California wildfires reversed years of climate change progress in 2020 alone, study says

SACRAMENTO, Calif. – California’s record-setting wildfires of 2020 destroyed 4.2 million acres of forest – and erased years of progress the state made on battling climate change.

A study by researchers at UCLA and the University of Chicago says the 2020 wildfires released nearly 140 million tons of carbon dioxide into the air. That was nearly as much greenhouse gas emissions as all the passenger vehicles in California generate in a typical year.

Put another way: Between 2003 and 2019, through a variety of measures, California managed to reduce annual carbon emissions by 71 million tons. The 2020 wildfire emissions doubled that figure, according to the study, which was published in the October issue of the academic journal Environmental Pollution.

Lead author Michael Jerrett said the devastation of 2020 – and the fact that fire seasons are generally getting worse in California – will put pressure on policymakers to reduce greenhouse gas emissions in other segments of society, such as motor vehicles, if the state can’t curb damage from wildfires.

“If you look at the runs, these are becoming much more common, these very large wildfire years,” said Jerrett, an environmental health sciences professor at UCLA. “That means we’ve got to look at these other emissions sources and see if we can get other reductions there.”

Most of the big 2020 wildfires were caused by freak lightning storms that blanketed much of Northern California over several days in August.

“There will be these curveballs that nature throws at us,” said the study’s co-author Amir Jina, a public policy assistant professor at the University of Chicago. “We’re going to have these extra shocks coming along.”

The emissions from the 2020 fires haven’t completely reversed the gains California has achieved in reducing its carbon emissions – far from it. Using 2003 as a baseline, California eliminated a total of more than 400 million tons of carbon that would have otherwise spewed into the air, according to state data.

The study, titled “Up in Smoke,” was published weeks after Gov. Gavin Newsom signed legislation designed to accelerate California’s fight against climate change.

One of the bills he signed commits California to reducing carbon emissions by 2045 to a level that’s 85% below what was in the air in 1990.

In terms of meeting the state’s near-term climate targets, the California Air Resources Board, which oversees pollution regulations, doesn’t count wildfire emissions. That’s because the agency, taking direction from the Legislature, has been focusing on human-caused greenhouse gases, like those from power plants or tailpipes, said agency spokesman Dave Clegern.

However, because of recent guidance from the Intergovernmental Panel on Climate Change, the state will include emissions from wildfires when tracking the state’s progress on achieving the 2045 goals, Clegern said.

Jerrett believes distinguishing between fires and other sources of carbon emissions has been a flawed approach, given that many wildfires are caused by humans in some way. Some of the worst wildfires of recent years have been ignited by power lines and other utility equipment, and California’s wildfire problem “has human fingerprints all over it,” he said.

On the other hand, Stanford University climate-policy expert Michael Wara said the study erred in equating carbon from wildfires with carbon from exhaust pipes. Wara, who’s advised the Legislature on climate and wildfire issues, said wildfire carbon probably isn’t as harmful to the climate because most of the trees will eventually grow back and begin soaking up carbon again.

Jerrett, however, said it will take decades for forests to recover from California’s new era of massive wildfires.

“That’s not going to help us meet our climate imperatives now,” he said. Scientists warn that without immediate, major reductions in carbon emissions, average global temperatures will soon rise to more than 1.5 degrees Celsius above pre-industrial levels – a threshold that will lead to disastrous results for the climate.