From WUWT, a particularly good summary of the gaping holes in Anthropogenic Global Warming theory (hereinafter, "AGW"):
The 22 Inconvenient Truths
1. The Mean Global Temperature has been stable since 1997, despite a continuous increase of the CO2 content of the air: how could one say that the increase of the CO2 content of the air is the cause of the increase of the temperature? (discussion: p. 4)
2. 57% of the cumulative anthropic emissions since the beginning of the Industrial revolution have been emitted since 1997, but the temperature has been stable. How to uphold that anthropic CO2 emissions (or anthropic cumulative emissions) cause an increase of the Mean Global Temperature?
[Note 1: since 1880 the only one period where Global Mean Temperature and CO2 content of the air increased simultaneously has been 1978-1997. From 1910 to 1940, the Global Mean Temperature increased at about the same rate as over 1978-1997, while CO2 anthropic emissions were almost negligible. Over 1950-1978 while CO2 anthropic emissions increased rapidly the Global Mean Temperature dropped. From Vostok and other ice cores we know that it’s the increase of the temperature that drives the subsequent increase of the CO2 content of the air, thanks to ocean out-gassing, and not the opposite. The same process is still at work nowadays] (discussion: p. 7)
3. The amount of CO2 of the air from anthropic emissions is today no more than 6% of the total CO2 in the air (as shown by the isotopic ratios 13C/12C) instead of the 25% to 30% said by IPCC. (discussion: p. 9)
4. The lifetime of CO2 molecules in the atmosphere is about 5 years instead of the 100 years said by IPCC. (discussion: p. 10)
5. The changes of the Mean Global Temperature are more or less sinusoidal with a well defined 60 year period. We are at a maximum of the sinusoid(s) and hence the next years should be cooler as has been observed after 1950. (discussion: p. 12)
6. The absorption of the radiation from the surface by the CO2 of the air is nearly saturated. Measuring with a spectrometer what is left from the radiation of a broadband infrared source (say a black body heated at 1000°C) after crossing the equivalent of some tens or hundreds of meters of the air, shows that the main CO2 bands (4.3 µm and 15 µm) have been replaced by the emission spectrum of the CO2 which is radiated at the temperature of the trace-gas. (discussion: p. 14)
7. In some geological periods the CO2 content of the air has been up to 20 times today’s content, and there has been no runaway temperature increase! Why would our CO2 emissions have a cataclysmic impact? The laws of Nature are the same whatever the place and the time. (discussion: p. 17)
8. The sea level is increasing by about 1.3 mm/year according to the data of the tide-gauges (after correction of the emergence or subsidence of the rock to which the tide gauge is attached, nowadays precisely known thanks to high precision GPS instrumentation); no acceleration has been observed during the last decades; the raw measurements at Brest since 1846 and at Marseille since the 1880s are slightly less than 1.3 mm/year. (discussion: p. 18)
9. The “hot spot” in the inter-tropical high troposphere is, according to all “models” and to the IPCC reports, the indubitable proof of the water vapour feedback amplification of the warming: it has not been observed and does not exist. (discussion: p. 20)
10. The water vapour content of the air has been roughly constant since more than 50 years but the humidity of the upper layers of the troposphere has been decreasing: the IPCC foretold the opposite to assert its “positive water vapour feedback” with increasing CO2. The observed “feedback” is negative. (discussion: p.22)
11. The maximum surface of the Antarctic ice-pack has been increasing every year since we have satellite observations. (discussion: p. 24)
12. The sum of the surfaces of the Arctic and Antarctic icepacks is about constant, their trends are phase-opposite; hence their total albedo is about constant. (discussion: p. 25)
13. The measurements from the 3000 oceanic ARGO buoys since 2003 may suggest a slight decrease of the oceanic heat content between the surface and a depth 700 m with very significant regional differences. (discussion: p. 27)
14. The observed outgoing longwave emission (or thermal infrared) of the globe is increasing, contrary to what models say on a would-be “radiative imbalance”; the “blanket” effect of CO2 or CH4 “greenhouse gases” is not seen. (discussion:p. 29)
15. The Stefan Boltzmann formula does not apply to gases, as they are neither black bodies, nor grey bodies: why does the IPCC community use it for gases ? (discussion: p. 30)
16. The trace gases absorb the radiation of the surface and radiate at the temperature of the air which is, at some height, most of the time slightly lower that of the surface. The trace-gases cannot “heat the surface“, according to the second principle of thermodynamics which prohibits heat transfer from a cooler body to a warmer body. (discussion: p. 32)
17. The temperatures have always driven the CO2 content of the air, never the reverse. Nowadays the net increment of the CO2 content of the air follows very closely the inter-tropical temperature anomaly. (discussion: p. 33)
18. The CLOUD project at the European Center for Nuclear Research is probing the Svensmark-Shaviv hypothesis on the role of cosmic rays modulated by the solar magnetic field on the low cloud coverage; the first and encouraging results have been published in Nature. (discussion: p. 36)
19. Numerical “Climate models” are not consistent regarding cloud coverage which is the main driver of the surface temperatures. Project Earthshine (Earthshine is the ghostly glow of the dark side of the Moon) has been measuring changes of the terrestrial albedo in relation to cloud coverage data; according to cloud coverage data available since 1983, the albedo of the Earth has decreased from 1984 to 1998, then increased up to 2004 in sync with the Mean Global Temperature. (discussion: p. 37)
20. The forecasts of the “climate models” are diverging more and more from the observations. A model is not a scientific proof of a fact and if proven false by observations (or falsified) it must be discarded, or audited and corrected. We are still waiting for the IPCC models to be discarded or revised; but alas IPCC uses the models financed by the taxpayers both to “prove” attributions to greenhouse gas and to support forecasts of doom. (discussion: p. 40)
21. As said by IPCC in its TAR (2001) “we are dealing with a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible.” Has this state of affairs changed since 2001? Surely not for scientific reasons. (discussion: p. 43)
22. Last but not least the IPCC is neither a scientific organization nor an independent organization: the summary for policy makers, the only part of the report read by international organizations, politicians and media is written under the very close supervision of the representative of the countries and of the non-governmental pressure groups.
