From Fracking to CAFOs, Methane Just Got a Lot Dirtier
It’s day two of the notorious federal government shut down, and some EPA employees may be wondering how to spend their free time. We have an idea for them—they can bone up on the findings of the Intergovernmental Panel on Climate Change (IPCC).
Last week, the committee released the first of several multi-thousand-page reports summarizing all of climate science in one enormous body of work. Surprise! Climate change remains an enormous problem, and natural gas remains a false solution.
We’ve known for a while that oil and gas development and industrialized food production release methane into the atmosphere. But this report states, unequivocally, that methane is significantly worse for the climate than stated in the IPCC’s 2005 report—36 percent worse, to be exact.
Deep in the report, about half way through the 2,216-page document, are updated estimates of so-called Global Warming Potentials (GWPs). These are numbers used to compare the warming effect of different greenhouse gases, relative to the warming effect that carbon dioxide has on our climate. You may have read, for example, that methane is a “potent greenhouse gas.” Using carbon dioxide as a basis of comparison, GWPs are estimates of just how potent.
In 2005, when IPCC last consolidated all of climate science in a single document, the notoriously conservative scientific consensus was that, pound for pound, methane is 25 times as powerful as carbon dioxide at trapping heat over a 100-year time frame. That is to say, methane has a 100-year GWP of 25.
This week, IPCC put that number at 34, an increase of 36 percent. That means the problem of methane emissions from the oil and gas industry, not to mention concentrated animal feeding operations, just got a lot more important. Now IPCC conservatively estimates that, for the 100 years after a plume of methane is released, it has the “carbon dioxide equivalence” of 34 plumes of carbon dioxide (of the same total mass).
We may well hit dangerous tipping points in the stability of our climate in much less than 100 years. It is important to understand the GWP of methane on shorter timeframes, not just the impact over a century. Looking at a 20-year timeframe, IPCC now estimates methane’s GWP is 86. That is, pound for pound, a plume of methane traps 86 times the amount of heat that a plume of carbon dioxide does over the 20 years after the plumes are emitted.
Bizarrely, the U.S. Environmental Protection Agency (EPA) is still using IPCC’s number from 1996! Back then, IPCC put methane’s 100-year GWP at 21. So, one way to think about it is that IPCC now says methane is 62 percent more potent than EPA currently assumes in its annual Greenhouse Gas Inventory. This means that U.S. carbon dioxide equivalent emissions are larger than the agency states, and that methane makes up a much bigger slice of these total emissions. So, using dated estimates of GWP massively understates the problem of methane emissions.
Not to worry, EPA is on top of it! There was a notice in the Federal Register earlier this year announcing that the agency planned to adopt GWPs from IPCC’s 2005 report. No, that is not a typo. The notice announces that EPA will soon adopt the notoriously conservative scientific consensus from 2005, not from this year.
What will it take for EPA to catch up to modern science? Will it really take the agency another decade to adopt the latest estimates from IPCC? Congress should move swiftly to forge an agreement that re-opens the federal government. The EPA has a lot of work to do.