Four recently published studies led by UCLA researchers highlight the role of climate change and displacement on homeless populations across the United States — and that recovery planning should focus on risks to those already without shelter or who lose housing because of disasters.
"Each home lost to climate-related events, per 10,000 people, was associated with a significant, 1 percentage point greater increase in homelessness," said Kathryn Leifheit, assistant professor of health policy and management in the UCLA Fielding School of Public Health and a lead author of the national study, which researched factors contributing to homelessness in all 50 U.S. states and the District of Columbia. "Our findings underscore the reality that homelessness can be seen as a predictable consequence of climate disasters, so governments should focus on housing stabilization in their disaster response plans, while dedicating adequate funding to provide housing-specific services."
In other research, authors found that along with some 200,000 people who lost their homes in the Los Angeles County wildfires, more than three-quarters of those already experiencing homelessness in the same communities reported injuries or other significant disruption to their lives due to the fires. The county is currently home to the largest unsheltered population in the U.S., with more than 52,000 people living on the streets or in vehicles on any given night, researchers said.
"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 Randall Kuhn, professor of community health sciences at the Fielding School, who coauthored three of the studies. "These findings, and the realities that climate change is very likely to lead to even more of these sorts of disasters, highlight the need for even more coordination between emergency response systems and homeless services to ensure that everyone is adequately protected during future disasters."
The peer-reviewed studies, all authored by researchers affiliated with UCLA and the University of Southern California or Johns Hopkins University, are:
- "Factors associated with rising homelessness within U.S. States, 2019 to 2024," in the Journal of the American Medical Association (JAMA Network Open)
- "Impact of the January 2025 Los Angeles Firestorm on People Experiencing Homelessness," in the American Journal of Public Health
- "What are the true medical concerns facing unsheltered homeless adults?" in Health Affairs Scholar
- "Criminalizing homelessness: Longitudinal associations of police encounters and homeless sweeps with psychosocial health among the unhoused community in Los Angeles," in Social Science & Medicine
In addition to the scope and scale of climate change's impact, the national study also suggests that interventions to prevent evictions and promote housing stability are important tools in any effort to prevent surges in homelessness.
"As an example, in the average state, homelessness rose by 11% from 2020 to 2022," said Dr. Craig Pollack, a physician and professor in the Johns Hopkins Bloomberg School of Public Health and a co-author of the national study. "If states and local governments had allowed evictions to proceed during that period, we estimate that the average increase would have been nearly 20%."
Further underscoring the importance of housing stability, one of the studies found that laws targeting behavior associated with homelessness, including sleeping or camping in public spaces, are associated with poorer physical and psychological health of the individuals involved. The study, published in the March edition of Social Science & Medicine, focused on various attempts to address homelessness in Los Angeles before the wildfires.
"The big takeaway is that roughly one-third of those we surveyed face a sweep every month, and almost half are displaced every month, which in turn causes more distress by separating them from their social connections and cutting them off from services," said Benjamin Henwood, a researcher at the USC Suzanne Dworak-Peck School of Social Work and a co-author of the study. "Policing doesn't work. 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."
The research published in Health Affairs Scholar found that housing and health care are complementary components of care for those experiencing homelessness, and support integrating field-based medical services with permanent housing investments, said Kuhn, who also led that study.
"Overall, these findings make clear the correlation of climate change, natural disasters and homelessness, and the reality that communities across the U.S. — and globally — can expect to see these problems arise, again and again in the future," Kuhn said. "But they also offer potential solutions, both in terms of immediate policy actions and, thinking more upstream, efforts to mitigate climate change. Together, these actions will reduce the risk of homelessness, before and after disasters."
