IPCC releases Fifth Assessment Report

摘要

The IPCC has released the Fifth Assessment Report, presenting a synthesis of current climate science research. Based on the review and analysis of several thousand published scientific papers, the report has been written and edited by scientists and experts in their field, drawn from 39 countries. The report has clearly outlined that, since 1750, atmospheric concentrations of CO_2, CH_4 and N_2O have all increased due to human activity. In 2011, concentrations of these GHGs were 391 ppm, 1803 ppb and 324 ppb, exceeding preindustrial levels by about 40, 150 and 20%, respectively, primarily from fossil fuel emissions and secondarily from net land-use change emissions.