In 1937, fresh off a landslide re-election victory, and frustrated at his New Deal policies being repeatedly overturned by the Supreme Court, President Franklin D. Roosevelt pushed to reform the court.

He proposed legislation allowing the president to appoint another justice to the highest court for every current member over 70 ½ years old, up to a maximum of six — effectively allowing him to load up the bench with hand-picked cronies. It's one of the most notorious moves of FDR's presidency, taught in schools as an ignominious abuse of power and one of his most shameful acts.

But it's none of those things. Changing the number of justices is a perfectly constitutional idea, and one of the few ways it's possible to get some democratic influence on the court outside of waiting for one of the justices to retire or die. It's time to bring it back.

The pressing need for court-packing is all about climate change. The most serious U.S. policy effort against this humanity-threatening problem is President Obama's Clean Power Plan, a complex EPA initiative to begin reducing the carbon emissions from America's power generation. It's also a keystone in the far-reaching international accord to tackle climate change, reached in Paris in December. The world is finally mounting a fairly aggressive attack on carbon pollution, and U.S. leadership is an indispensable part of the whole system.

But in an extremely unusual step, the Supreme Court recently halted the enforcement of Obama's EPA rule until various legal challenges have been worked out — which could take years. This severely threatens the entire structure of the Paris agreement, which depends critically on every nation, especially the United States, doing their fair share to reduce emissions.

As Coral Davenport reports, other nations are alarmed:

"If the U.S. Supreme Court actually declares the coal power plant rules stillborn, the chances of nurturing trust between countries would all but vanish," said Navroz K. Dubash, a senior fellow at the Center for Policy Research in New Delhi. "This could be the proverbial string which causes Paris to unravel." [The New York Times]

This is potentially as big as big deals get. Why shouldn't America's president flood the Supreme Court with his cronies if that's what it takes to ensure that the world aggressively fights climate change?

Climate change is the most serious problem in the world by a considerable margin, and time is very short. The world is already not moving nearly fast enough. A delay of the Clean Power Plan by some years is inexcusable — and an overthrow, which this decision may signal, would be an emergency. It is quite literally not an exaggeration to say that the Supreme Court is threatening human civilization as it now exists. Moreover, their reasoning is virtually certain to be some bogus technicality — Chief Justice John Roberts' recent attack on USDA price support programs, for example, was blatantly self-contradictory.

Furthermore, it's completely constitutional to add more justices to the Supreme Court. Nowhere in the Constitution does it stipulate there should be a specific number of Supreme Court justices. We began with six, and that figure has shifted several times between seven and 10. The current number (nine) is the result of the Judiciary Act of 1869, and mere convention has kept it there.

The next president, if he or she is a Democrat, ought to be prepared to load up the Supreme Court with climate-fighting cronies who will work hard to save the world from John Roberts and Co. If America's next president is a Republican, then climate policy is hosed anyway, so he wouldn't have to bother. And yes, I know that advocating this idea means a Republican president could theoretically engage in the same court-packing to advance his or her own favored cause. But that is already true — the current system is just one more wobbly convention, which a President-for-life Trump is unlikely to respect should it become inconvenient. In any case, saving the world from climate change is worth that price.

The Supreme Court's legal powers are theoretically infinite. It defines what "constitutional" means. But when it threatens serious harm to society, it shouldn't be surprised when the rest of the political system fights back.