Negotiators around the world are deliberating proposals for an international climate change treaty that will contain a glaring loophole: It won’t be binding.

That’s less than ideal, but it’s still worthwhile for several important reasons.

First, all treaties are essentially voluntary, short of violators being placed under severe sanctions or the threat of war. Second, the more binding the language of the treaty seems, the less likely it is that countries will make any commitment to act. And third, the only previous international treaty to reduce greenhouse gas emissions was surprisingly successful. For these reasons, the treaty to limit greenhouse gas emissions that may emerge from the December conference that is to take place in Paris — binding or not — is an important step forward in confronting climate change.

But we can’t count on it alone.

Countries will comply only if they judge it to be in their interest, and this will require public support in the years ahead.

Let’s explore further what “internationally binding” emissions agreements really are. The 1997 Kyoto Protocol is perhaps the most salient example. It required countries to have mandatory greenhouse gas emissions reduction requirements. The United Nations then monitored those requirements to determine whether countries met their commitments, but it couldn’t force compliance. Thus, the Kyoto Protocol was ultimately a political agreement that countries could later change their minds about. In this sense, even internationally binding agreements are voluntary.