increased evaporation —> increased precipitation

    Yeah, I know, sphaerica. Which is why I looked at the data … and found out perhaps it wasn’t that simplistic after all.

    But the water doesn’t evaporate and then precipitate in the same place, or in a dramatically changed climate in the same places as it used to. In addition, more of that added precipitation will quickly be lost again by evaporation.

    Gosh, you mean that the climate actually changes, and that rainfall patterns will change as well? Why didn’t someone warn us in 1895?

    Also, you say “more of that added precipitation will quickly be lost again by evaporation”. While some precipitation is always lost to evaporation, more rain never means less water in the ground. It means more water in the ground, despite increased evaporation.

    The changes that you see now are not necessarily the changes you will see as the planet continues to heat. The fact is, at the moment the amount of warming that has been seen is minimal, because the planet doesn’t warm instantly, but the CO2 in the atmosphere now has already committed us to at least 1.5C warming, where we’ve only seen 0.5C to date.

    Actually, the USHCN data claims that 1895-2009 the temperature rose 0.8°C … however, I’m glad to see you describe that as “minimal”. On the other hand, I’m not so happy to see your claim that we are “committed … to at least 1.5C warming.” What is your citation for that claim?

    But when the planet warms more, yes, some areas will see much more precipitation, and while you may oversimplify it and say “more water is good for crops,” it can also cause flooding, and continued, previously uncommon flooding can destroy habitats. Ecosystems will change.

    You mean water can cause flooding? Who would have guessed? And things are going to change? Say it isn’t so!

    sphaerica, if it looks like it is going to get drier, AGW folks go “Oh noes, here comes the droughts”. And if it looks like it is going to get wetter, its “Oh noes, here come the floods” … dude, weather changes. Better get used to it, because it’s not going to stop. Given my choice, I’d vote for more rather than less rain, perhaps because I grew up on a cattle ranch and I’ve seen what both too little and too much water can do. YMMV.

    Meanwhile other regions (like the southwest U.S.) will see more evaporation, with that water precipitating elsewhere, like in the northeast U.S. For regions that are already under stress for water, this is very bad news.

    Ya know, sphaerica, this question of the Southwest is one of the reasons why I did this study. Having lived in the Southwest at times, I wanted to see if the predictions of a dryer Southwest in a warming world were actually true. Turns out the USHCN data doesn’t support that prediction, the Southwest got wetter rather than dryer when the US warmed 0.8C.

    However, the actual data not supporting your argument doesn’t stop you or even slow you down, here you are again predicting doom for the Southwest … sometimes I wonder why I bother.

  67. stevengoddard (06:10:56)–

    With that shade of pink, Montana has either gone commie or it has trended drier as we discussed in your post about glaciers.

  68. Chris Riley (08:49:01)
    Any discussion that attempts to infer a link between increases in CO2 and decreases in the food supply as a result of (computer projections of) drought, that does not take into account the positive externalities of CO2 emissions is simply not science. It is propaganda
    Not forgetting that GREEN COLOR is the color we humans can best perceive best. Curious isn´t it?
    Green wavelength=560–490 nm
    Most probably the color The Prophet best perceives is the INFRARED (700 nm to 1mm). (Usually the devils´preferred color)

  69. MattB (05:00:48)

    Wow awesome 30 second disprove of what thousands of actual scientists are researching! Lets close the CSIRO her in Australia and just pay Mr Eschenbach a cool million for 5 minutes work a week and he can have the rest of the time off.

    Hmm I just realised that comment may not strike many of you as sarcastic. It is.

    MattB, given CSIRO’s pathetic record in even describing the rainfall in Australia, I might concur. Plus I could use the money.

    Seriously, if you’re an Aussie, you should call them to task for their repeated and egregious misrepresentations regarding climate.

    Or you could just believe them, I suppose …

    Hmm I just realised that comment may strike many of you as sarcastic. It’s not.

    PS – what exactly did I “disprove”?

  70. pwl (05:14:17)

    Interesting.

    Typo correction: “The MAIN area with decreased rainfall encompasses the Rocky Mountain states in the central Northwestern US.”

    Thanks, fixed.

  71. Rhys Jaggar (05:51:18)

    Do you results change in any way if your start date is 1855?

    Just interested….

    Haven’t a clue, Rhys. The USHCN data only goes back to 1895.

  72. Willis, more good stuff!

    Could you do the same thing with humidity?

    - and baro pressure?

    - and also windspeed?

    And, as a grand finale … if you show a graph of all four with temperature, we ought then to see what has happened to the US CLIMATE over the last 100 years …

    ( I assume that it is permissible to talk about the US having a ‘climate’ as opposed to just lots of ‘weather’ …)

    Anybody else tried to make sense of sphaerica’s point?

    ” …. water doesn’t evaporate and then precipitate in the same place, ………”

    Try living in the Tropics …

  73. Chris Riley (08:49:01) :

    “The science of Botany was well developed long before the politicization of climate science.”

    … and it goes on developing, refining the questions and getting better
    answers. You see, going from short-term experiments at leaf level to
    long term experiments on whole canopies, extrapolating to regions and
    …. the bets on this mechanism actually being significant is quite open.

    For instance: The interaction of rising CO2 and temperatures with
    water use efficiency. Eamus 2006. Plant, Cell & Environment
    Volume 14 Issue 8, Pages 843 – 852

  74. supercritical (10:46:20),

    Interesting point about the U.S. climate. From my handy electronic dictionary:

    The word “climate” means the weather conditions prevailing over an area over a long period of time; a region with particular prevailing weather conditions. The term originally denoted a zone of the Earth between two lines of latitude, then any region of the Earth, and later, a region considered with reference to its atmospheric conditions. [my emphasis]

    Continuing their sloppy science by using inaccurate language, GISS, CRU and just about everyone else on the peer review gravy train use the term “climate” when referring to the overall global temperature.

    It’s probably too late to change its recent widespread misuse, but the term climate, when referring to the entire globe from the poles to the equator, is more of a ‘climate catastrophe’ than the current condition of the planet, which is well within its normal range and actually quite benign.

  75. sphaerica (04:44:07)

    … The fact is, at the moment the amount of warming that has been seen is minimal, because the planet doesn’t warm instantly, but the CO2 in the atmosphere now has already committed us to at least 1.5C warming, where we’ve only seen 0.5C to date. …

    sphaerica, regarding your claim that there is heat “in the pipeline” as they say, see Dr. Pielke Senior’s posts here and here, and also the posts that he cites. It’s a good overview of the question.

  76. sphaerica (04:44:07)

    {The fact is, at the moment the amount of warming that has been seen is minimal, because the planet doesn’t warm instantly, but the CO2 in the atmosphere now has already committed us to at least 1.5C warming, where we’ve only seen 0.5C to date}

    can you elaborate on this statement please. It just does not come clear in my brain. :)

  77. Willis Eschenbach (11:14:23) :

    sphaerica (04:44:07)

    … The fact is, at the moment the amount of warming that has been seen is minimal, because the planet doesn’t warm instantly, but the CO2 in the atmosphere now has already committed us to at least 1.5C warming, where we’ve only seen 0.5C to date. …

    Interesting as your map of USA precipitation 1895-2009 is can you tell
    your readers please, that it does not disprove IPCC projections showing a South West USA dustbowl towards the end of 21th century.

  78. You might want to extend your analysis to global data. There are definitely areas that have dried over the past century:

    http://www.cgd.ucar.edu/cas/adai/papers/Dai_pdsi_paper.pdf

    EOF analyses of the PDSI revealed a linear trend
    during 1900–2002 resulting from a combination of precipitation
    and surface temperature trends, with drying
    over northern and southern Africa, the Middle East,
    Mongolia, and eastern Australia, and moistening over
    the United States, Argentina, and parts of Eurasia.

    (PDSI=Palmer Drought Severity index)

    And surface warming has caused a good portion of the more recent drying, along with El Nino and precipitation changes.

