Krugman writes in his Monday column that maybe we can breathe a little — the Paris climate agreement shows perhaps a new kind of impotence. "Republican attitudes haven’t changed, except for the worse: the G.O.P. is spiraling ever deeper into a black hole of denial and anti-science conspiracy theorizing," he writes. "The game-changing news is that this may not matter as much as we thought."

It’s true that America can’t take broad-based action on climate without new legislation, and that won’t happen as long as Republicans retain a lock on the House. But President Obama has moved to limit emissions from power plants — a big part of the solution we need — through executive action. And this move has already had the effect of restoring U.S. climate credibilityabroad, letting Mr. Obama take a leading role in Paris. Still, what reason is there to believe that the accord will really change the world’s trajectory? Nations have agreed both to emission targets and to regular review of their success or failure in meeting those targets; but there are no penalties other than censure for countries that fail to deliver. And achieving those emission targets would definitely hurt some powerful special interests, since it would mean leaving most of the world’s remaining fossil fuels in the ground, never to be burned. So what will stop the fossil fuel industry from buying enough politicians to turn the accord into a dead letter?

Krugman argues technology is "changing the rules":