A broader view of the role of humans in the climate system

The 2007 report from the Intergovernmental Panel on Climate Change Working Group I presents a narrow view of the state of climate science.1 Attempts to significantly influence regional and local-scale climate based on controlling carbon dioxide emissions alone cannot succeed since humans are significantly altering the global climate in a variety of diverse ways beyond the radiative effect of CO2. The IPCC assessments have been too conservative in recognizing the importance of these human climate forcings as they alter regional and global climate. When the IPCC focuses its policy attention on CO2, it neglects other important aspects of the impact of human activities on climate.