    The very dry areas (PDSI , 23.0) over global land
    have increased from ;12% to 30% since the 1970s,
    with a large jump in the early 1980s due to an El Nin˜o–
    induced precipitation decrease and subsequent increases
    primarily due to surface warming, while the very wet
    areas (PDSI . 13.0) have declined slightly. Together,
    the global areas in either very dry or very wet conditions
    decreased slightly by ;7% from 1950 to 1972, caused
    primarily by precipitation changes. Since 1972, the very
    dry or wet areas have increased from ;20% to 38% of
    the total land areas, with surface warming as the primary
    cause after the middle 1980s.

    So, yes droughts have been and will continue to be problematic as the world warms, despite the wetting of the US region.

  79. @ guidoLaMoto (04:02:05) :

    “The positioning of deserts has little to do with temperature, but mostly with geography: they form around 30deg N & S latitude due to Hadley Cell Circulation, and usually on the leeward side of mountain ranges.”

    That seems quite logical but forgive me for asking a question that might reveal my ignorance. What happened to the Sahara? Parts of North Africa used to be greener. Libya and Egypt have often been called “the granary of the Roman Empire.” When I was at school a common explanation of why they turned to desert was that goats ate all the vegetation. If goats really did turn the Sahara into desert then presumably manking could have just as devastating effect on our planet.

    Thanks to this blog I have become a lot more sceptical of claims of man-made global warming but the example of the Sahara is a rather worrying one.

  80. Doug in Seattle (09:46:53) :

    excellent observations. Both about Anazazi and the North Africa. There was an article ( not sure if it was national Geographic, but might have been ) That shows the extensive Aqueducts in Old Carthage Area, that shows there was enough rains in the mountains that they could cultivate large fields. It was warmer then than now.

  81. mikael pihlström

    ” the bets on this mechanism actually being significant is quite open.”

    This is as it should be, but for practical purposes, isn’t. As presented by the MSM, and even most skeptical politicians, (to paraphrase) “the science is settled and there are no positive components to the externality involved in the burning of carbon worth mentioning, much less measuring or accounting for. Exposure to these popular sources of information would lead a rational disinterested observer to conclude that the negative externality must be three or four orders of magnitude larger than the sum of all positive effects of increased CO2

    My point was that research that occurred prior to the politicization of this is much less likely to to have been influenced by politically motivated financing. Newer publications should not be given an automatic presumption of superiority, particularly when only the newer research was released after the issue became politicized. Both proponent and skeptical scientists are human and cannot be assumed to be immune to the personal-financial and personal-social consequences of the results they report.

    This is not meant to be a criticism of Eamus. I will read his paper. I will say that I will look harder at the “extrapolations” you mentioned than I would if the paper came out in 1986 rather than 2006.

  82. Since I’ve been interested in historical and paleo climate events related to our evolution and migration across the globe it seems to me to paraphrase our experience … ‘colder is drier’. This does not make the corollary true and with our geographical expansion you really are subject to local conditions. In my geographic area La Nina’s generally make it colder with more precipitation but it is highly variable. There have been dry, cold La Nina years.

    This past winter was welcome on the Northern Great Plains, but I expect and fear cold is coming of the scale Bastardi is describing in his crystal ball.

    http://www.accuweather.com/world-bastardi-europe-blog.asp?partner=accuweather

  83. If you read the IPCC AR4 peleo section it does indeed state that a warmer world is a wetter world. It is known fact to geologists etc….

    The IPCC AR4 body also discuss the effects of AGW on water supply and states a net benefit, though some areas may experiance more arid conditions. This is unfortunetly taken out of context in the SPM where it states more droughts are forecast. The whole “drought” claim seems to be something taken out of context which the scientists failed to correct.

    I also recall that the climate models used for AR3 didnt have volume balance checks which resulted in them loosing water over time plus they also underestimated evaporation / evapotranspiration rates by 3x over land. Seems the models had some very basic issues, this could have led to earlier claims of drought. The AR4 models now apply volume balance checks I believe (its modelling 101 to include volume balance checks!). I recall there was a paper published on this but I dont have it to hand.

    As someone who works modelling the hydrological cycle, its clear warming will increase evaporation / evapotranspiration, if the sea warms, evaporation will increase and the hydrological cycle will intensify. I am not sure how well they modell this, but as the hydrological cycle increases, it forms more of a cooling effect to counter the warmth. If the earth warms 1 degree than theoretically the atmosphere can hold an additional 8% moisture, which increases the rainfall potential. However, I live in an area that would suffer more droughts, but thats because rainfall here is determined by the mountains and the predominant wind direction. During the 1940′s warm period we had dry weather and the 1970 cool period gave us more rain and heavier rain.

  84. “mikael pihlström (11:47:28) :
    [...]
    Interesting as your map of USA precipitation 1895-2009 is can you tell
    your readers please, that it does not disprove IPCC projections showing a South West USA dustbowl towards the end of 21th century.”

    I see the word “Disprove” occur every time a pro-AGW person writes something. Please explain how one can disprove something that has never been proven, in this case the assumption that a dustbowl will occur (the fact that some model runs indicate so is not a proof.).

    Only because you think the AGW modelers have proven something doesn’t make it so. They have not even correctly projected the temperatures of the last 10 years – and they have never predicted anything because a prediction would be verifiable.

    The whole business of the pro-AGW people is making wild guesses and then saying: “Now disprove the things that i have just said.”

  85. Methow Ken (05:00:24) :

    As already pointed out by David Becker, Ph.D. (04:18:08):
    Adjoining WY and SD are at opposite ends of the scale.
    And not only that:
    ”High end” SD is surrounded by states that are all at the lower end of the scale.

    Even though there can indeed be significant divergences from expected standard deviations in the real world, since this data goes back at the way to 1895 it seems more than a little odd that SD should be such a significant ”local outlier”.

    This brings out a bit of my speculative brain, for what it is worth. Not all of the below ideas fit together, necessarily, but some may be pieces of the larger puzzle.

    Disclaimer for any warmers who might show up: This below is all weather anecdotes, with only a light suggestion of being climatic. I do know the difference between weather and climate, though I know it less than most who visit this site. But the particulars are worth noting, I think.

    1. At least eastern SD was involved in both huge Mississippi River floods, the 1993 one and the other, which was around 2005 or so. Those rain systems stalled over Iowa, pretty much, so SD was in the system rotation not far from the eye.

    2. I lived in Denver and know that the rain clouds that form in the Rockies behind the front range tend to dump their rain in the mid-afternoon east of the foothills. I assumed this was because a certain amount of convection/heat and time were needed in order for the clouds to get over the last range. If something like this occurs farther north, where the mountains are somewhat lower, perhaps the lesser altitude and its commensurate warmer temperatures means the rains hold out and fall farther from the mountains.

    3. I’ve lived the last 35 years around Chicago and observed that collisions of the warm Gulf air masses with the cooler dry continental air masses along a line that is generally from about San Antonio/Dallas to Madison, WI. These colliding air masses are what precipitate the tornadoes in central and eastern OK, KS and TX, and bleed into MO, IA and IL. This impacts me in the NW Chicago suburbs pretty often, where we are right on the edge and I’d hate to have to predict which way things are going to break. But this is just the general pattern. Depending on the strength of each air mass, it seems that the front shifts eastward or westward. Eastern SD is on the western edge of this activity, so if I am not mistaken, this is where the rainfall is greatest within the state and what makes it different from the other Great Plains states.

    4. There are times when the latter pattern has such a strong SSW wind pattern (with its warm gulf air), that the system from the west simply can’t move it, which causes the stalling and the great 100-year floods.

    (Just a note about these stalled systems: I recall in September 1986 driving south down the length of IL to Carbondale and a boat race. The pattern had stalled for weeks, and the flooding in the Chicago area was the greatest in memory. As I drove, the clouds were consistently moving across the sky from SSW to NNE at a rate I’ve never seen before or since, not for a huge system like it was. The dividing line turned out to be about 20 miles north of Carbondale. The air mass north of that had huge amounts of water and was very cool – around 50F or so. As I approached the edge of the system, the clouds were still making for a bat out of hell for the NNE, and then within a few hundred yards the sky became clear and warm, in the mid-70s. This pattern had lasted about 2 weeks straight, stalled and dumping all its water in narrow bands.)

    I suggest that eastern SD gets some of these stalled system effects from time to time, often enough to make it unique in the general area. And I suggest further that the warming since 1895 means stronger warm air masses coming off of the Gulf of Mexico.

