A new publication in Nature Climate Change puts the brakes on predictions that global warming/climate change may produce continental scale droughts into the late 21st century. For example, NCAR said in 2010: CLIMATE CHANGE: DROUGHT MAY THREATEN MUCH OF GLOBE WITHIN DECADES
Then they had to back down and correct the original, when they found the drought PDSI (Palmer Drought Severity Index) numbers were overestimated by double the amount:
Update – July 3, 2012
This news release has been revised to reflect a miscalculation in the original study that inadvertently resulted when simulations of historical drought were combined with simulations of future drought. The revised maps, below, indicate that drought levels on the Palmer Drought Severity Index may reach -10 in certain regions, whereas the levels reached -20 on the original maps. Similarly, upper-latitude areas become less moist than previously projected. Large portions of the globe are still expected to experience dryness that is extreme if not unprecedented. For many regions, the corrected data show the movement toward drought taking place about three decades slower than originally projected.
Here is what NCAR says the future drought scenario looks like under climate change over the next 80+ years:
In this new study published this week, it seems that the model predictions just aren’t lining up with observations, such as the recently observed greening of Earth and the measurements of evapotranspiration, which may have an embedded methodological artifact and failure to account for how plant stomata have been responding.
Potential evapotranspiration and continental drying
P. C. D. Milly & K. A. Dunne
By various measures (drought area1 and intensity2, climatic aridity index3, and climatic water deficits4), some observational analyses have suggested that much of the Earth’s land has been drying during recent decades, but such drying seems inconsistent with observations of dryland greening and decreasing pan evaporation5. ‘Offline’ analyses of climate-model outputs from anthropogenic climate change (ACC) experiments portend continuation of putative drying through the twenty-first century3, 6, 7, 8, 9, 10, despite an expected increase in global land precipitation9. A ubiquitous increase in estimates of potential evapotranspiration (PET), driven by atmospheric warming11, underlies the drying trends4, 8, 9, 12, but may be a methodological artefact5. Here we show that the PET estimator commonly used (the Penman–Monteith PET13 for either an open-water surface1, 2, 6, 7, 12 or a reference crop3, 4, 8, 9, 11) severely overpredicts the changes in non-water-stressed evapotranspiration computed in the climate models themselves in ACC experiments. This overprediction is partially due to neglect of stomatal conductance reductions commonly induced by increasing atmospheric CO2 concentrations in climate models5. Our findings imply that historical and future tendencies towards continental drying, as characterized by offline-computed runoff, as well as other PET-dependent metrics, may be considerably weaker and less extensive than previously thought.
References
- Characteristics and trends in various forms of the Palmer Drought Severity Index during 1900–2008. J. Geophys. Res. 116, D12115 (2011 Article
- , & Little change in global drought over the past 60 years. Nature 491, 435–438 (2012). Article
- & Expansion of drylands under a warming climate. Atmos. Chem. Phys. 13,10081–10094 (2013). Article
- & Increasing Northern Hemisphere water deficit. Climatic Change 132, 237–249 (2015).
- , & On the assessment of aridity with changes in atmospheric CO2. Wat. Resour. Res. 51, 5450–5463 (2015). Article
- , & Modeling the evolution of global drought and projections for the twenty-first century with the Hadley Centre climate model. J. Hydrometeor.7, 1113–1125 (2006). Article
- Increasing drought under global warming in observations and models. Nature Clim. Change 3, 52–58 (2012). Article
- , , & Global warming and 21st century drying.Clim. Dyn. 43, 2607–2627 (2014). Article
- & Responses of terrestrial aridity to global warming. J. Geophys. Res. Atmos. 119, 7863–7875 (2014). Article
- & Terrestrial aridity and its response to greenhouse warming across CMIP5 climate models. J. Clim. 28, 5583–5600 (2015). Article
- & Scaling potential evapotranspiration with greenhouse warming. J. Climate 27, 1539–1558 (2014).
- Drought under global warming: a review. WIREs Clim. Change 2, 45–65 (2011). Article
- Handbook of Hydrology (ed. Maidment, D. R.) Ch. 4 (McGraw-Hill, 1993).
