Methane reduction might slow warming
Rice paddies in Yunnan Province, China. Rice farming is one of several human activities that release methane, which is thought to contribute by as much as a third to all climate warming from greenhouse gases. (Changsheng Li)
JB: This is Earth and Sky. Most climate scientists agree that one of the largest contributors to global warming is carbon dioxide – or CO2.
DB: Now a study has shown that methane might be responsible for a third of all climate warming from greenhouse gases. Dr. Drew Shindell is a climatologist at NASA’s Goddard Institute for Space Studies in New York. He and his colleagues used computers to determine the impact of different gases on Earth’s climate. He said methane’s effect is now known to be greater because some methane reacts with other chemicals to produce yet another greenhouse gas – ozone.
JB: Some methane in our atmosphere is released by bacteria in wetlands. But much of it comes from human activities such as livestock farming, oil and gas drilling, rice farming and landfills. Environmental treaties have focused on curbing CO2 emissions as a way to reduce global warming. But Drew Shindell thinks we should also focus on methane.
Drew Shindell: Cleaning up methane gives you a reduction in worldwide ozone in the lowest level where it’s a toxic respiratory irritant for people and bad for crop yield and ecosystems in general and it helps reduce climate warming.
DB: Unlike C02, methane that’s captured before it reaches the atmosphere can be sold – and later used as a source of energy.
_JB: Methane capture and resale is already generating energy and revenue at some landfills. Our thanks today to NASA explore, discover, understand. We’re Block and Byrd for Earth and Sky.
For a breakdown of how much methane is produced by different natural and man-made sources in the U.S., visit this EPA website.
Download a PDF copy of Drew Shindell’s methane and climate study.
Satellite measurements of methane emissions. Blue areas have the lowest emissions; yellow and green areas are mid-range; and pink areas have the highest emissions. The measurements were collected from August through November 2003. Source: Assessing Methane Emissions from Global Space-Borne Observations, by C. Frankenberg, J. F. Meirink, M. van Weele, U. Platt, and T. Wagner, Science, 13 May 2005: 1010-1014.
Our thanks to:
Dr. Drew Shindell
NASA Goddard Institute for Space Studies
New York, NY
Additional Teacher Resources
EPA: Landfill Methane Outreach Program
EPA created the Landfill Methane Outreach Program (LMOP) in 1994 to significantly reduce methane emissions from municipal solid waste (MSW) landfills by encouraging the use of landfill gas (LFG) for energy, which has the added benefit of offsetting the use of fossil fuels such as coal and natural gas. Since the programs inception, LMOPs efforts have reduced landfill methane emissions by over 24 million metric tons of carbon equivalent (MMTCE). The greenhouse gas reduction benefits are equivalent to having planted 24 million acres of forest or removed the annual emissions from 17 million vehicles.
NASA: Methane Impacts on Climate Change May Be Twice Previous Estimates
Scientists face difficult challenges in predicting and understanding how much our climate is changing. When it comes to gases that trap heat in our atmosphere, called greenhouse gases (GHGs), scientists typically look at how much of the gases exist in the atmosphere
