Soot from wood stoves in developing world impacts global warming more than expected

October 24, 2006

New measurements of soot produced by traditional cook stoves used in developing countries suggest that these stoves emit more harmful smoke particles and could have a much greater impact on global climate change than previously thought, according to a study scheduled to appear in the Nov. 1 issue of the American Chemical Society journal Environmental Science & Technology.

Perhaps as many as 400 million of these stoves, fueled by wood or crop residue, are used daily for cooking and heating by more than 2 billion people worldwide, according to the study's lead authors, Tami Bond, Ph.D., and doctoral candidate Chris Roden of the University of Illinois, Urbana-Champaign. In a field test in Honduras, the researchers found that cook stoves there, which are similar to those used in other developing nations, produce two times more smoke particles than expected, based on previous laboratory studies. These dark, sooty particles, which are darker than those produced by grassland or forest fires, have a climate warming effect because they absorb solar energy and heat the atmosphere, according to Roden.

In earlier work, Bond estimated that burning firewood -- the principal fuel for cook stoves in the developing world -- produces 800,000 metric tons of soot worldwide each year. In comparison, diesel cars and trucks generate about 890,000 metric tons of soot annually. These two sources each account for about 10 percent of the soot emitted into the world's atmosphere each year, she said.

In addition to its environmental effects, smoke from cook stove fires is a major cause of respiratory problems, eye infections and tuberculosis, according to the researchers.

"Emissions from wood cook stoves affect the health of users -- especially of women and children -- neighborhood air quality, and global climate. Reducing these emissions, through the use of cleaner burning stoves and fuels, should have far-reaching benefits," Bond said.

In the past, scientists have relied on laboratory measures of pollutants from cooking fires because field tests have been difficult to conduct, in part, because of limited access to remote locations and a lack of power to operate the scientific equipment, according to Roden. To get a more accurate measure of the environmental impact of these stoves, Roden and Bond developed a portable battery-operated sampling cart, which includes sensors for measuring carbon dioxide and carbon monoxide, particle soot absorption, particle color and concentration, which they took to Honduras for field tests.

Honduras is typical of Central American countries, where more than 80 percent of families cook their meals over open wood fires, according to Trees, Water & People, an American nonprofit agency which, along with the Honduran Association for Development, helped facilitate this study. In most cases, these families can't afford or don't have access to electricity, gas or alternative fuel sources.

"We expected field measurements to be different from lab measurements, and we suspected the amount of black carbon from these stoves would be higher than open burning, but we were surprised by how much," Roden said.

Trees, Water & People and other nonprofit agencies are distributing new low-cost, wood-burning cook stoves in Honduras and other Latin American countries that appear to be less polluting and more fuel efficient, according to the researchers. However, further analysis is needed.

"Designing and distributing improved cook stoves may be an effective method of mitigating global climate change, and can improve the health of the users," Roden said. "However, the cook stoves must be well designed and properly tested. They must be built with local traditions and practices in mind and must be easy to use, or they may become expensive doorstops."
-end-
The American Chemical Society - the world's largest scientific society - is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

The online version of the research paper cited above was initially published Sept. 27 on the journal's Web site. Journalists can arrange access to this site by sending an e-mail to newsroom@acs.org or calling the contact person for this release.

American Chemical Society

Related Global Climate Articles from Brightsurf:

Global food production threatens the climate
Concentration of N2O in the atmosphere increases strongly and speeds up climate change.

Global food production poses an increasing climate threat
According to the authors of a new study published in Nature, rising nitrous oxide emissions are putting reaching climate goals and the objectives of the Paris Agreement in jeopardy.

Climate-friendly cooling to help ease global warming
A new IIASA-led study shows that coordinated international action on energy-efficient, climate-friendly cooling could avoid as much as 600 billion tonnes CO2 equivalent of greenhouse gas emissions in this century.

Reconstructing global climate through Earth's history
Accurate temperature estimates of ancient oceans are vital because they are the best tool for reconstructing global climate conditions in the past.

Global trade in soy has major implications for the climate
The extent to which Brazilian soy production and trade contribute to climate change depends largely on the location where soybeans are grown.

Study shows wetter climate is likely to intensify global warming
New study indicates the increase in rainfall forecast by global climate models is likely to hasten the release of carbon dioxide from tropical soils, further intensifying global warming by adding to human emissions of this greenhouse gas into Earth's atmosphere.

Do the climate effects of air pollution impact the global economy?
Aerosol emissions from burning coal and wood are dangerous to human health, but it turns out that by cooling the Earth they also diminish global economic inequality, according to a new study by Carnegie's Yixuan Zheng, Geeta Persad, and Ken Caldeira, along with UC Irvine's Steven Davis.

Climate signals detected in global weather
Searched for and found: climate researchers can now detect the fingerprint of global warming in daily weather observations at the global scale.

Climate change and the threat to global breadbaskets
Extreme climatic conditions could lead to an increased risk of unusually low agricultural harvests if more than one global breadbasket is affected by adverse climate conditions at the same time.

Global earthworm biodiversity patterns influenced by climate
Earthworm communities in soils worldwide -- and the critical ecosystem functions they provide -- could be substantially impacted by continued climate change, according to a new report that evaluated data from nearly 7,000 sampled sites in 57 countries across the globe.

Read More: Global Climate News and Global Climate Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.