    Combining these four anecdotal observations, it seems like SD is just far enough east of the mountains and just far enough north for the precipitation to fall there preferentially.

  86. Chris Riley (12:19:27) :

    “Both proponent and skeptical scientists are human and cannot be assumed to be immune to the personal-financial and personal-social consequences of the results they report”.

    “This is not meant to be a criticism of Eamus. I will read his paper. I will say that I will look harder at the “extrapolations” you mentioned than I would if the paper came out in 1986 rather than 2006.”

    Fair enough. I was always also not saying that the older paper you
    cited was flawed in any way. It was just about another research question.
    I don’t believe in the financial motives etc, but sure, science has its sociology
    and we have to be sceptic about enthusiasm.

    sociological

  87. DirkH (13:21:10) :

    “I see the word “Disprove” occur every time a pro-AGW person writes something. Please explain how one can disprove something that has never been proven, in this case the assumption that a dustbowl will occur (the fact that some model runs indicate so is not a proof.)”

    It is self-evident that no one can prove a prediction that something
    will happen in the distant future. We would always have to wait for the
    event. IPCC is not asking anybody to believe that something is proven -
    it is saying that examining all the existing evidence and applying rather
    good models we get these scenarios, we now have to make a risk
    assessment and decide on action/inaction.

    Then, the sceptic side retorts that the models are not good, or,
    also frequently that models are not science.

    But that is not enough, the temptation to come in and disprove ‘too
    early’ is so strong. Willis Eschenbach: “We should see decreased
    precipitation in the Southwestern US. Instead, all of the southwestern
    states have increased rainfall.”

    Is that not an attempt to disprove something ?

  88. Land use changes in New England was mentioned with woodlands replacing farmland through the 1900s. I wonder if the booming ice trade of 1820s and 1830s on influenced earlier New England temperatures or moisture: “total shipments of goods from the port of Boston in 1826-1827 at three thousand tons”. http://hbswk.hbs.edu/archive/3650.html

    Tens of thousands of tons of ice exported from Boston each winter until the development of air conditioning technology.

  89. Thanks for another great post Willis. Good to see yet another IPCC myth bite the dust!

    Same has happened here in the UK, with a trend of much more rain from 1961 to 2006, according to DEFRA. Link here:-

    So warmer, more CO2, more rain – it’s been plant heaven.

  90. Regarding Dave Springer (06:51:45) :

    I respect your conversation with Chris Riely, and would venture that you both know the subject better then me.
    I do take issue with you when you say this…”I don’t believe in the financial motives etc, but sure, science has its sociology and we have to be sceptic about enthusiasm.”

    I am not at all certain that montary dependency on grants for a pro CAGW POV results in just “enthusiasm” I feel that the climatgate e-mails clearly point this out, as well as many other points made on the corruption of climate research and peer review by Lindzen, Spencer, McIntyre, and many others. The light and dark side of human nature is invariable accross all religions, races, creeds and political perspectives, and the dark side is not properly defined as “enthusiasm”.

    I am glad you do not discount the earlier studies done which support the strong benefits of C02 in regard to plant growth. Have you read any critiques of the paper you quoted from. For Instance has Idso at C02 Science reviewed it? BTW, at CO2 science there are numerous other “recent” studies as well as :real world “observations” which support the view expressed by
    Chris Riley (08:49:01) : (Therefore I agree with his comment)
    “Any discussion that attempts to infer a link between increases in CO2 and decreases in the food supply as a result of (computer projections of) drought, that does not take into account the positive externalities of CO2 emissions is simply not science. It is propaganda.”

    If the world currently needed 20% more water to grow the same amount of food we would likely have complete economic collapse and numerous, perhaps worldwide wars.

    It is such a shame that we are not developing the energy resources we need that could make true envirementalism affordable.

  91. DirkH (13:21:10) :
    “…The whole business of the pro-AGW people is making wild guesses and then saying: “Now disprove the things that i have just said…”

    Spot on Dirk! What climate science has failed to understand is that no matter how many billions of cash you spent trying to prove the theory of CAGW, it just requires one piece of observational evidence to falsify it.

    There are so many pieces of evidence that now totally conflict with CAGW that it is now dead. I fear we are in for a long and painful funeral.

  92. Why would you use a Gaussian filter?
    It isn’t a valid technique when Mann uses it.
    It isn’t a valid technique when Britta uses it.
    It isn’t a valid technique when anybody uses it.

    It isn’t a valid technique.

    Use a normal running 10 year average if you want, and stop to the average line 10 years before the end of your data.
    Don’t claim to show us a smoothed average that continues up to the last datapoint.

  93. Willis,

    While I don’t subscribe to the dire predictions of the alarmists, I do not see how the pattern on the map is at odds with the prediction that the “desert belts would move poleward”. In fact the move of the desert belts poleward would require the current belts to show more precipitation (which the map does) along with a drop in precipitation in the region north of the current belts (which the map also shows).

    Again, I don’t buy into the alarmist rhetoric, but at the same time I can’t ignore the contradiction in the argument being presented.

    Could the answer be that the prediction is actually that the desert belts will stretch or extend poleward as opposed to moving poleward?

  94. Dennis Nikols (10:09:05) “Physiographic regions are a much better way to look at these things [...] I think the take home message is you can’t predict or model forward what you don’t understand.”

    Agree wholeheartedly – So Step 1: Develop understanding…

    Lake Eyre, Australia inflows:

    Compare with 25.6 year wave (grey) here:

    Similar patterns occur in coastal British Columbia, Canada precipitation:

    In fact, the pattern loosely matches global precipitation south of 55N – i.e. 55N-90S (very-loosely representing non-Arctic drainage – [when KNMI Climate Explorer starts taking physiographically-outlined coordinate-inputs, I'll refine...])

    However, we shouldn’t make the foolish mistake of simply extrapolating. There are a few layers of complexity…

    I am digging at the roots here:

    http://www.sfu.ca/~plv/VolcanoStratosphereSLAM.htm

    Earlier on I found correlations with solar system variables, but then I became aware of confounding of solar system dynamic variables with lunisolar tidal variables and switched focus.

    (Certainly the solar system has some role in influencing the relationship between Earth & Moon, but that’s a level higher in the causation chain and not necessarily of immediate concern in understanding lunisolar effects on the terrestrial hydrologic cycle.)

    Strongly Suggested:
    Let’s not trivialize the hydrologic cycle by inventing ridiculous (to be clear & blunt) claims that it shows a simple bivariate correlation with some global temperature index (…but certainly the hydrologic cycle needs to be front & centre in the climate discussion at this stage and I acknowledge the role of inflammatory comments in stimulating blog discussion, even if not necessarily the tactic I would choose …but many voices in the choir – many roles to be played… and more than one timescale to think about). It should be added that a discussion of precipitation is incomplete without a seasonal (particularly growing season) breakdown (including a look beyond averages at the nature of variability – many more discussions & blog posts to be had on important subjects – can’t squeeze all into one…)

    Important Question:
    What I want to know from any physicists participating in the discussion:
    When will the next nutation obliquity phase reversal occur?

    The last time one occurred, there was a major drought (the dirty 30s).

    One of the major keys to better understanding of the hydrologic cycle lies in the study of parallels between Earth orientation parameter (EOP) variations and the lunisolar harmonic spectrum. I base this comment on many analyses, most of which I have not publicized.

    tommy (10:12:41) “Norwegian weather [...] During this years unusually cold winter we also had the driest months in over 100 years in some areas of this country.”

    Caution: My understanding is that the Norwegian winter precipitation patterns share features with those of coastal British Columbia, Canada. The relationship between precipitation and temperature flips over between summer & winter here. The keys to understanding: the roles of the freezing point and arctic outflow winds. (Related: There is certainly a relationship between precipitation and inflow into the Arctic basin.) I have not studied the Norwegian summer patterns, but now you’ve got me curious to see what can be learned from a comparison (since Norwegian summers are not so drought-prone as those of western North America – could be informative about hazards of working with annual northern hemisphere averages…)

    Ed Murphy (09:22:23) “Water vapor that has little dust to cling to produces less clouds/rain. That all changes dramatically with a decent size eruption.”

