“It’s telling us we need to reverse emissions trends and turn the world economy on a dime,” said Myles Allen, an Oxford University climate scientist and an author of the report. “We were not aware of this just a few years ago.” The report was the first to be commissioned by world leaders under the Paris agreement, the 2015 pact by nations to fight global warming.Ībsent aggressive action, many effects once expected only several decades in the future will arrive by 2040, and at the lower temperature, the report shows. reports and a physicist with Climate Analytics, a nonprofit organization. The report “is quite a shock, and quite concerning,” said Bill Hare, an author of previous I.P.C.C. The report, issued on Monday by the Intergovernmental Panel on Climate Change, a group of scientists convened by the United Nations to guide world leaders, describes a world of worsening food shortages and wildfires, and a mass die-off of coral reefs as soon as 2040 - a period well within the lifetime of much of the global population. INCHEON, South Korea - A landmark report from the United Nations’ scientific panel on climate change paints a far more dire picture of the immediate consequences of climate change than previously thought and says that avoiding the damage requires transforming the world economy at a speed and scale that has “no documented historic precedent.” Want climate news in your inbox? Sign up here for Climate Fwd:, our email newsletter.