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Climate change could triple the frequency of large wildfires, says new federal report

Eyler Harrison of Grass Valley, a contractor for Cal Fire, cuts down dead trees amid the charred landscape of the Camp Fire, in Paradise, Cal, on Monday, Nov. 19, 2018. A new government report affirms that western wildfires will intensify as climate change brings longer dry spell and irregular precipitation to California and other states in the region.
Eyler Harrison of Grass Valley, a contractor for Cal Fire, cuts down dead trees amid the charred landscape of the Camp Fire, in Paradise, Cal, on Monday, Nov. 19, 2018. A new government report affirms that western wildfires will intensify as climate change brings longer dry spell and irregular precipitation to California and other states in the region. hamezcua@sacbee.com

Residents of the western United States should prepare for a potential tripling of large wildfires in the coming decades, a new federal report on climate change revealed Friday.

And, it warned, the region should also expect additional water shortages, heat wave deaths, and smoke pollution.

According to the Fourth National Climate Assessment, California and the West have already witnessed an expansion of catastrophic blazes due to climate change and rising warming, with twice as much acreage burned by wildfire than would have occurred otherwise.

“Higher temperatures sharply increase the risk of megadroughts—dry periods lasting 10 years or more,” says the report, administered by the National Oceanic and Atmospheric Administration with contributions from the Environmental Protection Agency, NASA and other research agencies.

Such “megadroughts” will trigger a cascade of impacts, including tripling the frequency of large wildfires — those roughly 20 square miles or larger — than what has historically occurred, the report said. Impacts could be lessened, it added, if action was taken to sharply reduce greenhouse gas emissions.

The report comes as California continues to count the dead from the Camp Fire in Butte County, which has killed at least 84 people, burned nearly 240 square miles and is 95 percent contained. More than 13,500 homes have been destroyed in the blaze, making it California’s most destructive in history.

NOAA, an agency of the federal Commerce Department, originally planned to release the report in December, then announced Wednesday it was moving that date to Friday afternoon, during the slow Thanksgiving holiday weekend. Environmental groups questioned if the timing was designed to limit the report’s exposure, as the White House continues to downplay the science of climate change.

President Donald Trump toured devastation caused by the Camp Fire last weekend, but declined to link the blaze to dry conditions exacerbated by climate change. He instead blamed them on lack of forest management, including “raking” of the forests.

On Tuesday, Trump also mocked findings that the Earth was warming, given the cold spell in the Northeast.

“Brutal and Extended Cold Blast could shatter ALL RECORDS - Whatever happened to Global Warming?,” Trump tweeted, again seizing on a single weather event in seeking to discredit decades of documented climatic trends.

Even before Trump commented on the Thanksgiving chill, NOAA earlier this week reported that last month was the second hottest October on record worldwide, and fourth hottest on record. NOAA also reported that conditions that summer set the stage for the Camp Fire and others in November.

“Summer 2018 was much warmer than average across the state — record warm in some places, especially at night — and in Northern California, precipitation ranged from below average to record dry,” NOAA said in a report earlier this week.

“Precipitation across much of the state was less than 5 percent of average in September, and the summer dry signal extended into beginning of the fall wet season, with below-average precipitation in October as well. With all the heat and dryness, the ground was dry to start November, with vegetation turned into excellent fire fuel,” NOAA added.

Mandated by Congress, the Fourth National Climate Assessment is product of the U.S. Global Change Research Program, aimed at helping the nation and world “understand, assess, predict, and respond to human-induced and natural processes of global change.”

Volume I of the report was released a year ago, and outlined the current understanding of the science behind climate change. Friday’s report went deeper into the known impacts of climate change, on a region-by-region level.

Overall, the report concluded that global average temperature has increased by about 1.8° Fahrenheit from 1901 to 2016. “Observational evidence does not support any credible natural explanations for this amount of warming,” the report said.

Fire Graph.jpg
A graph in the Fourth National Climate Assessment analyzes how wildfires have increased due to climate change and warming temperatures, since 1984. National Oceanic and Atmospheric Association

In a chapter on the Southwest’s climate, the report includes an analysis of forest area burned between 1984 and 2015, concluding that roughly 24 million acres burned during that period, twice the amount that would have been torched without climate change’s impact.

While some environmentalists praised the report for its strong language, others questioned why NOAA chose to release it on a day when many Americans are shopping on Black Friday and recovering from their Thanksgiving feasts.

“It’s an absolute disgrace to bury the truth about climate impacts in a year that saw hundreds of Americans die during devastating climate-fueled megafires, hurricanes, floods, and algal blooms,” said Collin O’Mara, president of the National Wildlife Federation, in a statement prior to the report’s release.

Stuart Leavenworth: 202-383-6070, @sleavenworth
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