    Bear in mind the other factors, like temperature. If a major stratosphere-class eruption cools the planet, you’re going to see LESS inflow into the Arctic basin (since inflow there is related to temperature – bear in mind that the freezing point is critical in temperature-precipitation relations). Seasons, geography, physiography, ….

  95. MattB (05:00:48) :
    ” …

    Hmm I just realised that comment may not strike many of you as sarcastic. It is.”

    As sarcastic, it comes across; as worthwhile and clever, not so much.

  96. A while back someone reported on the greening of the desert above the sahara, this was due the warming making it damper, in the article. The simple logic is something we need to cherish, it could also be called “common sense” this seems to be a by product of unobtanium in the green world. I find it depressing that we have to suffer under the green tyranny of eco laws, what dumbo banned incadesent lamps? then to compound the felony promote CFL glow worms? no research behind this travesty just thought it was good for us, the cat converter in our cars and the paint thinner and alcahol masquerading as real gas???? the technology changes but the solution stays the same, biofuel, another really daft idea, did no one think it through, plus what effect on older fuel systems? you need different “O” rings for ethanol, the normal ones break up, I am told this happens at over 10%. this is the failing of the MSM, they were zippy when Nixon was in the frame but now?????

  97. This is another bit of evidence that global warming does not cause droughts. Ian Plimer discusses this a number of times in his book “Heaven and Earth.” There are extensive ice core records that show much more dust in the ice during cold periods and ice ages due to desertification. Warm periods show much less dust in the ice.

    I believe this misconception that warming causes droughts comes from people associating droughts with hot dry periods in the summer. The warmists deliberately use such weather to further their claims and “forget” to remind people that their vaunted models predict that the warming actually should occur during winter nights. The geological evidence shows droughts are more common in cold periods

  98. David Becker, Ph.D. (04:18:08) :

    It is curious that one of the states that had the largest decrease in rainfall (Wyoming) abuts one that had one of the largest increases (South Dakota). It makes no sense that the rain stops at the border. I wonder if the data is corrupted. Did the measuring techniques change over time (and space?)

    I was thinking an isohyet map having contour lines of equal precipitation would be interesting as well.

  99. I have issue with the way the CSIRO and BoM “sell” their statistics to the public in Australia. I have probably covered this before on WUWT, certainly on JoNova, but given that it relates to rainfall it seems appropriate to link the offending report again.

    The following is a link to the annual roundup on climate for 2009 at BoM:

    http://www.bom.gov.au/announcements/media_releases/climate/change/20100105.shtml

    There is the usual alarmism on this being the warmest year/decade/millenium or whatever, but scroll down to the rainfall section titled:

    “Another drier than average year in the southeast mainland”

    Notice the qualifier at the end of the sentance? Most people will register the first half of the sentance and think… ah yes, another dry one. Fact of the matter is that it was wetter than average (for 1960-1990) and that the decadal average has been creeping upwards over the last 110 years.

    Check the graph below (at the linked report). The ten-year-average bars distract the eye to give a false horizon, but the average rainfall has erratically crept upwards over the period.

    In Australia the main problem is that certain areas tend to be experiencing less rainfall (the SW of Western Australia for example) while the increased rainfalls are up in the tropics where it is less useful to the majority of the population. This is an entirely different question, of course.

    Still it bugs me enormously that a tax-payer funded institution like the BoM deliberately word-smiths its reports to support AGW arguments.

  100. Mr. Eschenbach,

    You should continue to bother! Your posts and responses are informative, always supported by public-domain data and typically contrary to many of the current climate paradigms. It is people like you that expose people of the ecological-religion and faith-based-science factions for what they are NOT. The ecological-religion, faith-based-science crowd is clearly not interested in real climate science. Although, I am still in doubt about their underlying motive(s), their actions can be easily characterized as; the spreading of mis-information, fear and alarmism. They appear to have a situational-ethics-like compass at the core of their loose interpretations of data. By starting with carefully selected data, they then craft scary future senarios at the end of a trail of seemingly logical steps. They are good story tellers, I guess. On second thought, what is the primary motive of any major religion in regards to public policy? I would have to say it would be to “spread the good news”, “convert the masses” and increase the size of the congregation.

    So like it or not, Mr. Eschenbach, you and others on the website are the antidote to our current-day climate-opiate. Keep up the good work.

  101. “There is no discernible • trend in average
    precipitation since 1951, in contrast to
    trends observed in extreme precipitation
    events”
    “It is unlikely that a systematic change
    has occurred in either the frequency or
    area coverage of severe drought over the
    contiguous United States from the midtwentieth
    century to the present”

    This is what the CCSP report 2008 has to say about precipitation and drought trends since mid 20th century.

  102. Great work Willis!
    In the past 10 years I have made 30 or more field trips into the Great Sandy Desert of NW Australia. Originally part believing AGW, I soon came to the conclusion that this was a crock. The flora and fauna here was fantastically diverse, and the dune vegetation was better than my well watered garden on the coast, including what was thriving even on top of the dunes. Rainfall here is very spasmodic but is increasing over the last 20 years or more. Temperature in this desert is hot, (bounded by Marble Bar, Telfer and Balgo in the East) and it can be dry for longer than a year but can make up for it in a week when affected by a passing tropical cyclone. In Broome we have had 3 x 100 year rainfall events since 1970. The average temperature here has not increased by more than the ‘margin of error’ over the period of data collection since the 19th century.
    Better hot than cold.

  103. mikael pihlström (11:47:28)

    Willis Eschenbach (11:14:23) :

    sphaerica (04:44:07)

    … The fact is, at the moment the amount of warming that has been seen is minimal, because the planet doesn’t warm instantly, but the CO2 in the atmosphere now has already committed us to at least 1.5C warming, where we’ve only seen 0.5C to date. …

    Interesting as your map of USA precipitation 1895-2009 is can you tell
    your readers please, that it does not disprove IPCC projections showing a South West USA dustbowl towards the end of 21th century.

    Mikael, there is nothing that can disprove a projection of a SW USA dustbowl 90 years from now.

    There is also nothing that can disprove a projection of alien spaceships demolishing New York City ninety years from now.

    This is a recurring problem with the AGW hypothesis, that it does not make falsifiable predictions.

    Not sure what your point is here, though …

    w.

  104. mikael pihlström (14:07:49)

    It is self-evident that no one can prove a prediction that something will happen in the distant future. We would always have to wait for the event. IPCC is not asking anybody to believe that something is proven – it is saying that examining all the existing evidence and applying rather good models we get these scenarios, we now have to make a risk assessment and decide on action/inaction.

    Then, the sceptic side retorts that the models are not good, or, also frequently that models are not science.

    But that is not enough, the temptation to come in and disprove ‘too early’ is so strong. Willis Eschenbach: “We should see decreased
    precipitation in the Southwestern US. Instead, all of the southwestern states have increased rainfall.”

    Is that not an attempt to disprove something ?

    Scientific claims assuredly can be disproven (usually called “falsified”). However, you can’t falsify future events.

    If you had quoted my entire statement, it would be clear to everyone that I was referring to past events, not future events, viz:

    If these belts were actually moving poleward as the globe warmed over the last century, we should see decreased precipitation in the Southwestern US.

    The warming of the globe occurred in the past century, and the AGW claim was that this warming would make the desert belts move polewards. In the US, we haven’t seen that. I postulate two possible reasons it hasn’t happened.

    Science advances by falsification … but for a theory like AGW to be testable, it has to make falsifiable predictions. AGW makes very few such predictions.

    One of these few falsifiable predictions is the poleward movement of the desert belts in response to AGW. I don’t claim to have falsified that claim. I do claim that in the USHCN data there is no sign of movement of the desert belts in the SW USA over the 20th century …

    w.

  105. Duncan (15:51:26)

    Why would you use a Gaussian filter?
    It isn’t a valid technique when Mann uses it.
    It isn’t a valid technique when Britta uses it.
    It isn’t a valid technique when anybody uses it.

    It isn’t a valid technique.

    Use a normal running 10 year average if you want, and stop to the average line 10 years before the end of your data.
    Don’t claim to show us a smoothed average that continues up to the last datapoint.

