Exploring the co-benefits of a low-carbon future: reducing PM2.5 and ozone in Europe

15 January 2025

A new research paper, “The Co-Benefits of a Low-Carbon Future for PM2.5 and O3 Air Pollution in Europe” by Connor J. Clayton and colleagues, demonstrates that strong climate mitigation efforts not only combat global warming but also significantly improve air quality across Europe. However, less ambitious climate action fails to achieve these dual benefits.  EPCC researcher, Kirsty Pringle, who was involved in the design of the research, outlines the findings.

Air pollution: a persistent health threat

Particulate matter (PM2.5) and ozone (O3) are harmful pollutants affecting public health and ecosystems. PM2.5 comprises fine particles smaller than 2.5 micrometres, while O3 is a secondary pollutant formed through reactions involving sunlight and precursor gases like nitrogen oxides (NOx) and volatile organic compounds (VOCs). 

Three climate mitigation scenarios

To avoid the catastrophic effects of climate change, we must reduce emissions of greenhouse gases. To assess the impact of different levels of reduction, researchers consider different “emission scenarios”. This study uses a regional air quality model (WRF-Chem, 30 km horizontal resolution) to examine changes in particulate matter and ozone under three scenarios with different levels of climate mitigation (high level, moderate level and minimal mitigation).  

The study, as reported in the paper The Co-Benefits of a Low-Carbon Future for PM2.5 and O3 Air Pollution in Europe, revealed that under the high-mitigation scenario (SSP1-2.6), Europe experienced the most significant air quality improvements, with population-weighted PM2.5 levels reducing by 52% compared to 2014. The moderate-mitigation scenario (SSP2-4.5) achieved a 34% reduction, while the minimal-mitigation scenario (SSP3-7.0) saw only an 18% improvement. Interestingly, ozone concentrations showed contrasting trends: a 15% reduction in peak ozone levels under SSP1-2.6 but a 13% increase under SSP3-7.0. These changes underscore the importance of reducing emissions from sectors like agriculture and industry, which are critical for achieving meaningful co-benefits of climate mitigation policies.

Central and Eastern Europe benefited most from reductions in PM2.5, driven by decreased emissions in industrial and agricultural sectors. Coastal and rural areas saw smaller improvements due to the dominance of natural sources like sea salt and dust.

Policy implications

The study underscores the co-benefits of robust climate policies, highlighting their potential to dramatically improve air quality. It emphasizes the need for integrated strategies addressing both greenhouse gas and air pollutant emissions, particularly in agriculture and industry. Policymakers can leverage these findings to advocate for ambitious climate action by showcasing tangible local benefits alongside global environmental goals.

Author

Dr Kirsty Pringle