What's less clear is how much GHG is emitted on the way to power plants during natural gas development, production, transportation and storage. With differing methods and many more measurement points, estimates of pre-plant natural gas leakage rates vary widely, from 0.7%-2.6%.

The main component of natural gas is a compound called methane. Compared to carbon dioxide, methane has more warming potential but leaves the atmosphere much sooner. The higher the methane leakage rate, the lower the GHG advantage natural gas has for power generation.

Natural gas leakage is a perfect example of a sustainable development challenge: it increases greenhouse gas emissions, causes people concern and costs the company lost revenue. We don't want any of those things to happen. When properly contained, natural gas is a useful and valuable product. That's why small releases of natural gas are known as 'fugitive emissions' because we want to capture them rather than let them escape. It's not good for the environment. It's money disappearing into thin air. And it's something we take seriously.

So what can we do about it? We've already taken several steps:

  • In 2000, we joined the United States Environmental Protection Agency's Natural Gas Star program, a voluntary partnership that works cooperatively to reduce natural gas leakage.
  • We were one of the first companies to apply technology to reduce natural gas emissions when drilling shale gas wells. Since implementation in the United States in 2007, this "green completions" technology has already captured 3 BCF of natural gas that would have been released or flared.
  • In 2008, we implemented a Climate Change Action Plan with goals to reduce venting and flaring of natural gas, and to share best practices across the company. From 2009-2012, we reduced or avoided GHG emissions averaging 912,000 metric tons of CO2(e) per year from projects including reduced venting and flaring.
  • In 2013 we updated our plan with the release and flaring of natural gas as one of the continuing key focus areas.
  • This year, along with other industry partners, we are participating in the second phase of an important University of Texas study focused on collecting more data on methane emissions from liquids unloading and conducting further study of pneumatics devices. This scientific peer-reviewed study is expected to be published in 2014.

ConocoPhillips monitors and participates in many other studies to understand greenhouse gas emissions from natural gas production and use. We have teamed up with academics, industry, consultants and non-governmental organizations to learn more. For example, the company took part in a major study published by the Joint Institute of Strategic Energy Analysis in November 2012. This study found that greenhouse gas emissions from 16,000 shale gas sources in the Barnett Shale area amounted to less than half of those from coal when these fuels were used for electricity generation.

We also joined with many other industry members in a study of 91,000 wells operated by 20 companies across the United States. This study found that natural gas leakage volume was 53% less than the Environmental Protection Agency's estimate of 2%.

Better data helps us manage GHG challenges better. We're glad to have and share this information. Our results are posted on our Power in Co-operation website in a fact sheet – 'Natural Gas and GHGs'

For further information on regulation, standards, the life-cycle, and studies regarding the development of natural gas please consult the following: Natural Gas Studies