It also says it is "extremely likely" the majority of global temperature increases in the past 60 years are partially due to human influence. A government report on climate change that delves into the effects of greenhouse gases on global warming. They explain that "There are no convincing alternative explanations supported by the extent of the observational evidence".
"Many lines of evidence demonstrate that human activities, especially emissions of greenhouse gases, are primarily responsible for the observed climate changes in the industrial era, especially over the last six decades", the report says.
"Evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans", the CSSR reads.
As one commentator noted, "The leak of the report is a clear middle finger to Trump, Pruitt and their plan to derail federal climate research and policy, and it ensures the public has an opportunity to review it before they get their big, grubby mitts all over it".
In June, Trump announced that the US would withdraw from the agreement reached in Paris in 2015, in which almost 200 countries pledged to reduce emissions of heat-trapping greenhouse gases, saying the deal was bad for the country.
Since 1980, the average temperature in the USA has risen significantly, with the past few decades the warmest for 1500 years.
It's getting hotter. Average annual temperatures in the U.S. have increased by 1.8 degrees Fahrenheit between 1901 and 2016. At the same time, heavy precipitation events in the USA have increased in both intensity and frequency since the beginning of the 20 century - especially for the Northeast.
"The science is getting a lot more specific with being able to attribute the droughts, the floods, the heat waves, the specific events that we're experiencing to climate change and our human fingerprint on the earth's climate", the Environmental Defense Fund's Jeremy Symons said.
The White House Office of Science and Technology Policy, which coordinates federal climate reports, also had no staff in its science division left as of July 1. Average sea levels around the world have risen by about seven to eight inches since the beginning of the 20th century, with about three of those inches occurring since 1993. The move reverses the pledge made by then-President Barack Obama as part of the 192-nation coalition to keep global temperature rise to 2 degrees Celsius through 2100.
Climate scientists that worked on the report, however, were quick to point out it's been online since January.
"We're in some uncharted waters here", said an author of the report who asked not to be named.
The Paris climate accord, in which almost 200 countries participate, includes an agreement to cut or limit fossil fuel emissions.