There is a recent strain of modestly constructive writing about the need to take action on climate change that nevertheless claims to see Paris as flawed to the point of condoning opposition to it. Ross Douthat’s piece in the Sunday New York Times is an example. While this approach is far better than the nonsense emanating from the Trump administration, it is still mistaken, and I want to take a moment to explain why.

The agreement we negotiated over many years on the road to Paris had to clear a number of hurdles.

It had to be universal, unlike the 1997 Kyoto Protocol, whose obligations applied only to developed countries. That structure was unworkable given the growing majority of emissions from developing countries and the obvious lack of support there would be for any agreement that didn’t fully cover China and others.

It had to be ambitious, while recognizing that initial targets wouldn’t be enough.

It had to address the fears of countries that they might be forced to take measures inconsistent with their priority to develop and grow.

It had to be built to last, establishing a regime to carry us forward over decades, not a one-off exercise in which we’d be back at the negotiating table in five or ten years.

It had to overcome the “firewall” division between developed and developing countries, while understanding that countries with a wide range of capacities cannot be expected to do the same thing in every particular.

It had to be transparent, so all could see how countries were doing both on their emission inventories and their progress toward achieving targets.

It had to continue the tradition of aiding poor countries – embedded in the original 1992 climate convention and reflected in George W. Bush’s $2 billion pledge to the climate fund he launched in 2008 – without saddling the United States with either outsized or legally binding numeric obligations.

It had to be legally binding in at least some respects, but without making it impossible for some countries to join.

With sustained U.S. leadership, the Paris Agreement cleared these hurdles:

It was universal.

It set forth a long-term vision toward ambitious goals.

It began with national targets that made a good start in shifting the path of projected temperature downward. Based on a decision at an earlier conference, those targets had to be submitted well in advance of the Paris negotiation itself, so they would be exposed to public scrutiny, spurring countries do their best.

It includes an every five-year cycle starting in 2020, in which countries review their targets and are encouraged to enhance them.

It is built on a bottom-up structure in which each country determines its own emissions targets without fear that its ability to grow and develop will be compromised.

It replaces the old firewall with an understanding that all countries are treated the same legally, but with certain flexibilities available, based on country capabilities.

It includes strong provisions for reporting and review, with flexibility provided to those developing countries that need it in light of their capacities.

It promises continued financial support to poor countries, with clarity that the funding is to be mobilized from all channels, private as well as public.

It is built on a hybrid legal structure, with process provisions that are legally binding, such as the obligation to submit targets and to report and be reviewed on implementation, and substantive provisions that are non-binding, including the targets that countries submit. This structure recognizes that norms and expectations can often be more effective in encouraging robust action than legally binding requirements, which, paradoxically, can yield weaker action as some countries low-ball their targets for fear of legal liability.

In short, the Paris Agreement built a regime that was not only acceptable to all from the start, but designed to evolve in precisely the direction needed to meet our profound climate challenge.

It succeeds where every effort before, for some 20 years, had come up short. It breaks new ground in numerous ways, articulating a long-range goal to drive global efforts, creating a bottom-up structure for ambitious national action, outlining a continually renewing set of commitments, bridging the differences between developed and developing countries, establishing a hybrid legal structure. And it did this all in the context of an agreement that is not just a statement of shared global principles, but a joint undertaking in which all countries are expected to do their part to shape the global economy in a productive and sustainable manner.

The idea that it is rational to support climate action but reject Paris does not, in fact, make sense. The idea that an agreement materially different from Paris could win the consensus support of countries everywhere is a fiction. Paris is an imperfect, but nonetheless remarkable agreement. It needs to be defended, supported and implemented.