Pollution From Carbon Monoxide Has Fallen Steadily Since 2000, Data Show

As these NASA satellite maps show, carbon monoxide levels have decreased appreciably in much of the world since 2000, thanks to improved pollution controls on vehicles and factories and fewer forest fires. Carbon monoxide, which is produced whenever carbon-based fuels are burned, contributes to the formation of ozone, a pollutant that can have adverse health effects. A NASA satellite carrying a sensor called MOPITT — Measurements of Pollution in the Troposphere — measures carbon monoxide levels. Higher concentrations of CO are depicted on the map in orange and red and lower concentrations in yellow. NASA said that the decrease in CO levels from 2000 to 2014 was particularly noticeable in the northern hemisphere thanks to technological and regulatory innovations that have led to lower pollution levels from vehicles and industry. Carbon monoxide levels also have decreased in the southern hemisphere since 2000, due largely to a reduction in deforestation fires.