Stove Soot

Traditional cookstoves, fueled by wood and crop waste, emit smoke containing particles. Depending on their makeup, these particles can absorb or reflect solar energy, thereby heating or cooling the atmosphere. A recent field study in Honduras characterized the smoke released from stoves and measured the amount of global warming–related soot within the emissions. It found that traditional cookstoves may contribute to atmospheric warming more than previously thought.—Alison Snyder

Number of cookstoves in use worldwide every day: 400 million

Grams of soot emitted per kilogram of firewood based on:

Previous lab estimate: 0.75

Current field estimate: 1.5

Kilograms of firewood burned per stove per day, worldwide: 7.5

Minimum percent of light absorbed by particles that warm the atmosphere: 15

Percent absorbed by Honduran stove smoke: 65

SOURCE: Environmental Science & Technology Briefs, December 1, 2006