- & Evaporation from sparse crops—an energy combination theory. Q. J. R. Meteorol. Soc. 111, 839–855 (1985).
- Climate and Life (Academic, 1974).
- , , & A general framework for understanding the response of the water cycle to global warming over land and ocean.Hydrol. Earth Syst. Sci. 18, 1575–1589 (2014). Article
- & Land surface controls on hydroclimatic means and variability. J. Hydrometeor. 13, 1604–1620 (2012).
- et al. Multimodel assessment of water scarcity under climate change. Proc. Natl Acad. Sci. USA 111, 3245–3250 (2014). Article
- , , & Simulation of the impacts of climate change on runoff and soil moisture in Australian catchments. J. Hydrol. 167,121–147 (1995).
- , & Global pattern of trends in streamflow and water availability in a changing climate. Nature 438, 347–350 (2005). Article
- , & Unprecedented 21st century drought risk in the American Southwest and Central Plains. Sci. Adv. 1, e1400082 (2015).
- & A drier future? Science 343, 737–739 (2014). Article
- & Macroscale water fluxes 2. Water and energy supply control of their interannual variability. Wat. Resour. Res. 38, 24-1–24-9 (2002).
- , , & Crop Evapotranspiration—Guidelines for Computing Crop Water Requirements Irrigation and Drainage Paper 56, 15 (Food and Agricultural Organization of the United Nations, 1998).
h/t to Dr. Richard Betts
Do these “scientists” not understand that simply changing their models to follow what the real world has done is ludicrous?
I am so tired of the continually shifting changes that Alarmists make that are nothing more than a reflection and a reaction to reality.
Has there ever been a scientific theory that has had to change course so many times before it has been discredited?
I walked past an old bloke with a great white beard who was building a wooden boat down at the port the other day.. I asked him how big it was going to be and he said, “300 cubits long, 50 wide and 30 cubits high.” Said he worked for the NOAA or was it NOAH or NASA. Funny sort of bloke.
A pretty good example of how science is supposed to work. It takes time and repetition for true understanding to emerge. Peer review was never intended to supplant that, but peer review is often ballyhooed as imbuing credibility.
Hokum just like the Old Soviet Union use to devise and publish as PROVDA and in it’s science journals. Reading some of that stuff in the 1980’s was nothing short of a trip to Wonderland.
Down here in Oz, CAGW -> Endless Drought is the fantasy karmagedoom that brought our most eminent global warming fantasist Professor Tim ‘The Fool Man” Flannery (a.k.a. Tim Flam) undone some time back when the last El Nino disappeared up its own cyclical period and promptly filled up all our east coast dams.
And guess what – its doing it again – Oh Gaia, you sweet, sweet old bitch! Here in Launceston (Tasmania) We are having the biggest flood since 1929 and its in winter – our wet season. Who’d a thunk it… My daughter loves it, 2 days off scholl just hangin, out with Dad and going flood watching…
Glad to see you are in a good mood, M Seward! Let it rain!
And to think we committed the heinous sin of nearly running our dams empty (*) playing the mandated, subsidised renewable energy market in SE Oz yet still The Lady (Gaia) she giveth and she giveth and she giveth.
Halleluja TA, Halleluja. 🙂
* Tasmania is rather unique in that we are usually 100% hydro powered with a bit of wind ( its a wet, windy place) and naturally so for many decades now, nothing to do with the ecofascist regime of more recent times ( in fact the ecofascists opposed our hydro coz, like, it killed some trees and ruined some hiking trails).
Just you wait and see skeptic. There’ll be Tim Flannery’s drought underneath for sure just as soon as climastrologists can clear away all that pesky water and model it.
The drought is seen only in climate models. The weather stations are seeing record-breaking rainfall all over the world!
