It’s certainly possible that a Trump administration will drop the Clean Power Plan and renege on the Paris accord. But as long as it keeps the nation’s nuclear power plants online, continues tax incentives for wind and solar energy and stays out of the way of the shale energy revolution, Ms. Lovering and Mr. Nordhaus write, “the U.S. might outperform the commitments that the Obama administration made in Paris.”
For all his promises to bring back coal jobs in Appalachia, Mr. Trump might be drawn in a different direction by his own objectives of promoting natural gas and achieving energy independence. If he gives those goals high priority, he could well end up pursuing policies that would ultimately lower carbon emissions.
Striking a meaningful deal on climate has proved an elusive goal. The first try, in Kyoto, Japan, in 1997, committed advanced nations to reduce emissions between 1990 and 2010. But they actually achieved more in terms of reducing dependency on fossil fuels in the decade before the agreement than in the decade after.
If the Kyoto target survived, it was only because of other forces: First, the collapse of the Soviet bloc wiped out a lot of European carbon emissions along with the decrepit Eastern European industrial base; then the global downturn that started in 2008 reduced carbon emissions along with economic growth.
Even the most aggressive proposals by the Obama administration probably packed less punch than supporters believe. President Obama’s original cap-and-trade bill, which was blocked in the Senate in 2009, proposed emissions limits that were higher than what emissions have turned out to be. The steep decline was driven not just by the recession and slow recovery, but also by the wholesale move by the power sector over the last decade from coal to less polluting natural gas.
As Robert Stavins of Harvard University put it, “The most important factor in terms of carbon emissions in the United States is the price of natural gas.”
And for all the hand-wringing over the future of the Clean Power Plan, its demise might not even make that much of a difference. The shift from coal to gas will continue to happen anyway.
A study commissioned last December by the Environmental Defense Fund concluded that most states could comply “by relying exclusively on existing generation, investments already planned within each state and implementation of respective existing state policies.”
Of course, President Trump could do much more than simply stopping the Clean Power Plan, especially if he had eight years to work with. But why would he do that?
Production tax credits for renewables have already been extended by a Republican-controlled Congress until 2021. Mr. Trump supports nuclear energy, and could well be persuaded to extend federal subsidies to keep the nation’s teetering string of nuclear plants in operation.
Most importantly, climate objectives could mesh with Mr. Trump’s goal of energy independence. According to the 2016 edition of the International Energy Agency’s World Energy Outlook, the United States could pretty much become energy independent by 2040 — reducing its annual oil imports to 1 million barrels a day from 6 million in 2014 — as long as Washington sticks to current policies.
Part of this has to do with rising shale oil and gas production. But the main driver would be efficiency. The Trump administration only has to maintain the Obama administration’s CAFE standards, which require the average fuel economy of cars and light trucks to rise to 49-to-50 miles per gallon by 2025, from 34 today.
This is not to say that the world could survive forever an American administration that doesn’t believe in climate change and does nothing to contain it.
A recent analysis by scientists at the Massachusetts Institute of Technology concluded that the promises made in Paris would reduce the concentration of greenhouse gases in the atmosphere at the end of the century to 710 parts per million from 750. That is still far from the 450 p.p.m. ceiling needed to tip the odds in favor of staying under the temperature threshold scientists consider safe.
According to the International Energy Agency, the commitments made in Paris will cap the growth of greenhouse gas emissions between now and 2040 to 13 percent. The 450 p.p.m. target requires them to fall by 43 percent. Getting there will require rich countries like the United States to help finance much of the transition for poor countries. The role of global diplomacy will rise.
“It will be a big deal that will affect economic growth and jobs,” said David Victor of the School of Global Policy and Strategy at the University of California, San Diego. “We need a strategy to assure countries that their economic competitors are undertaking similar types of policies.”
For this to work, the United States, as the dominant economic player, must play ball. Simply pursuing energy independence will not go far enough.
In four years, the United States might have an administration that is less hostile to the concept of climate change. In any case, the rationale for policies to support low- and no-carbon energy sources will be even stronger then than it is today.
“If a Trump administration lasts only four years, the process could maybe absorb that,” said Oliver Geden, head of research at the German Institute for International and Security Affairs.
The bomb is ticking, but the world still has some time.