Integrating Health Co-benefits into Climate Mitigation Policymaking

Climate change mitigation can save lives and improve health through multiple pathways, such as reducing air pollution, promoting active transport, and facilitating healthier diets. These immediate health co-benefits can provide stronger incentives for climate action beyond mitigating health risks associated with global warming and extreme weather events. Thus, a comprehensive stocktake of mitigation costs, health co-benefits, and their consequent cost-effectiveness is critical to better prioritize health gains while achieving Nationally Determined Contribution (NDC) goals. This study first synthesizes findings on mitigation costs, health co-benefits, and cost-effectiveness of climate actions from global and regional health-included Cost-Benefit Analysis (CBA) studies. It then conducts an in-depth analysis of challenges in designing and implementing health-considered climate policies in real-world contexts, and finally proposes strategies for the scientific community to advance health-considered or even health-centered mitigation targets, technology pathways, and implementation strategies.

Global evidence indicates that air pollution-related health co-benefits of climate policies usually outweigh mitigation costs, with Benefit/Cost Ratios (BCRs) ranging from 1.10 to 2.45, meaning each $1 invested in mitigation yields $1.10~2.45 in health co-benefits (Figure 1). Notably, regional BCRs vary by up to 40-fold. Regions with high air pollution and population density (e.g., China and India) have greater health co-benefits, while developed regions (e.g., Europe, USA) with stringent pollution controls show lower co-benefits.

Figure 1 (a) Total carbon reductions (10 Mt), mitigation costs and health benefits (billion 2015 USD) from different original studies (n=332), and (b) regional distribution of annual BCR from different original studies.

Key recommendations include: (1) adopting policy-relevant methods (e.g., the Cost of Illness method, which incorporates tangible region-specific healthcare expenditure data to quantify the reduction of healthcare system burden) to monetize health co-benefits, replacing the Value of a Statistical Life (VSL)-based approaches; (2) fostering interdisciplinary collaboration (involving economists, political scientists, and sociologists alongside climate and health researchers) and strengthening cross-sector policy engagement, particularly engaging high-level decision-makers to establish interdepartmental collaboration frameworks that bridge fragmented governance; (3) conducting more national, subnational (especially in the Global South), or city-level localized studies and enhancing inter-study comparability through unified modeling frameworks and transparent data disclosure protocols (e.g., the Pathfinder Initiative, which integrates health impact data across pathways and regions); and (4) exploring health-optimized mitigation pathways (Figure 2) by addressing three core policy questions (i.e., target allocation across regions/sectors, optimal technology selection, and regionally tailored implementation), and incorporating health co-benefits into model objective functions to shift decision-making from traditional cost minimization to net benefit maximization. This work aims to provide actionable scientific guidance for integrating health co-benefits into climate mitigation modelling and policymaking, ultimately enhancing both climate and public health outcomes.

Figure 2 Conceptual framework for optimizing health-considered mitigation pathways. (a) 3 different research questions mentioned in the text. (b) Additional methods (in color red) to optimize climate policy with health co-benefits compared with current one-way assessment studies. (c) The mechanism of how the differentiated health benefits (in the color red) impact climate policymaking. (Source: Shen et al., Improving cost–benefit analyses for health-considered climate mitigation policymaking, Nature Climate Change, 2025)