Limitations on Anthropogenic Global Warming

by Leonard Weinstein, ScD

March 1, 2009

reposted from The Air Vent

It is not obvious what the ideal temperature and CO2 level should be for mankind. We tend to assume that the average of whatever has occurred in the recent past is the ideal level, since we have adjusted to that level, and changes from that level can cause disruptions in living conditions and activities. Significant temperature and CO2 increases in recent years have raised the issue of whether these were possibly related and were due to human activity, and whether this is a potentially significant problem.

Earth’s temperature has only been directly measured at enough locations to give a reasonably accurate global average for about the last 150 years, with the greatest accuracy (from satellites) only going back about 30 years. The “reliable” CO2 background level has only been directly continuously measured at one location (Mauna Loa) for about 50 years, and at a much larger number of locations for about 30 years. Some other direct and indirect CO2 measurements were made prior to 50 years ago, and the measurements thought to be most reliable were used to extend the CO2 curve back to 1850.

Figure 1 is a commonly used figure to show smoothed global variations of the temperature and CO2 concentration data from 1850 through 2000 AD. This data indicates the Earth’s surface has warmed about 0.7OC (1.3 OF) and the atmospheric CO2 appears to have increased by over 30%. These two pieces of information are the basis for the present “Anthropogenic Global Warming issue”.

Figure 1. Variation of global average temperature and CO2 concentration over last 150 years

(Sources for temperature and CO2: http://www.grida.no/climate/ipcc_tar/wg1/519.htm )

A more recent version of the temperature anomaly for the period 1850 through 2008 is shown in figure 2. The data, from http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/ is also shown as a smoothed yearly variation, including range of uncertainty.

Figure 2. Yearly anomaly of global temperature variation from 1850 through 2008

This newer data somewhat modifies the conclusion that had been inferred from the more limited temperature curve from figure 1, where the belief (supported by the IPCC) was that the increasing CO2 was the main cause of the increasing temperature. The temperature trend has peaked about 2002 and then rolls over and starts trending downward rather than continuing to rise as predicted. This apparent reversal contradicts the predicted trends in the IPCC models. While the downward trend has occurred only a over a few years, the entire period used to justify the “Anthropogenic Global Warming issue” is not much longer (1970-2000), and the 1970 level is significantly below the 1941 level!

There are several indirect ways to determine temperature variations that extend the record back much further than 150 years. These include (but are not limited to) historical written records, information from tree rings, glacier ice cores, sediment deposits, and borehole temperatures. The accuracy and distribution of these methods for the global average is thought to be fairly good to about 400 years ago. However, the limited number of locations for these records as we go farther back in time tends to decrease the absolute levels of confidence of the indirect records for an average global temperature prior to 400 years ago. The trend can be extended back about another thousand years or so, but with decreasing confidence in the global average the farther back you go. A few local sources showing temporal variations can extend the record back much farther in time, but these are not global averages.

Tree ring data can extend the temperature trend record back several thousand years, but do not give reliable absolute levels due to sensitivity to parameters such as being restricted to land, and having unknown rainfall, Solar insolation, local CO2 level, etc. They also do not show winter or nighttime data, and are thus not truly average temperature indicators. Borehole data is limited in temporal resolution, and only goes back reliably a few hundred years at most. In the end, glacier ice core data at a limited few locations, and sea floor sediment cores, are the most reliable and longest period data sources for temperature. The CO2 variations are also claimed to be obtainable from glacier ice cores, going back hundreds of thousands of years, but a question of the validity of that claim is discussed in more detail later in this paper. A combination of data from several techniques indicate that the average surface temperature was relatively warm about 1,000 years ago, and this period was called the “Medieval Climate Optimum”. This changed about 1,200 AD or so into a prolonged colder period called the “Little Ice Age”, which lasted until about 1850. The temperature variations were not uniformly distributed and it is not clear if the “Little Ice Age” extended to the southern hemisphere. The accurate average level of the temperature that occurred during the “Medieval Climate Optimum” and the speed at which it changed were not able to be reliably determined, due to the limited number of data points, and increased uncertainty in accuracy of many of the sources that far back in time.

The AGW proponents claim that the magnitude and level of the present global temperature, and the speed in which it increased, is unusually extreme and cannot be accounted for by natural variations. They claim the observed temperature increase is being caused by human activities such as the burning of fossil fuels, deforestation, and manufacture of cement. The observed recent increase in CO2 (and also Methane) is thought to have increased the greenhouse effect of atmospheric gases to trap more radiated heat and thus raise the surface temperature. In order to examine the AGW claims, temperature data is shown in figure 3 from three widely separated sources. The data covers the last three thousand years for a representative Greenland ice core and Sargasso Sea sediment core, and the last two thousand years for an Antarctic ice core (all data taken from web sources, including NOAA).

The ice core data was taken from locations on glaciers that had minimal lateral substrate movement, and did not melt on the surface in the summer. The yearly snow variation was sufficient to accurately identify the year of the layers in the compacted solid ice core. Oxygen isotope ratios were used to determine the temperature, and the data shows the variation in temperature relative to the year 2000. The Sargasso Sea sediment core temperature data were obtained from the Oxygen isotope ratio of the surface-dwelling planktonic foraminifera, and shows the sea surface temperature for the last 3,000 years. Conclusions from these curves are:

  1. The temperature varied several times over the period by 1.5 OC to 2OC for all three curves
  2. Temperature variations occurred fairly rapidly, with typical time scales of 50 to 200 years
  3. The rise rate over the last 150 years is not unusual compared to other rise rates
  4. The present level of temperature is near the average for the curves shown for both Northern hemisphere cases, and below several previous peaks
  5. The “Little Ice Age” and “Medieval Climate Optimum” show up in both Northern hemisphere cases
  6. The present temperature is not unusually high for the Antarctic

Figure 3. Temperature variations from the Greenland glacier ice core, the Sargasso Sea sediment core, and the Antarctic ice core. All 3 curves have lined up dates, and have the same vertical scale size.

The trend of the temperature for the Greenland and Sargasso Sea curves is also generally decreasing from 3,000 years ago, and the “Little Ice Age” was a cold and long lasting period. There are several other locations with indicated local temperature variation in this time period that generally tend to agree with the extent of the temperature variation during the little ice age and medieval climate optimum, and all show large variations occurring over the entire time period. If the present temperature is not unusual based on the above comparisons, why the AGW claims? In fact, it is based on two observations:

  1. The temperature has been warming over the last century and has increased the most within that period in the last 30 or so years.
  2. The CO2 and Methane levels have increased a lot over the last 30 to 60 years, and ice core records show them to be higher than any other time in the last several hundred thousand years.

