Largest body of geologists issues warning on global warming
January 24, 2008
The statement is the first revision since 2003 of the climate-change position of the AGU, which has a membership of 50,000 researchers, teachers, and students in 137 countries. The society adopted the statement at a meeting of AGU's leadership body, the AGU Council, in San Francisco, California, on 14 December 2007. AGU position statements expire in four years, unless extended by the Council.
Revised statement from the American Geophysical Union on climate change
The Earth's climate is now clearly out of balance and is warming. Many components of the climate system--including the temperatures of the atmosphere, land and ocean, the extent of sea ice and mountain glaciers, the sea level, the distribution of precipitation, and the length of seasons--are now changing at rates and in patterns that are not natural and are best explained by the increased atmospheric abundances of greenhouse gases and aerosols generated by human activity during the 20th century. Global average surface temperatures increased on average by about 0.6 degrees Celsius over the period 1956-2006. As of 2006, eleven of the previous twelve years were warmer than any others since 1850. The observed rapid retreat of Arctic sea ice is expected to continue and lead to the disappearance of summertime ice within this century. Evidence from most oceans and all continents except Antarctica shows warming attributable to human activities. Recent changes in many physical and biological systems are linked with this regional climate change. A sustained research effort, involving many AGU members and summarized in the 2007 assessments of the Intergovernmental Panel on Climate Change, continues to improve our scientific understanding of the climate.
0 Temperature anomalies that were present during 2007. Credit: NASA
This shows temperature anomalies for the 2007 calendar year relative to the 1951-1980 mean. Warmer areas in red, cooler areas in blue. Largest increases were in the northern hemisphere. Credit: NASA Goddard Institute for Space Studies (GISS)
With climate change, as with ozone depletion, the human footprint on Earth is apparent. The cause of disruptive climate change, unlike ozone depletion, is tied to energy use and runs through modern society. Solutions will necessarily involve all aspects of society. Mitigation strategies and adaptation responses will call for collaborations across science, technology, industry, and government. Members of the AGU, as part of the scientific community, collectively have special responsibilities: to pursue research needed to understand it; to educate the public on the causes, risks, and hazards; and to communicate clearly and objectively with those who can implement policies to shape future climate.