“Heavy rainfall events setting ever new records have been increasing strikingly in the past thirty years. .. An advanced statistical analysis of rainfall data from the years 1901 to 2010 derived from thousands of weather stations around the globe shows that over 1980-2010 there were 12 percent more of these events than expected in a stationary climate,.. In South East Asian countries the observed increase in record-breaking rainfall events is as high as 56 percent, in Europe 31 percent, in the central US 24 percent”
https://www.pik-potsdam.de/news/press-releases/record-breaking-heavy-rainfall-events-increased-under-global-warming?set_language=en
No, the drought is in the real world, too: http://www.forbes.com/sites/timdaiss/2016/05/25/why-vietnam-is-running-dry-worst-drought-in-nearly-100-years/#99959af7b805
Even though they are backpedaling, the Climate Liars are still lying their pants off. They are good at it too. Notice how they nest lies within bigger lies, e.g. the phrase “Worsening drought from climate change”. To begin with, there is no evidence that droughts have gotten worse. And conflating what man does with water with actual precipitation is just another way of lying. Building a city in a desert, for example, then crying about the lack of water is not “drought”. Then we get to the biggie, their favorite way of lying: “climate change”. It sounds so honest, too. Of course the climate changes, always has, always will. But that isn’t what they mean, and everyone knows it. They mean their mythical, fantasized manmade climate change.
“To begin with, there is no evidence that droughts have gotten worse. And conflating what man does with water with actual precipitation is just another way of lying.”
The results in California don’t support your conclusion: http://www.dailymail.co.uk/sciencetech/article-2863054/California-s-drought-worst-1-200-years-worse-come-warn-scientists.html
1) Whether or not it’s the worst in 200 years is debatable.
2) What’s not debatable is that the current drought pales besides other droughts of the last 1000 years or so.
Even if your claim was correct, one bad drought in 200 years is not evidence of any kind of trend. Even you should be able to figure that out.
1) Whether or not it’s the worst in 200 years is debatable.
2) What’s not debatable is that the current drought pales besides other droughts of the last 1000 years or so.
Information to support your claims? The one I quoted looked at tree rings, what is your statement based on? http://onlinelibrary.wiley.com/doi/10.1002/2014GL062433/full
What is mine based on. History, and all the other studies.
Haha, you say the word “history” and that’s your argument?
fair bit of snow falling in argentina brazil and chile/venezueala
and as usual it doesnt make any news reports
the aus flooding is, cos idiots like dinatale manage to get airtime;-(
The 3-day, 10-foot snowfall northeast of Santiago closed an important mine there. It made the financial news.
My local tv weather person reported that my area in the central U.S. is about 10 days late in reaching the first 90 F temperature of the season.
Unfortunately, that news will be reported in every major news outl…?
Nowhere.
Nobody will pick that tidbit up, nobody will report on it, 3 weeks from now it will have fallen off the page and “news” outlets and “scientists” will go back to quoting the original paper, predicting disaster, and nobody will call them out on it.
This happens every time.
The droughts seem to be getting worse in the most populated areas on the maps. Does that seem interesting to anyone else?
The regional reductions in precipitation caused by the warm AMO, should not get mistaken as being due to rising CO2, as the former is negative North Atlantic Oscillation driven, and the latter according to all the models will increase positive NAO.
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-3-5-6.html
In Texas, we have had two Springs in a row with slow-moving low pressure systems interacting with very moist air scooped up from the tropics. This week, that has moved off to the East, and the skies are much clearer. This link shows the moisture pattern this morning.
https://earth.nullschool.net/#current/wind/surface/level/overlay=total_precipitable_water/orthographic=-87.65,27.31,961/loc=-95.085,14.315
Anybody that projects for years 2090-2099 is truly delusional about what their models are capable of.
Observations tell us that the earth is greening up and low level moisture(dew points and precipitable water) have increased, along with the modest beneficial warming experienced over the last 4 decades. This also decreases the lifting condensation level of clouds(more low/cumulus clouds) which is a negative feedback to temperature increase.
Global drought has NOT increased so far but models tell us it WILL increase.
This is mainly based on what the humans programming the models think will happen.
It is more likely that the water cycle will just be amplified as it has been so far. This does lead to heavier rains/down pours, especially in the greenest areas that currently get the most rains.
However, this is not clear. Deserts have been greening up too the last 40 years…..not expanding(thanks in part to increasing CO2 fertilization and CO2 allowing plants to be more efficient with water use).