It is clear that we get excited at anything different that happens in a time period that spans a large fraction of a lifetime, and even dominates recent history, even if it is not unusual compared to time periods more distant in the past. Also, the claim that increasing CO2 (and Methane), likely with a significant contribution from human activity, can cause some global warming does have some theoretical and computational basis. The problem is that all of the physics governing the Earth’s climate, including ocean currents and cloud feed back, as well as particulate effects are not fully understood, and generally are put into models in artificially selected forms to try to force the models to agree with actual measurements. A discussion of one possible problem with the theories and models is made in: http://www.drroyspencer.com/research-articles/satellite-and-climate-model-evidence/

If we go back even further in time for the present interglacial period than shown in figure 3, even higher temperatures and larger temperature variations are encountered. While we clearly are presently in a period of warming (or at least were up to the last few years), there is no indication that this is an unusual period of warming! If the present were unusual, then all previous times of rapid change and high levels would also have to be unusual, and where is the anthropogenic causes for those times? However, it is not certain that anthropogenic causes are not significant factors in the recent warming, so a “what if” case has to be examined. For the following, the assumption is made that the CO2 increase is dominated by human activity and that this increase is assumed to be the cause of a significant part of the temperature rise. Five questions need to be addressed:

1) Is it likely that the anthropogenic greenhouse gas levels will continue to increase?

2) Has the increase in anthropogenic greenhouse gasses been the dominant contributor to the recent high global average temperature?

  1. Are there other problems (or advantages) from increasing CO2?
  2. Is it likely that the temperature will continue to increase significantly (and if it does, is this necessarily bad)?
  3. Has this temperature rise (whatever the cause) had a significant effect on rising sea level and changes in weather?

The answer to the first question is probably yes. However the rate of increase is less certain, since the present increasing trend may only be a transient lag in the ability of the Earth to come to a new equilibrium from human activity. The level will probably remain higher than previous levels, but when it will eventually level off, slow down, or just keep increasing, is not clear. A CO2 level of between 400 and 500 ppm, or even a bit higher may be possible (but not certain) by 2100 absent heroic efforts to reduce the rise. There is no reasonable basis for increases much beyond this, mainly due to the finite availability of easily obtained carbon based fuels. It should also be noted that the methane level, which had increased considerably from prior to 1850 to the mid 1990’s, has essentially leveled off for the last decade, so is not a factor in additional warming.

Question 2 can be restated as: how much of the temperature increase in the last 150 years is due to the CO2 (and methane) increase, and how much due to a general recovery from the Little Ice Age. I don’t think we can accurately answer that, but it appears almost certain that human activity did not cause much more than about 0.3OC of the increase, based on the net rise from the local peak from about 1940 to the latest trend at the end of 2008. This maximum plausible contribution is much less than the expected increase blamed on human activity for this time period. The larger portion of temperature rise occurred prior to most of the input of CO2, so that rise cannot reasonably be blamed on this cause. In fact, the temperature had already increased somewhat from 1600 to 1850, so the rise from 1940 to 2008 is only about 1/4th the actual total rise (~1.2OC) from the low around 1600. From this we can conclude that anthropogenic increase in the CO2 may have contributed to the recent warming, but at most only a very modest share, and the present temperature trend is down!

This modest increase also brings up the issue of the calculation of expected temperature increase from models. These models directly calculate the expected increase from greenhouse effects, and then add expected positive feedback effects due to increased water vapor caused by the higher temperatures. The models (including positive feedback) anticipated a total rise of ~1.5OC just due to anthropogenic causes from 1850 to the present. It appears they are at least a factor of 5 too high if only 0.3OC of the increase was due to the greenhouse gasses as stated above. In fact, the main part of the temperature increase was clearly a recovery from the little ice age, and occurred prior to the vast majority of CO2 increase! There are also models that anticipate a negative feedback from increased water vapor forming the types of clouds that reduce the heating. It is not yet certain why the temperature is at the present level, but it is clear that the models have not yet been demonstrated as valid!

The temperature drop between 1940 and 1970, along with the underperforming model estimates were recently blamed on “Global Dimming” caused by particulate pollution. In fact the particulate pollution took a large dive when oil and gas rather than coal became major home and business fuels many years earlier (as seen in glacier records). More recently, particulates from growing economies like China, along with aircraft contrails, have added more dimming in recent times. The prediction has been made that once we (and the Chinese?) clean up pollution, this dimming will decrease and warming will be even worse than previously predicted. This presumes that greenhouse gas output is a separate problem from particulate pollution, but it is more likely that they will go up or down together.

A more recent study has concluded that an ocean current (Pacific Decadal Oscillation) not previously included in the “Global Warming Models” will dominate the effect of greenhouse gas temperature increases for about a decade or more (until about 2015 to 2030), and that this is the cause of the unexpected reversal of temperature trends for the last several years. It is curious that this new factor was not found until the temperature trend reversal became clear. It appears new factors will be found as needed to explain any deviations from the present “understanding of the Global Warming Problem”. Since the entire time of temperature rise used to show that there is an unusual period of heating was only about 30 years long (1970 to 2000), it now appears that we are told by global warming modelers that 30 years of a selected time of heating, sandwiched between one 30 year period of cooling, and being followed by another period of cooling (of unknown length, but at least 10 or more years), is proof of their claims – because it is a period of a local maximum temperature over a period of several hundred years. This despite the clear records that show such rapid variations and even maximum levels are common over the last several thousand years, and that the present level is not even as high as several other previous levels in that relatively recent time period.

The answer to the third question may be that there is a generally positive effect if the only change to the atmosphere was a significant increase in CO2 concentration. Most plant growth increases at higher levels of CO2. It also appears that some concerns for negative effects on ocean life from increased ocean acidity from CO2 were exaggerated, or even totally wrong (as will be discussed more later) (also see http://www.seafriends.org.nz/issues/global/acid.htm). A significant change in ocean pH would cause some changes, and there would be some winners and some losers in ocean life, but it appears that for realistic level changes this would not be a major problem. In fact, combining the slightly higher temperature with higher CO2 levels should significantly increase world crop growth if these are the only factors, and this is clearly a generally positive effect.

The fourth question combines the question of whether the natural temperature variation combined with the anthropogenic causes of temperature increase will result in significant continued temperature increase. The warming alarmists models predict a rise of an additional 2OC to 5OC as being likely by 2100, but I do not see that as being justified based on present information. Based on a combination of historical trends over the last several thousand years with the recent trends reasonably attributable to anthropogenic causes of temperature increase, it appears that some small additional increase might be reasonably possible (but not certain) by 2100, but most likely within a range < 0.4OC, which would put it in the range of several warm periods in historical times that were particularly productive times.

There are two issues that have to be considered for the fifth question. The first is the effect of rising oceans. The site: http://sedac.ciesin.columbia.edu/mva/WR1987/WR1987.html models the expected increase in ocean level due to thermal expansion for a 0.6 OC to 1OC global temperature rise over several decades. They conclude that a total rise of only about 4 to 8 cm. would be caused by the temperature rise. In addition, several studies have concluded that the rise in sea level from Greenland and Antarctic ice cap melt water would not exceed 0.5 mm/year (5 cm/100 years), and this would probably drop off soon or even go negative due to the high altitude of the remaining glaciers, and increasing snowfall adding more ice than is removed by melting. Water from other melting glaciers has contributed to an additional level increase of about 0.5 to 1 mm/year for about the last 150 years, over the general warming trend effect on the oceans. However, much of the added source from melting glaciers is now decreasing, and some glaciers are nearly gone (many of these glaciers were actually formed during the little ice age). The total of all of these contributions is probably less than 15 cm, or 6 inches in the next 100 years, and even much less additional rise in following times. The most interesting point of the sea level problem is that only about 2 to 3 inches of the possible rise to 2100 is even plausibly related to anthropogenic causes of temperature increase, and this is the maximum that would be able to be stopped even with a 100% drop in human contribution! A huge but possible effort costing TRILLIONS of dollars and negatively impacting growing economies most would likely only prevent less than 1 inch of the rise!

