A power plant that runs on natural gas emits fewer greenhouse gasses than one that burns coal. Does that mean that natural gas is a key part of the solution to the climate change dilemma?
According to the latest scientific research, it turns out that natural gas has only a small a role to play in reducing climate change, if any. Understanding why requires us to take a look at the whole process of generating power from natural gas, from extraction to electrical generation.
First, the process of natural gas extraction releases a significant amount of methane into the atmosphere. The U.S. EPA evaluates the Global Warming Potential (GWP) of many kinds of pollutants over time.
If a pollutant has a GWP of 1, it means that every pound of that pollutant will contribute to global warming as much as 1 pound of CO2. If a pollutant has a GWP of 20, one pound of that pollutant will contribute to global warming as much as 20 pounds of CO2. Over a 100-year time period, methane has a GWP of 20 — meaning that it is 20 times more potent than CO2 as an agent of climate change. (See Intergovernmental Panel on Climate Change, page 212.)
Methane emissions from the fracturing process will be reduced as U.S. EPA rules come into effect that that will require drilling companies to capture “fugitive emissions” that escape from the well after fracturing is completed, but before the infrastructure to capture gas and pipe it off for sale is installed.
Nonetheless, emissions of other greenhouse gasses will persist at all stages of the process of extracting, refining, transporting, and finally burning natural gas. And the process of building natural gas power plants and refineries will require significant additional greenhouse gas emissions, all while our current coal fleet stays online.
All together, scientific models predict that it could easily take more than 50 years for us to see any significant benefit from transitioning a substantial part of our coal infrastructure over to natural gas. And 50 years from now, we will either be heavily utilizing low-emissions renewable energy or suffering the consequences.
That is why we need a firm commitment to renewable energy and energy efficiency. While natural gas may make a small contribution towards reducing long-term emissions, these renewable resources are the only way that we are likely to make any significant reduction to climate change.