Pricing carbon reduces global health risks and inequities from air pollution exposure
Abstract
Putting a price on carbon emissions has been proposed as an avenue to mitigate climate change and to provide health co-benefits through improving air quality. However, some studies suggest potential health co-harms when decarbonization disrupts land-use patterns and increases the air pollutant emissions from bioenergy use and deforestation. Given a wide range of future uncertainties, it remains unclear whether a carbon price will yield robust co-benefits and how it might affect current health inequities. Here we use coupled economic, climate, and health impacts models to assess the impacts of a carbon price on mortality risks and health inequities. To sample socioeconomic and technological uncertainties, we use a large-scale scenario ensemble constructed by a process-based integrated assessment model (i.e., Global Change Assessment Model) for 2015-2100. We then assess the exposure level to ambient particulate matter using a reduced-form air quality model (TM5-FASST) and quantify the premature mortality risks using concentration-response relationships. With a globally-uniform carbon price, we find robust health co-benefits in lower-income regions, due to substantial reductions in fossil energy use and associated air pollution. However, small health co-harms are observed in some middle- and high-income regions. This is because when a carbon price is imposed only on the energy sector, it encourages residential biomass use which emits particulate matter. The competition for land further leads to more deforestation, increasing the emissions of particulate organic carbon. These health co-harms are particularly prevalent in scenarios with SSP1 and SSP5 agricultural and land use assumptions (e.g., high food demand). Globally, a carbon price reduces current health inequities across world regions, since it lowers the mortality risks stronger in lower-income regions. Because lower-income regions are expected to have larger ageing populations, pricing carbon also results in greater mortality risk reductions among elderly populations, the age group that is most vulnerable to air pollution exposure. Such improvements in health equities persist across future states of the world characterized by varying socioeconomic and technological development trajectories.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC25G0727H