A second issue of the consequence of temperature rise is possible severe changes in weather. There have been many claims of super storms, tornados, heavy rain, and drought associated with the temperature changes. Keep in mind that the temperature difference between the low and high latitudes is the driver for these storms, and the main predicted effect of AGW is to DECREASE this difference!! It is very likely that there will be slightly fewer hurricanes, but they may tend to be slightly stronger due to the higher absolute humidity possible with higher temperature. The issue of more frequent and stronger tornados is difficult to evaluate, but records going back about 100 years do not show a significant trend of increasing overall activity of the stronger tornados. There are periods of large numbers and strong tornados going back in history that pre-dated the period of recent warming. The recent severe US tornado outbreak may even have been a record for recorded times (keeping in mind that fairly complete records only cover a very short period), but any one-year record may be unusually large or small, and only longer time trends are meaningful. The average rainfall will likely increase in some locations due to higher absolute humidity possible at higher temperatures, and the locations of high and low average rainfall (and drought) would shift somewhat.

There would be winners and losers in any change in climate and weather, but the overall effect of higher CO2 and slightly higher temperature would be a more productive Earth. The real fact to face is that there always is change in climate and weather over periods of several decades to centuries. We should not make heroic efforts to change the climate but concentrate on being able to adapt to the changes. This is especially important when we do not know for sure if our effort may actually worsen the situation,

The possible problems with CO2 data

The CO2 curve of figure 1 was actually made from three separate parts. The data from one location (Mauna Loa in Hawaii) was used from 1958 to the present. Additional locations started making measurements about 1980, and agreed reasonably well with the Mauna Loa results. A few selected land based measurements made in the previous several decades were also spliced to the Mauna Loa results. Glacial ice core data trends with a large offset time correction were then spliced to the previous two sources (with offset selected to make it fit!). This was then the source of the CO2 curve from 1850 to the present. The ice core data was then also used to show the CO2 variation over the last several hundred thousand years. It should be noted that the CO2 level was obtained directly from gas bubbles trapped in the ice cores.

There are numerous potential problems with some of the CO2 data in figure 1. The Mauna Loa and other recent direct measurements are probably basically reliable as a “background level”. However, far bigger uncertainties occur for the other two parts that made the CO2 curve in figure 1, and also in the longer time ice core records. A few selected sets of direct measured CO2 data made before the Mauna Loa measurements started were used to extend the curve to earlier times. A recent paper by Ernst Beck, who reviewed all of the older direct CO2 measurements, concluded that the papers selected to show the CO2 measurements before Mauna Loa were cherry-picked to agree with prior conceptions. All of the earlier measurements were limited in that they were made over land, and could have been biased by industrial activity, the proximity of cities, agriculture, etc. (and these limitations in reliability could also be applied to tree ring data). In fact Beck’s summary paper shows what may be unrealistic high CO2 data levels, especially in the early 1800’s and the period of the 1930’s, but the point is that this was direct measured data at numerous locations, and generally showed that CO2 levels may have been significantly higher in the near past than claimed. There are no clearly reliable direct measurements in this period that prove otherwise. The best approach probably would be to reject all of the direct measured CO2 data collected before the Mauna Loa and other recent stations were established due to the uncertainty of the applicability of these measurements to determine the global average background level.

The questionability of ice core CO2 determination

CO2 determined from glacier ice core gas bubbles has been used to indicate the atmospheric CO2 level at the time the bubbles formed. The frozen core sample is crushed to obtain the trapped gas from the bubbles and directly find the CO2 concentration. There is no direct supporting evidence that this is a valid technique. In order to examine the reasonableness of the process, the following discussion examines three possible issues.

The first issue arises from the porous nature of the compressing ice, which may take from about a hundred years to possibly as long as thousands of years before it seals off completely. This would result in diffusion averaging of composition, and very likely lose resolving even large variations in atmospheric CO2 occurring over shorter periods than the time to seal off. This is probably the cause of the near constant indicated CO2 composition over long periods.

The second issue arises from the comparison of levels and trends of CO2 made by other techniques. In particular, a set of measurements was made using the inverse relation between atmospheric carbon dioxide concentration and stomatal frequency in tree leaves to provide a method for detecting and quantifying century-scale carbon dioxide fluctuations (Wagner, F., Bohncke, S.J.P., Dilcher, D.L., Kurschner, W.M., van Geel, B. and Visscher, H. 1999. Century-scale shifts in early Holocene atmospheric CO2 concentration. Science 284: 1971-1973.). The results indicated CO2 levels varied considerably over the last several thousands years, and in some cases came much closer to present high levels than indicated in ice cores (to at least as high as ~348 ppm). In fact, a significant part of the difference between stomatal frequency based data and ice core data may be related to the first issue above.

The third issue relates to the CO2 content of trapped air being selectively reduced by dissolving in either a quasi-liquid or liquid layer. According to an article by John S. Wettlaufer and J. Greg Dashbears at: http://www.bushwalking.org.au/FAQ/FAQ_MeltBelowZero.htm

“Ice has a quasi-liquid film, a natural state of solid ice formed by a process called surface melting, at temperatures down to near –40OC”. This layer has some structural characteristics of the solid below it but has the mobility and solubility of a fluid. This layer can contain dissolved gases such as CO2. In addition, there is the possibility of some liquid water being present in the ice even at temperatures below normal freezing. The rise in summer temperature and prolonged sunlight could even form melt layers (possibly subsurface) during glacier formation. When the melt liquid forms, the high solubility in the liquid could preferentially (compared to O2 and N2) take in a significant quantity of CO2. At release of pressure, when cores are drilled and raised, there could be some preferential CO2 loss from the micro cracks in the cores, or the ice could retain excess CO2 separate from the air bubbles.

Conclusions from the above are:

  1. The process of the formation of glaciers may result in temporal smoothing of results on a time scale long enough to miss large level variations of CO2 lasting possibly hundreds of years.
  2. Some alternate techniques that determine CO2 concentration over time contradict the slow changing ice record, but this may in fact be due to 1). This could mean present levels are not quite so extremely high or unusually fast changing as thought.
  3. Quasi-liquid films and liquid water occurring during glacier formation could be a significant source of CO2 removal from trapped air bubbles, especially near the freezing point. Significant amounts of CO2 may preferentially dissolve even in a small amount of quasi-liquid or liquid. This could result in a preferential reduction of the CO2 concentration in the larger gas bubbles.

The final result is that there is some room for doubt for the reliability of ice core bubble composition to determine older CO2 concentrations in air, and a more reliable method to determine older CO2 atmospheric concentrations is badly needed.

