Nitrogen oxide emissions in the European Union 1990-2020, by sector

Nitrogen oxide emissions in the European Union have fallen significantly across most sectors over the past few decades. In 1990, the transportation sector emitted 6.9 million metric tons of NOx. By 2020, this figure had fallen to 2.4 million metric tons. Despite these reductions, transportation is still the main contributor to nitrogen oxide emissions in the EU - specifically road transportation. This is followed by the agriculture sector, which emitted more than one million metric tons of NOx in 2020 - over a 40 percent decline compared to 1990 levels. Nitrogen oxides are a group of gases composed of nitrogen and oxygen, which include nitrogen dioxide.