claim: In a paper published online this week in the Journal of Geophysical Research-Atmosphere, economics professor Ross McKitrick says the resulting discrepancies may be leading to an overstatement of the role of greenhouse gases in the atmosphere.
evidence: The executive summary of the WG I Summary for Policymakers report says they are certain that emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases, resulting on average in an additional warming of the Earth's surface.
category: Intergovernmental Panel on Climate Change