The federal government on Friday afternoon published a massive report detailing how climate change is already playing out across the nation, from increases in heavy rainfall in the Northeast to more large forest fires in the West and Alaska.
This study’s release follows months of speculation about whether the Trump administration, which is skeptical of climate change and has rolled back or eliminated many environmental rules, would attempt to censor it.
Several scientists had expressed concern in August about government officials interfering with the report’s findings and final release, and a copy of the then-latest version of the report was leaked to the New York Times. The Times published two different draft copies, incorrectly claiming that neither had been released publicly when one already had. Following the Times’ snafu, the White House and climate skeptic Rep. Lamar Smith from Texas accused scientists and the newspaper of politicizing the report.
There ultimately was no government interference. “I think whatever fears we had weren’t realized,” David Fahey, a scientist at the National Oceanic and Atmospheric Administration and a lead study author, said at a press briefing on Friday. “This report says what scientists want it to say, even down to the confidence and likelihood statements,” he added.
This 477-page Climate Science Special Report reaffirms the scientific consensus on climate change, even as President Donald Trump and many of his top officials question it. Earlier this week, for example, Energy Secretary Rick Perry said during an interview with Axios and NBC: "I still think the science is out on" whether humans are the driving factor behind climate change. And US officials are reportedly planning to tout the benefits of fossil fuels at an upcoming conference.
The White House declined to comment on the new report’s conclusion that humans are largely to blame for recent climate change. “The climate has changed and is always changing,” Raj Shah, principal deputy press secretary at the White House, said in a statement emailed to BuzzFeed News.
He then referenced a section of the report outlining both the human and natural influences on climate change — and the uncertainty of future impacts: “As the Climate Science Special Report states, the magnitude of future climate change depends significantly on ‘remaining uncertainty in the sensitivity of Earth’s climate to [greenhouse gas] emissions.’ In the United States, energy related carbon dioxide emissions have been declining, are expected to remain flat through 2040, and will also continue to decline as a share of world emissions.”
He did not mention any of the report’s key findings, which paint a very different picture. “This period is now the warmest in the history of modern civilization,” the report states. What’s more, the evidence suggests humans are to blame.
“This assessment concludes, based on extensive evidence, that it is extremely likely human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warning since the mid-20th century,” the report states. “For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.”
Scientists have “very high confidence” that annual average temperatures over mainland US have increased about 1 degree Celsius between 1901 and 2016. And over the past 50 years, there’s been an especially fast rise in temperatures across Alaska and the Arctic. Scientists also have “high confidence” that’s there’s been a rise in the frequency and intensity of heavy rain events in most parts of the US, especially the Northeast.
What happens next will largely depend on how much and how quickly humans can limit their greenhouse gas emissions in the future, the report says, and there’s a chance things can get very dire. Coral reefs could die, for example, and the melting of the Greenland Ice Sheet could dramatically increase global sea levels.
More than 50 federal and other scientists poured over thousands of science studies to develop the technical report, and then it went through six rounds of review. It’s the first part of what’s called the National Climate Assessment, a review of how climate change is impacting the US that’s required every four years by Congress.
The second part, due out next year, will cover how the US is responding to climate change. A draft of it was published today and is now open to public comment.
“The Climate Science Special Report lays out the most recent scientific evidence of climate change, once again confirming that climate change is real, it’s happening now, and human activity is the primary cause,” Rush Holt, chief executive officer of the American Association for the Advancement of Science, said in a statement.
It’s an open question if and how the administration will use this report to inform its future decisions on climate change. According to the White House’s Shah, the US will continue to support affordable and reliable energy, in addition to technology, innovation, and infrastructure, as ways to help reduce emissions and address future climate risks.