Role of Air Pollutants

Apart from carbon dioxide (CO2), the climate system is affected by other substances in the atmosphere with human sources, including non-CO2 greenhouse gases and air pollutants. Air pollutants have a much shorter residence time in the atmosphere than CO2. Long-term goals, like holding warming below 1.5 and 2°C, will be achieved more easily if those substances that have a net warming effect are reduced not too long before the peak in temperature is reached, probably during the second half of the 21st century. We study the extent to which reducing air pollutants can help achieving long-term climate goals.


Limiting global warming to 1.5 or 2.0°C requires strong mitigation of anthropogenic greenhouse gas (GHG) emissions. Concurrently, emissions of anthropogenic aerosols will decline, due to coemission with GHG, and measures to improve air quality. However, the combined climate effect of GHG and aerosol emissions over the industrial era is poorly constrained. This study shows the climate impacts from removing present-day anthropogenic aerosol emissions and compares them to the impacts from moderate GHG-dominated global warming.