implementation of the non-binding paris accord. >> reporter: a climate report just released by donald trump's own administration outlined $400 billion in costs to the u.s. since 2015 from natural disasters strengthened by climate change. a number that is expected to increase as the world grows warmer. trump's response? >> i don't believe it. >> you don't believe it? >> no, no, i don't believe it. >> reporter: the tectonic shift not only the worsened trend. brazil has rescinded its offer to host the u.n. climate conference next year with the incoming foreign minister calling climate change, quote, a marxist hoax. but the world meteorological organization says otherwise, warning the planet's long-term warming trend has far from abated. >> 2016 was the warm est year on record and 2017 was the second warm est recorded.