The Health Impacts of Climate Change on People Who Use Alcohol and Other Drugs: Position Statement of AMERSA,Inc. (Association for Multidisciplinary Education and Research in Substance use and Addiction)

Background

Climate change broadly threatens the health of individuals and communities by introducing new environmental hazards and exacerbating fundamental social, economic, and geographic disparities influencing the health of populations and particularly those populations that are most vulnerable and marginalized. As the adverse health effects of climate change become more prevalent, researchers are just beginning to examine the impact of climate-related events (CREs) such as extreme temperatures and intensified hurricanes on the health and well-being of people who use alcohol and other drugs (PWUD).

CREs can disproportionately impact PWUD and those with substance use disorder (SUD) by disrupting access to substance use treatment, prevention, and harm reduction services,^1-4 producing drug market volatility, ⁵ and increasing risk for overdose, toxicity, withdrawal,^2,6,7 other injuries,^8,9 and exacerbation of preexisting chronic disease. Insofar as PWUD and those with SUD are often predisposed to greater socioeconomic vulnerability, ¹⁰ the adverse impact of CREs on capacity to meet basic needs (eg, housing, food, electricity, childcare)^11,12 may be especially significant. During and in the aftermath of a CRE, these myriad challenges contribute to the broader intersectional risk environment, ¹³ that shapes an individual’s morbidity and mortality.^14-16 Longitudinally, CREs are shown to influence initiation and worsening severity of alcohol and other drug use, retention in substance use treatment, and incidence of concomitant mental health diagnoses such as depression, anxiety, and post-traumatic stress disorders.^17-21

The interacting health impacts of CREs, acute symptoms of substance use, and intoxication, and conditions resulting from or exacerbated by SUD are influenced by factors operating at individual, interpersonal, institutional, community, and structural levels.^22-24 Figure 1 applies a social-ecological model to illustrate some of these relevant factors and is followed by an illustrative vignette.

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Figure 1.

A social-ecological presentation of multilevel factors influencing the intersecting health impacts of CREs, substance use, and SUD. CRE, climate-related events; SUD, substance use disorder.

Vignette

Consider the example of Sam, a 45-year-old Hispanic male with a history of opioid use disorder who has recently enrolled in an opioid treatment program (OTP) to begin methadone treatment for the first time. Sam lives in a mid-sized Midwestern city that experienced severe flooding. The flood has rendered his home uninhabitable, and he is forced to evacuate on foot to an emergency shelter, leaving his car behind due to impassable roadways. At the individual level, Sam’s SUD diagnosis, recent treatment initiation, and loss of housing and transportation may place him at higher risk for adverse health outcomes. Before the flood, Sam drove daily to his OTP, located in a neighboring city. With that facility no longer reachable, his ability to continue taking methadone will depend on community-level alternatives, such as access to other, more proximal OTPs that are open, operational, and willing to guest-dose or provide take-home doses, the ability to receive his medication at a shelter, or the rapid restoration of transportation infrastructure.

There is no guarantee that emergency shelters will have bed availability or accept an individual currently on medications for opioid use disorder. Some but not all shelters may be equipped with medical personnel, supplies, and medications. Additionally, loss of electricity and cellular service, as well as limitations on interagency data access, may make it difficult to coordinate Sam’s care or confirm details of his medical history. Providers Sam encounters may have variable levels of comfort and clearance to prescribe or fill medications for Sam in the absence of this information.

With Sam’s treatment interrupted, he faces increased risk of opioid withdrawal. This, coupled with housing instability, stress, or other exposures, may precipitate a return to unregulated opioid use. Sam may lack access to harm reduction supplies to facilitate safer use and may be unable to store any supplies he does have securely. If he is unable to maintain shelter and is engaging in substance use, sedation and other effects of opioid use may increase his risk of harmful environmental exposures, such as overheating, burns, hypothermia, or dehydration, depending on the time of year. Sam may find himself reliant on interpersonal and community-level resources, such as friends and family, emergency departments, and mutual aid organizations, to meet basic needs, escape the elements, and ultimately restore social, economic, and medical stability. He may struggle to connect with these resources unassisted, absent cellular service or transportation. The availability and accessibility of these resources and services depend upon institutional, local, state, and federal policies that underpin the preparedness of the systems of care designed to support the wellbeing of individuals like Sam. In turn, these policies and their enforcement reflect broader cultural sentiment and historical investment by public and private sector stakeholders in climate change readiness and consideration of the needs of PWUD and those with SUD.

Issue

Sam and others are caught at the crossroads of 2 simultaneous crises. Amidst an ongoing climate crisis, the frequency and severity of CREs affecting the United States are increasing. ²⁵ The National Oceanic and Atmospheric Administration (NOAA)’s National Centers for Environmental Information (NCEI) reported 27 large-scale CREs in 2024 alone that individually resulted in more than $1 billion in damages, costing the United States an estimated $182.7 billion in total. ²⁶ Healthcare expenses comprise a substantial portion of the costs associated with CREs. A 2019 analysis of 10 CREs that occurred in 2012 estimated the associated healthcare expenses at $10 billion, accounting for deaths, hospitalizations, emergency department utilization, and related medical services. ²⁷ This does not account for downstream healthcare costs in the months and years following a CRE.

The current overdose crisis is characterized by broad suffusion of fentanyl in the unregulated opioid supply and, increasingly, stimulant and benzodiazepine supplies as well. ²⁸ Emerging adulterants (eg, xylazine, medetomidine) have introduced a new constellation of health risks and complications for PWUD. While available data indicate that overdose deaths have declined in recent years, ²⁹ the annual death toll remains significant. The Centers for Disease Control and Prevention provisionally estimate that over 70 000 overdose deaths occurred in the 12-month period ending September 2025. ³⁰ Cumulative healthcare costs associated with addiction and overdose in the United States are estimated in the trillions of dollars. ³¹

CREs exacerbate the health harms of substance use and addiction, and vice versa, disproportionately affecting populations that are, in many cases, already at heightened vulnerability and disadvantage. It is imperative that researchers, policymakers, and health care service providers improve their understanding of and capacity to respond to these intersecting crises. To date, however, research, evaluation, and practice innovation in this area are quite limited. ³² As a result, when CREs occur, systems of care serving PWUD and those with SUD are often unprepared, producing service disruptions and associated adverse outcomes. ³³

Policy and Practice Recommendations

Policy and practice recommendations to improve understanding of CREs as they impact PWUD and those with SUD and capacity to mitigate and respond to such events, should broadly focus on expanding resources available to study the nexus of climate change and substance use, integrate substance use and SUD considerations into general emergency planning and adapt existing treatment, harm reduction, and prevention services to ensure continuity of care during and after CREs.

AMERSA’s recommendations fall within 3 core interventional domains: