As coal use declines, natural gas appears to be stepping in as the new fuel of choice for new power plants or conversions, at least where it is widely available, as it is here in the US. Indeed, burning natural gas has a significant advantage when it comes to combustion, as shown here on the EEI government website, How much carbon dioxide is produced per kilowatt hour when generating electricity with fossil fuels? According to this site, natural gas produces roughly sixty percent of carbon emissions per kWh compared to coal when combusted. OK, that’s good so far – “what is less harmful, coal or gas?” – clearly its gas.
But there is more to the story – its not just about combustion, apparently, but includes the entire supply chain, where leaks emit dangerous methane into the atmosphere, as this article from the Environmental Defense Fund (EDF) shows: Aliso Canyon leak sheds light on national problem uses a FAQ format to explain the impact of methane on climate change (my bold).
Methane: Potent climate polluter Methane is a strong greenhouse gas that carries 84 times the warming power of carbon dioxide in the initial decades after it is released. “Emitting just a little bit of methane greatly accelerates the rate of climactic change,” says EDF Chief Scientist Steven Hamburg.
How common are methane leaks? Very. Aliso Canyon is a particularly egregious example of a problem that’s happening every day across the country. Our extensive research effort revealed that methane is leaking at every stage of the oil and gas supply chain.
Aliso Canyon is a natural gas well site in Southern California that became notorious in October 2015 when the well sprung a leak and began spewing methane directly into the atmosphere, unchecked for over 100 days, becoming the largest gas leak in US history, as described here: Utility agrees to pay $4 million for massive Aliso Canyon gas leak.
SoCal Gas pleaded no contest to one misdemeanor count of failing to immediately alert state authorities to the leak when it first began in October of 2015, instead waiting days to contact state emergency services. The leak continued for 112 days, releasing 97,100 metric tons of methane into the atmosphere and prompting the evacuation of at least 8,000 residents from the Porter Ranch community. While the storage facility was leaking, it became the largest man-made source of methane in the country, and eventually became the largest gas leak in U.S. history. Methane is 86 times more effective at trapping heat in the atmosphere than carbon dioxide.
One key challenge: leaks are an inherent, unavoidable risk associated with fossil fuel extraction and transportation. So its not just about combustion.
Today, this article caught my eye and led to this post. NASA: Fracking is source of the massive methane “hot spot” in the American Southwest. Here we go again. A key challenge of continued pursuit of fossil fuels to generate electricity is that regardless of fuel choice, there will be emissions, both along the supply chain and when the fuel is combusted. To get serious about climate change, we will need to get serious about pursuing alternatives to any fossil fuels, whether “clean” natural gas, liquid petroleum or coal.