    I love your style, science by assertion, as though repeating something over and over makes it true. Nowhere do you say what might be wrong with using a Gaussian filter, I mean, explanations are so last week. Then there is the crude attempt at “guilt by association” by mentioning Michael Mann and Keith Briffa …

    Sorry, I’m not impressed.

    I use Gaussian smoothing because it reveals the slower changes in the data by smoothing out the high frequency changes. It is a perfectly valid technique that has been used for that purpose for many, many years.

    I run it out to the end because the way I do it, the error at the ends is both measurable and quite small. I wrote a paper on this, it’s available here. In it, I demonstrate that the method that I use to deal with the ends is far superior to the bogus method used by Michael Mann. I also show how to calculate the end errors, and show their size in a sample dataset.

    In future, if you say something like “Willis, why do you use Gaussian smoothing, and how do you handle the end effects”, you won’t come off looking like you forgot to take your meds … and I’ll say “Hey, Duncan, thanks for asking, here’s the answer.”

  106. Area Man (16:24:15)

    Willis,

    While I don’t subscribe to the dire predictions of the alarmists, I do not see how the pattern on the map is at odds with the prediction that the “desert belts would move poleward”. In fact the move of the desert belts poleward would require the current belts to show more precipitation (which the map does) along with a drop in precipitation in the region north of the current belts (which the map also shows).

    Again, I don’t buy into the alarmist rhetoric, but at the same time I can’t ignore the contradiction in the argument being presented.

    Could the answer be that the prediction is actually that the desert belts will stretch or extend poleward as opposed to moving poleward?

    Area Man, the thing you are missing is that the SW USA is at the north edge of the ~ 30°N desert belt. In this area the belt forms the Sonora Desert, which stretches southwards from the SW US for hundreds and hundreds of miles into Northern Mexico.

    If the desert belt moves northward, the SW US would move from being at the top edge of the Sonoran Desert to being more in the middle of the Sonoran Desert … and I guarantee you, the middle of the Sonoran Desert is much, much drier than Arizona and New Mexico.

    This would show up in the record as the SW US becoming drier, which doesn’t appear to be happening.

    w.

  107. Now Bulldust – my issue is that these sort of articles, which actually say just about nothing, are written to be intentionally interpreted by the hungry masses as “This disproves AGW”. My reference to DocWatt is to point out that this article is taken as such by that poster. It is an incitement to frenzied climate ignorance.

    However the reality is that IPCC 2007 says “Increasing temperatures tend to increase evaporation which leads to more precipitation (IPCC, 2007). As average global temperatures have risen, average global precipitation has also increased.” So Willis’ line is actually the IPCC line. http://www.epa.gov/climatechange/science/recentpsc.html

    I for one would like to see sources for “One of the claimed dangers of a few degrees warming of the Earth is increasing drought.” as I doubt it is as blanket a statement are presented, rather a localised issue with local ramifications.

    As Willis points out – higher temps = higher evaporation, which also means that higher rainfall does not necessarily mean more water available to crops. Annual rainfall also does little to look at cropping cycles and seasonal droughts, again with significant issues for agriculture management.

  108. Willis… “This would show up in the record as the SW US becoming drier, which doesn’t appear to be happening.” hmm it really appears to me again you are trying to disprove something here, by producing graphs that concur with the IPCC? Maybe you should update your article above to say “Willis Eschenbach agrees with IPCC records for rainfall over USA”.

  109. Also, did you look at the percentages of what falls as rain and what falls as snow? That would be an interesting exercise to accompany this one. Unica una sugerencia.

  110. “mikael pihlström (11:47:28) :

    Interesting as your map of USA precipitation 1895-2009 is can you tell
    your readers please, that it does not disprove IPCC projections showing a South West USA dustbowl towards the end of 21th century.

    It doesn’t disprove my prediction that the South West USA will not be a dustbowl towards the end of the 21st century, either. But since the ipcc has not got any projection right so far, including a couple of eventualilties involving the the real occurrence of conditions opposite to what the ipcc projected as critical, and now the “lost” heat, I’m feeling very confident in my prediction. How about you, yours?

    But I guess they’re bound to get one right sometime, perhaps the exception which proves the real rule, and we’ll probably have to wait at least that long, so maybe you’re onto something.

    Yet on the other hand, China and India, and apparently Russia, are betting against CO2CAGW at least in regard to their little areas of the world, so there’s that, too……

  111. There you see MattB… if you actually bother to put in the effort you can put forth an argument worth debating. Shame you didn’t bother the first time, eh?

    As for inciting the masses, this web site certainly doesn’t do that, but I would bet the proverbial farm that some of the web sites you frequent do exactly that. I have seen your abuse of others at other sites mate. You have form.

    But keep digging your hole here… it will be amusing to see you dismantled argument by argument… much like Keating taking apart Hewson.

    BTW My word what is this in an IPCC report?!? An executive summary even?!?

    “Increased precipitation intensity and variability are
    projected to increase the risks of flooding and drought
    in many areas. The frequency of heavy precipitation events
    (or proportion of total rainfall from heavy falls) will be very
    likely to increase over most areas during the 21st century, with consequences for the risk of rain-generated floods. At the same
    time, the proportion of land surface in extreme drought at any
    one time is projected to increase (likely), in addition to a tendency
    for drying in continental interiors during summer, especially in
    the sub-tropics, low and mid-latitudes.”

    Source: http://www.ipcc.ch/pdf/technical-papers/ccw/executive-summary.pdf

    Increased drought… not decreased. The logic in incredible… I mean really. I call this the “have my cake and eat it” approach to logical reasoning.

  112. Willis Eschenbach (21:27:32) :

    You are right: I am off my meds, I’ll try to be more coherent. But then, I thought this was the internet. My apologies to Briffa too; upon reflection the paper I was mentally blaming him for was by someone else.

    A moving weighted average seems more appropriate to me.
    Use of a filter seems appropriate where there there is an underlying signal and high-frequency noise. I fail to see how a 17-year filter reveals any underlying signal.
    The only difference I see is that using the filter could give a trend line centered on the middle of the data with small blank areas at the left and right margins, compared to the moving average which would show the lack of data to make a trend line all on the right edge.

    As to end point smoothing, yes that is my real objection. Why smooth the end points? Why not just end the smoothed line where you have full data to smooth the line?

    I look at stock charts all day long. If I add a moving average to my stock charts, I don’t expect the line to go to the last data point. I can’t even remember a stock analyst trying to hype a stock with a moving average smoothed to the end of the data, so I’d bet the SEC has rules about that kind of thing.

    I read the paper you linked and I am impressed with the effort you put into finding a “best” smoothing algorithm. I don’t understand why the best method is better than no method. Fundamentally, it seems to me like an effort to fill in data where you don’t have enough data. When Mann did it with temperature data in the GRL paper you reference, it obscured important information: that the line was so heavily smoothed it should not be used to infer anything about current trends.

    In your rainfall graph above, it wouldn’t have hurt anything to just end the smoothed line a couple years before the end of the graph. Would have set a good example, imo.

  113. mikael pihlström (14:07:49): … we now have to make a risk assessment and decide on action/inaction.

    Here’s my risk assessment: WARMER IS BETTER. More rain, longer growing seasons, more productivity, more biodiversity, more food, more fiber, etc. etc.

    It is a stone cold fact that humanity prefers warmer climes. Canada is not crowded; Bangladesh is. Which is warmer? Siberia is not crowded, Rwanda is. Which one is cold, which one is warm? See:

    http://en.wikipedia.org/wiki/File:Countries_by_population_density.svg

    In fact, Life Itself prefers it warmer. The most bio-diverse places in the world are on the Equator. The least are in polar regions.

    Regarding action/inaction, my advice is the combined governments of the world should pursue policies that do not cool the globe but instead make the globe warmer. The reasoning is that WARMER IS BETTER.

  114. I think the AGW argument is that water vapour is a GHG so increased evaporation will warm the atmosphere, which will not be able to dissipate the heat and so it will reduce precipitation. This is, of course, wrong. If it were correct then increased evaporation would increase warming, which would increase evaporation, etc. The equator would be a boiling fog!

    It appears the equation for water vapour forcing was just made up, probably by Hansen, as a fudge factor :

    http://climaterealists.com/index.php?id=5563

    In fact research has shown that water vapour has a negative feedback on temperature, cooling warmer regions and warming cooler regions, essentially acting as a thermostat. For example, the temperature difference between the poles and the equator is small compared to the difference in energy received. Also consider an area with little or no water, such as the Sahara. The sand will be incredibly hot during the day and freezing overnight. We intuitively ‘know’ water has a moderating effect on climate.

    These ideas are covered in detail in this very readable article :

    http://www.landshape.org/dokuwiki/doku.php?id=introduction

    Although covering a lot of ideas, it is based around an explanation of Miskolczi’s theory where he tries to put the effects of water vapour on to a precise scientific footing. I would certainly recommend a read. [Actually, probably a few reads. It has a lot of detail!]

  115. I am particularly attuned to rainfall because I own a company that does whitewater rafting photography and video production (Click the website for a vid), and am an old river runner. It has been a rough decade, with only a couple of good years for rain.

    Here in Northeast Wisconsin we are in mid-summer drought conditions when we should be in spring run off. The last two summers featured stretches of 6 weeks at a time with no rain. The last few winters featured no storms of a foot or more of snow, two medium sized storms all winter, and we have only had a small fraction of our spring rain. We have had about 2 good wet years since Y2K.

    It seems that every time a storm threatens to get north of Green Bay, high pressure comes from the north and blocks it. It is uncanny the excuses and strange patterns that keep it from raining here. It has been going on long enough that it is heading from weather to trend status. We are seeing a lot of stress on the plant kingdom, and are seeing record low levels in lakes and rivers. We are not at desertification yet, but there are changes like trees sprouting in dry lake beds.

    My home rivers (~45N) are at record low levels, or just above record lows. The 11 year mean flow on the one river is 887cfs, and today we are at 204(record low). The second river has a 17yr mean flow today of 4360cfs, today it runs at 998(record low). It can run 20k cfs in spring. River three has a 43 year mean of 907cfs, and is at 254 today. That one is also 20cfs off of the record low set in 2002. Area lakes are almost 2′ lower than usual. My little pond should have 3-6 feet of water, and you could walk across it without getting your ankles wet.

    The point is we are seeing some real moderate to long term drought in NE WI. At the same time southern Wisconsin has been seeing a lot of rain and show, and even severe flooding. As Dr Becker and others pointed out, state lines are a bad delineation for this. Maybe NWS zones would be more accurate.

  116. A couple of clarifications, if I may.

    The sand deserts of Australia are extensive. Goat herders are, for all reasonable study, negligible, and always have been. The carrying capacity of much land is about one wombat a square mile.

    The far S-E of Australia (non-desert) had drought from 2000 to 2009. However, this decade was the second wettest since 1900-1909 for the whole of Australia.

    For agricultural purposes, there is vast movement of underground water (e.g. the Great Artesian Basin) which is often overlain by desert.

    Desert can be relieved at the mouth of the Murray River, by rainfall some months beforehand in Queensland, some 1,400 km away. This can upset correlations at a fixed location.

    David Stockwell has written on Niche Modeling that there has been no increase in drought incidence in Australia since recording began. A recent paper asserting the opposite is alleged to have inadequate statistics.

    Evaporimeter measurements are not always reliable. One cause of errror was from birds bathing in the pans, now covered by mesh.

    “Desert”, loosely defined, covers some 2,800 x 2,000 km in area. While much of it is loosely bound by vegetation, there are extensive areas of shifting sand dunes. The desrt extens to the Indian Ocean for about half of its N-S extent.

    The N-S extent of desert is about from 17 to 34 degrees south latitude. A movement to or from the Pole would not be easy to measure.

    Only a small percentage of the desert was affected by land clearing by man, so far as can be reconstructed. Most present desert was desert shown by early expeditions (Burke & Wills 1860 confirming this along their central N-S path, Eyre in 1839-41 for E-W along the Southern edge).

    At Alice Springs, in the centre, the annual temperature range is about 17 deg C from summer to winter. The highest daily temperature temperature was about 45 deg C, the lowest about -5 deg, since the WWII move to the airport weather station.

  117. Mattb (21:59:59)

    Now Bulldust – my issue is that these sort of articles, which actually say just about nothing, are written to be intentionally interpreted by the hungry masses as “This disproves AGW”. My reference to DocWatt is to point out that this article is taken as such by that poster. It is an incitement to frenzied climate ignorance.

    However the reality is that IPCC 2007 says “Increasing temperatures tend to increase evaporation which leads to more precipitation (IPCC, 2007). As average global temperatures have risen, average global precipitation has also increased.” So Willis’ line is actually the IPCC line.

    Mattb (22:02:13)

    Willis… “This would show up in the record as the SW US becoming drier, which doesn’t appear to be happening.” hmm it really appears to me again you are trying to disprove something here, by producing graphs that concur with the IPCC? Maybe you should update your article above to say “Willis Eschenbach agrees with IPCC records for rainfall over USA”.

    My line “is actually the IPCC line”? My graphs “concur with the IPCC”? Say what?

    Mattb, perhaps you should actually read the IPCC reports. Others have, including myself. From the IPCC Fourth Assessment Report Summary for Policymakers (FAR SPM), Table SPM.2:

    Phenomenon and Direction of Trend: Area affected by droughts increases.

    Likelihood that trend occurred in late 20th century (post 1960): Likely in many regions since 1970s.

    Likelihood of a human contribution to observed trends: More likely than not.

    Likelihood of future trends based on projections for 21st century using SRES scenarios: Likely.

    So yes, the IPCC very clearly states that it is “likely” that there will be increasing droughts. I didn’t have to get past the SPM to prove my point. You sure you are up to date with the IPCC report?

    If you are, surely you have gone beyond the SPM to read Chapter 10, “Global Climate Projections”. In it I find:

    There is a tendency for drying of the mid-continental areas during summer, indicating a greater risk of droughts in those regions.

    and

    A long-standing result from global coupled models noted in the TAR is a projected increase in the chance of summer drying in the mid-latitudes in a future warmer climate with associated increased risk of drought. This is shown in Figure 10.12, and has been documented in the more recent generation of models.

    and

    Droughts associated with this summer drying could result in regional vegetation die-offs (Breshears et al., 2005) and contribute to an increase in the percentage of land area experiencing drought at any one time, for example, extreme drought increasing from 1% of present-day land area to 30% by the end of the century in the A2 scenario (Burke et al., 2006).

    The models project droughts going from 1% of the planet to 30% of the planet, and you are talking about how I agree with the IPCC? My friend, you’ve lost the plot. Chapter 10 continues:

    In a warmer future climate, most Atmosphere-Ocean General Circulation Models project increased summer dryness and winter wetness in most parts of the northern middle and high latitudes. Summer dryness indicates a greater risk of drought.

    The US warmed by 0.8°C from 1895 to 1909. If warmth brings “increased summer dryness” and a “greater risk of drought”, why haven’t we seen it?

    You say of my article, “It is an incitement to frenzied climate ignorance” … seen a mirror lately? Look at the update to the head post above, there is very little change to the US Palmer Drought Severity Index (PDSI). Overall, the trend in the US is towards less drought, not more.

  118. Oh sorry Willis – silly me for thinking we were discussing the rainfall trends over the USA as per your article above. I also think you are confusing what has happened in the past with what is predicted for the future.

  119. Regarding Willis Eschenbach (02:04:42) :
    Quote from the IPCC…
    “This is shown in Figure 10.12, and has been documented in the more recent generation of models.”
    It is quite astounding how a computer model is treated as an observation and then “documented”. The advocates feel they have the basic global view long settled, now they are narrowing the field to local effects.
    Let it never be said about you that your arrogance exceeded your ignorance. Unfortunately it is to late for some in the field of climate science.

  120. The distribution of precipitation is even more uneven than temperatures. A cooling planet could spell more draughts for some areas due to the interactions of different oscillations. Take for instance the severe, long term drought that hit the Tidewater States during the coldest decades of the LIA. But, in the subtropics and tropics, severe long term drought occured during some of the warmest decades of the MWP (See Central America and the West Sahara). In both cases, oscillations like ENSO and the AMO had a direct impact on precipitation patterns.

