The strategies that policymakers take to mitigate climate change will have considerable implications for human exposure to air quality, with air quality co-benefits anticipated from climate change mitigation. Few studies try to model these co-benefits at a regional scale and even fewer consider health inequalities in their analyses.   We analyse the health impacts across Western and Central Europe from exposure to fine particulate matter (PM2.5) and surface level ozone (O3) in 2014 and in 2050 using three scenarios with different levels of climate change mitigation, using a high-resolution atmospheric chemistry model to simulate future air quality. We use recent health functions to estimate mortality related to the aforementioned pollutants. We also analyse the relationship between air quality mortality rate per 100,000 people and Human Development Index to establish if reductions in air quality mortality are achieved equitably.   We find that air quality-related mortality (PM2.5 + O3 mortality) will only reduce in the future following a high-mitigation scenario (54%). It could increase by 7.5\% following a medium-mitigation scenario and by 8.3% following a weak mitigation scenario. The differences are driven by larger reductions in PM2.5-related mortality and a small reduction in O3-related mortality following the sustainable scenario, whereas for the other scenarios, smaller improvements in PM2.5-related mortality are masked by worsening O$_3$-related mortality.   We find that less developed regions of European countries have higher mortality rates from PM2.5 and O3 exposure in the present day, but that this inequity is reduced following greater climate change mitigation.

The Australian 2019/2020 bushfires were unprecedented in both their extent and intensity, causing a catastrophic loss of habitat and human and animal life across eastern-Australia. Between October 2019 and February 2020 hundreds of fires burned, peaking in size in December and January and releasing the equivalent of half of Australia’s annual carbon dioxide (CO2) emissions. We use a high-resolution atmospheric-chemistry transport model to assess the impact of the bushfires on particulate matter with a diameter less than 2.5 µm (PM2.5) concentrations across eastern Australia. The health burden from short-term population exposure to PM2.5 is then quantified using a concentration response function. We find that between October and February an additional ~1.9 million people in eastern-Australia were exposed to ‘Poor’, ‘Very Poor’ and ‘Hazardous’ air quality index levels due to the fires. The impact of the bushfires on AQ was concentrated in the cities of Sydney, Newcastle-Maitland and Canberra-Queanbeyan during November, December and, also in Melbourne, in January. The health burden of bushfire PM2.5 across eastern-Australia, regionally and at city level is also estimated. Our estimate indicates that between October and February 171 (95% CI: 66 – 291) deaths were brought forward. The health burden was largest in New South Wales (109 (95% CI: 41 – 176) deaths brought forward), Queensland (15 (95% CI: 5 – 24)) and Victoria (35 (95% CI: 13 – 56)). At a city level the health burden was concentrated in Sydney (65 (95% CI: 24 – 105)), Melbourne (23 (95% CI: 9 – 38)) and Canberra-Queanbeyan (9 (95% CI: 4 – 14)), where large populations were exposed to high PM2.5 concentrations due to the bushfires.