Natural Gas Not Climate Savior

Emissions databases underestimate the methane released from fossil-fuel extraction in the U.S. Southwest, a new study concludes. The news comes as other studies document that increased use of natural gas may not mitigate climate change and that low-carbon technologies benefit the environment.

“A global gas boom is not a replacement for energy and climate policies,” write Steven J. Davis and Christine Shearer of the University of California, Irvine, in commentary accompanying one paper.

The area where Arizona, New Mexico, Colorado, and Utah meet is known for fuel extraction and processing. A team led by Eric A. Kort of the University of Michigan, Ann Arbor, has now used satellite-based observations to determine that actual methane emissions in that region are about 2 to 3.5 times more than estimated (Geophys. Res. Lett. 2014, DOI: 10.1002/2014gl061503).

The results underscore the need to more accurately measure emissions from fossil-fuel extraction to assess mitigation strategies, Kort and colleagues say.

In a separate study, researchers led by Haewon C. McJeon of Pacific Northwest National Laboratory looked at the effects of low-cost, abundant natural gas in an integrated global energy, economic, and climate model (Nature 2014, DOI: 10.1038/nature13837).

A switch from coal to natural gas cuts carbon emissions, McJeon says, but if the fuel is low-cost and abundant, it displaces not just coal but also low-carbon energy technologies, such as solar and wind. All said, more natural gas use will not reduce global warming.

Low-carbon energy has its trade-offs, such as emissions from mining and manufacturing materials, but on balance it’s better than fossil fuels, says a third study. A team led by Thomas Gibon and Edgar G. Hertwich at the Norwegian University of Science & Technology conducted global, long-term life-cycle assessments of low-carbon systems (Proc. Natl. Acad. Sci. USA 2014, DOI: 10.1073/pnas.1312753111). They found that implementing such systems at large scale could double the world’s electricity supply by 2050 while stabilizing or decreasing pollutant emissions.