Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on the day's biggest business stories

Subscribe to Axios Closer for insights into the day’s business news and trends and why they matter

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Stay on top of the latest market trends

Subscribe to Axios Markets for the latest market trends and economic insights. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sports news worthy of your time

Binge on the stats and stories that drive the sports world with Axios Sports. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tech news worthy of your time

Get our smart take on technology from the Valley and D.C. with Axios Login. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Get the inside stories

Get an insider's guide to the new White House with Axios Sneak Peek. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Denver news?

Get a daily digest of the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Des Moines news?

Get a daily digest of the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Twin Cities news?

Get a daily digest of the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Tampa Bay news?

Get a daily digest of the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Charlotte news?

Get a daily digest of the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Nashville news?

Get a daily digest of the most important stories affecting your hometown with the Axios Nashville newsletter.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Columbus news?

Get a daily digest of the most important stories affecting your hometown with the Axios Columbus newsletter.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Dallas news?

Get a daily digest of the most important stories affecting your hometown with the Axios Dallas newsletter.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sign up for Axios NW Arkansas

Stay up-to-date on the most important and interesting stories affecting NW Arkansas, authored by local reporters

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

A wildfire near the village of Vinzili, Russia, on May 18. Photo: Maxim Slutsky\TASS via Getty Images

"Zombie fires" may sound like something straight out of science fiction, but they're a real phenomenon that is likely to become more common in the area ringing the Arctic, and possibly the Arctic itself, as climate change continues, a new study finds.

Why it matters: The study, published in the journal Nature, provides conclusive evidence that zombie or "holdover fires" exist and can be monitored, and it helps to begin to quantify their impact on global climate change.

Context: Zombie fires are blazes that ignite and burn in one season and then smolder through the winter by slowly combusting within peat and other soils, emitting smoke but little or no flames. Then they reemerge during the next spring, erupting into flames once again.

  • Numerous zombie fires were reported in Siberia last summer, which featured a particularly severe fire season, and such fires were also anecdotally reported during the summer of 2019, Merritt Turetsky, a University of Colorado professor who studies peat and wildfires, tells Axios. (Turetsky was not involved in the new study.)
  • Peat is damp soil that contains decaying plant material, and when burned, it can release large amounts of global warming pollutants.
  • Zombie fires have long been discussed in certain corners of the wildfire and climate science communities, but with this study, they've finally been quantified.
  • Turetsky describes zombie fires as a "legacy" in the climate, where one fire season can return to "haunt" the following one. "It's like a ghost of last year's fire season continuing to pop up and influence the contemporary season," she said.

How they did it: For the new study, researchers focused on fire activity in two sections of boreal forest, one in Canada's Northwest Territories and another in Alaska. They used an algorithm to detect zombie fires using satellite imagery as well as data from the ground.

What they found: Holdover fires in boreal forests tend to be more prevalent during long, hot summers, which have become more frequent in recent decades. In general, the Arctic is warming at more than twice the rate of the rest of the globe.

  • The study finds that between 2002 and 2018, zombie fires (referred to in the study as "overwintering" fires) caused about 1% of the total burned area in the study regions. However, this varied considerably — in some years, such blazes accounted for nearly 40% of the total burned area.
  • A key indicator of a zombie fire versus a new ignition, the study concludes, is that new fires tend to start later, when the lightning season commences. In contrast, zombie fires can ignite again as soon as the weather warms up and vegetation begins to dry out.

By the numbers: The researchers found that between 2002 and 2018, zombie fires in Alaska and the Northwest Territories emitted 3.5 million metric tons of carbon. The majority of these emissions occurred in just two fire seasons: 2015 and 2010.

  • The study cautions that this may be an underestimate, however, since computer models may not capture well the smoldering phase of these fires.
  • The carbon emissions from zombie fires comprise a relatively small amount (0.5%) of the total carbon emissions from fires in Alaska and the Northwest Territories. "Yet this fraction may grow larger with climate warming," the study states.

The big picture: Global warming is already supercharging fire seasons in the Arctic and sub-Arctic, as evidenced by the destructive fire seasons of 2019 and 2020. Some, like Turetsky, are worried recent severe Arctic fire seasons are a sign that climate change is destabilizing ecosystems, with severe fire seasons becoming the norm.

  • There are three main factors that help drive zombie fires and that are tied to global warming: summer temperature extremes, large annual fire extents, and fires that burn deeper into the soil.
  • Already this spring, fires are erupting in Canada and Siberia, with scientists tracking them, often via Twitter, using satellite imagery, Turetsky said.

What they're saying: The paper underscores the need for governments to start collecting official statistics on holdover fires and early season peat fires, said climate researcher Jessica McCarty of Miami University in Ohio, who was not involved in the study, in an email to Axios.

  • "More importantly, this paper gives our first estimates of how much holdover fires may be contributing to annual burned area totals and from there we can better understand emissions," she said.

Go deeper

Climate change made deadly European floods more severe: study

The town of Euskirchen, Germany, after severe rain and flash floods hit on July 18. Photo: Abdulhamid Hosbas/Anadolu Agency via Getty Images

Human-caused climate change increased the likelihood and intensity of the heavy rainfall that helped cause the devastating floods in Europe in July, an international team of 39 climate scientists stated Monday.

Why it matters: The study, released Monday, demonstrates how global warming is already influencing extreme weather events in ways that ramp up disaster risks.

California governor declares drought emergency for entire state

California Gov. Gavin Newsom speakinng to reporters in Los Angeles in September. Photo: Allen J. Schaben/Los Angeles Times via Getty Images

California Gov. Gavin Newsom (D) extended a drought emergency declaration to cover the entire state on Tuesday.

Why it matters: "California is experiencing its worst drought since the late 1800s, as measured by both lack of precipitation and high temperatures," per a statement from the governor's office. This past August was the driest and hottest one on record, "and the water year that ended last month was the second driest on record," the statement added.

Updated 2 hours ago - World

Reports: Brazil leader to be accused of crimes against humanity over COVID

Brazilian President Jair Bolsonaro. Photo: Andressa Anholete/Bloomberg via Getty Images

A Brazilian Senate panel will recommend President Jair Bolsonaro be charged with "crimes against humanity," alleging his COVID-19 pandemic response led to hundreds of thousands of deaths, per the New York Times and the Washington Post.

The latest: The lawmakers initially said Bolsonaro should be charged with mass homicide and genocide, but lawmakers updated the report to replace these recommendations with the new charge, its lead author, Sen. Renan Calheiros, told the NYT.