ad info

 Headline News brief
 news quiz
 daily almanac

 video archive
 multimedia showcase
 more services

Subscribe to one of our news e-mail lists.
Enter your address:
Get a free e-mail account

 message boards

CNN Websites
 En Español
 Em Português


Networks image
 more networks

 ad info



Don't forget methane, climate experts say

Landfills are a major source of man-made methane, a significant greenhouse gas.
Landfills are a major source of man-made methane, a significant greenhouse gas.  

November 10, 1999
Web posted at: 11:41 a.m. EST (1641 GMT)

The inclusion of methane, the primary component in natural gas, in emission strategies is key to curbing global warming, according to a team of atmospheric scientists, economists and emissions experts. The scientists found that by including methane in abatement strategies, the costs of meeting United States emission-reduction targets could be lowered.

"In our study, we assessed the potential cost savings of introducing an additional greenhouse gas, methane, into a carbon dioxide emission-reduction strategy," said Katharine Hayhoe, a researcher in atmospheric sciences at the University of Illinois and the lead author of a report published in the Oct. 29 issue of the journal Science. "We estimate that for short-term targets, methane can offset carbon dioxide reductions and reduce U.S. abatement costs by more than 25 percent compared to strategies involving carbon dioxide alone."

Saving the environment

Global Climate

Because methane remains in the atmosphere about 12 years, a short time compared to other greenhouse gases, concentrations will respond quickly to emission reductions, producing an immediate and significant impact on climate change, said Atul Jain, a University of Illinois atmospheric scientist. It takes carbon dioxide, the top human-caused greenhouse gas, anywhere from 50 to 200 years to disappear from the atmosphere.

"Methane is the second-most important greenhouse gas. Together, methane and other non-carbon dioxide gases are currently responsible for about 40 percent of the global warming problem," said Don Wuebbles, a University of Illinois professor of atmospheric sciences. "However, reducing carbon dioxide emissions is still the primary means of achieving significant long-term mitigation of climate change."

Over the last two centuries, methane concentrations in the atmosphere have more than doubled, largely due to human-related activities, according to the U.S. Environmental Protection Agency.

World leaders established the Kyoto Protocol in 1997 to create standards to stabilize six greenhouse gases in order to lessen global climate warming. Members of the industrialized world committed to improving emissions based on a five-year budget period from 2008 to 2012. The targets cover emissions from carbon dioxide (CO2), methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride.

Cattle and other livestock contribute significantly to methane emissions.  

The United States has not agreed to the terms of the protocol. However, using the latest carbon dioxide and methane abatement costs for the United States, the scientists showed that a control strategy for both methane and carbon dioxide could meet the protocol's target and timetable at a lower overall cost when compared with previous estimates that account for carbon dioxide only.

Cost is based on the amount of 1992 dollars needed to achieve emission reductions through implementing various technological options, said Hayhoe.

Methane is naturally occurring, but human-related activities such as fossil fuel production, animal husbandry (digestive processes of ruminant livestock and manure), rice cultivation, biomass burning and waste management release significant quantities of methane into the atmosphere. Methane's natural sources include wetlands, natural gas and permafrost.

Landfills, coal mining, livestock, manure and the production and transmission of natural gas are the five major sources of human-produced methane in the United States. A significant amount of these emissions can be reduced by applying available and economically worthwhile options such as capturing the methane and recovering the cost of the emission-reduction technology by selling the gas or using it to substitute for other energy inputs, according to the scientists.

"Methane is produced by several sources where gas can be contained and measures can be taken to prevent it from being released to the atmosphere," said Hayhoe. "For example, cattle manure can be collected and placed in a (closed) digestor. As anaerobic decay occurs, methane is produced. This methane can be removed from the digestor and used to generate electricity."

By capturing methane lost during normal operations, companies can benefit by using this fuel source onsite, selling it to utilities, or selling it directly to end users while benefiting the environment. Many U.S. industries are participating in voluntary programs with the EPA to target methane emissions.

Collaborators on the study included Hugh Pitcher and Chris MacCracken of the Pacific Northwest National Laboratory, Reid Harvey and Dina Kruger of the U.S. Environmental Protection Agency and Michael Gibbs of the ICF Kaiser Consulting Group.

Copyright 1999, Environmental News Network, All Rights Reserved

Study hints at extreme climate change
October 28, 1999
Nations meet again to battle global warming
October 25, 1999
Nations meet again to battle global warming
October 25, 1999
Differences mark global warming summit start
October 25, 1999
NASA images show shrinking ozone hole
October 1, 1999
Fire's role in global warming studied
September 27, 1999
Global warming unpredictable, scientists say
September 20, 1999

U.S. energy activists propose lofty goals
Most abundant greenhouse gas, focus of talks
Global warming unpredictable, scientists say
It's time to phase out coal, group says
Telling the 'global warming' tale
Global warming ad blitz under way
Note: Pages will open in a new browser window
External sites are not endorsed by CNN Interactive.

Committee for the National Institute for the Environment - CNIE
  •Global Climate Change Treaty: The Kyoto Protocol
U.S. Global Change Research Program
Consumer Alert Global Warming Information Page
Global warming cost
NCPA Environmental Policy Idea House
Science Magazine
University of Illinois at Urbana-Champaign
Climate Change - Methane and Other Greenhouse Gases
EPA Global Warming Site
Note: Pages will open in a new browser window
External sites are not endorsed by CNN Interactive.

Enter keyword(s)   go    help

Back to the top   © 2001 Cable News Network. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines.