The decreases in the United States’ carbon dioxide emissions are due mainly to the economic recession, not a switch away from coal use, a new study concluded.
The study published Tuesday in Nature Communications said that although the 11 percent drop in carbon emissions from 1997 to 2013 has largely been attributed to increased use of natural gas, such a conclusion is purely speculative.
“In our results, natural gas plays a bit part in decreasing emissions,” Steven Davis, a University of California Irvine professor who co-authored the study, said in a statement.
“The real heroes are consuming less stuff and using energy more efficiently,” he said.
Researchers found that a large, 10 percent drop in carbon from 2007 to 2009 accompanied dramatic changes in how Americans consumed products and energy, and various changes to manufacturing and other energy-intensive industries.
Those changes accounted for about three-quarters of the carbon decrease between 1997 and 2013, while changes in the mix of electricity fuel accounting for only 18 percent, the study found.
“Lots of people are enthusiastic about the fact that we suddenly have affordable and abundant supplies of natural gas, including many who are concerned about the climate,” Davis said. “Our study shows the overriding importance of other factors and warns against wishful thinking.”