Problems with seawater pH determination, and its effect on AGW predictions

Researchers aboard the Wecoma, an Oregon State University research vessel, discovered that significantly “acidified” seawater (pH = 7.6) from the deeper ocean is being “upwelled” within 20 miles from shore along the Pacific coast (www.physorg.com/news130693309.html). The researchers stated that this water was on the surface about 50 years ago. This despite the assumed fact that the atmospheric CO2 level was no higher than 310 ppm around the time the water would have been on the surface (according to current theories). The present level of 385 ppm of CO2 in the air has made surface pH levels go to 8.1. The CO2 level would have to be >1,000 ppm to come close to the pH value of 7.6 found from the upwelled seawater. The researchers indicated that phytoplankton blooms, caused by the slightly elevated CO2 levels, decayed to raise the CO2 level even higher. Since the blooms took Carbon out of the water to form, and since the blooms could not change the overall Carbon mass balance, the local CO2 concentration would have to be balanced by depletion of CO2 somewhere else. This indicates that measuring local seawater pH levels is not necessarily a valid indicator of average atmospheric CO2 level and its change over time, and thus its effect on sea life.

If you type:

[PDF] SEAWATER pH AND ANTHROPOGENIC CARBON DIOXIDE

in Google, and hit search, then hit the first site with that title shown, this will allow you to download a pdf of a paper by Marsh. That paper relates CO2 concentration to seawater pH more accurately than currently used linear approximations, and concludes the current projected pH levels that are widely used are unrealistic even if the CO2 level rose to over 2 times present levels! It also discusses ocean mixing, and it shows that mixing is likely much faster than simple models show. If surface water can be pushed to a large depth in a relatively short time, the increase in CO2 concentration due to human activity would be reduced by mixing with larger volumes of seawater than just the uppermost mixing layer. There is no logical reason the well-mixed seawater pH would go as low as feared, just based on the maximum amount of new Carbon that is available from anthropogenic causes and the dilution effect that is assured.

We do need to look at “what if” cases to be sure we are not risking catastrophe. Even if the atmospheric CO2 levels increase as much as the AGW predictions, and assuming this resulted in the projected drop in surface ocean pH (using the unrealistic linear extrapolation method), the results would still not be as unfavorable as stated. The following web sites discuss the effect on Earth’s calcifying corals and other marine organisms caused by lowering the calcium carbonate saturation state of seawater due to lowering the pH. The sites also have connections to other related topics including increasing temperature effects. The conclusions at these sites contradict AGW warnings on the problems that may occur in the oceans due to increasing CO2 in the atmosphere.

http://www.co2science.org/articles/V11/N21/EDIT.php

http://www.co2science.org/subject/c/summaries/calcification.php

http://www.co2science.org/subject/c/summaries/calcificationother.php

If AGW and ocean acidification are not problems even with some CO2 increases, why the big issue. In the end, the improved productivity of the biosphere due to higher CO2 would mainly be a blessing. There is no general downside and AGW concerns are misplaced for that time scale. However, the problems of pollution (not greenhouse gasses), and the increasing cost of fossil fuels, are driving efforts to find alternate sources of energy. This will cause the increase of CO2 to slow down and eventually reverse long before CO2 levels get high enough to be a real problem, even if most of the rise is anthropogenic.

The Methane issue and Siberia

It is interesting to note from figure 3 (and also from data from earlier in the present interglacial) that periods of rapid temperature increase and long periods of temperatures higher than present often occurred. It is certain that methane was released from Siberia and other sites (Artic seabed, Alaska, etc.) at those times as well as seems to be happening at the present. Where is the indication of recent (<3,000 years) past catastrophe? The present level of atmospheric Methane may be higher than at those times due to human activity, but lack of significant additional level rise from temperatures that were even higher than the present seems to contradict the claims of temperature induced massive release. We do know the atmospheric Methane level has been nearly flat for the last several years, so where is the rapid rising trend?

Some final points:

We know from many records that significant changes in temperature and climate have frequently occurred through historical as well as Geological time periods, and often result in significant consequences.

Previous interglacial periods tended to last 10,000 to 20,000 years, and in fact most did not have temperatures as slow changing as the present one. Since the present interglacial started about 18,000 years age, and reached the plateau about 11,000 years ago, we probably should be more concerned with a possible impending major ice age than a fraction of a degree or so of warming. In fact, the best possible outcome would be that the (relatively modest) contribution from AGW might help delay the onset of a new ice age.

The magnetic field of the Earth has changed a lot over geological times. There were periods of weakening and then reversal occurring about every 200,000 years until about 780,000 years ago. At the present time, the field is again weakening. If the field weakens too much, the Earth’s magnetosphere would not block cosmic rays and Solar ions as well, and this could greatly affect cloud structure and thus weather. The Solar radiation and magnetic storms could also profoundly affect power transmission and electronics.

Preparing for the possibility of an impending ice age along with the possible consequences of a reduction in Earth’s magnetic field are real concerns. Concern with relatively small effects of possible anthropogenic caused global warming is a misplaced distraction, and will probably lead to the public losing confidence in scientists, and could weaken the support needed when real problems occur.

Decreasing availability of oil and anthropogenic pollution (not greenhouse gasses) are real issues. Acid rain, smog, and dirty water sources do need to be fixed. The problems associated with high fuel prices, and dependence on sources of energy from possibly less than friendly foreign countries are critical. While we can’t solve the problems with a single magic bullet, more nuclear power plants, along with wind and Solar power, could fill much of the gap. There are solutions, but first we have to identify the correct problems.

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Experiments conducted in the early 20th Century by scientists including R.W. Wood and Niels Bohr proved that “greenhouse” gases like CO2 cannot increase air temperature by “trapping” infrared radiation. The results of R.W. Wood’s research were published in Philosophical magazine , 1909, vol 17, p319-320 – back when science relied on experiments, not computer models. Four years later Niels Bohr reported his discovery that the absorption of specific wavelengths of light didn’t cause gas atoms/molecules to become hotter. Empirical science proves that CO2 will not warm our atmosphere by trapping IR. The Earth will continue to warm and cool according to the natural cycles of the sun, the oceans, volcanism, orbital variations, and numerous other natural factors. The 0.038 percent concentration of CO2 in the atmosphere is a drop in the bucket and totally irrelevant and insignificant
http://www.giurfa.com/gh_experiments.pdf

George E. Smith

Wow what a lot of stuff to absorb. The first figure intrigues me; CO2 versus temperature ; well ersatz temperature without a scale. Having no temperature scale certainly makes it easier to make the two curves look somewhat the same; well Al Gore is a master at this subterfuge using it on page 66/67 of his “An Inconvenient Truth”.
Well I’m not against using an arbitrary temperature scale like AlGore did; or no temperature scale like this one does; it does help to have similar visual amplitudes to both curves.
One of the nice things about either no scale or an arbitrary one, is that you can also have an arbitrary zero point; and that gives you the ability to separate the two curves vertically to make it more difficult for the viewer to compare them. In Al Gore’s case he separated his CO2 and Temperature curves vertically, instead of overlapping them to prevent the viewer from easily spotting the only useful information that was present, which was the fact that the CO2 rising and falling edges come later than the temperature rise and fall; letting slick Al claim that the CO2 caused the temperature; instead of the clearly discernable fact even in Al’s book, that the temperature was the cause and the CO2 was the effect, some 800 years or so later.
Which by the way could make the mediaeval Warming period a prime suspect in the current CO2 rise situation.
Now with the present first graph, we also have no temperature scale and hence an arbitrary zero point enabling the cuves to be separated vertically; but to disguise what ?
Well maybe to disguise the basic shapes of the two curves.
A different zero on the temperature scale would let you overlap the red on the green around 1854, and that would make it easier to discern basic shape differences.
And of course the modellers tell us that the temperature goes as the logarithm of the CO2; So why wouldn’t one plot log(CO2) instead of CO2 itself.
Oh well nothing one can say without the necessary information; it would be nice to have a temperature graph with a temperature scale. or even a proxy for one would be better than nothing.

