There is currently considerable debate about carbon cap and trade as a remedy to the purported climate change due to emissions of greenhouse gases. It is curious that in this debate there has been no attention paid by the media to the predictive failure of the general circulation models (GCMs) on which the anthropogenic global warming (AGW) hypothesis is based. Given the draconian energy policy initiatives that are justified by the anthropogenic global warming (AGW) hypothesis, it is difficult to understand the lack of journalistic curiosity regarding the merits of the GCMs (rather than hard science) that form the basis for the AGW hypothesis.

The AGW hypothesis starts with the well-known fact that carbon dioxide absorbs infrared radiation in narrow bandwidths around wavelengths of 2.7, 4.3, and 15 microns. Simple analysis shows that doubling of the amount of carbon dioxide in the atmosphere considered alone would increase the temperature of the atmosphere by perhaps 2F due to increased absorption of infrared radiation from Earth. The AGW hypothesis holds that this atmospheric temperature increase would lead to an increase in the amount of water vapor, the dominant greenhouse gas, in the air. (The amount of water vapor that can be carried in the air increases exponentially with temperature according to the Clausius-Clapyron equation.) The increase in the amount of water vapor in the air would cause a further increase in the temperature of the air. This is called a “positive feedback.” Something that reduced air temperature as carbon dioxide increased would be termed a “negative feedback.” Increased cloudiness that reflects sunlight as a result of the increase in water vapor in the atmosphere would be an example of a negative feedback. (The GCMs assume that the increased cloudiness is in high altitude cirrus clouds that absorb radiation from the ground rather than the clouds below about 10,000 feet altitude that reflect sunlight.) The amount of water vapor that can be contained in the air depends on temperature, and at the equator the amount of water vapor is about 20,000 ppm(v) compared to about 380 ppm(v) for carbon dioxide. So, at the equator carbon dioxide is not very significant compared to water vapor, so the temperature increase there would be expected to be small. But, at the poles there is little water vapor in the air because of the low temperature, so larger temperature increases would be expected. This temperature increase could lead to polar ice melting. Ice reflects sunlight while water absorbs it, at least at high incidence angles. Thus the air temperature increase at the poles would be expected to result in less reflected solar energy, a positive feedback that further increases air temperature. This reasoning seems logical and indicates that a slight increase in the amount of carbon dioxide in the atmosphere would eventually cause the air temperature to increase at an accelerating rate. The GCMs used by the United Nation Intergovernmental Panel on Climate Change (UN IPCC) have many positive feedback loops, and no negative feedback loops. These models show temperature steadily increasing in the future. The supporters of the AGW hypothesis initially predicted that temperature would increase monotonically with increasing carbon dioxide levels regardless of natural effects.

When atmospheric scientists stopped being concerned about an impending ice age, and became concerned about global warming around 30 years ago, many people pointed out that history does not support the idea that all feedbacks are positive. The world has gone through many cycles of glaciations followed by meltdowns, and though the cause of these dramatic climate changes is unknown, they obviously occurred before man had any impact. There was also indication that carbon dioxide level had been at least an order of magnitude higher than in modern times, and the temperature did not accelerate upwards. Then there was the inconvenient warm period of 7000 years ago when temperature was much higher than today, the Roman Warm Period, the Medieval Warm Period, and Little Ice Age starting about 600 years ago. Since the end of the last ice age about 12,000 years ago there have been nine cycles of lower to higher temperatures, and back. There is an embarrassing email trail of global warming enthusiasts discussing the need to “get rid of the MWP and the LIA,” and researchers set out to do just that. The result was the infamous Mann “hockeystick” which showed that temperatures were higher at present than at any time in the last 1000 years. But after Congressman Joe Barton forced release of the data behind the Mann hockeystick (one feature of the global warming debate is the curious reluctance of the supporters to share their data in contra variance to normal scientific practice), Canadian independent researchers Steve McIntyre and Ross McKitrick showed that the work was irreparably flawed. This should have settled the issue of whether or not the MWP and the LIA actually happened, but the global warming enthusiasts more or less ignored the facts. But most people now accept that there have been many cycles of ice ages followed by thaws, and that temperatures have been both higher and lower during the current interglacial than they are now. And there is no accepted explanation as to what the natural mechanisms are that caused the glaciations and thaws.

