Thanks to the natural gas boom, carbon dioxide emissions dropped in the United States. But those emissions savings were probably completely undone thanks to U.S. coal exports.
That’s the finding from new research by CO2 Scorecard, which looked at how the U.S. coal industry increase its exports in order to deal with the rise of natural gas in the nation’s power market.
Many, including the White House, have touted natural gas as a “bridge fuel” to renewable power, since burning it only releases about half the carbon emissions as coal. One problem with this argument is methane leaks, which could make natural gas every bit as bad as coal in terms of climate change. But even if the leaks aren’t an issue, the coal that natural gas replaces in the U.S. would need to stay in the ground for the climate to benefit.
According to CO2 Scorecard, that didn’t happen. Instead, the coal just went to other countries.
The researchers used data from the Energy Information Agency (EIA) to tease out how much coal-fired generation was displaced by natural gas versus other sources of electricity from 2007 to 2012. They then looked at how U.S. exports of coal behaved over the same period. From 2002 through 2006, those exports remained relatively steady. But then they spiked after 2007, following the arrival of America’s natural gas boom:
CREDIT: CO2 Scorecard
Specifically, the researchers calculated that the rise of natural gas in America’s energy mix cut our carbon emissions by 86 million tons over that time period. But the spike in exports increased carbon emissions from U.S. coal burned abroad by around 149 million tons.
As CO2 Scorecard notes, U.S. coal is relatively cheap on the global market. So it’s possible coal exports from other countries declined in reaction because they couldn’t compete. Unfortunately, EIA data also shows that global coal consumption rose steeply over the 2007-2012 time period, suggesting the primary effect of U.S. coal exports was to drive down the fossil fuel’s global price and encourage demand.
CREDIT: Energy Information Agency
Overall, this is a reminder that fossil fuel consumption and carbon dioxide emissions are a global problem requiring a coordinated and international solution. The Obama Administration hopes the carbon dioxide regulations the Environmental Protection Agency is prepping for the nation’s power sector will earn it the goodwill and political capital with other countries to push for more aggressive international action.
But what will eventually be needed is interlocking efforts to cut carbon emissions among all countries. The CO2 Scorecard study suggests the use of border taxes to raise the price of U.S. coal exports on the global market. And another paper by a group of climate scientists at the end of last year proposed a bilateral agreement by China and the U.S. to establish a carbon tax in both countries, and then impose import taxes on products from countries without a carbon tax to encourage the policy to spread.