Every 10 homes lost to a climate-related disaster per 10,000 residents is associated with a 1 percentage point increase in homelessness, according to a sweeping new national study led by UCLA researchers — findings that its authors say should fundamentally reshape how governments plan for natural disasters.
The study, published in April in JAMA Network Open, tracked factors contributing to homelessness across all 50 states and the District of Columbia from 2019 to 2024. It is one of four peer-reviewed studies released this month by researchers from UCLA, the University of Southern California and Johns Hopkins University examining the intersection of climate change, disaster response and homelessness.
"Our findings underscore the reality that homelessness can be seen as a predictable consequence of climate disasters," said Dr. Kathryn Leifheit, an assistant professor at the UCLA Fielding School of Public Health and lead author of the national study. "Governments should focus on housing stabilization in their disaster response plans, while dedicating adequate funding to provide housing-specific services."
The research arrives more than a year after the January 2025 wildfires devastated communities across Los Angeles County, displacing roughly 200,000 residents. A companion study published in the American Journal of Public Health found that the fires also took a severe toll on those already living on the streets: more than three-quarters of homeless individuals in affected communities reported injuries or significant disruption to their lives as a result of the blazes.
Los Angeles County is home to the largest unsheltered population in the United States, with more than 52,000 people sleeping on streets or in vehicles on any given night, the researchers noted.
"The wildfires were among the most devastating urban wildfires in history, and as traumatic as they have been for those who lost their homes, those living on the street suffered as well," said Dr. Randall Kuhn, a professor at the UCLA Fielding School and co-author of three of the studies.
The national study also found that policy decisions made during the COVID-19 pandemic had a measurable effect on homelessness rates. In the average state, homelessness increased 11% between 2020 and 2022. Without eviction moratoriums in place during that period, researchers estimate that figure would have climbed to nearly 20%, said Dr. Craig Pollack, a physician and professor at the Johns Hopkins Bloomberg School of Public Health and co-author of the national study.
"The data show that we saw the largest increases in states that either had severe natural disasters resulting in loss of homes, or had limited eviction protections during the pandemic," Leifheit said, pointing to Louisiana, which saw a sharp rise in homelessness in the aftermath of Hurricane Ida.
Long-term solutions, she said, include expanding the supply of affordable housing, funding legal representation for tenants facing eviction and helping residents relocate away from high-risk climate zones.
A fourth study, published in Social Science & Medicine, examined the effects of anti-camping laws and police sweeps on homeless individuals in Los Angeles — and found the policies inflict measurable physical and psychological harm without reducing homelessness. Approximately one-third of those surveyed reported being subjected to a sweep every month, and nearly half said they were displaced monthly as a result of enforcement actions.
"Policing doesn't work," said Dr. Benjamin Henwood, a researcher at the USC Suzanne Dworak-Peck School of Social Work and co-author of that study. "The physical and mental health damage is both immediate and cumulative, and in many cases, just moves the individual from one spot to another — it doesn't really solve the problem."
Kuhn said the wildfires illustrated a broader failure: anti-homeless enforcement tends to push people into more marginal spaces, potentially closer to wildfire perimeters and farther from outreach services. When disaster strikes, he noted, homeless outreach workers are often redeployed to emergency shelters, creating a gap in support precisely when it is most needed.
"These findings, and the realities that climate change is very likely to lead to even more of these sorts of disasters, highlights the need for even more coordination between emergency response systems and homeless services," Kuhn said.
The studies draw on data from the U.S. Department of Housing and Urban Development's Point-in-Time counts as well as the Los Angeles County-based Periodic Assessment of Trajectories of Housing, Homelessness and Health Study.