The European Union’s top climate negotiator, Frans Timmermans, and the White House special envoy for climate, John F. Kerry, announced on Monday that two dozen additional countries have joined the methane pledge. Canada, the Central African Republic, Nigeria and Pakistan were among those that signed the pledge, which is now backed by nine of the world’s top 20 methane-emitting countries. But the pact is still missing some major methane emitters, including Russia, China, India and Brazil, The Washington Post’s William Booth and Steven Mufson report.