The American Geophysical Union released a revised statement on climate change on Thursday. The new statement is a bit bolder, strongly linking human activities to global warming and including a call for collaboration with industry and government.
While the previous AGU statement, released in 2003, said human activities contribute to climate change, the new statement decrees a clear causal connection:
The cause of disruptive climate change, unlike ozone depletion, is tied to energy use and runs through modern society.
At a press conference on Thursday, Michael Prather, who chaired the committee that drafted the new statement, said “two major advances,” 21st century data and advanced modeling, have solidified the science in the past 5 years. The new statement is the first in a line of three AGU statements on climate change to call for a reduction of greenhouse gases.
Of particular concern, the statement now says, is the potential of hitting a global temperature rise greater than 2 degrees C above 19th century levels, a threshold the union says would trigger the decline of biodiversity and agricultural productivity and the eventual loss of the Greenland ice sheet, raising sea levels by several meters. To prevent this 2 degree Celsius rise, the AGU says net CO2 emissions much be reduced by more than 50 percent in this century.
Rachel Courtland, Nature Washington bureau