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The good news on climate change is that the politics and the technology arrayed to transition the world away from greenhouse gasses are both moving rapidly and in tandem. The bad news is that the scale of the challenge itself may also be accelerating. A new study finds that the West Antarctic ice sheet may be melting at a far more rapid pace than previously believed. Sea-level rise is just one of the dangers posed by climate change, but that danger may be more imminent than anybody believed.

Let’s review the state of play heading into the presidential election. The Obama administration’s Clean Power Plan is the largest element of its domestic program to reduce carbon emissions — it’s a set of targets for every state to reduce the greenhouse-gas emissions from its power system. The Clean Power Plan faces a legal challenge from Republicans. The Supreme Court recently froze implementation of that plan until the courts resolve its status.

The challenge will be heard in the D.C. Circuit court on June 2. The panel hearing that case will consist of two Democratic appointees and one Republican appointee, and is nearly certain to affirm the administration’s plan. Republicans will then appeal the case to the Supreme Court. But since the Court is currently tied 4–4, and five votes would be needed to overturn the D.C. Circuit, the case would be upheld. However, if Republicans block the appointment of Merrick Garland to the Court, which seems likely, and win the presidential election, which is possible, they can appoint the deciding justice. And that justice could well be seated in time to hear the appeal, quite likely dooming the Clean Power Plan.

A president determined to keep working to limit climate change could easily regroup in the face of a legal defeat and design a different set of climate regulations. The Clean Power Plan’s requirements do not take effect until 2022. But a Republican president would not do anything to limit climate change. The Republican Party is institutionally committed to blocking any action to reduce greenhouse-gas emissions. The largest and most influential bloc of thought within the party dismisses the field of climate science as a massive hoax concocted by scientists to increase their own power (a theory expounded by Senator James Inhofe, chairman of the Committee on Environment and Public Works, author of The Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future, and a believer that the existence of snow in February in Washington disproves climate science).

Senator Snowball.

A tinier, far less influential bloc within the party accepts the legitimacy of climate science but argues against any political action on the grounds that it would be impossible or hopelessly expensive. For instance, the Manhattan Institute’s James Manzi — one of the most moderate voices on climate science within the party — has urged Republicans to come up with non-science-denying reasons to permit the continued cost-free dumping of greenhouse-gas emissions into the atmosphere. “The challenge posed by climate change is not one of averting a global disaster in which Manhattan becomes an underwater theme park … ” Manzi wrote in his last climate manifesto. “Despite the dire warnings from progressives, the best models show us that global warming is a problem that is expected to have only a limited impact on the world economy.”

In reality, the Manhattan-as-underwater-theme-park scenario remains very much in play. The latest modeling projects a sea rise of five to six feet by the end of the century, with a sea-level rise of a foot per decade after that. That rise could be mitigated if the political response under way worldwide continues. And things are happening. China is reducing the carbon intensity of its economy very rapidly. Innovators in the private sector, responding to signals from political leaders who have committed to carbon reductions, have brought down the cost of clean energy nearly to parity already, and the cost curve is continuing to head downward. It sounds partisan to say, but it remains true: The fate of humanity rests to a very large degree on keeping the Republican Party out of power for as long as possible.