Kerosene lamps are the main light source for more than 1 billion people in developing countries. According to a new study, the black carbon produced by kerosene lamps has been ignored in previous estimates of greenhouse gases. The new findings led to a 20-fold increase in black carbon emissions from kerosene fuel lighting. The good news is that we have affordable and cleaner alternatives.

According to the results of field and laboratory tests, 7% to 9% of kerosene in the lamp wick lamps used by 250 million to 300 million households without electricity is converted into black carbon during combustion. In contrast, only 0.5% of the carbon emitted by burning wood is converted into black carbon.

Considering the new research results, the black carbon emission of kerosene fuel lighting is estimated to increase by 20 times. The previous estimates come from established databases used by the Intergovernmental Panel on Climate Change and other agencies. The author said that one kilogram of black carbon is a by-product of incomplete combustion and an important greenhouse gas. Its warming in one month is equivalent to that of 700 kilograms of carbon dioxide in 100 years.

Tammy Bond, the research leader and associate professor of civil and environmental engineering at the University of Illinois at Urbana-Champaign, said: "The orange light in the flame comes from black carbon, so the brighter the light, the more black carbon will be produced." "If it is not burned, it will enter the atmosphere."

The research results were published in the journal Environmental Science and Technology this month, while the United Nations Climate Change Conference opened in Doha, Qatar. Although officials around the world are seeking effective policies and guidelines to reduce greenhouse gas emissions, the authors of this study pointed out that the simple act of replacing kerosene lamps may have an impact on this effort.

Co-author of the study, Professor of the School of Public Health at the University of California, Berkeley, and Director of the Global Health and Environment Program, Kirk Smith, said: "There is no panacea to solve all of our greenhouse gas problems, but replacing kerosene lamps is an easy goal to achieve. We do not have many such examples in the field of climate." "There are many cheap and cleaner alternatives to kerosene lamps, and there is almost no obstacle to using them."

Smith pointed out that lanterns equipped with light-emitting diodes can be powered by solar cells, and even advanced stoves can generate electricity through the heat generated. Smith said that this technology is already available in developing countries.

Researchers used kerosene lamps purchased from Uganda and Peru, and conducted field experiments there to measure emissions. They repeated the test in the laboratory using wick of different heights and materials, and kerosene purchased in the United States and Uganda.

The author of the study pointed out that switching to cleaner light sources is not only beneficial to the earth, but also conducive to improving people's health. For example, a recent epidemiological study conducted in Nepal by Smith and other researchers from the School of Public Health of the University of California, Berkeley, found that women who reported using kerosene lamps in their homes were 9.4 times more likely to suffer from tuberculosis than women who did not use kerosene lamps.

Nicholas Lin, the main author of the study and a graduate student of environmental health science at the University of California, Berkeley, said: "Getting rid of kerosene lamps seems to be a trivial step, but considering the collective influence of hundreds of millions of families, it is a simple act that affects the earth."