U.N. issues ‘red alert’ on climate warming

Source: Jean Chemnick and Chelsea Harvey, E&E News reporters • Posted: Tuesday, October 9, 2018

It’s still possible to avoid catastrophic climate change, but it will require immediate and aggressive action, said a long-awaited United Nations report.

The document from the U.N.’s Intergovernmental Panel on Climate Change, a consortium of the world’s leading scientists, found allowing the planet to warm even a half-degree more — 2 degrees Celsius versus 1.5 degrees above preindustrial levels — could have substantially greater consequences for both natural ecosystems and the humans who depend on them.

Small islands and vulnerable developing nations would experience some of the most immediate effects. That’s why they’ve pushed for the tighter 1.5-degree limit to be adopted as the goal of international climate efforts since before the Paris Agreement three years ago.

The High-Ambition Coalition, led by the Marshall Islands and backed by the European Union and other parties, called yesterday’s report “both a red alert and a call to arms” to increase ambition.

“The report confirms some of our worst fears, including that if we go beyond 1.5°C of average global temperature increase, we would be entering a dangerous new paradigm which will have severe impacts on our planet and which we will neither be able to fully adapt to, nor reverse,” environment ministers from nations as diverse as Argentina and Finland said in a joint statement following the report’s release.

The world is already about 1 degree Celsius above the baseline, and maintaining safe levels will require a more rapid and wide-reaching transformation of the world’s economy than has ever happened before. The world would have to cut its greenhouse gas output in half by 2030 and become effectively carbon-neutral by midcentury.

Most of the report’s scenarios explore the possibility of overshooting the 1.5 degree threshold and then taking steps to bring temperatures back down. It notes that exceeding the threshold even temporarily could have irreversible impacts.

The mandate for the report came from the same 2015 summit that produced the Paris deal, which set a goal of keeping warming to “well-below” 2 degrees Celsius with best efforts toward 1.5 degrees.

Global maneuvers to contain warming had long centered on the higher temperature threshold, and the scientific consensus was that such a goal would be enough to avert warming’s worst impacts. The new IPCC report establishes the more-ambitious 1.5 degrees as the safe limit.

The study, which draws on thousands of scientific papers, shows that by 2100, global sea-level rise would be about 4 inches higher at 2 degrees of warming than at 1.5 degrees.

An additional 10 million people would be affected at the higher warming threshold. At 2 degrees, the Arctic would also be expected to experience the total loss of its sea ice during the summer months at least once per decade, compared with just once a century at 1.5 degrees.

“Every extra bit of warming makes a difference,” said Hans-Otto Pörtner, co-chair of the IPCC’s Working Group II and one of the report’s authors, during a news conference announcing the findings.

“Limiting global warming to 1.5 compared to 2 degrees would reduce the number of people exposed to climate-related risks and susceptible to poverty by up to several hundred millions by 2050,” he said.

The report comes two months before nations are asked to participate in a first stock-taking of actions toward the Paris accord, and it is expected to strengthen calls for countries to put forward more ambitious commitments by 2020.

If countries do only what was promised in Paris, the world is expected to warm nearly 3 degrees Celsius. Some countries — including the United States — have abandoned even their initial Paris contributions.

The U.S. State Department issued a statement yesterday expressing appreciation to the scientists but stressing that the U.S. does not endorse their findings.

“In light of references to the Paris Agreement in the Summary for Policy Makers, we reiterate that the United States intends to withdraw from the Paris Agreement at the earliest opportunity absent the identification of terms that are better for the American people,” it noted.