Carbon Dioxide Removal (CDR) includes all methods which aim at the reduction of Carbon dioxide (CO2) in the atmosphere. CO2 is the most important greenhouse gas (GHG). Global annual mean CO2 concentration has increased by 50% since the start of the Industrial Revolution, from 280 ppm … to 420 ppm as of April 2021. (https://en.wikipedia.org/wiki/Carbon_dioxide_in_Earth%27s_atmosphere)