Mark Perry explains:
The chart above shows the Department of Energy’s estimates of CO2 emissions per capita from 1973 to 2040. Total energy-related carbon emissions are expected to fall to a 20-year low this year, and on a per-capita basis will be the lowest since at least 1973 when the Department of Energy’s data begins. From the current level of 17 tons per capita, we can expect CO2 emissions per capita to fall to 14 tons per capita in 2040, a 25.2% decrease. One of the largest contributing factors in the reduction of CO2 emissions is the switch from coal to gas for electricity generation and the switch from fuel oil to natural gas as a fuel source for heating homes and commercial buildings.