‘Irreversible change’ more likely as emissions rise, says UN draft report

The Intergovernmental Panel on Climate Change warned the “risk of abrupt and irreversible change increases as the magnitude of the warming increases,” according to a New York Times account of the draft, which could change before its expected final release in November.

Nations are looking to secure commitments at U.N.-hosted climate talks next year in Paris to restrain enough greenhouse gas emissions by 2020 to prevent a 2 degrees Celsius global temperature rise by the end of the century. An overwhelming scientific consensus says that humans are driving climate change, largely through burning greenhouse gas-emitting fossil fuels.

The draft report said it was technically possible to reach that goal, but that waiting and playing catch-up later would be economically painful. As such, it said that emissions are already barreling toward a point where some of the most catastrophic effects of a warming planet will be locked in.

It notes, for example, that nearly enough greenhouse gas emissions are in the atmosphere to seal the fate of the ice sheet that covers much of Greenland. The melting would occur over centuries, resulting in a 23-foot sea level rise, according to the Times’ account of the draft report.

Other findings include that companies and governments hold fossil fuel reserves four times greater than could be safely burned and that global greenhouse gas emissions had accelerated from annual increases of 1.3 percent between 1970 and 2000 to 2.2 percent each year the following decade.

The draft report, however, noted that emissions in western countries are falling as a result of a focus on low-emission energy technology and energy efficiency.

The Obama administration is trying to cut emissions more through proposed power-plant regulations that seek to cut electricity-sector emissions 30 percent below 2005 levels by 2030 — President Obama has tried to position the proposal as a model for other nations entering the Paris talks. The proposal, due for finalization next June, has heartened environmental and public health groups, but angered industry and conservatives who say it would hurt economic activity.

But the report said the decline in western emissions is outweighed by a jump from developing countries that are trying to bring millions of their citizens out of poverty, partly through expanding access to electricity.

That dynamic has dogged climate negotiations in the past. As such, many experts are doubtful that nations can reach the necessary agreements in Paris.

“[O]ur analysis concludes that these international efforts will indeed bend the curve of global emissions,” said an MIT study released earlier this month. “However, our results also show that these efforts will not put the globe on a path consistent with commonly stated long-term climate goals.”