NEW RESEARCH: Ecological Forest Thinning and Prescribed Burns Lower Insurance Premiums Significantly

New study by TNC and Willis Towers Watson finds a 41% decrease in residential insurance premiums when ecological forestry is applied to relevant areas

A house with a raging fire approaching.
“Glass Fire” The “Glass Fire” burns homes and wildland in the Skyhawk Community in Santa Rosa, California, September 27-28, 2020. © Jerry Dodrill

Media Contacts

A portion of the premium savings on premiums can pay for forest treatment creating a “virtuous cycle”

The Nature Conservancy, working with Willis Towers Watson, the third largest insurance broker in the world, has today published analysis that shows how ecological forest management, which reduces the risk of severe wildfires in fire-adapted forests, can be combined with insurance and significantly reduce insurance costs.

By modeling the impact on insurance of controlled burning and ecological thinning of overgrown forests, researchers at TNC and WTW were able to quantify insurance premium savings. In turn, these savings could be used to fund further investments in sustainable forest management.

The report, Wildfire Resilience Insurance: Quantifying the Risk Reduction of Ecological Forestry with Insurance, finds that the practice known as ecological forestry, which includes prescribed burns and the removal of smaller trees and other vegetation in overgrown forests (i.e.: thinning), leads to decreases in total insurance premiums by 41% for homes and a range of decreases for commercial property, while also reducing the likelihood of extreme wildfires in these communities.

The report explores how the insurance savings from ecological forestry could be captured and applied to pay debt service on bonds which would be issued to pay for ecological forest treatment.  In this way, the insurance savings can contribute to funding or financing the ecological forest treatment, creating a “virtuous circle”.

For the first time, the project tested “parametric” insurance as applied to the intensity and acreage of wildfires, resulting in a reduction in both losses and premiums. Such a parametric product, which can provide instant access to funds to pay for costs not covered by indemnity insurance, would be new to the market and is an innovative way for insurers to cover fire risk.

The project used an ecological forest restoration project in the watershed of Placer County Water Agency in the Tahoe National Forest in northern California. The researchers found that ecological forestry in the watershed reduced the risk of wildfire substantially for the 81,000 homes in and around the watershed, which in turn could reduce aggregate home insurance premiums $21 million a year

“For the first time we are demonstrating that insurance modeling and pricing can account for the severe wildfire risk reduction benefit of ecological forest treatment,” said Dave Jones, Senior Director of Environmental Risk at The Nature Conservancy and former California Insurance Commissioner.  “These widely-supported forest treatment practices -- prescribed burns and ecological thinning -- provide the triple benefit of improving forest health,  decreasing the risk of catastrophic wildfires, and providing a pathway to keep insurance available. Insurers’ models do not currently take into account forest treatment, but now that we have shown it can be done, we expect insurers will begin doing so.” 

Due to the high risk of wildfires and associated losses, insurers are finding it a challenge to write insurance in areas at risk of wildfire. In late 2020, the California Department of Insurance reported that between 2018 and 2019 there was a 61% increase in non-renewals by insurers for homes in ZIP codes having an area with moderate to very high fire risk, and a 203% increase in the top 10 counties with the highest exposure of homes in high to very high fire risk. The results of the study indicate that funding more ecological forestry treatments can reduce wildfire risk and provide a better opportunity for insurers to continue writing insurance in high risk areas. 

“Wildfire risk in California and throughout the western United States is becoming uninsurable thanks to increasing risks due to climate change and overgrown forests laden with fuel,” said Dr. Nidia Martínez, Director of Climate Risk Analytics at the Climate and Resilience Hub, Willis Towers Watson. “The state-of-the-art analytics described in this report provide insurers across the board with tools to incorporate the true value of wildfire risk reduction through ecological forestry into underwriting decision making. And the product innovations we present offer new approaches to protecting communities and businesses in the Wildland-Urban Interface through  insurance.”

“If we want to continue to have insurance in these areas and to reduce the loss of life and property, we need a lot more private and public funding for ecological forestry in national and other forests,” said Jones. “This spending is really an investment in the future of these areas.”

The case study results are applicable to other similarly forested regions in California and other western states. The work also opens up the possibility to consider combining nature-based risk mitigation and  risk transfer in other fire-prone regions around the world. 

The report also includes a series of recommendations, including for federal, state and local policymakers to fund more forest treatment in national and other forest lands, so that communities and businesses can see the resulting risk reduction and insurance benefits shown in the paper.

The Nature Conservancy will continue its comprehensive approach with these stakeholders to improve wildfire resilience, including through the upcoming launch of a collaborative discussion series in partnership with the Aspen Institute.

Read our full report and summary here.

The project and paper were funded in part through an Innovative Finance in National Forests (IFNF) Grant from the United States Endowment for Forestry and Communities, with funding from the United States Forest Service (USFS).  The United States Endowment for Forestry and Communities, Inc. (the "Endowment") is a not-for-profit corporation that works collaboratively with partners in the public and private sectors to advance systemic, transformative and sustainable change for the health and vitality of the nation's working forests and forest-reliant communities.

The Nature Conservancy is a global conservation organization dedicated to conserving the lands and waters on which all life depends. Guided by science, we create innovative, on-the-ground solutions to our world’s toughest challenges so that nature and people can thrive together. We are tackling climate change, conserving lands, waters and oceans at an unprecedented scale, providing food and water sustainably and helping make cities more sustainable. Working in more than 70 countries and territories, we use a collaborative approach that engages local communities, governments, the private sector, and other partners. To learn more, visit or follow @nature_press on Twitter.