Scientists confirm that nighttime wildfire activity is increasing

Firefighting agencies need to make changes to deal with the the new normal

Day-night proportion of fire activity
Fig. 9 from the study below showing the proportions of heat detected on wildfires at night, vs. during the day. The MODIS (black) time series spans 2003–2020 and the VIIRS (red) time series spans 2012–2020. The horizontal dotted line at 28% indicates the CONUS-wide value detected by MODIS from 2003–2020.

In a study of wildfires in the conterminous United States from 2003 to 2020 researchers found that while fire activity increased during the day in the 18-year period, it increased even more at night.

Heat sensing data from satellites showed significant increasing trends in nighttime wildfire fire activity, with a +54%, +42% and +21% increase in the annual nighttime sum of Fire Radiative Power (FRP), annual nighttime active fire pixel counts, and annual mean nighttime per-pixel values of FRP, respectively, in the latter half of the study period. Activity during the day increased also, with rates of +36%, +31%, and +7% respectively.

Analysis of coincident 1000-hour fuel moistures indicated that as fuels dried out, satellites detected increasingly larger and more intense wildfires with higher probabilities of nighttime persistence.

The information above is from the study “Large wildfire driven increases in nighttime fire activity observed across CONUS from 2003–2020,” by Patrick H. Freeborn, W. Matt Jolly, Mark A. Cochrane, and Gareth Roberts.

Average wildfire size, US, 1985-2000 (except Alaska)

The reason wildfires typically exhibit less activity at night is due to diurnal changes in weather. Nighttime generally brings lower temperatures, higher relative humidity, decreasing winds, and higher fuel moistures in light fuels.

But a warming climate with occasional multi-year droughts and higher temperatures can lead to nighttime higher temperatures and lower humidities. Drought will lower the fuel moistures in live and dead vegetation. These changes can result in fuels at night remaining available for significant and continuous fire spread. This is causing wildfires to burn with more intensity, spread more quickly, and have more resistance to control 24 hours a day.

Annual temperature change

About 15 to 20 years ago firefighters could usually count on wildfire activity slowing significantly at night as long as the wind was not extreme. Night shift crews could make good progress constructing direct fireline near the edge of fires. In the last few years weather and fuel conditions that permit direct attack by ground personnel, day or night, are less common. Fires are getting larger. Megafires that blacken 100,000 acres are no longer rare.

So now what?

As fires show increasing resistance to control we need to ramp up our fuel treatments, including prescribed fires, by a factor of 10. Less than full suppression of carefully selected fires when the season-ending weather event is on the horizon can have a place also, if they are very carefully planned and actively tracked and managed using all of the predictive tools available run by very smart, experienced personnel.

We also need to realize that we will never be able to prevent all wildfires from burning into populated areas, so property owners must realize they have to live with fire, using FireWise principles. Here are six things that need to be done to protect fire-prone communities.

And, community destruction during extreme wildfires is a home ignition problem. Here is an excerpt from the article written by Jack Cohen and Dave Strohmaier:

Uncontrollable extreme wildfires are inevitable; however, by reducing home ignition potential within the Home Ignition Zone we can create ignition resistant homes and communities. Thus, community wildfire risk should be defined as a home ignition problem, not a wildfire control problem. Unfortunately, protecting communities from wildfire by reducing home ignition potential runs counter to established orthodoxy.

We also have to realize that the fire suppression manpower staffing model that was created 50 years ago is obsolete. The agencies that fight wildfires, especially the federal agencies, need to increase the numbers of Interagency Hotshot Crews and engine crews. The crews must be configured and managed to allow personnel to have a reasonable amount of down time at the home unit even during the busiest times of the fire year. They can’t be away from home 90 percent of the time and expect to have a decent work/life balance. One National Forest will begin a pilot program in 2022 increasing the sizes of Hotshot and Engine crews to 30 and 10 people, respectively. This is intended to improve work/life balance and increase the availability of resources.

The reforms in the just-passed infrastructure bill to improve the pay and working conditions of firefighters must be implemented immediately. Slow-walking those improvements, a tactic too often used by the Federal agencies, should not be tolerated.

Technology needs to be adopted to make firefighting more safe and efficient. Firefighters down to the crew supervisor level should have access to real time data about the location of the fire and other firefighting resources 24 hours a day. Communications capabilities need to be robust and bomb proof.