  121. ***************
    Mattb (02:16:22) :

    Oh sorry Willis – silly me for thinking we were discussing the rainfall trends over the USA as per your article above. I also think you are confusing what has happened in the past with what is predicted for the future.
    *******************
    The climate models are no doubt in worse shape than Toyota’s computer models for their car computer. Do you REALLY BELIEVE the computer model projections??? REALLY???

  122. Geoff Sherrington (01:34:13) :

    “The far S-E of Australia (non-desert) had drought from 2000 to 2009. However, this decade was the second wettest since 1900-1909 for the whole of Australia.”

    This and other things you say is good information for sure. But,
    if we go back to IPCC projections for end of 21th: a pronounced
    drying is projected for SE USA, but only slightly or not at all for Australia.

    BTW. I think someone said here, that the SW of Western Australia has
    some drought?

  123. If you had quoted my entire statement, it would be clear to everyone that I was referring to past events, not future events, viz:

    If these belts were actually moving poleward as the globe warmed over the last century, we should see decreased precipitation in the Southwestern US.

    ——
    Partly true: if I would have quoted the entire statement, I would
    have understood better your argument. But, I think your interpretation
    is wrong. Poleward movements cited by IPCC seem to be individual
    species and e.g. treelines, most of them in arctic/alpine environments.
    In fact I don’t think a prairie/semidesert/desert example is given.

    My point is that a shift of whole vegetation zones poleward would come
    after significant warming, the one we see right now could not do that.

    Poleward movements of species: it is not a closed case yet, but yes
    there is movement. I remind you that a catastrophic escalation in the
    worst IPCC scenarios could trigger mass extinction.

  124. Re: Willis Eschenbach (Apr 18 21:32),

    Understood, Willis – thanks.

    Technically, if the desert belt movement was occurring quickly enough it could result in a signature like the one shown in the map (since the lower edge of the desert belt could have already passed by the SW US), but practically I doubt even the most alarmed of the alarmists would say that’s predicted!

  125. Glad to see this article today. Last night (Sun 4/18), The Weather Channel had an apocalyptic program on at 10pm EDT, “The Future Earth”, which was predicting terrible drought, major dust storms damaging Las Vegas, huge locust swarms invading Europe, etc. By around 2025, if I recall correctly.

    Exciting cinema but bad science, it seems.

    Thanks all.

    David

  126. David Smith (09:31:58) :

    willis, your main point about the lack of a drying trend in the US is a good one.

    As an exercise, though, I do wonder, though, whether “increased temperature = increased evaporation = increased precipitation” is necessarily correct. Evaporation is a function of temperature and of the humidity of the air into which it evaporates. The humidity of the air is a function of how well the precipitation cycle (mostly the Hadley-Walker aspect) works.

    The precipitation cycle depends on how well each leg works. If the cooling/sinking leg does not work so well with increased CO2 then perhaps the upper troposphere becomes “clogged” with relatively warm air, which inhibits the formation/size of rain clouds.

    Something to ponder.

    David

    REPLY:

    I think the formation of rain clouds is more closely linked to particulate (aerosols) acting as nuclei for rain drop formation.

    “…Secondly, rain drops cannot form without aerosols. They start the clouds off by providing the moisture with points around which to collect, called condensation nuclei. Every single raindrop needs one of these tiny particles, which have diameters of less than one thousandth of a millimetre, as a starting point. The moisture from the rising air condenses on the aerosol particles. This releases the heat that was originally needed to evaporate the water.

    If there are only few particles in the air, the drops grow so quickly that they fall before all the water can condense….”

    Aerosol particles can consist of sea salt, sand grains, soot particles, sulfates and other materials of organic and inorganic origin….” http://www.sciencedaily.com/releases/2008/09/080909111026.htm

  127. I don’t know how many times I have posted this. Willis observes:-

    “”” Increased temperature —> increased evaporation —> increased precipitation. “””

    So check out SCIENCE for July-7, 2007. Authors Frank Wentz (RSS Santa Rosa cA.) et al; “How Much more Rain will Global Warming Bring ?”

    They provide the how much; from actual real observations; not Playstation Game playing.

    Specifically:- A one deg C (1 C) increase in global mean surface Temperature, results in a 7% increase in total global Evaporation, and in Total Global Precipitation; and also in total Atmospheric Water Content.

    This strongly disagrees with the Playstatyion GCMs. Now the first part Evap = Precip is well understood and the modellers agree; if it wasn’t true then we would end up with the oceans up in the sky. But the modellers say that the amount of evap/Precip, is only 1% to 3% per deg C, not the 7% that Gaia says it is; as observed by Wentz et al. (there’s that obligatory 3:1 climatology fudge factor) The GCMs do agree with the 7% increase in total Atmospheric Water Content.
    So this supports the warming = drought^-1 rather than drought.

    Left unsaid; but obvious to any 8th grade high school science student, is that a 7% increase in precipitation might be expected to be accompanied by something in the range of a 7% increase in total global precipitable cloud cover; as in dark rain clouds. That increase might be a combination of increased cloud area, increased cloud water content, and hence optical density, and increase in cloud persistence time.

    All of which would imply a strong negative feedback surface cooling due to extra blocking of ground level solar insolation (increased albedo, and increased optical density).

    So I wish people would download a copy of the Wentz et al Paper so that this subject doesn’t have to come up all the time. Along with the John Christy et al paper from Jan 2001 (I think in Geophysical Research Letters) that reported on about 20 years of ocean buoy data of simultaneous water Temperature (-1 metre depth) and near surface Air Temperature (+3 metres height) that showed that water temperature increases exaggerated the warming of the near surface atmosphere (izzat lower Troposphere) by something like 40%, over that near 20 year period (starting presumably about 1980).
    The more important result was that those two temperatures are not correlated (why on earth would anyone expect them to be); which means that prior to 1980, near surface air temperatures canot be recovered from the 150 years of the bucket of water ocean surface temperature data.

    To me that means we don’t have any idea what global air temperatures were prior to 1980.

    Those two papers, are to me the biggest stumbling blocks of the whole AGW mantra.

    As I have said many times; “It’s the Water, Stupid !”

  128. mikael pihlström (14:07:49) :

    “….Then, the sceptic side retorts that the models are not good, or,
    also frequently that models are not science.

    But that is not enough, the temptation to come in and disprove ‘too
    early’ is so strong. Willis Eschenbach: “We should see decreased
    precipitation in the Southwestern US. Instead, all of the southwestern
    states have increased rainfall.”

    Is that not an attempt to disprove something ?”

    If you do not understand that is a basic in science, then I suggest you read
    CARGO CULT SCIENCE by Richard Feynman

    ” ….But there is one
    feature I notice that is generally missing in cargo cult science.
    That is the idea that we all hope you have learned in studying
    science in school–we never explicitly say what this is, but just
    hope that you catch on by all the examples of scientific
    investigation. It is interesting, therefore, to bring it out now
    and speak of it explicitly. It’s a kind of scientific integrity,
    a principle of scientific thought that corresponds to a kind of
    utter honesty–a kind of leaning over backwards. For example, if
    you’re doing an experiment, you should report everything that you
    think might make it invalid–not only what you think is right about
    it: other causes that could possibly explain your results; and
    things you thought of that you’ve eliminated by some other
    experiment, and how they worked–to make sure the other fellow can
    tell they have been eliminated.

    Details that could throw doubt on your interpretation must be
    given, if you know them. You must do the best you can–if you know
    anything at all wrong, or possibly wrong–to explain it.
    If you
    make a theory, for example, and advertise it, or put it out, then
    you must also put down all the facts that disagree with it, as well
    as those that agree with it. There is also a more subtle problem.
    When you have put a lot of ideas together to make an elaborate
    theory, you want to make sure, when explaining what it fits, that
    those things it fits are not just the things that gave you the idea
    for the theory; but that the finished theory makes something else
    come out right, in addition.

