In 2013, carbon monoxide (CO) emissions reached 6301 kilotonnes (kt), a decrease of 91 kt (1%) from 2012 levels. CO emissions in 2013 were 10 510 kt (63%) lower than in 1990.
The decline in CO emissions is mainly attributable to a reduction in emissions from transportation (road, rail, air and marine) and off–road vehicles due to the progressive introduction of cleaner and more efficient technology in vehicles.