In a strategic retreat in the fight against climate change, the United Nations has acknowledged that Earth has lost its chance to prevent some of the worst of global warming's harms. So now the world must figure out how to get temperatures below the danger zone and back to safety, officials say. Earth is soon going to exceed the safe temperature threshold agreed upon by the world in the 2015 Paris climate accord because of warming from the burning of coal, oil and gas, according to a bleak first-of-its-kind report issued by the United Nations Environment Programme Wednesday. Instead of giving up, scientists and U.N. officials recommend trying to limit excessive warming and then bring the temperature back down to the agreed-upon threshold. But it still will mean decades of increased weather-related disasters, rising seas, extinctions and melting ice and glaciers. “Humanity is speeding past the limit to avoid climate catastrophe,” United Nations Secretary-General António Guterres said. After a period of over-the-limit warming, the new strategy envisions getting back below the limit by