At the COP26 climate meeting in Glasgow on Tuesday, global leaders announced that more than 100 countries had signed a pledge to reduce their methane emissions 30 percent by 2030.

If the whole world were to achieve that goal, temperatures in the next few decades would rise 0.2 degree Celsius (0.4 degree Fahrenheit) less than they would otherwise—a potentially huge savings that could, theoretically, keep global warming levels below 1.5°C (2.7°F).

But several major emitters, like China, Russia, and India, have not yet joined the Global Methane Pledge. Those countries account for about 35 percent of all human-sourced methane emissions.

Cutting methane emissions will “not just address future climate change but … curb the climate change that’s happening right