Earth Scientists Express Rising Concern about Global Warming

The map shows areas in 2007 that were warmer (reds) and colder (blues) than the mean annual temperature from 1951-1980. (Credit: NASA/GISS)

The American Geophysical Union, the world’s largest organization representing earth and space scientists, put out a fresh statement on the causes and consequences of recent climate change and possible responses. The union’s statement is firmer and has more policy prescriptions than the one from 2003.

"Warming greater than 2°C above 19th century levels is projected to be disruptive, reducing global agricultural productivity, causing widespread loss of biodiversity... If this 2°C warming is to be avoided, then our net annual emissions of CO2 must be reduced by more than 50 percent within this century."