The number of California properties at risk of severe wildfires will increase sixfold over the next 30 years if only the effects of climate change are taken into account, a nonprofit research group predicts. announced on Monday.
Just over 100,000 properties in the state currently have a 1% or more chance of being affected by wildfires annually. The number is expected to reach around 600,000 by 2052, according to data from the First Street Foundation.
According to Jeremy Porter, the fund’s director of research, the model marks the first attempt to calculate the fire risk of individual properties in the United States, assuming that growth will be constant and taking into account only input climate.
The study is being peer-reviewed.
“When within 30 years you have a sixfold increase in the most severe category, with 600,000 homes at that level, it’s unbelievable when you think about how rapidly the effects change compared to the relatively small change in heat,” said Matthew Eby, founder and chief executive officer of the First Street Foundation. “And just the effects of heat on fuel, humidity and drought cause large fluctuations in the probability of these events occurring.”
Overall, more than half of properties in the lower 48 states – nearly 80 million – are at risk of being impacted by wildfires, with about 1.9% of properties facing an annual risk of 1% or more. , according to the First Street Foundation. This number is also expected to increase.
“On average, the probability of a fire — the likelihood of a wildfire occurring — will double over the next 30 years, and that’s nationwide,” Porter said. “So on average, any asset that has a risk doubles that risk. And that also leads to the fact that a lot of places that are not at risk today will be at risk of turning into the future. “
The climate signal on fire appears to be much stronger than what the researchers saw when they modeled the increasing flood risk a few years ago, he added.
In California, more than 4.6 million properties – about 41% – have a 0.03% or more chance of having a wildfire-related wildfire this year. This is expected to grow 7.6% over 30 years to include more than 5.5 million properties, according to projections by the First Street Foundation.
According to the forecast, the California county with the highest level of risk over the next 30 years is Sonoma, with a 41.6% increase, followed by Napa, Marin, Yolo and Santa Barbara. The 2017 wine country fires, which consumed parts of Napa, Lake, Sonoma, Mendocino, Butte and Solano counties, were among the state’s deadliest, with some 8,400 buildings damaged. destroy.
The analysis used the 0.03% threshold as the basis for significant risk as it means a 1% chance of the property being affected by a fire over 30 years, the average life of a mortgage. The nonprofit’s goal is to ensure that people have the information they need to understand the climate risks for a particular property when they buy or rent it, Eby said.
When it comes to the absolute number of properties facing a fire risk this year of at least 0.03%, Southern California counties make up three of the top five spots in the US: Riverside County comes out on top, with 684,400 , or 77.2% of its assets. ; Los Angeles ranked third, with 514,500, or 24.5%; and San Bernardino County ranked fifth, with 471,700, or 57.4%. But when it comes to counties with the highest percentage of annual fire risk properties of 0.03% or higher, no California county ranks in the top 20; The top counties are New Mexico and Texas.
The researchers created simulations using the 2016 Wildfires dataset, updated with additional sources to account for more recent cases of burns and regulated disorders, to assess condition of the fuel, Eby said. He said they used a weather dataset from the National Oceanic and Atmospheric Administration, provided a 10-year time series, and updated it with information from the Intergovernmental Panel on Climate Change. Queen.
The researchers used this information to run hundreds of millions of simulations to understand the fire probability of every 30 by 30 meter pixel across the country both this year and 2052, he said.
The results differ from existing risk mapping from the federal government and the California Department of Forestry and Fire Protection because they predict risk over time and take into account specific asset-level information, for to building materials, vent exposure, and the amount of protectable space around an Eby indicate a home, which can be obtained from taxpayer records and satellite imagery.
Federal employees are prohibited from endorsing or failing to endorse private businesses, the Forest Service said. But Greg Dillon, director of the Fire Modeling Institute at the agency’s Rocky Mountain Research Station, says the approach sounds sound.
“I think the more we can get homeowners and communities to think about their risks and what they can do to address them, the better,” he said.
Dillon led the modeling efforts used in the Forest Service’s Forest Fire Risk to Community mapping, which modeled fire risk at the community level. He said the agency does not go into the parcel level in its modeling because of potential uncertainties and because it believes the community is an appropriate scale to act when risk mitigation is needed. .
“If a house in the neighborhood works to reduce wildfire risk, but their neighbors do nothing, they are not reducing the risk very effectively,” he said. “It needs community action.”
Forest Service researchers are working to determine the best way to incorporate climate change projections into wildfire risk models, but it’s a complicated process, Dillon said.
“There are Forest Service researchers doing similar work, and they also find the risk of fire increases over time,” he said. “But again, I think we’re still really trying to get the science on track before we get there.”
The First Street Foundation’s data is surprising both in terms of the overall increase in wildfire risk and the places facing the most dramatic increases in risk, Eby and Porter said. For counties facing the biggest 30-year percentage increase in real estate with at least 0.03% fire risk, for example, Georgia takes three of the top five spots. (Two more counties are in Oklahoma and Montana.) At the same time, Porter added, areas in the South tend to have higher rates of small and medium wildfire risk, while areas in the West have higher rates. higher assets at a higher level of risk.
“It’s not that it didn’t grow in the West,” he said. “It’s just that it’s going to become a more common problem across America. It’s not really going to be just a Western problem going forward.”
https://www.latimes.com/california/story/2022-05-16/california-properties-at-risk-of-wildfire-expected-to-grow California properties at risk of wildfire expected to grow