Ahead of the landmark UN climate talks in Paris next week, 174 countries have filed pledges outlining how far they will go to reduce carbon emissions. These plans will be crucial in determining the outcome of the conference, which aims to create a universal agreement to keep global warming under 2 degrees Celsius—the point beyond which scientists believe climate change will be irrevocably catastrophic.
The pledges represent a huge step forward for the planet. For the first time, almost every country is now taking climate change seriously and investing meaningfully in mitigations. But these national pledges are not enough, on their own, to keep the planet’s thermometer from rising beyond that dangerous threshold.