President Joe Biden will detail one of his most consequential climate pledges at the COP26 conference in Scotland later on Tuesday with a plan to slash global methane emissions by 30 percent by the end of this decade. But, while the president has persuaded an impressive alliance of 90 countries, including, for the first time, Brazil, to sign up to the plan, China, Russia, and India have all refused. Biden’s pledge was first announced in September but the White House has since been trying to persuade more nations to sign up, and he’ll formally set out his action plan at COP26 in Glasgow on Tuesday. Methane, one of the main components of natural gas, is the second-biggest contributor to climate change among greenhouse gases. Biden’s alliance includes two-thirds of the global economy.