Trump decided that the U.S. will withdraw from the Paris climate change agreement signed last year:

“I was elected to represent the citizens of Pittsburgh, not Paris,” Trump proclaimed in a forceful, lengthy and at times rambling speech from the Rose Garden of the White House. He added, “As of today, the United States will cease all implementation of the nonbinding Paris accord and the draconian financial and economic burdens the agreement imposes on our country.”

All things considered, this is a bad decision made for dubious reasons. If the agreement is non-binding (and it is), the only burdens that the U.S. is under are those that we choose to impose on ourselves. A non-binding agreement can’t impose anything on anyone. The reason that the agreement has near-universal support around the world is that it formally requires very little of its adherents. While that means that withdrawal from the agreement is not quite the disaster many claim it is, it also shows that withdrawal is an unnecessary repudiation of a commitment that the U.S. just made. As Paul Pillar put it earlier tonight:

The non-binding nature of the agreement meant that there was not some unbearable onus that could be removed only through withdrawal.

An agreement that is “non-binding” cannot also be “draconian,” and the fact that Trump chose to describe it both ways confirms that he doesn’t really understand it, or is simply being fed lines to recite, or both. David Roberts sums up nicely how the agreement works:

Instead, the Paris accord relies on the power of transparency and peer pressure. It asks participants only to state what they are willing to do and to account for what they’ve done. It is, in a word, voluntary.

That doesn’t mean it doesn’t matter. Public pledges are a powerful driver. They can spur and organize domestic policy. Failure to live up to them can bring reputational damage. But they have no legal force in and of themselves.

One problem in withdrawing from an agreement such as this is that it needlessly creates rifts with other governments whose cooperation we need on many other issues, and it makes the U.S. seem less trustworthy when it joins international agreements. Indeed, it reeks of unilateralism for its own sake, and doesn’t take into account the potential costs for the U.S. that will come from doing this. If we want U.S. commitments to mean something now and in the future, it does no good to renege on them as soon as the president that made them is out of office. Insofar as the U.S. encourages more constructive behavior from others by leading by example, that is another reason to remain a party to the agreement.

Trump’s statement included some bizarre claims that he would be able to come up with a better agreement:

And we’ll sit down with the Democrats and all of the people that represent either the Paris Accord or something that we can do that’s much better than the Paris Accord.

One of the persistent flaws in Trump’s view of international agreements is that he seems to think that it puts pressure on other parties to walk away from an agreement that has already been made. Far from forcing a better deal from the other parties, this just demonstrates that our government isn’t interested in making a deal, and the other parties to the agreement respond accordingly. Trump can’t possibly improve on a non-binding agreement that calls for voluntary contributions, and the other signatories aren’t interested in talking to him about it in any case. This decision gains the U.S. nothing it didn’t already have, and it harms our relations with many allies in the process.

It will take years before Trump’s decision finally extricates the U.S. from the agreement:

The U.S. withdrawal from the Paris agreement cannot actually be finalized until near the end of Trump’s term because of the accord’s legal structure and language.

Meanwhile, the costs of gratuitously antagonizing dozens of our closest allies and trading partners will be felt much sooner than that. Trump’s decision on this agreement will overshadow his entire term in office while delivering precisely zero benefits to the U.S., and it will give many governments around the world political cover to refuse cooperation with the U.S. on other issues.