"This figure shows worldwide greenhouse gas emissions by sector from 1990 to 2010. For consistency, emissions are expressed in million metric tons of carbon dioxide equivalents. These totals include emissions and sinks due to land-use change and forestry.
Note that the sectors shown here are different from the economic sectors used in U.S. emissions accounting (see the U.S. Greenhouse Gas Emissions indicator). Emissions from international transport (aviation and marine) are separate from the energy sector because they are not part of individual countries’ emissions inventories. The energy sector includes all other transportation activities." - United States Environmental Protection Agency
This figure illustrates the accelerating increase in global greenhouse gas emissions every five years for the past two decades. A majority of the increase in aggregate emission levels is due to the substantial increase in greenhouse gas emissions from the energy sector, which is undoubtedly due to its response in providing electricity and energy for the rapidly growing world population.