People who have been actually looking at the data with regards to the temperature of Earth and the accuracy of the projections of the general circulation models(GCMs) used by the IPCC have known for a long time that the greenhouse gas induced global warming hypothesis is not valid. The supporters are aware of that also, so they have changed there spin to 'climate change.' Here is a piece from the blog 'Greenie Watch' that discusses this transformation.

THE MORPHING OF "CLIMATE CHANGE" POLITICS

An email from Henry N. Geraedts, PhD [arbutuspoint@gmail.com]

Might we be witnessing the third morphing of "Man-made Global Warming/Climate Change" politics? I think so. The first iteration was the original "Man-made-CO2-driven Anthropogenic Global Warming" [AGW], aka Hansen and Gore, Opus 1, 1988. When however, it became evident to all but the most shuttered dogmatists that global temperatures peaked in 1998, levelled off and that since 2003 key temperature metrics show what appears to be an accelerating decline, AGW handlers deftly and conveniently morphed it into its second iteration, and it took on the more nebulous form of man-made "Climate Change".

So what if the data runs counter to your contention that [Man-made] CO2 is the causal agent in "Global Warming"? Just buttress CO2 with other previously insignificant "greenhouse gases" [at all cost avoiding mentioning water vapour, by far the dominant GHG but likely a negative forcing..] and voila, the man-made component of the "climate crisis" can now again be held up as the determining driver in what just happens to be the most complex, multi-variate, non-linear and poorly understood system known to mankind. The fact that all of this irrevocably relegated the AGW/ACC case to the realms of alchemy, astrology and other pseudo "sciences" didn't bother the dogmatists in the least.

Inconveniently however, "climate change" for the past 6 years or so has meant an increasingly well documented global cooling trend. To the point where this is becoming politically bothersome. Two governments with enough backbone to do so -in New Zealand and Canada respectively- have ever so cautiously indicated that there are sufficient question marks in the margin to slow down the pace of environmental policy commitments, focus firmly on economic matters and even [may the heavens forbid] undertake a critical review of the "science" said to prove "man-made climate change". In the recent election, Canadian voters singularly punished the Liberal Party which ran on a carbon tax based "Green Shift" platform.

My sense is that given that the enviro-political gearbox clearly is not meshing as smoothly as before, we are starting to witness AGW's third political morphing in which both the EU and the US serve up to their voters a reworked political message about the need for GHG reductions, gradually unwinding the purported "climate crisis" argument in favour of the a new and overarching need to secure "energy independence" [from Russia for Europe and OPEC for the US]? Current attempts to salvage the EU's 20/20/20 GHG mitigation program are increasingly being held up in that light, and Obama's read-between-the-lines messages about the environment and energy appear to fit the mould.