A new study by researchers from UC Berkeley and the University of Illinois shows that we've been overlooking a significant source of black carbon pollution: Kerosene lanterns, used as a primary light source for millions of people worldwide.
It turns out that the black carbon soot from kerosene lanterns is twenty times higher than is currently assumed when factoring in this light source into calculations of total black carbon emissions.
The researchers found that 7-9% of the kerosene ends up in the atmosphere as black carbon.
Black carbon is increasingly being cited as a significant factor in global warming, as well as in glacier melting. Rather than being a greenhouse gas, like CO2 or methane, black carbon is particulate air pollution. It increases warming, but once the source of the pollution is removed the warming it causes drops rapidly, unlike greenhouse gases.
This means that if we can phase out or at least significantly reduce the sources of this pollution—open cookstoves used by millions of people in poor nations, older diesel engines, as well as kerosene lanterns—we can reduce warming with a much quicker timescale to see results than in reducing carbon emissions, even though doing the latter is hugely important, as well.
Study co-author Kirk Smith, from the UC Berkeley School of Public Health:
There are no magic bullets that will solve all of our greenhouse gas problems, but replacing kerosene lamps is low-hanging fruit. There are many inexpensive, cleaner alternatives to kerosene lamps that are available now, and few if any barriers to switching to them.
That is, few barriers except perhaps resistance to changing habitats and family priorities, such as been experienced with efforts to replace older cookstoves with cleaner-burning alternatives in Bangladesh.
What are the cleaner alternatives? Pretty much any light source powered by electricity generated from solar power, either from solar panels, or from cookstoves that produce electricity, as well as cook food.
The study authors rightly point out there's another big benefit of switching to cleaner forms of lighting that kerosene lanterns: Reducing indoor air pollution.
Similarly to older cookstoves, the fumes and smoke from kerosene lanterns significantly contribute to seriously health problems in people, disproportionately women and children, resulting from exposure to the fumes. In fact, 1.9 million people die annually from bad indoor air quality, according to UN stats.