Global changes in air pollutant emissions 1990-2022, by type and region

There were stark regional differences in how emissions of air pollutants changed worldwide between 1990 and 2022. While emissions of most air pollutants have fallen across Europe and North America over the last three decades, those in Africa and Asia have seen considerable increases.

For example, nitrogen oxides (NOx) emissions in Africa and Asia increased by 106 and 86 percent between 1990 and 2022, respectively. In comparison, NOx emissions in both Europe and North America were cut by more than 60 percent. NOx pollution is emitted by a range of sources and activities, including road vehicles and boats, as well as industrial sources such as power plants.