Additional info from The Fletcher Forum
You’ve probably heard at some point that natural gas is 50% cleaner or has half the carbon pollution as coal. This is misleading. While it is true that burning the same amount of natural gas and coal results in lower carbon dioxide emissions from the former, combustion is only the final stage of the natural gas lifecycle. There are significant global warming impacts from previous stages that are glossed over when looking only at combustion.
Chiefly, the problem is methane, a global warming gas over 34 times better at trapping heat than carbon dioxide over the course of a century. In a shorter, 20-year timeframe, methane has nearly 86 times the global warming potential as carbon dioxide. The shorter window is key because science overwhelmingly indicates that we have to sharply reduce global warming pollution within the next decade to have good odds of curbing runaway climate change and keeping the temperature increase to a level that could avert the most devastating consequences.
Natural gas is primarily methane. Some of this methane leaks out during the extraction of natural gas, i.e. during hydraulic fracturing of the shale rock holding the deposits (“fracking”). Specifically, when “fracking” fluid rises back to the surface from natural gas wells, dissolved methane in it escapes. Methane also leaks from pipelines. Science shows that if the leakage rates are above 3.2%, then natural gas is just as bad for climate change as coal. While industry-wide measures for leakage rates are scanty, leakage rates are estimated at anywhere between 2 and 8 percent. As more data emerges, it appears leakage rates are actually at the higher end of this range. Some researchers warn that even if leakage is reduced, increasing our reliance on natural gas could still have a worse impact than coal. In fact, the International Energy Agency (IEA) observed that even with a host of best practices, a natural gas boom will result in temperature rise this century of about 3.5 degrees Celsius, nearly twice the warming we’ve already experienced and are starting to see impacts from.
Currently, one of the most worrying impacts of natural gas is that its cheap prices have made it harder for low-carbon energy to compete in the market. Instead of an expansion in renewables like solar and wind, investment is growing in natural gas, keeping our infrastructure further locked into a carbon-based energy source. Bear in mind that this discussion of natural gas and climate change did not even touch on the other hugely damaging impacts of fracking, including freshwater depletion (fracking a single well requires two to five million gallons of water; America already has over half a million natural gas wells, including in water-scarce regions), water contamination, toxic waste, and disruption of local communities by industrial incursion.
All of this means we should not look to natural gas as a tool to mitigate global warming. The good news is that we have proven technologies that are cleaner, and we need to ramp those up immediately. Building the natural gas “bridge” does not get us to where we want to be in terms of curbing climate change, and instead could lock us into carbon-based infrastructure for decades. We must recognize that fossil fuels such as natural gas are yesterday’s story. To safeguard tomorrow we quickly need to replace high-risk 20th-century habits with smart 21st-century solutions.
A version of this article was originally published by The Fletcher Forum of World Affairs.