World's top companies urge action on nature loss ahead of U.N. talksSome of the world's biggest companies on Monday backed growing calls for governments to do more to reverse the accelerating destruction of the natural world and support broader efforts to fight climate change. More than 560 companies with combined revenues of $4 trillion including Walmart , Citigroup and Microsoft signed up to a statement calling for action over the next decade. The call comes as the United Nations prepares to host a biodiversity summit later this month, aiming to build momentum towards forging a new global pact to ward off threats to nature exemplified by recent fires in the Amazon and California.