With the lack of clarity of these effects over the last 40 years(contradictory in some cases) how on earth somebody can project a ten year period at the end of this century based on something so uncertain completely annihilates any legit scientific credibility of the source of such a product.
…………..and we who question this junk science are labelled as “deniers”
To be anything other than skeptical of this kind of science, a scientist would have to have their mind captured/brainwashed……….. like a follower of a cult.
At the height of the Holocene optimum, earth was quite a bit warmer than today. Deserts were fewer and smaller; most of the Sahara was grassland. This would imply warmer weather means more moisture in the air and more precip. But models show the opposite. History must be wrong.
A warm world is a tropical green Earth. A cold world is filled with deserts and soil erosion. Why? Think positive ocean evaporation leading the water cycle and filling the air with water vapor. Now conjure up negative evaporation starving the atmosphere of water vapor. The AGW talking points have it ass-backwards.
Make that windblown soil erosion filling valleys and hill shadows with loess soil and diminishing fine-grained top soil.
This is EXACTLY how real science should operate – the projected consequences of a hypothesis are tested against empirical measurements, the statistically significant divergences are identified, and the hypothesis is modified to make the divergences from reality disappear.
Modifying the measurements is a sign of a failed hypothesis being defended by a scientist who is either incompetent or malicious (Hanlon’s Razor).
“By various measures (drought area1 and intensity, climatic aridity index, and climatic water deficits), some observational analyses have suggested that much of the Earth’s land has been drying during recent decades, but such drying seems inconsistent with observations of dryland greening and decreasing pan evaporation. ”
Doesn’t exactly sound like the science is settled.
Australia, well known for droughts, is now experiencing flooding rains and is getting greener. To Tim Flannery’s horror the dams are full not dry.
CO2 affect on stomata leading to lower water going out from a leaf is, in part, countered by the larger leaf area CO2 engenders & thus the leaves total number of stomata being greater is a factor in how much water is going out into the air from soil. While this may seem insignificant it also relates to the physical characteristics any particular type of soil one is referring to; some soils readily “lose” water anyway & more stomata in a larger leaf area adds another factor to soil moisture dynamic.
Warning! After reading the Abstract, I assumed the study is a critique of climate models. Then I read the study. It is not a critique of models but of “offline analyses of model outputs” using a “potential evapotranspiration estimator” called the “Penman-Monteith method.” The paper explains that “Global climate models, despite their course spatial resolution and imperfect physical parameterizations, are nevertheless internally consistent representations of the climate system.” Hence “Care must be taken in the use of external impact models,” especially analyses of potential evapotranspiration (PET), “a hypothetical construct that generally is neither anchored by direct measurement no computed in climate models, but is nevertheless often used in several measures of impact.” The paper concludes that “Drying trends might more meaningfully be assessed by direct examination of climate-model variables (for example, runoff, actual ET [evapotranspiration], soil moisture, and relative humidity…” I think that’s a call for empirical studies but the authors do not elaborate.
I note, that eventhough the range is no longer -20 to +20 in their data (now only -10 to +10) they left the color scale unchanged, so -10 still looks just as bad as -20 looked.
Correct the record? When you are 2x wrong you retract.
worse than we thought fails again
I found the graphs rather confusing. They do not show where it was or is expected to be DRY or WET but where it is expected to be dryER or wetTER than it is now, so the legend is misleading. The top graph shows 2000-2009, which is in the past. The Red Heart of Australia is shown green, that is, wetter than “now”, whenever “now” was. But that does not mean floods in the desert. And the green coast of Australia is shown yellow, orange, and red. But that doesn’t mean actual droughts. The thing I would like to see is where is it expected to be too dry/just right/too wet for agriculture as currently practised in each region.
The other thing that occurs to me is that we’ve had six years of actual stuff happening that could have been
compared with the original and improved models. That’s what I want to see above all:
anomalies for 2010-2015 from the original model
anomalies for 2010-2015 from the improved model
anomalies for 2010-2015 from actual history
all on the same scales.