The global climate is getting warmer and humans are to blame, according to a massive new report from 13 different U.S. federal agencies released on Friday.
The National Climate Assessment is a nearly 500-page document produced by hundreds of scientists. They evaluated more than 1,500 studies to reach a series of conclusions that paint a dire picture of the increasingly unstable global climate.
After a 1.8 degree Fahrenheit increase in temperatures over the last 115 years, we are now living in the warmest period of modern civilization, the report says. And humans are the reason why. “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century,” the report says. “For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.”
Greenhouse gases, the primary cause of warming, aren’t just making the planet hotter, the report says. They’re also warming the oceans, melting glaciers, and increasing water vapor in the atmosphere.
In addition to looking at how we got here, the report projects forward. Global sea levels will rise by one to four feet by 2100, it says, with an eight-foot increase not out of the question. Extreme weather events will also become more common. Heavy rains, uncontrollable wildfires, and record-setting droughts will become more frequent across the U.S. as temperatures continue to rise in the coming decades.
Though largely filled with doom and gloom, the report lays out one simple way to stave off the changes that will inevitably follow increased global temperatures: Reduce greenhouse gas emissions. “Without major reductions in emissions, the increase in annual average global temperature relative to preindustrial times could reach 9°F (5°C) or more by the end of this century,” it says. “With significant reductions in emissions, the increase in annual average global temperature could be limited to 3.6°F (2°C) or less.”
One way to limit the global temperature increases is for countries to meet the goals put forward as a part of the Paris climate accord, the report says. That’s the same climate deal President Trump backed out of, leaving the U.S. as one of only two countries not participating.
The Trump administration will find little to like in this report. Its conclusions run counter to the firmly held (and publicly stated) opinions of many in the Executive branch, including Energy Secretary Rick Perry, who just this week said the “science is out” on whether humans are the main drivers of climate change, and EPA administrator Scott Pruitt, who’s written that the debate over climate change “is far from settled.”
Unfortunately, Pruitt is more powerful than the hundreds of scientists who wrote this report. Just last month, he announced his plan to repeal the Clean Power Plan, an Obama-era attempt to reduce power-plant emissions, which account for about 30 percent of the greenhouse gases released in the U.S.
Before the plan is officially repealed, though, climate scientists will be able to weigh in on the harmful consequences of such a decision. All they’ll have to do is travel to the only scheduled public hearing on the matter, which will be held in Charleston, West Virginia, or as Pruitt called it, “the heart of coal country.”