Geoff

George, the simple answer could be that the right side of the graph was cut off 😉

Allen63

Great summary article.

The important thing to remember is that while mathematics is an important “tool”, indeed, indispensible to science, it is not reality, and as any “tool” can be misused, resulting in bad outcomes (outcomes that fail to reflect reality).
Mathematics is the servant not the master of Science.
As one of the previous comments states the assumption that CO2 is a “trapping” chemical molecule in the atmosphere is a dubious proposition.
In too many disciplines of Science, mathematics has become unhinged from observation & measurement.
Science in all the disciplines must revert back to the empirical method — observation & measurement.
Mathematical extention by (seemingly endless) abstract equations (computer programs) beyond observation & measurement has led to unwarranted conclusions.
It is the scientist in the laboratory, not the mathematician at his desk, who will lead Man forward to better understand the world around us.

rickM

Ok, somewhat off topic but germains to this still I think.
In my Geology course today, the professor stated that if we were to acept the Milankovitch Hyopthesis as more or less fact, and with the combination of precession and obliquity, since we seem to be more near “maximum” in our elliptic orbit, the temps should be going down, instead of going up.
I’m an old guy, looking at a second career, and I’m tired of gritting my teeth in this course as more anthropogenic CO2 “education” is forced into the minds of me and my fellow students. A little help would be appreciated.

Skeptic Tank

A very comprehensive and fair perspective of AGW issues, at a level intended for reasonably intelligent and educated laypeople.
Excellent.

rickM,
Here are some resources. You can print out the charts, and use the handbook to line up your position [but don’t win the argument with the professor if it means getting a lower grade].
In fact, the global temperature has been declining recently. Always remember the central point in the CO2=AGW/runaway global warming hypothesis: that it is/will be caused by CO2. It’s hard to defend that hypothesis when temps are going down as
CO2 rises. The first chart below puts CO2 in perspective:
http://www.drroyspencer.com/library/pics/50-years-of-co2-0-to-100.gif
http://junkscience.com/MSU_Temps/NCDCabs.png
http://wattsupwiththat.files.wordpress.com/2009/04/uah_global_temperature_anomaly_mar2009.png
http://www.ianschumacher.com/img/TempsvsIPCCModelsWM.jpg
http://icecap.us/images/uploads/Temperatures_since_2003.jpg
http://icecap.us/images/uploads/TEMPSvsCO2.jpg
http://joannenova.com.au/2009/05/03/shock-global-temperatures-driven-by-us-postal-charges
http://joannenova.com.au/globalwarming/the_skeptics_handbook_2-22_lq.pdf

Morley

Geoff’s suggestion about the graph being cut off is correct as shown by looking at the original posting at Air vent. The right ordinate scale is temperature anomalies compared to 1979.
Weinstein’s critique is superb – the most comprehensive and intelligent (as well as intelligible) I have seen.
Morley

Adam from Kansas

As I said before, CO2 is good, and it also looks like a combination of that and a lot of rain this spring as well will result in larger than normal leaves on a number of trees around our backyard again for the second year in a row.
Seriously, at the rate the leaves on two young walnuts are growing, it’ll look like they’ve been crossed with a Sony Jumbotron, the two older walnuts have smaller leaves but they got burned pretty bad two years ago by a late freeze and they never leafed out so early since.
Our mulberry and hackberry trees are growing larger than normal leaves again this year it seems as well.

Hank Hancock

An excellent article! It connected some of the dots for me in a way that the total CO2 picture is making better “rational” sense.
I started off buying into the AGW concerns some 20 years ago. However, my analytical nature has taught me hysteria and alarmism are the products of overactive imagination – sort of the case of the hysteric seeing monsters in every dark setting because they’ve been told darkness is the condition under which monsters appear.
I am now a convinced skeptic of the AGW hypothesis because it draws far ranging conclusions that are mostly unsupported by the hard data. Further, having a research background, I am always concerned with the presence of confounding variables, enough to realize that there are far too many of them now for the AGW hypothesis to stand, particularly when the actual data behind the AGW hypothesis has been steadily weakening and calls to authority and circular citations are needed to keep it in play. In my circles, such things indicate the demise of the hypothesis is just a matter of time.
AGW’ers see global warming in every climate scenario because they’ve been told CO2 is the condition under which warming appears.

Glug

Again, Anthony, your outsourcing to internet loons has lowered the standards of this fine blog. When Leonard states that the most recent temperature trends are inconsistent with the IPCC models he is blatantly ignoring the actual predicted natural variability which present in the IPCC’s model output archive.

Jim Papsdorf

Good News !!!!
Listening to NPR about an hour ago I learned that the Cap and Trade bill that came out of the Waxman-Markey committee hearings today were so watered down that Greenpeace will not support it. Hopefully, by the time something really destructive comes up in Congress, the real implications of our hibernating sun will deep six Cap and Trade forever !!!!

“rickM (15:43:12) :
Ok, somewhat off topic but germains to this still I think.
In my Geology course today, the professor stated that if we were to acept the Milankovitch Hyopthesis as more or less fact, and with the combination of precession and obliquity, since we seem to be more near “maximum” in our elliptic orbit, the temps should be going down, instead of going up.”
The orbital cycles would suggest the following changes in insolation between 1950 and the year 2950. The northern hemisphere winter variation from average goes from 0 Langleys per day at 90 degrees north, -2 at the equator to -4 at 90 degrees south. During the northern hemisphere summer -4 at 90 degree north to +3 at the equator to 0 at 90 degrees south. The year 1950 was set to zero. Absolute 1950 values are for the northern hemisphere winter 0 langleys per day at 90 north, 876 at the equator and 712 at 90 degrees south. For northern hemisphere summer the values are 712 at 90 degrees north, 839 at the equator and 0 at 90 degrees south. The largest variation (for all latitudes) was the -4 variation at the north and south poles during their respective summers or a 0.56 percent decrease. Overall the during northern hemisphere summers the Earth should cool a bit and during northern hemisphere winters the Earth should be slightly warmer since the equatorial contribution to heating is much large than the polar ones. Data is from “Long-Period Global Variations of Incoming Solar Radiation by Vernekar (1972)

Pete W

Interesting link from above;
http://icecap.us/images/uploads/Temperatures_since_2003.jpg
However we’ll need to wait a few more years to know if this is a trend, or just a natural variance.
http://en.wikipedia.org/wiki/File:Instrumental_Temperature_Record.png
In other words, we shouldn’t put too much stock in short-term data.
Pete

Frank K.

Glug (16:40:53) :
” When Leonard states that the most recent temperature trends are inconsistent with the IPCC models he is blatantly ignoring the actual
HINDCASTED
natural variability which present in the IPCC’s model output archive.”
…there..fixed it for you…

George E. Smith (14:43:59) :

The first figure intrigues me; CO2 versus temperature ; well ersatz temperature without a scale. Having no temperature scale certainly makes it easier to make the two curves look somewhat the same….

