CO2 Spiral , 2016
Between 1950 and 1986, annual carbon dioxide emissions have tripled. The principal source of these emissions is fossil fuel combustion, but natural gas flaring and cement production also contribute to the rising level. Carbon dioxide is the major cause of the Greenhouse Effect. Global shipping contributes about a billion tons of CO2, more than the entire economies of Germany or the UK. Moving goods by ship is 100 times more efficient than shipping by air.