It is important to consider the politics behind the formation of the UN IPCC. Maurice Strong, the Canadian socialist billionaire, was the primary mover in the formation of the IPCC. He has clearly stated that his intent was to save the world, and that to do that it was necessary to destroy Western Civilization. His focus was on energy production by fossil fuel. The charter of the IPCC was to determine how man was affecting climate, not to determine what natural forces affect climate. The IPCC concentrated on greenhouse gases as the primary forcing mechanism in climate, and paid scant attention to other activities of man that clearly influence climate on a local level, such as land use. The reason appears to be that the goal was to advance public policies that reduced energy consumption. It is revealing that the IPCC produces two reports, one a report for policy makers, and another report by scientists. Many have commented on the IPCC procedure in which bureaucrat politicians write the report for policy makers before the scientist’s report is completed, and that the bureaucrats then coerce the scientists to conform to what the public policy report says, or simply ignore the scientist’s review comments.

Since 1998 the average temperature has not increased, and in fact, has declined so that at present the temperature is about the same as it was in 1979. The four major agencies that measure global temperature anomalies are NASA/GISS, NCDC/NOAA, HAD/CRU, and RSS/MSU. NASA/GISS (James Hansen and Gavin Schmidt) continually massages the raw data with the effect that past temperatures are continually revised downward, while current temperatures are revised upwards. It would be expected that if the errors in the raw data were random, that some corrections would go one way and some the other. But, with NASA/GISS the past always is revised down and current up. NASA/GISS is an outlier compared to the data of the other three agencies, and so should be disregarded. The GCMs, of course have projected temperatures continuing upward even as actual temperature has gone down. Recently, the modelers have said that “natural effects” are the reason for the discrepancy. Ten years ago the position was that natural effects were overwhelmed by increases in carbon dioxide, so temperature would continually go up uninterrupted. The GCMs not only have been wrong with regard to average global temperature, but also in the minute details. The troposphere temperature at mid-latitudes has gone down rather than up as required by the AGW hypothesis. The South Pole has gotten colder with time. Greenland has warmed, but is still colder than in 1930. The Antarctic ice mass has been increasing. Sea level stopped rising around 2003. Arctic sea ice has recovered to normal levels recently. The ocean temperature, according to over 3000 Argos sea buoys is not increasing, and appears to be falling, with the change within the accuracy of the measurements. It appears that cirrus cloud cover has declined rather than increasing. (Cloud formation is not predicted by the GCMs based on first principles of physics, and is basically an input parameter in the GCMs.) The supporters of AGW have explained that the cooling of the southern United States over the past 70 years as the result of increased release of natural aerosols from plants caused by the increase in atmospheric carbon dioxide that accelerated plant growth. This, of course, would be a negative feedback due to the increase in carbon dioxide that was not included in the GCMs. (This increased growth phenomena is present around the world in places like the Gobi desert where plants are now growing where there were none a few decades ago. It appears that increased carbon dioxide permits plant growth where there is limited water availability.)

Given the demonstrated failure of the GCMs to predict future climate, and given that the AGW hypothesis is built on projections of the GCMs, it seems ill advised to embark on draconian public policy initiatives that will negatively affect most people in the United States. This is particularly true since the GCM projections are that the policies, if implemented, will have little or no effect in any case, but are rather just “feel good” gestures. It would be better to expand research to improve the GCMs by determining as best we can all of the feedbacks, negative as well as, and to better understand the natural phenomena that clearly are more important to climate than assumed in the GCMs.