DOE released a report that questioned the broad scientific consensus on climate change, asserting that “Attribution of climate change or extreme weather events to human CO2 emissions is challenged by natural climate variability, data limitations, and inherent model deficiencies,” and that “solar activity's contribution to the late 20th century warming might be underestimated.” The report went on to state that: "Both models and experience suggest that CO2 -induced warming might be less damaging economically than commonly believed, and excessively aggressive mitigation policies could prove more detrimental than beneficial. Social Cost of Carbon estimates, which attempt to quantify the economic damage of CO2 emissions, are highly sensitive to their underlying assumptions and so provide limited independent information…. U.S. policy actions are expected to have undetectably small direct impacts on the global climate and any effects will emerge only with long delays."