As other have noted, it’s cut off. On Firefox (at least on Linux with a
three button mouse), if you right-click on the figure, you get various
options. “Copy link location” gives the odd URL
http://docs.google.com/File?id=dnc49xz_17kxf56d5_b that resolves to a
.png file. The “view image” option should take you directly to the image.

Tom in Florida

rickM (15:43:12) : Ok, somewhat off topic but germains to this still I think.
In my Geology course today, the professor stated that if we were to acept the Milankovitch Hyopthesis as more or less fact, and with the combination of precession and obliquity, since we seem to be more near “maximum” in our elliptic orbit, the temps should be going down, instead of going up.
I’m an old guy, looking at a second career, and I’m tired of gritting my teeth in this course as more anthropogenic CO2 “education” is forced into the minds of me and my fellow students. A little help would be appreciated.”
Tell your professor that it is the conjunction of maximum obliquity and NH summer solstice at perihelion that is most important in warming the planet out of an ice age. This happens about every 100,000 years and was the condition about 10,000 years ago. As conditions change from that we will get cooler then colder and eventually be out of this current warm period; however that will take quite a while. The eccentricity of the Earth’s orbit is currently about 0.0167. The eccentricity varies from nearly 0.0034 to almost 0.058 so we are not near maximum.(http://en.wikipedia.org/wiki/Orbital_eccentricity).

rbateman

The IPCC and the AGW’ers have been making predictions of catastrophic overheating, and their proof is nowhere to be found. Instead, the climate is on a 10 year cooldown. Their models are just that, models, with no basis in reality.
30 years ago much the same people were predicting impending catastrophic freezing.
Boiling, freezing, melting, drought, flood, monster storms, etc.
They should just settle for thier Chariots of the Gores book, and make sci-fi movies.

peter_ga

Consider the non-radiative heat loss from the earths surface which is not emitted directly to space. This averages 200W/m2. If the surface/atmosphere had “black-body” character, all the heat would be radiated directly to space, there would be no losses by any other mechanism, and the temperature would be 32K lower. Simply straight-line this for a feedback of 32K/200 = 0.16 degK/Wm-2. While this curve is likely to be non-linear, there is no sound argument as to why non-radiative surface heat loss would saturate.
So the current greenhouse gas increase induced warming of 1.5W/m2 would result in about a quarter of a degree of warming, the maximal increase of 3W/m2 would result in half a degree. This amount of warming would be quite steady, largely beneficial, and obscured by natural variations.
I conclude global warming is a non-issue.

Just Want Truth...

Frank K. (17:20:46) :
Thank you Frank. I was going to write a comment to Glug about the peer-reviewed works that show the flaws in climate models. But since your short comment set the record straight for Glug I won’t be needing to— I don’t want to feed a troll.

Steven Hill

Very good info here, very well done!
thanks,
Steve

Steptoe Fan

What is really bothering me is that the politicians who are driving this CO2 madness are all ” past the science ” you can’t get your hands on their schedule to force them to sit down and listen to current science, but if you could, it wouldn’t matter they are all ” past the science ” – the bad science that has been sold to them.
The perfect example – given by the current governor of my home state, Washington, testifying yesterday before that scham held by the EPA in Seattle. Today, the same person is giving bold and decisive orders to the state agencies to identify sources of CO2 and to begin formulating a plan to cut emissions ! These people are marching to beat of their own drum – they will not stop.
per the WSJ, it is the coming of the enviro – industrial complex !

nicholas

rickM, Wally, et al,
I may be stating the obvious, but the failure of orbital cycles to explain temperature fluctuations in no way makes the case for AGW. It is not an either/or proposition.
The fact of the matter is that the big heat engine in the picture is the sun. The notion that the sun’s energy output is a constant is known not to be the case. There are significant variations in sun spot activity, with resultant variations in energy output, and small changes in the sun’s output will mean a great deal to planetary energy absorption. Also, we know that our own planetary magnetic field has periodically reversed itself, which necessarily will affect the degree of absorption of radiant energy from the sun, plus many, many other factors that make attempting to assign man made CO2 levels as the responsible entity for perceived changes in global temperature a crap shoot.
The fact of the matter is, we don’t know. We ought to get used to it. A mere hundred years ago we were unaware there were galaxies other than our own. We had no idea those smudgy stars were not stars at all, but rather were collections of stars unbelievably far away. We also were unaware that the galaxies were in motion relative to each other, and that they were uniformly moving away from each other. Those are big changes in our understanding, from going to the idea that the stars were constant and never changing in position, to the notion that they were all moving away from a common center point, or a moment of beginning.
Addressing the uncertainty, you could simply ask a few questions, like “Could it also be true that the energy output from the sun may play a role?” or “Are we certain what the history of the sun’s energy output is?” or “Might there be other factors that could influence energy absorption from the sun?”, but the boys are right, no one likes being challenged or, heaven forbid, shown up, so you’d have to be able to pull it off and be tough skinned about the attempts to make you feel foolish for seeming to challenge “the settled science of man made global warming”, because he will know where your questions are going. Ultimately, you’re not going to be able to fix what’s wrong with this picture. The AGW people are hoping to make a lucky guess based on political aspirations rather than science. I mean, the leading proponent is a quack named Al Gore, the self-proclaimed inventor of the internet, who assures us there is no reason to question him on the science of his heartfelt convictions. Chicken Little was a better proponent for impending disaster.
My advise for the professor, if he feels lucky he should head down to Vegas. Best not devise energy policy based on feelings.

C Colenaty

Dr. Weinstein,
Many thanks for providing such an even-handed exposition of the overall coverage of”climate change” issues. It strikes me (and I hope you will not take offense) that while this essay is not pitched at the level of the reading public, it could serve as a platform for creating a much needed objective version of a “Climat Change for Dummies” book.

kuhnkat

Peter-Ga,
the fallacy in that computation of the earth’s temperature is in the hypothesis that GHG’s cause that 32K.

kuhnkat

GLUG,
GLUG GLUG GLUG GLUG GLUG GLUG GLUG GLUG GLUG GLUG GLUG GLUG GLUG
MMMMMM that Kool Aid is excellent huh??

Keith Minto

Wally (17.12.15)
“Overall the during northern hemisphere summers the Earth should cool a bit and during northern hemisphere winters the Earth should be slightly warmer since the equatorial contribution to heating is much large than the polar ones. Data is from “Long-Period Global Variations of Incoming Solar Radiation by Vernekar (1972)”
As a southern hemispherian I guess the reverse would apply so I do not look forward to warmer winters and hotter summers.
Should we all migrate north?

