authors of this report say they expect many of those events to continue to increase or worsen. >> and the warning trend can be explained by human activities especially emissions of greenhouse gas into the atmosphere. >> if there's not sustained mitigation in efforts the report warns climate change is expected to cause growing losses to america's infrastructure and property and impede the rate of economic growth over this century. this report is over 1600 pages, it looks at the impacts of climate change now and in the future. some aspects of our economy could see some improvement in a warmer world but long term officials say it's going to hurt the u.s. economy. according to report weather and climate disastrous have cost the u.s. nearly $400 billion since 2015. this sort of assessment is released every four years, it's mandated by congress and the global change research act of