Climate-change report contradicts U.S. stance

WASHINGTON — Directly contradicting much of the Trump administration’s position on climate change, 13 federal agencies unveiled an exhaustive scientific report Friday that says humans are the dominant cause of the global temperature rise that has created the warmest period in the history of civilization.

Over the past 115 years, global average temperatures have increased 1.8 degrees Fahrenheit, leading to record-breaking weather events and temperature extremes, the report says. The global, longterm warming trend is “unambiguous,” it says, and there is “no convincing alternative explanation” that anything other than humans — the cars we drive, the power plants we operate, the forests we destroy — are to blame.

The report was approved for release by the White House, but the findings come as President Donald Trump’s administration is defending its climate change policies. The United Nations convenes its annual climate change conference this week in Bonn, Germany, and the U.S. delegation is expected to face harsh criticism over top administration officials’ stated doubts about the causes and effects of a warming planet.

“This report has some very powerful, hard-hitting statements that are totally at odds with senior administration folks and at odds with their policies,” said Philip Duffy, president of the Woods Hole Research Center.

The climate science report is part of a congressionally mandated review conducted every four years known as the National Climate Assessment. The product of hundreds of experts within the government and academia and peer-reviewed by the National Academy of Sciences, it is considered the United States’ most definitive statement on climate change science.

The White House put out a statement Friday that seemed to undercut the high level of confidence of the report’s findings.

“The climate has changed and is always changing,” Raj Shah, a White House spokesman, said in the statement. “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, he added.

Despite the scientific consensus presented in the report, the Environmental Protection Agency has scrubbed references to climate change from its website and barred its scientists from presenting scientific reports on the subject.

EPA Administrator Scott Pruitt has said carbon dioxide is not a primary contributor to warming. Rick Perry, the energy secretary, asserted Wednesday that “the science is out” on whether humans cause climate change.

Their agencies referred questions to the National Oceanic and Atmospheric Administration, which oversaw the research.

Also on Friday, Pruitt appointed more than five dozen new scientific advisers to the EPA, a move that is likely to shift its research objectives as well as the recommendations that form the basis for key regulations over the next few years.

Pruitt has placed 66 new experts on three different EPA scientific committees, many of whom hail from industry or state government. Two of the new chairmen — Texas’ top toxicologist Michael Honeycutt, who will helm the Scientific Advisory Board, and consultant Louis Anthony Cox, who will chair the Clean Air Scientific Advisory Committee — have harshly criticized the way the EPA has conducted science in the past.

Honeycutt has accused the EPA of “overstating” the risks associated with mercury, a neurotoxin, and of disregarding “good science which demonstrates a chemical is not as toxic as it thinks it is.” Cox wrote that the EPA’s methods for calculating the public health benefits of stricter national smog standards are “unreliable, logically unsound, and inappropriate for drawing causal inferences.”

Pruitt said the appointments to the Scientific Advisory Board and its clean air panel, along with the even-larger Board of Scientific Counselors, would bring new perspectives to the agency. He told reporters Tuesday that he was seeking to diversify the groups’ geographic representation, to include more experts from the Midwest and West.