Sorry… Out of Topic, but it is… Hahaha… I never thought I would read something of the kind. Water is toxic also… Oh, Wikipedia!
http://www.answers.com/topic/water-intoxication
Now the term “toxic” has been “adjusted” for convenience of some policy-makers… From now on everything in this Universe is toxic. Hah!
Dear moderator, snip it if you wish… I know it’s fairly out of topic.

septicus

Mr Watt, are you aware of this? Of all the AGW critics I have read this gentleman seems to know most what he is talking about.
http://www.rocketscientistsjournal.com/2009/03/_internal_modeling_mistakes_by.html#more

Keith Minto

The stability of the Great Barrier Reef is always an emotive issue(bleached coral always provides a good photo op) so I was interested in the conclusion provided in the first of those three latter links on CO2,salt water and acidification.
“As for the real-world implications of their work, the three researchers note that over the next century the predicted increase in atmospheric CO2 concentration “will result in about a 15% increase in oceanic HCO3-,” and they say that this development “could stimulate photosynthesis and calcification in a wide variety of hermatypic corals.” This well-supported conclusion stands in stark contrast to the outworn contention of the world’s climate alarmists that continued increases in the air’s CO2 content will, as restated by Herfort et al., “cause a reduction in coral growth and planktonic calcification.” This claim, as they and many others have now demonstrated, is about as far from the truth as it could possibly be.
Sherwood, Keith and Craig Idso”
Can’t the warmists get anything right?

nicholas

Keith,
The time period spoken of is over a thousand years long. The time periods for the historical experience is on the order of tens to hundreds of thousands of years. The time periods predicted in Malinkovitch’s cycles were 26,000 years for precession and 70,000 years for inclination. The scale is quite different than what we are used thinking in.
No need to sell the house based on climate models.

Francis

This long discussion seems like an attempt to muddy-up my simple understanding that came from the 2001 IPCC. Computer models could hindcast the 1850-1970 temperature changes, based on natural causes. But the man-made CO2 effect had to be added to replicate the post 1970 increases.
Now, to that other graph: the hockey stick.
…..1…..We can get around the no-MANN problem, by only using those that do not have his name on them.
…..2…..I choose to not accept the author’s generalizing of these graphs. As temperatures increase (the La Nina is over; April was, cruelly, the fifth warmest) the hockey stick declines in significance. I’ve no dog in this fight. But let it be settled by a preponderance of data points.
…..3…..So, I am stipulating that the Medieval Climate Optimum, and the Little Ice Age, are regional situations.
Which, of course, is my point. That you can’t compare regional situations with the global situations that AGW’ers refer to.
Say The Day After Tomorrow brought back the north american glaciers. The global consequence, from this 2% of its surface, would be small.
Reuters (May22, 2009) “A rise in concentration of a powerful greenhouse gas ((methane)) over the Arctic after a decade of stability is stirring worries about possible vast stores trapped in permafrost, experts said.”
Reuters (May22, 2009) “A new study…’the most exhaustive end-to-end analysis of climate change impacts yet performed’… the MIT-based research found a 90% probability that worldwide surface temperatures will rise at least 9 oF by 2100.”

Juraj V.

The first graph is wrong. Actual “unprecedent” global temperature rise in the second half of 20th century has been was less steep than in 1907-1950. Not speaking about the habit of screwing the scale of CO2, putting the baseline at 280ppm.
http://www.climateaudit.org/phpBB3/viewtopic.php?f=6&t=356&start=37 – this is worth a separate article.

John F. Hultquist

This is a gem of a post but the comments contain a few nuts. So first to Dr. Weinstein: This is a well thought out and well written piece. I applaud you! The included links are appreciated. And I had no problem with the lack of a temperature scale that my display had – I have now seen this (the red line) line of historic temperatures so often, I could have nearly labeled it.
Then in the comments I am hit with walnuts, Glug and the IPCC, and Gregoire (Gov. of Washington State). Given the choice I’d prefer dinner with walnuts rather than the others. Along with Gore, Waxman, Peloise, and Obama, Glug and Gregoire will get footnotes in history for their inability to understand simple facts while believing passionately they have all the correct answers.
And to the person taking the geology class – get the best grade you can without antagonizing the instructor. Geology is noted for some first class jerks who worked diligently from their academic offices to undermine young, insightful, field researchers. Review the history of the Channeled Scablands and the Missoula Floods for an example.

Keith Minto

Correction….’cooler winters and hotter summers’.

John F. Hultquist

It would be helpful if all would stop using the term “greenhouse effect” and use the term “atmospheric effect.” The atmosphere is very large and is mostly nitrogen and oxygen gas with a few other way-smaller components. The world’s oceans are significant. Convection and conduction are the important processes, not trapping radiation by a small fraction of the atmosphere.

Mike Bryant

Speaking of AGW, Record lows in 28 states on May 19:
http://www.ncdc.noaa.gov/oa/climate/research/records/index.php?ts=daily&elem=mint&month=5&day=19&year=2009&submitted=Get+Records
Maybe someone has already commented on this. Imagine the hoopla if this had been record highs in 28 states.

Excellent. Thank you Dr. Weinstein.
I especially appreciate the discussion regarding whether warming, should it occur, will result in mostly positive or mostly negative effects on the biosphere and humanity. His conclusions match mine: Warmer Is Better, for the various reasons stated.

The Engineer

Sorry off subject – but has anyone attempted to explain the two warming periods (1910-45 and 1975-98) with respect to the vast differences in a) CO2 concentrations or b) Human CO2 emissions during the 2 periods. See figure 1.
A link perhaps ??
PS I think Humans CO2 emissions were at least 4 times greater (pr year) during the second warming period than the first.

MalagaView

Wonderful article… plays to all my perceptions and prejudices…
I think the saddest thing is that we really haven’t come a long way since the 1970s…
Then we had “rough numbers” and “rough guesses”…
But somewhere along the line this morphed in the main stream media into “hard numbers” and “settled science”…
Perhaps that is why I stopped reading newspapers and watching television twenty years ago….
So much “science” seems to have been corrupted by “money”…
So much “science” seems to be “economical with the truth”….
Today every number seems to be “cooked”…
Extrapolating these numbers we are headed into the “dark ages” yet again…
My guess is that the “Spanish Inquisition” has already arrived in guise of “peer review”….
So Anthony, please, KEEP ON TRUCKING…
You are bringing light and hope into this dark age…

Generally a good article. A couple of things bug me a bit though… Mostly these cycle around accepting some of the premises of the AGW crowd for the purpose of showing some flaw in their data or argumentation; yet it implicitly endorses what look to me like broken premises:
First, the notion of a global average temperature measured in tenths of a degree based on USHCN data measured in Whole Degree F. You just can’t do that. Any computation made from whole F must end up with whole F or you have false precision.
http://chiefio.wordpress.com/2009/03/05/mr-mcguire-would-not-approve/
That you simply accept the notion of a “global average temperature” and then measure it in tenths is a fundamental flaw. (One I think negates the whole AGW thesis all by itself… but also cuts against some of the counter AGW arguments too. Both sides are just dancing in the error bands of False Precision.) What meaning is there in the “global average gender”? Does the fact that it’s a few percent female mean anything? Would it mean anything else if it changed to slightly male? That’s what you get by averaging high and low temps. The “anomaly” in the global average gender is not very useful, nor is the “global average temperature anomaly”…
I know everyone does it, but do you really need to have your charts vertical scale be such that the absolute changes are exaggerated? Why not start at zero? Then you can see the percentage changes are really near nothing… Those dramatic 45 degree rising lines become much more nearly a flat line. And more truthful.
The percentage of the worlds thermometers that actually have any length of history is small, and those are almost entirely stuck in the USA, Europe, and a bit of Japan. That is not a representative sample of the earths surface. You can make no claims about historical “global” anything based on the thermometer distribution in the past:
http://chiefio.wordpress.com/2009/02/24/so_many_thermometers_so_little_time/
Your temperature graph implicitly accepts a time scale starting at the bottom of the little ice age. This is wrong:
http://chiefio.wordpress.com/2009/03/02/picking-cherries-in-sweden/
As you can see, on a longer time scale, there has been no temperature rise.
The notion of “30 year climate” is just broken. We have 30 year weather, but climate is something that only changes on a geologic time scale. Thousands of years, at least. Until one recognizes that Bond Events are a normal cycle (and I’d assert it’s a weather cycle) looking at anything less than a 2000+ year period is just going to cause erroneous panic over a normal cyclicality:
http://chiefio.wordpress.com/2009/04/06/bond-event-zero/
Again, I appreciate the article, but accepting the errors of the AGW’s as a premise is, er, problematic.

