I agree with that statement is carbon dioxide is still the worse greenhouse gas in the world. Because carbon dioxide accounts for about 80% of human-crated greenhouse gas emissions. With develop of industry right now, The carbon dioxide emissions to atmosphere is very much. Nowadays, in the world the carbon dioxide level in the atmosphere is more than 400 parts per million, it’s very high in hundred of thousand of years. carbon dioxide need about one thousand years for decomposed. Carbon dioxide emissions every day by daily activities of human. Example in Viet Nam, main vehicles in road is motorcycle, carbon dioxide emissions is very high by them. Or the carbon dioxide emissions by the factories activity , this is main reason make increasing greenhouse. Although methane is most powerful greenhouse gas but with the short life time in environment. I think carbon dioxide still main reason make increase the greengouse