Climate Signals, Growing Louder
April 02, 2014, 3:00am

New York Times.

Perhaps now the deniers will cease their attacks on the science of climate change, and the American public will, at last, fully accept that global warming is a danger now and an even graver threat to future generations.

On Monday, the Intergovernmental Panel on Climate Change, a United Nations group that since 1990 has been issuing increasingly grim warnings about the consequences of a warming planet, released its most powerful and sobering assessment so far. Even now, it said, ice caps are melting, droughts and floods are getting worse, coral reefs are dying. And without swift and decisive action to limit greenhouse gas emissions from fossil fuels and other sources, the world will almost surely face centuries of climbing temperatures, rising seas, species loss and dwindling agricultural yields. The damage will be particularly acute in coastal communities and in low-lying poor countries — like Bangladesh — that are least able to protect themselves.

The report’s conclusions mirrored those of a much shorter but no less disturbing report issued two weeks ago by the American Association for the Advancement of Science, the world’s largest scientific society. Like the panel, the association declared that the world is already feeling the effects of global warming, that the ultimate consequences could be catastrophic, and that the window for effective action is swiftly closing.

The intergovernmental panel’s report (a companion report later this month will discuss what governments should do) could carry considerable weight with delegates to next year’s climate change summit meeting in Paris, at which the members of the United Nations will again try, after years of futility, to fashion a new global climate treaty. And together, the two reports could build public support for President Obama’s efforts to use his executive authority to limit greenhouse gases, most recently with a plan issued on Friday to reduce methane emissions from landfills, agricultural operations and oil and gas production and distribution.

The methane strategy is one of several weapons in Mr. Obama’s broader Climate Action Plan, announced last year, that seeks to reduce emissions by circumventing an obstructionist Congress by aggressively using his executive authority under the Clean Air Act and other statutes. The most important of these are two rules from the Environmental Protection Agency — one already proposed, another in the works — that would regulate emissions from new and existing coal-fired power plants, the largest source of industrial carbon pollution. He has also promised to increase energy efficiency in appliances and buildings, and double renewable energy capacity on public lands by 2020.

The methane abatement plan is a welcome addition to that arsenal. Methane, a product of animal wastes and of decomposing material in landfills, and the main component in natural gas, contributes only about 9 percent of America’s greenhouse gas emissions. And natural gas, as a fuel, is much cleaner than coal. But methane is a powerful atmospheric pollutant, 20 times more potent than carbon dioxide, and thus a major driver of global warming.

The burden for fulfilling the president’s promise will fall on the E.P.A., which is charged with developing regulations to plug methane leaks in pipelines and in oil and gas production systems. Given everything we now know, public and congressional acceptance of these initiatives should be close to automatic. But, of course, it is not. Senator Mitch McConnell, the leader of the Senate Republicans, seeks to block the coal regulations. Industry groups are complaining in advance about methane regulations.

Some of this may be attributable to public misunderstanding. A poll last year found that one-third of Americans believed that scientists disagreed on whether global warming was happening. These studies suggest virtually no disagreement. The hope among advocates is that the latest show of scientific solidarity will clear up any confusion about the causes and consequences of climate change and the need for action.