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By Pep Canadell, CSIRO Pep Canadell, CSIRO 8 September 2015 6 min read

The Conversation is fact-checking claims made on Q&A, broadcast Mondays on the ABC at 9:35pm. Viewers can request statements to be FactChecked via Twitter using hashtags #FactCheck and #QandA, on Facebook or by email.

Tom Switzer and Naomi Klein, speaking with Tony Jones on Q&A, August 31, 2015.

TOM SWITZER: Now is as good a time as any to say that the United States didn’t ratify the Kyoto Protocol but its carbon emissions are actually levelling off and it’s due largely not to carbon taxes or cap and trade schemes, which the president’s own party, the Democrats, won’t support in Congress.

TONY JONES: Coal seam gas.

TOM SWITZER: It’s because of coal seam gas. It’s a free market revolution, the coal seam gas.

NAOMI KLEIN: No, it’s not.

TOM SWITZER: Yes, it is.

NAOMI KLEIN: New research has come out and says that the vast majority of that emission reduction came from the economic downturn and only 30% is due to gas.– US Studies Centre research associate Tom Switzer, the presenter of RN’s Between The Lines, speaking with activist and author Naomi Klein and Q&A presenter Tony Jones on ABC TV’s Q&A program, August 31, 2015.

Tom Switzer has clarified via an email to The Conversation that he intended to say “shale gas” before Tony Jones interjected with “coal seam gas”. But even then, his statement is not supported by the most comprehensive attribution analysis to date examining why US emissions declined over the period 2007 to 2013.

Naomi Klein was not right either. She referenced the aforementioned recent analysis but quoted 30% as gas' contribution to the overall emission reduction. The 30% was the contribution of all changes in the energy mix, that analysis found. That figure includes shale gas but also a larger fraction of renewable energies.

What’s happening to US emissions?

Carbon emissions in the US declined by about 11% between 2007 and 2013, as this graph shows.

US agencies, the International Energy Agency (IEA) and the Intergovernmental Panel on Climate Change have all acknowledged the climate benefits of the shale gas revolution over coal. For example, the IEA has noted that

When replacing other fossil fuels, natural gas can also lead to lower emissions of greenhouse gases and local pollutants.

However, the most comprehensive analysis to date on this question – published recently in the journal Nature Communications – found that the decline was largely due to changes related to the global financial crisis.

Gas played a part, but its role was smaller, the study found.

Looking at the data

When asked to provide evidence to support her assertion, a spokesperson for Klein referred The Conversation to the Nature Communications study, authored by a research team led by Kuishuang Feng from the University of Maryland.

This quantitative analysis looked at how US emissions output had been affected by complex factors like economic growth, population growth, changes in the fuel mix, overall consumption, offshoring of emissions-intensive industries, and other structural changes in the economy (such as the trend toward services over manufacturing).

The researchers looked at the period 2007 to 2013 (when US CO2 emissions declined 11%) and found that:

After 2007, decreasing emissions were largely a result of economic recession, with changes in fuel mix (for example, substitution of natural gas for coal) playing a comparatively minor role.

Despite population growth over that period, the researchers found that emissions declined due to a number of factors, including changes in production structure (-6.1%), fuel mix (-4.4%), consumption volume (-3.9%), energy intensity of GDP (-0.5%) and changing consumption patterns (-0.4%).

Contributions of different factors to changes in the US CO2 emissions between 1997 and 2013.

Feng et al, Nature Communications

Thus, fuel mix, which includes increase in shale gas and also increase in renewable energies (among other changes), was responsible for less than one-third of the overall downward trend. Most of the remaining attribution is largely associated with the global financial crisis and some longer-term trends.

Criticism of the study

When asked by The Conversation to provide data to support his statement, Switzer provided several articles and said:

Before I even had a chance to say the shale gas revolution, the moderator Tony Jones interjected and said “coal seam gas” … It suggests that even Tony Jones recognises the merit in my argument. I am on very strong ground. The economic downturn was both temporary and throughout the Western world. But the levelling off in CO2 emissions and sharp decline in emissions per head is peculiar to the US. It is only in the US that there has been the dramatic shift in electricity generation from coal to gas, and this is entirely due to the shale revolution. This is indisputable. I should stress that the moderator Tony Jones interjected with the coal seam gas (comment). I genuinely was about to say shale gas. This is important for your fact checker. They are not quite the same, but both coal seam gas and shale share the key feature of generating only half the carbon dioxide compared with coal when burned.

An article Switzer provided to support his assertion was published by Energy In Depth (launched by the Independent Petroleum Association of America in 2009). It includes quotes from a range of well-informed sources noting the role shale gas has had on reducing carbon emissions such as:

EPA administrator Gina McCarthy has said: “Responsible development of natural gas is an important part of our work to curb climate change.”

Secretary of Energy Ernest Moniz has said: “About half of that progress we have made is from the natural-gas boom.”

Such quotes do not serve as proof or disproof of a robust quantitative attribution analysis that has been peer-reviewed and published by a major journal.

Among several points (including describing the authors of the study as having an anti-fossil-fuel agenda), the critique raises the issue that the analysis extended only to 2013, omitting a full year and half of data – a period in which shale gas has grown even faster.

However, processing energy and greenhouse gas statistics takes some time, and the US Environment Protection Agency in charge of reporting emissions has data only to 2013, the end year of Feng’s analysis.

Interestingly, for the last reported year (2013), US CO2 emissions increased by 2%, and recent estimates from the International Energy Agency show that CO2 emissions in the US continued to increase in 2014.

If shale gas was having an even larger influence on emissions, the opposite trend would be expected.


Tom Switzer’s statement is not supported by the most comprehensive attribution analysis to date examining why US emissions declined.

Naomi Klein incorrectly quoted 30% as the contribution of gas to the overall emission reduction. The 30% was the contribution of all changes in the energy mix, the same analysis found.


The writer has cited recent credible research to, in my view, correctly point to the significant impact of the most recent recession on US CO2 emissions. This work correlates with recent work of Shahiduzzaman and myself, more generally pointing out the asymmetric effect of US business cycle expansions and contractions on emissions.

We found emissions reduce much faster in contractions than they increase in expansions. In addition, in the most recent US expansion, emissions per capita were still lower in October 2013 than they were at the start of the expansion in July 2009, more than four years into the current expansion. This means that it is possible that the recession may have had an impact on emissions well beyond its end.

We also found little evidence to date coming from fossil fuel mix effects. – Allan Layton

Have you ever seen a “fact” that doesn’t look quite right? The Conversation’s FactCheck asks academic experts to test claims and see how true they are. We then ask a second academic to review an anonymous copy of the article.

You can request a check at Please include the statement you would like us to check, the date it was made, and a link if possible.

The Conversation

Pep Canadell, Executive director, Global Carbon Project, CSIRO

This article was originally published on The Conversation. Read the original article.

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