Human Dimensions of Global Warming



To understand emissions sources, it's useful to categorize those emissions.  One such way to do that is by sector.  This lesson is going to look specifically at Energy, which is the biggest source of anthropogenic GHG emissions (by far!).  More specifically, we are going to break down energy into a few subcategories:  power generation, transportation, and industrial processes, as shown below. This lesson, we'll be focusing on the subset of that big almost-the-whole-piece-of-the-pie energy sector.

pie chart depicting sectoral contributions to global GHGs with an inset further describing subcategories of energy sector
This pie chart illustrates GHG emissions by sector and calls out specifically the contributing sources within the energy sector.
Click here for a text alternative to the figure above
GHG Emissions By Sector
Sector Percentage
Energy 72%
Agriculture (MtCO2e) 11%
Industrial (MtCO2e) 6%
Land Use Change and Forestry (MtCO2e) 6%
Waste (MtCO2e) 3%
Bunker Fuels(MtCO2e) 2.2%

The Break Down of GHG Emissions in the Energy Sector
Source Percentage
Electric and Heat (MtCO2e) 31.0%
Transportation (MtCO2e) 15%
Manufacturing and Construction (MtCO2e) 12.4%
Other Fuel Combustion (MtCO2e) 8.4%
Fugitive Emissions (MtCO2e) 5.2%
Source: Climate Analysis Indicators Tool by the World Resources Institute, 2017 is licensed under CC BY 4.0

Energy use and consumption produce more GHG emissions than any other realm of human endeavor. A brief look at the socioeconomic drivers of energy use and consumption helps explain some of the reasons why. Current technologies for generating energy focus on GHG-intensive fossil fuels; the economic system favors producing the greatest amount of energy at the lowest cost and does not account for the environmental costs of energy production; political and legal institutions promote and protect fossil-fuel industries and typically fail to foster alternative energy sources adequately, and Western lifestyles are energy-intensive but many non-Westerners aspire to a Western lifestyle. Add to that the exponential growth of Earth’s human population and it is no wonder that GHG emissions continue to grow rapidly.