Thursday, October 2, 2014

CO2 Emissions in the U.S. are Rising

As delegates gathered for the United Nations Climate Summit, both the U.S. Energy Information Agency and the Global Carbon Project released their carbon dioxide (CO2) emissions data for the first half of 2014. The data from the Global Carbon Project projects that for 2014 37.0 ± 1.9 Giga metric tons of CO2 , will be released into the earth’s atmosphere. That is a 2.5% increase over last year and a 65% increase over 1990 CO2 emission levels. The top four emitters of CO2 in 2014 are expected to be the same as in 2013 when the share of emissions was: China at 28%, the United States at 14%, the European Union at 10% and India at 7%.
data from EIA

The EIA data shows that for the first half of 2014 carbon dioxide (CO2) released into the atmosphere in the United States increased by 2.7% over last year continuing the upward trend in CO2 emissions which were at their lowest in 2012. As can be seen in the graph above and chart below, there has been a general downward trend in CO2 emissions since 2007 in all sectors of the economy. (Please note that both the residential sector and industrial sector include part of the electrical generation emissions so that the parts add up to more CO2 than the total emission from the economy. The chart includes the commercial sector and removes the mixed sector electrical category.) Though overall emissions of CO2 in the United States have fallen 10.4% since 2007 and that is generally true in all sectors of the economy; the largest share of reduction in CO2 emissions was from reduction in emissions from electrical generation which have fallen 15% over the period. Over the same period, CO2 emissions from burning coal in manufacturing, transportation, and industry are down 21%. However, CO2 emissions from burning coal are up 3.25% in the first 6 months of this year and emissions from burning natural gas are up 4.9%. The increase in natural gas appears to be divided fairly evenly among the commercial, industrial and residential sectors.
data from EIA

Electricity generation accounts for approximately 38% of the CO2 emission in 2013 down from 40% in 2007. In 1990 electricity generation accounted for only 36% of the total U.S CO2 emissions. In 2013 the industrial sector accounted for 28% of all CO2 emissions, but back in 1990 industry accounted for 34% of total CO2 emissions. Back in the days when I was a plant engineer, the industrial sector accounted for 40% of all CO2 emissions. Over this period the industrial output has not shrunk, but the labor and energy inputs to industry have shrunk and production has surged and fallen with  recessions as can be seen in the chart from the Federal Reserve.
US industrial production from the Federal Reserve

 As you can see in the chart to the left the CO2 emissions from the generation of electricity have fallen since 2005. A portion of the reduction in CO2 emissions was from the reduction in power generation, the rest was due to a change in the mix of fuels used to produce the electricity and the increase in power produced by renewable energy. As can be seen in the chart below power generation from renewable sources increased by 241% since 2007, but represent only 6% of the power generated in the united states. The big change was the move away from coal to natural gas. Coal fell from 48% of generation in 2007 to 39% of generation in 2013. While natural gas increased from producing  22% of  electricity in 2007 to 27% in 2013.

from EIA

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