U.N. Draft Report Lists Unchecked Emissions’ Risks

Runaway growth in the emission of greenhouse gases is swamping all political efforts to deal with the problem, raising the risk of “severe, pervasive and irreversible impacts” over the coming decades, according to a draft of a major new United Nations report.

Global warming is already cutting grain production by several percentage points, the report found, and that could grow much worse if emissions continue unchecked.  Higher seas, devastating heat waves, torrential rain and other climate extremes are also being felt around the world as a result of human emissions, the draft report said, and those problems are likely to intensify unless the gases are brought under control.

The world may already be nearing a temperature at which the loss of the vast ice sheet covering Greenland would become inevitable, the report said.  The actual melting would then take centuries, but it would be unstoppable and could result in a sea level rise of 23 feet, with additional increases from other sources like melting Antarctic ice, potentially flooding the world’s major cities.

The report was drafted by the Intergovernmental Panel on Climate Change, a body of scientists and other experts appointed by the United Nations that periodically reviews and summarizes climate research.  It is not final and could change substantially before release.

The report, intended to summarize and restate a string of earlier reports about climate change released over the past year, is to be unveiled in early November, after an intensive editing session in Copenhagen.  A late draft was sent to the world’s governments for review this week, and a copy of that version was obtained by The New York Times.

Using blunter, more forceful language than the reports that underpin it, the new draft highlights the urgency of the risks that are likely to be intensified by continued emissions of heat-trapping gases, primarily carbon dioxide released by the burning of fossil fuels like coal, oil and natural gas.

The report found that companies and governments had identified reserves of these fuels at least four times larger than could safely be burned if global warming is to be kept to a tolerable level.

That means if society wants to limit the risks to future generations, it must find the discipline to leave a vast majority of these valuable fuels in the ground, the report said.

The draft report comes a month before a summit meeting of world leaders in New York that is meant to set the stage for a potential global agreement on emissions that would be completed next year.  However, concern is growing among climate experts that the leaders may not offer ambitious commitments in their speeches on Sept. 23, a potential continuation of the political inaction that has marked the climate issue for decades.

The draft report found that past emissions, and the failure to heed scientific warnings about the risks, have made large-scale climatic shifts inevitable.  But lowering emissions would still slow the expected pace of change, the report said, providing critical decades for human society and the natural world to adapt.

U.N. Draft Report Lists Unchecked Emissions’ Risks