Most federal policy decisions involving climate change refer to the UN Intergovernmental Panel on Climate Change; Agency Report No. 4 (IPCC AR4) as the definitive source for how human activity is effecting future climate change.  The US Environmental Protection Agency (EPA), through its National Center for Environmental Economics (NCEE) has become increasingly concerned that federal agencies and countries have paid too little attention to the science of global of warming.

In March of 2009, NCEE issued a draft report that noted six deficiencies in the climate change science, and call into question the validity of the IPCC AR4 analysis.  They are:

1. Global temperatures are actually declining, not increasing.  The cooling trend has continued for 11 years with a particularly rapid decline in 2007-08. This is in contrast to the climate change models that predicted global temperatures would increase over the same time period.  Clearly, the models are incorrect.
2. Hurricane activity is not increasing.  Conventional wisdom is that past, present and future Atlantic hurricane behavior is changing due to global warming. The logic was that global warming is leading to (and will lead to) more frequent and intense storms. Now the consensus is much more neutral, arguing that future Atlantic tropical cyclones are predicted to be similar to those of the past.
3. Greenland’s ice sheet does not appear to be disappearing.   The idea that warming temperatures will cause Greenland to rapidly shed its ice has been greatly diminished by new results indicating little evidence for the operation of such processes.
4. Predictions of greenhouse gas emissions are overstated.  One of the worst economic recessions since World War II has greatly decreased greenhouse gas emissions compared to the assumptions made by the IPCC AR4. The current draft by IPCC does not reflect the changes that have already occurred and are likely to occur in the future as a result of the recession.
5. Climate models may be based upon false assumptions.  A 2009 paper finds that the crucial assumption in the global climate models concerning water vapor is not supported by empirical evidence.
6. The IPCC AR4 report failed to account for solar activity that drives global temperatures on earth.   A 2009 paper suggests that the IPCC used faulty solar data which dismissed solar variability as an effect agent on global temperatures. Research by Scafetta and West suggests that solar variability could account for up to 68% of the increase in Earth’s global temperatures.

In conclusion the EPA report states, “the extensive portions of the EPA’s Technical Support Document (TSD) that are based upon old science are no longer appropriate and need to be revised“.