The governing body of the IPCC is made of a minority of scientists almost all of them promoters of the environmentalist ideology, and a majority of state representatives and of non-governmental green organizations. (discussion: p. 46)
Do read the entire post along with the explanatory appendix. This is as good a summary as I've seen in some time. The first two facts noted by the author are really the meat of it all. The foundational theory of AGW is that, as more CO2 is pumped into our atmosphere, temperatures will rise proportionately. There is no support for this theory in the historical record predating modern temperature records, nor does the theory find any empirical support in the modern records, given that we have been pumping large amounts of CO2 into the air since 1997 with NO corresponding rise in temperature.
I am always amazed when the left, most of whom seem to embrace the AGW theory, accuse the right of being "anti-science" or "science deniers." It stands reality on its head. In a sane world, the gaping holes in AGW theory would lead scientists to discard the theory and start anew. The reality is that, as more facts show the fatal flaws with AGW theory, the left just becomes more strident in trying to shut down debate and in their claims that "the science is settled."
The truth is that there is much more than science at stake for the AGW crowd. For a very significant number of players, there are hundreds of billions of dollars at play in this scam, whether from carbon credits, renewable energy scams, cushy jobs at foundations, or even outright transfers of wealth from wealthy countries to third world nations (all to be administered by the UN, of course). And there seem to be more than a few watermelons (green on the outside, red on the inside) pushing this AGW canard for whom the thought of saving Gaia comes with an underlying motivation to do away with capitalism and democracy. Then there are the scientists riding the gravy train of grants and recognition who have, in some cases, falsified or presented deeply misleading research, as well as attempted to severely restrict the voices of any who would raise questions about AGW. And lastly, there are the useful idiots at the bottom who unthinkingly embrace AGW and go to bed thinking themselves not only morally superior for doing so, but as they are constantly told by AGW cheerleaders, much smarter than those on the right who object to AGW on the basis of unreliable and contrary data.
No area of science is more bastardized than "climate science." I have no problems following science experiments wherever they might lead, so long as the scientific method is practiced. But all too often in climate science, there is a complete failure in this regards. It is criminal the number of climate scientists who fail to adhere to the scientific method, trying to claim peer review as the gold standard of reliability rather than a complete posting of their experiment in such detail as to allow for reproduction and verification by other scientists. Even as I write this, the EPA is preparing to issue regulations that will cost our economy tens of billions of dollars, and which regulations are based on "secret science" that has never been made public so as to subject it to reproduction or verification. It is a mockery to call it "science." It is faith being sold as science.
Yet another significant concern I have is with the numerous unexplained changes to the historical record of our temperature data, something that Jim Hansen, then at NASA, started doing in the late 90's and which continues to this day. As it stands, I have no faith whatsoever in the historical temperature record relied upon by the UN IPCC. Though, it should be noted, those records only begin about the 1880's, with the first relatively reliable efforts to collect data from thermometers.
This is not an academic debate about AGW. People's lives across the world are being effected by this scam. Hundreds of billions of dollars that could be used productively are being wasted in this fraud. Economies are being strangled by regulations designed to drive out a trace gas necessary for life on this planet. It is a travesty and, indeed, criminal. A very large number of people need to be jailed over this fraud.
Update: A perfect illustration of why such green energy scams are unforgivable in their impacts on people's lives comes from Germany:
According to EU data, Germany’s average residential electricity rate is 29.8 cents per kilowatt hour. This is approximately double the 14.2 cents and 15.9 cents per kWh paid by residents of Germany’s neighbors Poland and France, respectively, and almost two and a half times the U.S. average of 12 cents per kWh. Germany’s industrial electricity rate of 16 cents per kWh is also much higher than France’s 9.6 cents or Poland’s 8.3 cents. The average German per capita electricity consumption is 0.8 kilowatts. At a composite rate of 24 cents per kWh, this works out to a yearly bill of $1,700 per person, experienced either directly in utility bills or indirectly through increased costs of goods and services. The median household income in Germany is $33,000, so if we assume an average of two people per household, the electricity cost would amount to more than 10 percent of available income. And that is for the median-income household. The amount of electricity that people need does not scale in proportion to their paychecks. For the rich, $1,700 per year in electric bills might be a pittance, or at most a nuisance. But for the poor who are just scraping by, such a burden is simply brutal.
While here at home, we are but a half step behind Germany:
The Environmental Protection Agency (EPA) is preparing to finalize its Clean Power Plan, which aims to reduce power plant carbon dioxide emissions by 30% from 2005 levels over the next 15 years. Looking at some of the best-case scenarios for CO2 reductions, the plan could potentially cut roughly 300 million tons of CO2 annually. Because global man-made CO2 emissions reach roughly 30 billion tons annually, it’s estimated that the EPA plan could result in a possible 1% reduction in annual man-made CO2. Overall, man-made CO2 accounts for only 4% of total atmospheric CO2. So the true atmospheric reduction in CO2 from the EPA plan would be approximately 0.04%. The cost for this plan is estimated at $50 billion annually, with the loss of roughly 15,000 U.S. jobs each year. Increases in household utility bills could reach $100 billion annually.