Berkeley - Contrary to conventional wisdom, the use of fossil fuels for household cooking and heating may make more environmental sense for the estimated 2 billion rural poor in the world, according to a researcher from the University of California, Berkeley. Because they contribute to greenhouse gas emissions, fossil fuels have been largely dismissed as a viable alternative for the one-third of the world's population who now use coal and local biomass - including wood, crop residues and dung - for cooking and heating, said Kirk R. Smith, professor and chair of environmental health sciences at UC Berkeley's School of Public Health. Efforts have been focused on equipping the rural poor with renewable energy sources, such as solar and wind power.
But in an editorial appearing this week in the journal Science, Smith argues that switching all 2 billion of the world's poor to liquefied petroleum gas for household use would add a scant 2 percent to the global greenhouse gas emissions of fossil fuels. At the same time, using gas fuel would decrease the environmental impact on local biomass resources.
The environmental impact of this dependence on local biomass for household fuel has already been documented in some regions of the world. According to the 2001 Annual Report by The Nature Conservancy, a non-profit environmental organization, the use of wood to fuel cook stoves and to heat homes in China's Yunnan Province is leading to deforestation and contributing to soil erosion.
"There are also significant health reasons for helping these poor households to stop relying upon wood to cook in simple stoves," said Smith. "Liquefied petroleum gas burns much cleaner than the biomass fuels the rural poor are using now. We know that the indoor smoke the people in these households are being exposed to every day, year after year, is adversely affecting their health."
Smith led the research team analyzing the health effects of indoor smoke from solid fuels for a recent World Health Organization report. The report, published in October, found that indoor smoke from solid fuels ranked as one of the top 10 risk factors for the global burden of disease, accounting for 1.6 million premature deaths each year.
In addition to having a miniscule effect on greenhouse emissions, Smith argued that liquefied petroleum gas would have minimal impact on world oil supplies compared with the demand from the modern sector of the economy, including automobiles and aircraft.
He said the cost of switching to gas in households is significant, but would be offset by health and other benefits, including time saved from gathering biomass fuel. For the millions of people who have no choice but to use wood, he said, efforts should also be made to improve the efficiency and ventilation of their stoves so they burn more cleanly and cause less air pollution exposure.
Smith pointed out that the bulk of the global greenhouse gas emissions comes from developed nations, particularly the United States. He calculated that if a person driving an SUV getting 14 miles per gallon were to switch to a sedan meeting U.S. fuel efficiency standards of 27.5 miles per gallon, the fuel saved in one year would provide enough cooking fuel for about eight poor families. Switching to a hybrid car would save even more, providing cooking fuel for about 12 poor families a year.
In addition, if the entire U.S. passenger vehicle fleet were required to meet the current fuel economy standard of 27.5 miles per gallon, enough fuel would be saved to supply the entire cooking needs of the 2 billion poorest people in the world.
"Making that switch to more fuel efficient vehicles shifts the burden of reducing emissions onto the richer nations," said Smith. "We in the United States have the obligation to do more to reduce greenhouse gas emissions because we've enjoyed the benefits of high emissions with our higher standard of living. It doesn't make sense to ask the rural poor to shoulder this burden."
