Atmospheric Chemist Daniel Jacob Address the Role of Methane in Greenhouse Gas Emissions and Global Climate Change in Newest Episode of
“Environmental Insights”
Podcast is a production of the Harvard Environmental Economics Program
CAMBRIDGE MA. – Debates about global climate change policy often overlook the role of one very important type of greenhouse gas emissions – methane. Daniel Jacob, the Vasco McCoy Professor of Atmospheric Chemistry and Environmental Engineering at Harvard, shared his perspectives on methane and its sources, transport, and measurement in the newest episode of “Environmental Insights: Discussions on Policy and Practice from the Harvard Environmental Economics Program,” a podcast produced by the Harvard Environmental Economics Program. Listen to the interview here.
Hosted by Robert N. Stavins, A.J. Meyer Professor of Energy and Economic Development at Harvard Kennedy School and director of the Harvard Environmental Economics Program and the Harvard Project on Climate Agreements, Environmental Insights is intended to promote public discourse on important issues at the intersection of economics and environmental policy.
Jacob, an expert and world leader in the development of powerful inverse methods to infer methane emissions from satellite observations of concentrations, explained that methane comes from a variety of sources.
“There's a natural source from wetlands. That's about one third of the total source of methane right now. Two thirds are sources from human activity, and those sources include livestock, and in particular cattle, landfills, wastewater treatment plants, coal mines,… oil and gas operations, and rice paddies,” he remarked.
Jacobs argued that as a greenhouse gas, methane has similar impacts on climate as CO2, but there are very significant differences between the two.
First, methane is a vastly more potent greenhouse gas than CO2. Its global warming potential is about 30 times that of CO2 over a 100-year period and measured over a 20-year period that ratio grows to about 80 times the effect of a unit of CO2. The reason for the difference when measuring impacts over varying time scales is the significant difference in the atmospheric residence times of the two gases.
“Methane has a 10-year lifetime in the atmosphere because it gets oxidized. Whereas CO2 [is more] complicated, but you can think of it as having about a 200-year lifetime,” Jacob explained. “What that means is that methane is responsible more for near term climate change, but also it means that acting on methane can give us a short-term response to climate. So, if we are trying to address climate change over the next decade or two, methane is a very powerful lever.”
Jacob continued, “If I emit methane today in the atmosphere, then after about 10 years it's gone. Which means that a hundred years from now there will be no memory of the climate effect from that methane that I emitted today. Whereas if I emit CO2 today, the effect will linger on for a few centuries.”
Jacob’s work with satellite observations of methane is extremely important, Stavins stated, because under the terms of the Paris Climate Agreement there is a need to accurately assess the national methane inventories that are reported. Accurate measurements are also necessary under the terms of the new Global Methane Pledge, in which 119 countries have agreed to cut global emissions by 30 percent by 2030. But there has been tremendous uncertainty regarding the quantity and location of emissions.
Jacob and his Harvard team use satellite observations of methane concentrations in specific locations at particular points in time, combined with additional information, to infer statistically, geographically, and temporally differentiated emissions patterns.
“[One of the things] we can do uniquely from satellite is…look at recent changes in emissions, because the emission inventories that are coming out of individual countries are based on statistics that will typically be two or three years old,” Jacobs remarked. “But if we're going to try to change the emissions rapidly, and to verify those changes in emissions, the only way that I can think of is to do it from satellites.”
Jacob said his satellite observations research should have substantive impacts on climate policy in the years ahead.
“What I would like to see is that we can contribute to continuous monitoring of emissions, to be able to detect changes in emissions, particularly if those are correctable, and point to the need for action. Say for example, if you have a flare that goes off, we should be able to see it from space, and then be able to take action on that,” he stated.
Jacob’s interview is the ninth episode this year in the Environmental Insights series, with future episodes scheduled to drop each month.
“Environmental Insights is intended to inform and educate listeners about important issues relating to an economic perspective on developments in environmental policy, including the design and implementation of market-based approaches to environmental protection,” said Stavins. “We speak with accomplished Harvard colleagues, other academics, and practitioners who are working on solving some of the most challenging public problems we face.”
Environmental Insights is hosted on SoundCloud and is also available on Amazon Music, iTunes, Pocket Casts, and Spotify.
LINK TO PODCAST:
https://soundcloud.com/environmentalinsights/methane-and-climate-change-policy-a-conversation-with-daniel-jacob/s-AFUxWOtnAo9 OR https://tinyurl.com/3z2ks4vh
TRANSCRIPT OF PODCAST:
https://heep.hks.harvard.edu/files/heep/files/daniel_jacob_podcast_transcript_for_9.8.2022.pdf