Historical anthropogenic emissions of carbon monoxide, 1850 - 2000

We present a bottom-up emission inventory of carbon monoxide (CO) from fossil fuel and biofuel combustion from 1850 to 2000. We reconstruct fuel consumption data of brick and cement industry, as well as production data of iron and steel industry. We develop technology divisions for the four industries and also add several new technologies in the past for mobile sources. We collect emission factors of all fuel and technology combinations through extensive literature review, and apply them to the activity data to build the historical emission inventory. CO emissions increased almost linearly until 1950, totaling about 84 Tg in 1850, 128 Tg in 1900, and 209 Tg in 1950. Residential biofuel combustion has been the dominant source during that period. After 1950, there is a rapid increase of CO emissions due to gasoline vehicle emissions. Emissions of CO peaked in 1975 with 433 Tg, and then decreased to 360 Tg in 2000. The decline is mainly due to reduced vehicle emissions in the United States and Europe after a series of vehicle emission standards were implemented. Residential and vehicle sectors together make up more than 78% of the total CO emissions during the entire period. The contribution to total emissions from brick, cement, iron and steel industry increased from around 3% in 1850 to 15% in 2000. Previous work suggests a slight decrease in CO emissions from 1990 to 2000. Our work indicates an emission decline since the 1970s, mainly because of implementation of vehicle standards at that time. Our result is in line with the recent CO concentration trend measured in Greenland firn air