An increase in onshore wind from 3 to 4 percent of world electricity use to 21.6 percent by 2050 could reduce emissions by 84.6 gigatonnes of carbon dioxide. For offshore wind growing from 0.1 percent to 4 percent could avoid 15.2 gigatonnes of emissions. At a combined cost of $1.8 trillion, wind turbines can deliver net savings of $8.2 trillion over three decades of operation. These are conservative estimates, however. Costs are falling annually and new technological improvements are already being installed, increasing capacity to generate more electricity at the same or lower cost.
“Drawdown: the most comprehensive plan ever proposed to reverse global warming”, pp. 2-4.