On the afternoon of November 16, 2021 we initiated a 24-hour online poll on Twitter, asking for firefighters’ observations about nighttime wildfire activity.

Fire that ordinarily helps the boreal black spruce forests now threatens them too

12:37 p.m. PDT Oct. 31, 2021

Swan Lake Fire Alaska
Black spruce burning in the Swan Lake Fire near Mystery Creek southwest of Anchorage, AK in 2019. Alaska DNR photo.

This is an excerpt from an article at Canadian Broadcasting Corporation.

Warmer, drier conditions that lead to more frequent fires in Canada’s vast boreal forests are threatening the dominance of black spruce trees that for thousands of years thrived in a healthy relationship with forest fires.

Black spruce trees and the thick layer of peat they take root in are great fuel for the fires. So typically, every 100 years or so, a fire would sweep through and take out a stand of these iconic boreal trees.

That same fire would warm up the black spruces’ waxy cones, releasing its seeds that would allow the black spruce forest to regenerate.

But in recent years, climate change has undermined the healthy relationship between black spruce trees and forest fires. More frequent wildfires are pushing large areas of black spruce forests past their recovery point.

As a result they’re being replaced by other species, and sometimes the forest doesn’t regenerate at all.

“We do see evidence of shifts away from black spruce dominance in more than one third of the sites,” said Jennifer Baltzer, the Canada Research Chair in Forests and Global Change at Wilfrid Laurier University.

This shift away from black spruce dominated-forests could have far reaching implications for the wildlife that depend on them — like caribou — and for the massive amount of carbon these forests store underground.

Baltzer is the lead author of a new study that analyzed more than 1,500 former burn sites across the North American boreal forest, between 1989 and 2014.

“This is one study, in a growing body of evidence, that we’re pushing ecosystems toward these tipping points that we don’t really know what comes next,” Baltzer told Quirks & Quarks host Bob McDonald.

Billions in losses, thousands could die if wildfire response unchanged: report

Cub Creek 2 Fire
Cascade Type 2 IA crew on Cub Creek 2 Fire in Northern Washington, July 25, 2021. InciWeb.

A team of scientists from British Columbia, the United States, and Spain say Western Canada must address the threats posed by highly destructive wildfires or face deadly consequences.

The scientists, including Mathieu Bourbonnais, assistant professor of earth and environmental sciences at the University of British Columbia Okanagan, predict devastating wildfires such as those currently burning in B.C. and elsewhere in the country will be commonplace by 2050.

The group has released a paper predicting billions of dollars in suppression and indirect fire costs as well as hundreds or thousands of premature deaths due to exposure to wildfire smoke if climate change and fire causes are not resolved.

The warning comes as statistics from the B.C. government show 1,251 wildfires have charred more than 4,500 square kilometres of bush since the start of the fire season on April 1.

Three dozen of those blazes are considered extremely threatening or highly visible and include the 395 square kilometre fire southwest of 100 Mile House that remains out of control and prompted an evacuation alert for another 161 properties on Wednesday.

Environment Canada has issued heat warnings or special weather statements for inland sections of the north and central coasts and much of southern B.C., as the BC Wildfire Service warns the combination of high temperatures and low relative humidity will make wildfires even more intense.

Bourbonnais, who spent years working as a wildland firefighter, says in a statement that a new long-term plan is needed because it’s simplistic and insufficient to blame the wildfire crisis on the forest sector or wildland fire management agencies.

“Wildfires affect so many facets of our society and environment including health, the economy, biodiversity, ecosystem function and more,” he says in the release.

“Wildland fire management must engage additional proponents, including Indigenous Peoples, industry and communities, to help people learn to live with the realities of landscapes and ecological systems that include wildfires but, over time, work to reduce their more catastrophic effects.”

The economic and social costs of wildfire response are unsustainable, the scientists argue.

First published by The Canadian Press

US Congressman asks if the US Forest Service can modify the orbits of the Earth or moon

Rep. Louie Gohmert
Rep. Louie Gohmert. Still image from video of the July 8 hearing.

A member of the United States House of Representatives elected by the people of Texas had an unusual question for an employee of the US Forest Service Tuesday.  Jennifer Eberlein, the Associate Deputy Chief for the National Forest System in Washington, was testifying during a live streamed broadcast of a hearing before the House Natural Resources subcommittee on national parks, forests and public lands.

Rep. Louie Gohmert asked her a question. The topic at the time was climate change.

“I understand from what’s been testified to the Forest Service and the BLM you want very much to work on the issue of climate change,” Rep. Gohmert said. “I was informed by the immediate past director of NASA that they found that the moon’s orbit is changing slightly and so is the Earth’s orbit around the sun,” he continued. “And we know there’s been significant solar flare activity. And so is there anything that the National Forest Service or BLM can do to change the course of the moon’s orbit or the Earth’s orbit around the sun? Obviously, that would have profound effects on our climate.”

After a pause, Ms. Eberlien replied. “I would have to follow up with you on that one, Mr. Gohmert,” she said with a smile.

“Yeah, well, if you figure out a way that you in the Forest Service can make that change,” Rep. Gohmert said, “I’d like to know.”

After word got around about the unusual question, Rep. Gohmert tweeted about it. But he only wanted to clarify that he was referring to the Bureau of Land Management, not Black Lives Matter, and to make an accusation of “fake news” when someone quoted him correctly.

Astrophysicist Katie Mack weighed in:

The East is getting warmer and wetter — the West is warmer and drier

Over the last 40 years

Temp-Precip changes
Combined shift in temperatures/precipitation for the 1991-2020 period compared to the 1981-2010 period. By Brian Brettschneider.

About 32 percent of the United States has gotten warmer and drier over the last 40 years, primarily in the West. The eastern two-thirds, about 66 percent, is warmer and wetter.

That leaves 2 percent of the country that is cooler and wetter — across the northern areas of Montana, North Dakota, Michigan, and Minnesota. A very tiny fraction, 0.06 percent in the northeastern tip of Minnesota, is cooler and drier. (Data from The Prism Climate Group and Brian Brettschneider)

And, it’s not only the U.S. that is getting warmer:

climate 2020

The fire season in California this year might be worse than in 2020:

The U.S. is on track to shatter the record for the average size of wildfires this year

The number of fires is decreasing, but fires are growing larger

Average wildfire size in the United States 1985-2020
Average wildfire size in the United States, except Alaska, 1985-2020.

While all the wildfire statistics for 2020 are not yet available, the data through December 2, 2020 shows that the United States is on track to shatter the record for the average size of wildfires. Looking at the last 35 years, the average size of fires this year was the highest ever, 168 acres. This number has been growing rapidly year to year (see the chart above). The second highest was 145 acres in 2018, and third highest was 132 in 2017.

From 1985 through 1993 the average size was 27 acres — 16 percent of the average size in 2020, 168 acres.

Total wildfire acres US 1985-2020
Total wildfire acres US except Alaska, 1985-2020
Number of wildfires US 1985-2020
Number of wildfires US except Alaska, 1985-2020

From looking at the data, here are some highlights:

  • During the last 35 years, the number of acres burned this year in the lower 49 states was the 5th highest.
  • The number of fires has been declining. This year was the fourth lowest number in the last 35 years. The first, second and third lowest were 2013, 1989, and 2019 respectively.

Fewer, but larger fires — why?

The number of fires may be declining because we are better at preventing them. NFPA data shows the number of highway vehicle fires has declined from 456,000 in 1980 to 182,000 in 2018. The highway vehicles fires per billion miles driven has decreased over that same period from 299 to 56.  In addition, we may have better spark arrestors on equipment, and, fewer people are smoking and those that do, smoke less.

Higher temperatures most likely has led to lower live and dead fuel moistures, more preheating of vegetation, extreme weather, more rapid fire spread, and increased resistance to control of fires. And when there is more fire on the landscape, the same number of forestry technicians year after year can’t suddenly increase their firefighting output by 300 percent.

Increasing temperature last 200 years

All of the wildfire data in our charts here excludes Alaska. I treat that state separately because:

  • They don’t fully suppress most fires in Alaska, or sometimes just try to herd them away from communities. Fires can grow huge which really skews the numbers for the nation.
  • Alaska’s burned acres can vary widely from year to year. For example, so far this year they have only burned 181,234 acres; the other 49 states burned 8,708,060. In 2015   5,111,404 acres burned in Alaska.

I also do not show on charts the numbers before 1985 because the data available from NIFC shows wide shifts between 1982 and 1984. It appears that a different record-keeping system was introduced at that time.