Natural Gas From Shale as “Bridge Fuel” Would Worsen Climate Change

by Duane Nichols on January 25, 2012

Cornell University

Instead of being a “solution” to climate change, natural gas extracted from shale is a huge contributor of greenhouse gases when both methane and carbon dioxide are considered, according to a major new study by three Cornell University researchers. Methane, which is a far more powerful greenhouse gas than carbon dioxide, is the culprit, according to the new report.

The study titled  “Venting and Leaking of Methane from Shale Gas Development,” has been prepared by Professor Robert Howarth and Renee Santoro, of the  Department of Ecology & Evolutionary Biology at Cornell University, and  Anthony Ingraffea, a Professor in the School of Civil and Environmental Engineering at Cornell. It has been accepted for publication in Climatic Change and available online now at:

Professor Howarth said:   “We believe the preponderance of evidence indicates shale gas has a larger greenhouse gas footprint than conventional gas, considered over any time scale.  The greenhouse gas footprint of shale gas also exceeds that of oil or coal when considered at decadal time scales, no matter how the gas is used.  We stand by the conclusion of our 2011 research:  ‘The large [greenhouse gas] footprint of shale gas undercuts the logic of its use as a bridging fuel over coming decades, if the goal is to reduce global warming.’” 

{ 2 comments… read them below or add one }

Duane January 25, 2012 at 11:27 pm

Anthony Ingraffea, Dwight C. Baum professor, School of Civil and Environmental Engineering, Cornell University, said: “Can shale-gas methane emissions be reduced? Clearly yes, and proposed EPA regulations to require capture of gas at the time of well completions are an important step. Regulations are necessary to accomplish emission reductions, as economic considerations alone have not driven such reductions. And it may be extremely expensive to reduce leakage associated with aging infrastructure, particularly distribution pipelines in cities but also long-distance transmission pipelines, which are on average more than 50 years old in the U.S. Should society invest massive capital in such improvements for a bridge fuel that is to be used for only 20 to 30 years, or would the capital be better spent on constructing a smart electric grid and other technologies that move towards a truly green energy future?”


Dee Fulton January 26, 2012 at 12:08 pm

The first paragraph of the abstract makes the claim that this study rebuts the study of fellow Cornell professor Cathles and explains the defects in the Cathles study. “In April 2011, we published the first comprehensive analysis of greenhouse gas (GHG) emissions from shale gas obtained by hydraulic fracturing, with a focus on methane emissions. Our analysis was challenged by Cathles et al. (2012). Here, we respond to those criticisms. We stand by our approach and findings. The latest EPA estimate for methane emissions from shale gas falls within the range of our estimates but not those of Cathles et al, which are substantially lower. Cathles et al. believe the focus should be just on electricity generation, and the global warming potential of methane should be considered only on a 100-year time scale. Our analysis covered both electricity (30% of US usage) and heat generation (the largest usage), and we evaluated both 20- and 100- year integrated time frames for methane. Both time frames are important, but the decadal scale is critical, given the urgent need to avoid climate-system tipping points.


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