Pierre Gosselin

These posts just keep getting longer.
There’s been too much focus on the last 150 years.
It’s been warming since 1700, long before anthroprogenic CO2 emissions.
Temps fluctuted throughout the Holocene, when CO2 was pretty much constant at 280 ppm.
And they fluctuated immensely through the ice ages, and throughout the history of the earth.

Robinson

In other news, an ex-BBC Environmental Correspondant has slammed his old bosses at the BBC as being evangelical, shallow and sparse, particularly with respect to the reporting of “climage change” stories.

EM Smith
I think we both share scepticism at the idea of a global temperature, let alone such an acurate one based on so few stations in 1850/1880 with a base line that is ever changing.
I don’t know if you saw my other post to you suggesting it would be useful if you could summarise on chiefio the background to Global temperatures and the problems with Giss data. It is rather technical at the moment for the laymen I point in your direction.
TonyB

Lars Kamél

The CO2 measurments at the South Pole has been going on as long as those at Mauna Loa, so there are long data records for two places, not one.

Christopher Hanley

rickM (15:43:12)
Far be it from me to contradict a geology professor, but it looks to me that the temperature trend in this Milankovic cycle is down.
http://muller.lbl.gov/pages/IceAgeBook/Image3.gif

Stephen Skinner

There is a interesting book ‘How to Lie with Statistics’ written by Darrell Huff in 1954. In this book Darrell shows how removing the left hand scale in a graph or by only showing a graph reduced to the range of data it is possible to imply something different to what the data has to offer. Having read this I created a graph of the CO2 increase with a Y axis of a million. Is this unreasonable?

It’s good to see discussion still going on, it might be time to choose a new King Canute; and go down to the sea and command it to go back. I will send for my jester and minstrel that we may begin.

Pofarmer

…..2…..I choose to not accept the author’s generalizing of these graphs. As temperatures increase (the La Nina is over; April was, cruelly, the fifth warmest) the hockey stick declines in significance. I’ve no dog in this fight. But let it be settled by a preponderance of data points.
Two things. Number one, you would expect it to still be warmer coming off the 1998 peak. It’s not going to fall directly off a cliff.
Number two. We know that Hansens “adjustments” among others, have LOWERED past temperatures. Anything using GISS numbers is suspect.
…..3…..So, I am stipulating that the Medieval Climate Optimum, and the Little Ice Age, are regional situations.

Yeah, so?
It seems that in the fairly recent past the vegetation zones were much closer to the poles than they are today. The remains of some plant species can be found as far as 1,000km farther north than they are found today. Forests once extended right up to the Barents Coast and the White Sea. The European tundra zones were non-existent. In northern Asia, peat-moss was discovered on Novaya Zemlya. And, this was no short-term aberration in the weather. This warming trend seems to have lasted for quite a while. Consider the following comments from Borisov, a long time meteorology and climatology professor at Leningrad State University:
From Ancient Ice
http://naturalselection.0catch.com/Files/ancientice.html#Woolly%20Mammoths
“During the last 18,000 years, the warming was particularly appreciable during the Middle Holocene. This covered the time period of 9,000 to 2,500 years ago and culminated about 6,000 to 4,000 years ago, i.e., when the first pyramids were already being built in Egypt . . . The most perturbing questions of the stage under consideration are: Was the Arctic Basin iceless during the culmination of the optimum?”8
Also
The well preserved “mummified” remains of many mammoths have been found along with those of many other types of warmer weather animals such as the horse, lion, tiger, leopard, bear, antelope, camel, reindeer, giant beaver, musk sheep, musk ox, donkey, ibex, badger, fox, wolverine, voles, squirrels, bison, rabbit and lynx as well as a host of temperate plants are still being found all jumbled together within the Artic Circle – along the same latitudes as Greenland all around the globe.39
The problem with the popular belief that millions of mammoths lived in very northerly regions around the entire globe, with estimates of up to 5 million living along a 600 mile stretch of Siberian coastline alone,39 is that these mammoths were still living in these regions within the past 10,000 to 20,000 years. Carbon 14 dating of Siberian mammoths has returned dates as early as 9670± 40 years before present (BP).41 So, why is this a problem?
Contrary to popular imagination, these creatures were not surrounded by the extremely cold, harsh environments that exist in these northerly regions today. Rather, they lived in rather lush steppe-type conditions to include evidence of large fruit bearing trees, abundant grasslands, and the very large numbers and types of grazing animals already mentioned only to be quickly and collectively annihilated over huge areas by rapid weather changes. Clearly, the present is far far different than even the relatively recent past must have been. Sound too far fetched?
Consider that the last meal of the famous Berezovka mammoth (see picture), found north of the Artic Circle, consisted of “twenty-four pounds of undigested vegetation” 39 to include over 40 types of plants; many no longer found in such northerly regions.43 The enormous quantities of food it takes to feed an elephant of this size (~300kg per day) is, by itself, very good evidence for a much different climate in these regions than exists today.39 Consider the following comment by Zazula et. al. published the June 2003 issue of Nature:
“This vegetation [Beringia: Includes an area between Siberia and Alaska as well as the Yukon Territory of Canada] was unlike that found in modern Arctic tundra, which can sustain relatively few mammals, but was instead a productive ecosystem of dry grassland that resembled extant subarctic steppe communities . . .
Abundant sage (Artemisia frigida) leaves, flowers from Artemisia sp., and seeds of bluegrass (Poa), wild-rye grass (Elymus), sedge (Carex) and rushes (Juncus/Luzula) . . . Seeds of cinquefoil (Potentilla), goosefoot (Chenopodium), buttercup (Ranunculus), mustard (Draba), poppy (Papaver), fairy-candelabra (Androsace septentrionalis), chickweed (Cerastium) and campion (Silene) are indicative of diverse forbs growing on dry, open, disturbed ground, possibly among predominantly arid steppe vegetation. Such an assemblage has no modern analogue in Arctic tundra. Local habitat diversity is indicated by sedge and moss peat from deposits that were formed in low-lying wet areas . . .
[This region] must have been covered with vegetation even during the coldest part of the most recent ice age (some 24,000 years ago) because it supported large populations of woolly mammoth, horses, bison and other mammals during a time of extensive Northern Hemisphere glaciation.” 42