Traditional cook stoves recipe for pollution.

• Position: Environmentalism - Brief article

New measurements of soot produced by traditional cook stoves used in developing countries suggest that these units emit more harmful smoke particles and could have a much greater impact on glob al climate change than previously thought, maintain researchers at the University of Illinois, Urbana-Champaign.

Perhaps as many as 400,000,000 of these stoves, fueled by wood or crop residue, are used daily for cooking and heating by more than 2,000,000,000 people worldwide. In a field test in Honduras, 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--darker than those created by grassland or forest fires--have a climate-warming effect because they absorb solar energy and heat the atmosphere.

In earlier work, scientists estimated that burning firewood--the principal fuel for...