The previous post reported that total U.S. GHG emissions declined by 1.6% in 2011, the last year for which data has been published. There is no way, however, to compare total GHG emissions among the states. The closest one can come is to compare carbon dioxide emitted by the combustion of fossil fuel. CO2 is the most important greenhouse gas, and the combustion of fossil fuel is the most important emitter of CO2, accounting for 79% of all U.S. GHG emissions.

The first chart at right shows United States CO2 emissions from combustion of fossil fuel from 1990 to 2011. This data is calculated from energy consumption data, which I reported in a series of posts starting here. The energy and CO2 series are similar, but not identical, as GHG emissions depend not only on the amount of energy consumed, but also on the type of fuel.

(Click on chart for larger view.)

First, total emissions have grown by about 8.4% since 1990. They peaked in 2007, and have declined about 8.6% since then.

Second, electricity generation accounts for the largest portion of emissions, some 38.4% in 2011.

Third, the Commercial Sector accounts for less than 5% of CO2 emissions in this series, where it often accounts for a larger fraction in other GHG inventories. The emissions attributed to electricity generation in this inventory are for electricity consumed in other sectors, and most, if not all, of the discrepancy would disappear if it were distributed out to its end use.

Fourth, the fraction accounted for by each sector has changed over the years. Electricity generation has risen from 35.6% in 1990 to 38.4% in 2011. Industrial, on the other hand, has declined from 21.9% to 17.6%.

The second chart at right shows Missouri CO2 emissions from combustion of fossil fuel from 1990 to 2011.

(Click on chart for larger view.)

First, Missouri CO2 emissions grew by about 32.1% between 1990 and 2011 (compared to only 8.6% nationally).

Second, electricity generation accounts for an even larger percentage of emissions here than it does nationally – 55.0%, more than all other sources combined.

Third, in 2011 the Commercial Sector accounted for less than 3.0% of emissions, even less than it did nationally. As above, CO2 is emitted when fossil fuel is burned to generate electricity that is consumed in other sectors, and if the emissions were distributed to their end-use sector, the data would look quite different.

Fourth, the fraction accounted for by each sector has changed even more than it has nationally. Commercial, industrial, residential, and transportation emissions have all declined, while emissions from the generation of electric power have increased by 63%!

The very first post in this blog reported on the 1990 Missouri GHG inventory, which reported data on CO2 emissions from fossil fuel combustion. Those data align with the data in this report pretty well. From the Missouri inventory I was able to construct a chart that distributed GHG emissions to their end-use sector, and I’ve reproduced the chart here for comparison purposes.

(Click on chart for larger view.)

With emissions distributed to their end use, transportation emerged as the largest source of GHG emissions in the state.

The data suggest that nationally in 2011 CO2 emissions came primarily from the combustion of fossil fuel. They have grown significantly since 1990. Economic downturns cause CO2 emissions to decline, but policy initiatives are probably also causing them to decline. In Missouri, our emissions have grown at a rate almost 4 times the national rate.

Sources:

EPA. 2013. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011. EPA 430-R-13-001. EPA » Learn the Issues/Climate Change » Greenhouse Gas Emissions » National Data. http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html.

EPA. 2013. CO2 Emissions from Fossil Fuel Combustion. EPA Home » State and Local Climate And Energy Program » Resources » State Energy CO2 Emissions. http://epa.gov/statelocalclimate/resources/state_energyco2inv.html.

Missouri Department of Natural Resources. 2015. Greenhouse Gas Emission Trends and Projections for Missouri, 1990-2015. http://www.dnr.mo.gov/energy/cc/ghg.htm.