November 19, 2009. Robert H. Austin, Princeton University, Corresponding Author: Over 160 highly qualified scientists request that the APS change wording about climate change. Greenhouse gas emissions accompany human industrial and agricultural activity. While substantial concern has been expressed that emissions may cause significant climate change, measured or reconstructed temperature records indicate that 20th 21st century changes are neither exceptional nor persistent, and the historical and geological records show many periods warmer than today.
