Khushboo is 11, and the girls in her home usually take up cooking duties as teenagers. But the smoke that billows from the wood and dried dung they burn, stinging the older girls’ eyes and throats, already affects her.
The air in the semi-open courtyard of the Kushwaha family’s home is heavy and choking. The older girls patiently prepare food for as long as six hours a day, sifting flour, rolling dough and tending to the vegetable and lentil dishes that bubble atop rough-hewn clay stoves.
“I don’t like the smoke,” Khushboo said. “I cough when food is being made,” and her eyes get red.
About three billion people, more than 40 percent of the world’s population, cook and heat their homes with dirty fuels like wood, dung and coal, burned on open fires or in traditional stoves, according to the World Health Organization. From China and Laos to Nigeria and Ethiopia, the resulting smoke prematurely kills about four million people a year, the organization says.
The smoky fuels, known as chula in India and biomass among scientists, are also a driver of climate change, in part because the black carbon particles they create absorb heat from the sun. It is not clear, however, whether a mass switchover to the alternative most readily available in India, liquefied petroleum gas, or L.P.G., would benefit the climate or be a small detriment, said Kirk Smith, professor of global environmental health at the University of California, Berkeley, and a leading voice on household air pollution.
From a health perspective, though, the pressing need for L.P.G. or other alternatives is clear, and renewable options like solar-powered cooking, while growing fast, are not yet widely available. It would be unconscionable for rich nations to demand “that the world’s poor should bear the burden of lowering carbon emissions, when essentially minuscule increases would have such huge benefits,” Dr. Smith said in an email. “It is not the cooking of the poor that threatens the climate, it is you and me.”
India, the world’s third-largest emitter of planet-warming greenhouse gases, is a key player at the climate summit meeting in Paris, and its leaders have long argued that they must prioritize improving the lives of the poor over tackling global warming. The competing agendas of wealthy nations, which have put most of the accumulated carbon dioxide in the atmosphere, and poorer ones worried that curbing their own growing emissions will hamper economic growth have long been a sticking point in efforts to reach a global climate deal.
About 700 million Indians, more than 55 percent of the country’s population, rely on biomass stoves. Household air pollution is the second-biggest risk factor for death in India, and the third-biggest risk to health, causing stroke, heart disease, lung cancer, pneumonia and more, according to 2013 data from the landmark Global Burden of Disease study.
The suffering was apparent during a spring visit to Khushboo’s mud-walled home, in a village near the northern city of Lucknow, where her family scrapes out a living farming wheat and potatoes. Her mother’s vision is worsening, and she often feels too ill to cook, so an older daughter, Renu, 17, has taken up that responsibility.
Renu Kushwaha works beneath a bit of thatched roofing in a corner whose walls are black with soot. She suffers from dizziness and a constant headache.
Even the youngest knows what would solve their problems. “There’s no smoke in a gas stove,” Khushboo said. “It’s much easier.”
L.P.G., made up of propane and butane, is the cooking fuel families like the Kushwahas aspire to, smoke-free and far more convenient than the time-consuming chula. For many, though, L.P.G. is too expensive or simply unavailable, in part because India’s poor infrastructure hampers distribution.
Improving that infrastructure is key. Also critical, Dr. Smith said, is an overhaul of India’s L.P.G. subsidies, which largely go to the middle classes and the wealthy, not the rural poor who need them most.
Priti Kushwaha, a neighbor of Khushboo’s family, has an L.P.G. stove, but says she uses it sparingly. Buying the fuel means a motorcycle trip of 10 kilometers, or 6.2 miles, and the process is so cumbersome she often has to go twice.
A canister of gas costs 665 rupees, or about $10, she says, a third of which is covered by a government subsidy. Priti Kushwaha, who is not related to the other Kushwahas, would love to cook with L.P.G. more often. “It is much easier to use the gas stove,” she said. “It is just the inconvenience of getting it, and the cost.”
She cooks most often with a wood- and dung-burning stove that is more modern, and much cleaner, than her neighbors’ primitive ones. Provided by the Energy and Resources Institute, or TERI, a New Delhi-based research group, it is made of steel, with an electric fan that improves efficiency by forcing air into the burning chamber.
Increasingly, experts are seeing links between dirty fuels in the home and India’s wider air pollution problem. About 25 percent of the country’s outdoor pollution comes from households, said Kalpana Balakrishnan, a professor of environmental health engineering at Sri Ramachandra University in Chennai.
In the last 25 years, Venezuela, Chile and Costa Rica moved almost all households to L.P.G., Dr. Smith said. Ecuador did so in the 1990s and is now pushing for conversion to electric induction stoves, he said. Brazil achieved nearly universal gas use, but 10 percent of households returned to biomass when subsidies were scaled back, he said.
In India, more people are gaining access to L.P.G. But without a push from the government, it will take 20 to 30 years before gas and other clean-burning fuels are widely available, Dr. Balakrishnan said. “It’s the vaccine analogy, it’s the life-saving drug analogy,” she said. “You don’t wait for people to become rich before you get life-saving drugs to them. You step in and get them what they need.”
The Society of Environmental Journalists funded travel for this article.