Climate Actions That Heal or Harm: Landmark Review Maps Health Co-Benefits Across North America

When governments cut carbon emissions or build defenses against a warming world, the effects ripple far beyond the atmosphere. A sweeping new scoping review published in Regional Environmental Change has systematically mapped how climate change adaptation and mitigation actions across North America affect human health, revealing both a rich trove of hidden benefits and a set of underappreciated risks. Led by Rebekka Schnitter and Sherilee L. Harper of the University of Alberta’s School of Public Health, together with colleagues at the University of Waterloo and ICLEI Canada, the study analyzed 183 peer-reviewed articles to answer a deceptively simple question: what do we actually know about the health consequences of the climate actions themselves, rather than the climate change they are meant to address?

The methodological rigor behind the review is worth appreciating. The research team searched five academic databases and applied pre-determined eligibility criteria, with two independent reviewers assessing each article before data extraction and analysis. This scoping review approach, following the framework first articulated by Arksey and O’Malley and reported against the PRISMA-ScR checklist, is designed not to statistically pool results but to chart the extent, range, and nature of an entire evidence landscape. The result is a cartographic snapshot of nearly two decades of research, showing where knowledge is dense, where it is thin, and where the field has quietly drifted away from what decision-makers actually need.

One of the most striking findings is temporal: the number of published articles describing climate actions with health co-benefits or risks has increased steadily over time, signaling growing scholarly recognition that climate policy is health policy. Yet the geography of that scholarship is lopsided. Most of the 183 articles originated in the United States, with comparatively less attention paid to Canada and Mexico. Because these three nations differ enormously in energy systems, urban form, agricultural practices, and health-care infrastructure, the review’s authors caution that findings from one jurisdiction cannot simply be transplanted to another. The concentration of evidence in one country leaves substantial blind spots for policymakers elsewhere on the continent.

Even more consequential is what the reviewed studies were actually about. The vast majority described climate actions that were hypothetical, modeled scenarios rather than actions that had been formally proposed or concretely implemented. This is a critical distinction. Modeling a hypothetical coal-plant retirement and estimating the avoided cases of asthma is scientifically valuable, but it cannot tell us whether real-world programs deliver the promised benefits, how implementation barriers erode them, or whether unexpected harms emerge once policy meets reality. The review suggests the field has, in effect, been rehearsing on paper while the actual performance goes largely unmeasured.

The thematic balance also tilts heavily toward mitigation. Articles primarily focused on greenhouse gas emission reduction activities, and the energy sector dominated the literature, encompassing studies of renewable energy deployment, power-plant retirements, building efficiency retrofits, and transportation electrification. Adaptation articles were rare by comparison, and those that did exist primarily examined green infrastructure, such as urban tree planting, stormwater management, and vegetated spaces that cool cities and buffer floods. This asymmetry matters because adaptation actions, which are accelerating worldwide as climate impacts intensify, can carry their own health consequences, both positive and negative, and the evidence base to anticipate them remains sparse.

The health co-benefits documented in the literature are nonetheless substantial and often monetized. Studies of power-sector decarbonization consistently found reductions in fine particulate matter and ozone, translating into avoided premature deaths, fewer cardiovascular events, and reduced respiratory illness. Research on the Regional Greenhouse Gas Initiative and proposed decarbonization policies in the eastern United States quantified benefits specifically to children’s health, a population uniquely vulnerable to air pollution. Transportation studies modeling cleaner vehicles and expanded active mobility found gains from both reduced emissions and increased physical activity. Dietary shifts toward lower-emission food systems showed simultaneous benefits for chronic disease outcomes. Many articles went further and attached dollar values to these health gains, often finding that monetized co-benefits could offset a large share of mitigation costs.

Yet the review also surfaces a persistent gap between evidence and action. While many studies calculated the monetary value of health co-benefits, few provided actionable policy recommendations that decision-makers could directly use. This is a familiar critique of academic research: sophisticated modeling that ends where governance begins. The authors point out that translating findings into policy requires more than numbers; it requires framing health outcomes in terms that sectoral decision-makers, whether in energy, transportation, agriculture, or urban planning, can integrate into their own mandates and constraints. Without that translational step, even the most compelling co-benefit estimates risk remaining confined to journal pages.

The risks side of the ledger deserves equal attention. Climate actions are not automatically benign for health. The broader literature the review situates itself within includes cautionary concepts such as maladaptation, the phenomenon in which adaptation interventions inadvertently increase vulnerability. Energy-efficient building retrofits, for example, can alter indoor air quality in ways that require careful ventilation management. Forest management changes intended to reduce emissions can shift wildfire smoke regimes. Individual adaptation behaviors, such as staying indoors during pollution or heat events, carry their own equity and wellbeing implications. The review’s framing makes clear that identifying and limiting these health risks is as important as maximizing the benefits, and that both demand deliberate attention during policy design.

The authors’ central recommendation follows directly from their findings: engaging and collaborating with health professionals in the design, implementation, and evaluation of climate actions can help decision-makers across health-determining sectors identify and maximize health co-benefits while limiting health risks. This cross-sectoral collaboration echoes guidance from the World Health Organization, which has published frameworks for quantifying and economically valuing health outcomes from both health and non-health climate actions, and quality criteria for integrating health into nationally determined contributions. It also aligns with the growing Lancet Countdown enterprise, which tracks the health dimensions of climate change annually and argues for a health-centred response to a world facing irreversible harms.

For a continent grappling with wildfire smoke, extreme heat, aging grids, and transportation systems that remain stubbornly carbon-intensive, the review arrives at a pivotal moment. Its message is ultimately optimistic but demanding: the health dividend of climate action is real, large, and increasingly well quantified, but it is not automatic. It must be designed in, measured in practice rather than only in models, and evaluated with health expertise at the table from the start. The 183 studies charted here represent a foundation, and the field’s next chapter, the authors imply, should be written less in hypothetical scenarios and more in the messy, instructive reality of policies actually put to work in North American communities.

Subject of Research: Health co-benefits and risks of climate change adaptation and mitigation actions in North America

Article Title: What are climate change adaptation and mitigation actions that have health co-benefits and risks? A scoping review in North America

Article References: Schnitter, R., Berry, P., Gokiert, R., Banuet-Martinez, M., Gerend, S., Terreros-Rodriguez, A., Jackson, E., & Harper, S. L. (2026). What are climate change adaptation and mitigation actions that have health co-benefits and risks? A scoping review in North America. Regional Environmental Change, 26(4), Article 205. https://doi.org/10.1007/s10113-026-02679-8

Image Credits: AI Generated

DOI: 10.1007/s10113-026-02679-8

Keywords: climate change, health co-benefits, scoping review, mitigation, adaptation, North America, green infrastructure, air quality, energy sector, public health, policy, maladaptation