By Hannah Brock
Rising temperatures and drier weather could double the probability of wildfires occurring in the Great Lakes region by the end of the century, according to a recent study.
The study published in ScienceDirect shows fire probability increasing across the lower 48 U.S. states, including areas like the Great Lakes that aren’t known for large wildfires.
The culprit is climate change and an increase of fire fuel, said John Kupfer, a geography professor at the University of South Carolina and an author of the study.
“What happens is that warming is increasing the growth rate of forests up there, which generates more leaf matter and other fuel for potential fires,” Kupfer said. “And then the warming and drying contributes to the fact that once they start, there’s a greater risk that they’re going to spread.”
The model of the risk of fire only considers annual maximum temperature, annual precipitation and elevation, said Peng Gao, the lead researcher on the study. The project is a potential situation, not a definite projection, Gao said.
The study runs two scenarios to understand potential fires.
One is a model reflecting the reality of greenhouse gas emissions, called RCP 8.5. Another model reflects a decrease in greenhouse gas emissions, called RCP 4.5, said Morgan Varner, the director of research at the Tall Timbers Research Station in Tallahassee, Florida.
RCP 4.5 suggests that, “as a society, we dramatically change our source of electricity, transportation, etc, which we haven’t seen today. And most climate modelers don’t believe that’s a realistic expectation,” Varner said.
Right now we’re seeing mild consequences of climate change, which is comparable to RCP 4.5, Varner said. According to the study, under the more realistic future of RCP 8.5, fire probability could double in the Great Lakes region.
To remain under the more mild model, greenhouse gas emissions need to be reduced so the overall change in climate can lessen, Kupfer said.
Another implication of more fires is air pollution from smoke, Gao said.
Drier conditions caused an uptick in Michigan wildfires this year, said Paul Rodgers, a wildfire prevention specialist at the Michigan Department of Natural Resources.
A majority of wildfires in Michigan are caused by people burning brush and leaves, Rogers said. Following an especially dry summer, Rogers said his team has been fighting fires up until the last week of September.
Rogers said he’s seen multiple instances this year where people don’t make sure their ash pile is out. For example, there may have been a light rain while the person burned, but a few days later there are high winds and all it takes is a few embers and “it’s off to the races,” Rogers said.
The DNR is also hoping to create better awareness during droughts like the one this year, Rogers said. Just because it’s raining doesn’t mean the rain has been enough to replenish dry conditions, he said.
“The biggest reaction we get is ‘we never thought it would move that fast,” Rogers said. “…We had a very, very busy year this year for fires in the state of Michigan.”
But fire is beneficial to the landscape of the Great Lakes region, said Lane Johnson, a research forester with the University of Minnesota. Over the last century, fires have been put out because they are viewed as a hazard, Johnson said.
In the absence of fire, forests become thicker and create more fuel for uncontrolled fires, Johnson said.
“So what happens is fires that do start become difficult to control and then they burn larger and hotter and you can’t really contain them,” Johnson said.
Johnson, a Minnesota resident, has seen the effects of a dry year on his state where people experienced more wildfires than they’re accustomed to, he said.
However, fire managers have been increasingly fighting fire with fire, or using controlled burns to maintain the landscape and make it more fire resistant, Johnson said.
“We need to be using a combination of mechanical treatments, which we’ll just call timber harvests or thinnings, and prescribed burns to essentially emulate what nature did for us in the past,” Johnson said.
In Michigan, prescribed fires are used more for ecological management, like treating invasive species, maintaining ecosystems and helping species that need carbon and the regeneration of trees, Rogers said.
The DNR focuses on creating fuel breaks, which are areas where trees that are more likely to burn are removed so if a fire hits that area, it will be more likely to stop, Rogers said. Since a fire is less likely to burn there, it also creates a good defensive spot for firefighters to go if a wildfire starts, he said.
When firefighters arrive on the scene of a wildfire, their main goal is to hit fires with as much equipment as possible to keep it under 10 acres, Rogers said.
“Once a fire reaches 10 acres, it starts producing its own winds, it can change temperatures and humidities,” Rogers said.
The DNR is also working on public outreach so Michiganders know there are a lot of wildfires in Michigan, but they have a better chance of being contained due to more wet weather conditions in comparison to the Western US where states stay dry for months, Rogers said.
This story was updated Oct. 19, 2021 to correct the order of a Peng Gao’s name.