Cornell vs. Cornell: Turns out shale gas emissions really are lower than coal

A Cornell University study came out last spring with what many thought was an unbelievable finding that lifecycle emissions from shale gas could be higher than those of coal.

A subsequent Cornell University study has shown that finding really was unbelievable.

This subsequent study, recently published by Professor Lawrence Cathles and his colleagues at Cornell, criticizes the methodology and findings of last year’s study by Cornell Professor Robert Howarth and his colleagues.

In the journal Climatic Change (where the first study by Howarth was published), Cathles lays out several fundamental errors that led Howarth to unreliable conclusions about the emissions from shale gas production:

“[Howarth et al.’s] analysis is seriously flawed in that they significantly overestimate the fugitive emissions associated with unconventional gas extraction, undervalue the contribution of “green technologies” to reducing those emissions to a level approaching that of conventional gas, base their comparison between gas and coal on heat rather than electricity generation (almost the sole use of coal), and assume a time interval over which to compute the relative climate impact of gas compared to coal that does not capture the contrast between the long residence time of CO2 and the short residence time of methane in the atmosphere.”

By “using more reasonable” data, Cathles and his colleagues confirm that “gas has less than half and perhaps a third the greenhouse impact as coal. Since gas also possesses other important emission advantages such as no particulates, SO2, NO2, or ash, it is clearly the ‘cleaner’ option in comparison to coal.”

Researchers at Carnegie Mellon came to a similar conclusion back in August in their study on the emissions from Marcellus Shale production. Their study found that preproduction emissions “are not substantial contributors to the life cycle estimates” – making Marcellus Shale gas essentially the same as conventional natural gas, which emits about 50 percent fewer emissions than coal when used for power generation.

Clearly, Howarth’s flawed findings about shale gas emissions were the anomaly. But you wouldn’t have known it from the media coverage. Howarth’s study received an avalanche of coverage, including articles in the New York Times, Washington Post and Wall Street Journal. Their stories fueled critics of hydraulic fracturing throughout the summer.

Meanwhile, the major news outlets that covered the Howarth study largely ignored Carnegie Mellon’s, which only garnered the attention of local outlets like the Pittsburgh Post-Gazette and West Virginia Gazette.

We weren’t the only ones who noticed this glaring disparity in how the media covered the two studies. Surveying U.S. media coverage on hydraulic fracturing, George Mason University professor Robert Lichter found that, by a ratio of 12 to 1, major media outlets reported on the negative Cornell study while ignoring Carnegie Mellon’s.

We’ve called out some of the deficiencies in coverage of shale gas issues by some media outlets before. Even the public editor of the New York Times said one of the Times’ stories about shale gas was “out on a limb” with questionable sourcing and little context.

Just last week, however, the Cathles research showing lower emissions for shale gas did receive some attention – but mainly because Howarth issued a response saying he stands by his findings.

Cathles isn’t the only one who has refuted Howarth’s findings. Check out this report from the experts at IHS CERA for analysis of the flaws in Howarth’s approach, plus more details about how natural gas wells are drilled. Take a look at the Carnegie Mellon study as well.

And by all means read the research by Professor Cathles at Cornell. His findings are the latest in the mounting evidence that Howarth’s “seriously flawed” study was the exception, not the rule.