Carbon dioxide released from burning fossil fuels is the largest contributor to U.S. greenhouse gas emissions. The Energy Information Administration has just released its analysis of carbon dioxide emissions for 2015 and reports that after a slight uptick in 2013 and 2014 energy-related emissions have again fallen. The agency notes, "U.S. energy-related carbon dioxide emissions were 12% below the 2005 levels, mostly because of changes in the electric power sector." The agency further notes that most of the reductions have occurred as a result of switching from coal to natural gas to generate electricity. Overall, the EIA reports that "the fuel-use changes in the power sector have accounted for 68% of the total energy-related CO2 reductions from 2005 to 2015." The bottom line is that this reduction in carbon dioxide emissions results largely from cheap natural gas from shale produced by horizontal drilling combined with fracking.
More good news: Companies are wringing more and more value out of each unit of energy consumed and each ton carbon dioxide emitted. The EIA reports that "on a per-dollar of gross domestic product (GDP) basis, in 2015, the United States used 15% less energy per unit of GDP and produced 23% fewer energy-related CO2 emissions per unit of GDP, compared with the energy and emissions per dollar of GDP in 2005."
Warmer winter weather also contributed to lower emissions as Americans burned less fuel to keep themselves comfortable. Interestingly, I reported earlier that a new study has concluded that climate change so far appears to be making the weather more pleasant for most Americans.
While U.S. carbon dioxide emissions from declined by 12 percent, the Environmental Protection Agency reports that as of 2014 overall greenhouse gas emissions, including methane, nitrous oxide, fluorinated gases, are only about 9 percent lower than they were in 2005. The Obama Administration has promised the United Nations that the U.S. will cut by 2020 its greenhouse gas emissions by 17 percent below their 2005 levels. And by 2025, U.S. emissions are supposed to fall by 26 to 28 percent below their 2005 levels.