Researchers measured world carbon emissions from 1950 to 1986 and found that the United States, with about 5% of the world's population, was responsible for 30% of the cumulative emissions, whereas India, with 17% of the world's population, was responsible for less than 2% of the emissions. It is as if, in a village of 20 people all using the same bathtub, one person had shed 30% of the hair blocking the drain hold and 3 people had shed virtually no hair at all.