U.N. climate panel endorses ceiling on global emissions

The New York Times reports that the world’s top climate scientists have formally embraced an upper limit on greenhouse gases for the first time, “establishing a target level at which humanity must stop spewing them into the atmosphere or face irreversible and potentially catastrophic climatic changes.”

The paper reported on the unveiling of the latest United Nations assessment of climate science and noted that experts warned that climate changes are likely to accelerate and “expressed virtual certainty that human activity is the main cause.”

“Climate change is the greatest challenge of our time,” said Thomas F. Stocker, co-chairman of the Intergovernmental Panel on Climate Change, the United Nations-sponsored group of scientists that produced the report. “In short, it threatens our planet, our only home.”