The world is currently 1°C warmer than pre-industrial levels. Nearly 200 countries have signed the 2015 Paris Climate Agreement, which pledges to cap the global temperature increase in this century to 2°C, while pursuing 1.5°C as a stretch target. However, the use of non-binding “nationally determined contributions” is the agreement’s Achilles’ heel, as there are limited international levers to ensure that each country fulfills its stated contributions.