    In summary, the idea is to try to give all of the information to
    help others to judge the value of your contribution; not just the
    information that leads to judgment in one particular direction or
    another…..”
    Adapted from the Caltech commencement address given in 1974

    http://www.lhup.edu/~DSIMANEK/cargocul.htm

  129. mikael pihlström (06:21:15)

    … Poleward movements of species: it is not a closed case yet, but yes there is movement. I remind you that a catastrophic escalation in the worst IPCC scenarios could trigger mass extinction.

    I love the “could”, “might”, “may” school of doomsday catastrophism. You are 100% right. It could trigger mass extinction. And a pickle could jump out of a jar and squirt juice in my eye … but I doubt both greatly.

    See my post, “Where Are The Corpses”, for facts rather than “mights” and “coulds” about extinction.

  130. Willis Eschenbach (11:01:39) :

    I love the “could”, “might”, “may” school of doomsday catastrophism. You are 100% right. It could trigger mass extinction. And a pickle could jump out of a jar and squirt juice in my eye … but I doubt both greatly.

    The pickle jumping is now or within hours. When I say ‘could’ I have the
    100 year perspective inside my head and I see a myriad of pathways, which
    range from likely to improbale, hence …
    I could stop saying could, but then I would use ‘risk’ and I don’t suppose
    it would change a thing.

  131. “”” Willis Eschenbach (11:01:39) :

    mikael pihlström (06:21:15)

    … Poleward movements of species: it is not a closed case yet, but yes there is movement. I remind you that a catastrophic escalation in the worst IPCC scenarios could trigger mass extinction. “””

    Well have you ever heard of the Ballroom floor phenomenon ?

    In ballroom dancing; in contrast with what the Teener set thinks of as dancing these days; it is actually traditional to hang on to your partner; so that everybody on the floor, knows that is who you are dancing with; and not that gal/guy over there in that distant corner.
    And you always dance with your hands held high and your elbows sticking out prominently to erect a barrier of encroachment. If some other churl comes waltzing into your spot; well you just nudge hom out of the way, with a well planted elbow right in the middle of hs back or ribs. It is not gentlemanly to nudge the invading lady out of the way; your partner however is free to do that (or step on her ankle).

    From time to time, open spaces appear on the ballroom floor, where nobody is dancing; and every leading man in the vicinity, steers his partner over to that vacant space to shwo their prowess to the rest of the dancers.

    Well in the process of course the hole in the ballroom floor, moves off to some other place; to be chased again by the dancers.

    The people move inot what seems to be underutilized quarters.

    Who wants to bet, that flora and fauna species don’t do exactly the same thing as the ballroom hole migration.

    To argue that because the mocking birds woke you up five minutes earlier this morning, means that something catastrophic is happening, just isn’t realistic. Animal populations do move around in response to periodic changes in the competition for resources; the trees get up and move to where there is more sunlight in the forest; well an individual tree might not; but it will certainly try to spread its progeny into a nice sunny clearing nearby; and those offspring will try to outgrow the competitors to reach the canopy and bask in their new found glorious sunshine.

    Too much is read into these random walk processes, that are just Gaia redistributing her resources to use the available space efficiently.

  132. The Boston area had a 100 year event or more last march. 18 inches of rain from 2 storms was the most in a month since records were kept going back to the 1870′s.

    Doesn’t mean anything of course, but it seems every year I go back to visit it is wetter and wetter there.

    As for the Southwest, that has historically been a dust bowl. The 20th century was actually unusually wet for the area. If average climate over the last 1000 years returns, they will be looking at drought conditions. Nothing to do with AGW though.

  133. A clear signal for the poleward movement of the North American desert belt must surely be there as the models say. It is hard to detect because It is currently being obscured by an obviously temporary 114 year weather phenomenon.

    Willis, you must be careful not to let these transient weather phenomena obscure the century-scale wisdom of the models. It just confuses folks.

  134. Chris Edwards (16:53:46) :

    “….. no research behind this travesty just thought it was good for us, the cat converter in our cars and the paint thinner and alcahol masquerading as real gas???? the technology changes but the solution stays the same, biofuel, another really daft idea, did no one think it through,…”

    Of course “they” thought it through Cargill and Monsanto posted record earning in 2008.

    It is no coincidence that Robert Shapiro CEO of Monsanto was chief foreign trade adviser to Bill Clinton when VP of Cargill Dan Amstutz wrote the World Trade Organization’s Agereement on Ag and the 1996 “freedom to farm bill”

    Nicole Johnson does a much better job of going into the history (with 5 pages of references) at History HACCP and the Food Safety Con Job

    Food is a target for control as well as the control of energy through “green” taxes and regulations. They already succeeded in getting control of the money supply at the G20 summit last year in April. Obama agreed to sign off on International control over our US financial institutions by the Financial Stability Board. “They want control over every detail, not surprisingly right down to setting pay and compensation levels….” See Investors Insight: The End of America’s Financial Independence

    Also see my comment at Gail Combs (20:33:26)

    http://wattsupwiththat.com/2010/04/16/reply-to-ice-cap-thaw-may-awaken-icelandic-volcanoes/

  135. George E. Smith (15:13:56) :
    “”” Willis Eschenbach (11:01:39) :
    mikael pihlström (06:21:15)
    … Poleward movements of species: it is not a closed case yet, but yes there is movement. I remind you that a catastrophic escalation in the worst IPCC scenarios could trigger mass extinction. “””

    The only poleward migration I have personally observed in Kansas is the northward movement of the Texas lapdog (armadillo). My fervent desire is that some action by me would trigger a catastrophic mass extinction.

  136. ” Geoff Sherrington (01:34:13) :

    A couple of clarifications, if I may.

    The sand deserts of Australia are extensive. Goat herders are, for all reasonable study, negligible, and always have been. The carrying capacity of much land is about one wombat a square mile.”

    You will find that the great Australian deserts are a product of the Australian Aboriginals behavior; they burnt down the rain forests that were there. It is not PC to point the finger of blame at the aboriginals, but they ancestors did make the great Australian deserts. The carcoal is a bit of a give away.
    They also, accidentally, made Eucalyptus a fire resistant tree and wiped out huge numbers of large animals and birds.

  137. Willis—

    Nice plug tonight on the John Batchelor show (WABC radio, 9 PM-1AM, syndicated nationwide, and streaming from WABCradio.com) from Bob Zimmerman, specificially mentioning this post about precipitation.

    John and Bob are clearly avid readers of WUWT, and fans of your technique of showing how much the warmists make of so little.

    I just wish the useful idiots of the MSM were listening to them.

    /Mr Lynn

  138. ******
    19 04 2010
    RayB (00:03:16) :

    It seems that every time a storm threatens to get north of Green Bay, high pressure comes from the north and blocks it. It is uncanny the excuses and strange patterns that keep it from raining here. It has been going on long enough that it is heading from weather to trend status. We are seeing a lot of stress on the plant kingdom, and are seeing record low levels in lakes and rivers. We are not at desertification yet, but there are changes like trees sprouting in dry lake beds.
    *******

    Local and/or regional drought tends to perpetuate itself. Rainfall is a result of imbalance — rising air vs sinking air. A drought area will be less moist than surrounding areas, so high-pressure tends to form/reform above because dry air is heavier than moist air. A drought gradient (dry area right up against a wet area) reinforces itself because it’s a perfect place for a relatively local imbalance to develop when cloud moisture comes over. Moist air will rise & then rain over the moist area at the expense of the dry area (which provides the sinking air to support it).

    Such a north/south drought gradient was present just a few yrs ago here in the northern mid-Atlantic states. The “line” was just a few miles south of and parallel to the MD/PA border. Rainfall would continuely pass over the wet areas to the north but dissipate just south of the gradient border.

  139. Mr Lynn says:
    April 20, 2010 at 8:37 pm (Edit)

    Willis—

    Nice plug tonight on the John Batchelor show (WABC radio, 9 PM-1AM, syndicated nationwide, and streaming from WABCradio.com) from Bob Zimmerman, specificially mentioning this post about precipitation.

    John and Bob are clearly avid readers of WUWT, and fans of your technique of showing how much the warmists make of so little.

    I just wish the useful idiots of the MSM were listening to them.

    /Mr Lynn

    Thanks for the info, Mr. Lynn. I’ll look it up and have a listen.

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