WASHINGTON (AP) -- As California's catastrophic wildfires recede and people rebuild after two hurricanes, a massive new federal report warns that these types of extreme weather disasters are worsening in the United States. The White House report quietly issued Friday also frequently contradicts President Donald Trump.
The National Climate Assessment was written long before the deadly fires in California this month and Hurricanes Florence and Michael raked the East Coast and Florida. It says warming-charged extremes "have already become more frequent, intense, widespread or of long duration."
The federal report says the last few years have smashed records for damaging weather in the U.S., costing nearly $400 billion since 2015. "Warmer and drier conditions have contributed to an increase in large forest fires in the western United States and interior Alaska," according to the report.
"We are seeing the things we said would be happening, happen now in real life," said report co-author Katharine Hayhoe of Texas Tech University. "As a climate scientist it is almost surreal."
And report co-author Donald Wuebbles, a University of Illinois climate scientist, said, "We're going to continue to see severe weather events get stronger and more intense."
The air pollution from wildfires combined with heat waves is a major future health risk for the West, the report says. During the fires in northern California, air quality hit "hazardous" levels, according to government air monitoring agencies.
"There's real concern about how the West will be able to manage this increasing occurrence," said report co-author Kristie Ebi, a University of Washington public health professor. She said global warming is already harming people's health, but it will only get worse.
The report is mandated by law every few years and is based on hundreds of previously research studies. It details how global warming from the burning of coal, oil and gas is hurting each region of United States and how it impacts different sectors of the economy, including energy and agriculture.
"Climate change is transforming where and how we live and presents growing challenges to human health and quality of life, the economy, and the natural systems that support us," the report says.
That includes worsening air pollution causing heart and lung problems, more diseases from insects, the potential for a jump in deaths during heat waves, and nastier allergies.
What makes the report different from others is that it focuses on the United States, then goes more local and granular.
"All climate change is local," said Pennsylvania State University climate scientist Richard Alley, who wasn't part of the report but praised it.
While scientists talk of average global temperatures, people feel extremes more, he said.
"We live in our drought, our floods and our heat waves. That means we have to focus on us," he said.
The Lower 48 states have warmed 1.8 degrees since 1900 with 1.2 degrees in the last few decades, according to the repot. By the end of the century, the U.S. will be 3 to 12 degrees hotter depending on how much greenhouse gases are released into the atmosphere, the report warns.
Outside scientists and officials from 13 federal agencies wrote the report, which was released on the afternoon following Thanksgiving. It was originally scheduled for December. The report often clashes with the president's past statements and tweets on the legitimacy of climate change science, how much of it is caused by humans, how cyclical it is and what's causing increases in recent wildfires.
Trump tweeted this week about the cold weather hitting the East including: "Brutal and Extended Cold Blast could shatter ALL RECORDS - Whatever happened to Global Warming?"
Friday's report seemed to anticipate such comments, saying: "Over shorter timescales and smaller geographic regions, the influence of natural variability can be larger than the influence of human activity ... Over climate timescales of multiple decades, however, global temperature continues to steadily increase."
Releasing the report on Black Friday "is a transparent attempt by the Trump Administration to bury this report and continue the campaign of not only denying but suppressing the best of climate science," said study co-author Andrew Light, an international policy expert at the World Resources Institute.
Trump, administration officials and elected Republicans frequently say they can't tell how much of climate change is caused by humans and how much is natural.
Citing numerous studies, the new climate report says more than 90 percent of the current warming is caused by humans. Without greenhouse gases, natural forces -- such as changes in energy from the sun -- would be slightly cooling Earth.
"There are no credible alternative human or natural explanations supported by the observational evidence," the report says.
