Assessment of air pollution health co-benefits of Net-zero climate policies

Outdoor air pollution is responsible for a substantial amount of premature deaths and severe illnesses. Just in 2019, according to the GBD, it caused 124.21 million (95% CI 98.89-147.63) DALYs and 4.505 million (95% CI 3.625-5.364) deaths. Several air pollution co-benefits derive directly from the climate change mitigation policies, that have recently included a new carbon budget design: the net-zero pathway. However, a lot of factors add uncertainty to the estimation of health impacts. We aim to study the main drivers of uncertainty in mortality, as well as their interaction, with a special focus on the relative risk impact functions in the role of the decarbonization path. To do so, the climate mitigation scenarios from the ENGAGE database are considered, as well as a source-receptor model to estimate concentrations and several relative risk impact functions to compute premature deaths. The study further identifies that net-zero climate policies rise the health co-benefits and reduce the risk of extreme mortality outcomes. Moreover, this is of especial importance for stringent climate targets aiming to limit the temperature increase well below 2ºC, with particular relevance in Asia and Africa