Actions to reduce emissions of greenhouse gases (GHG) can have near-term, positive health benefits that generally offset a significant portion of the costs to implement mitigation policies, and accrue sooner than the direct benefits of reducing GHG emissions. Because these benefits are not those directly intended by the mitigation activities, they are termed “health co-benefits.” The value of health co-benefits is often ignored in net estimates of mitigation policy costs.

Researchers from the University of Washington’s Center for Health and the Global Environment (CHanGE) collaborated with national and international colleagues to conduct a comprehensive literature search and systematic review of health co-benefits studies. They evaluated studies published since 2009 that estimated the health co-benefits of reducing air pollution associated with GHG emissions from energy production, increasing biking and walking (thus reducing emissions from transportation), and reducing consumption of red meat and other dietary changes (and thus reducing emissions from cattle and sheep). The purpose was to identify and recommend best practices to inform policy development.

Of the 42 studies, most indicated significant, nearer term, local health co-benefits resulting from the mitigation policies investigated. However, the diversity across the studies means that it is not possible to provide overall estimates of the magnitude of benefits that could be incorporated into cost-benefit analyses of specific policies or to compare the relative benefits of policy options. Increasing consistency in modeling choices, including consistent approaches to population projections, health outcomes, scenarios, time slices, and discount rates, as well as closer linkages between policymakers and research scientists in posing research questions, would enhance comparability across policy choices, and allow stakeholders to consider potential synergies and dis-benefits of baskets of mitigation options.

Chang KM, Hess JJ, Balbus JM, Buonocore JJ, Cleveland DA, Grabow ML, Neff R, Saari RK, Tessum CW, Wilkinson P, Woodward A, Ebi KL. Ancillary health effects of climate mitigation scenarios as drivers of policy uptake: a review of air quality, transportation and diet co-benefits modeling studies. Environmental Research Letters 12 (2017) 113001. https://doi.org/10.1088/1748-9326/aa8f7b.

Source: University of Washington