What are NOx (nitrogen oxides)?

NOx or nitrogen oxides are one of the major greenhouse gases emitted from the exhausts of fuel-powered cars. The term includes nitric oxide (NO) and nitrogen dioxide (NO2), which are both created when an engine burns fuel. Releasing high volumes of NOx into the air is associated with the formation of acid rain and smog, and is also known to damage the atmosphere's ozone layer.

Tightening emissions standards have led to a general reduction in the amount of nitrogen oxides released by modern fuel-powered cars compared to their predecessors. Nevertheless, more drivers need to transition away from engine-driven to battery-powered electric cars if we want to see a meaningful reduction in global NOx emissions.