Fire and Ice: A Closer Look at Cooking and Climate

In Search of the 21^st Century, Dung-Fired Hearth

In the course of researching my new book Fire and Ice – which tells the interconnected stories of the global health and climate impacts of black carbon pollution, and the inspiring efforts of a remote Himalayan village to reinvent itself - I spent a lot of time in smoke-filled kitchens, from India’s remote Zanskar region to China’s Yunnan Province to the Langtang Valley of Nepal.

In Zanskar one evening, I watched as my friend Zangmo baked bread in her kitchen, feeding dried cakes of dung into an open fire under a slab of stone. We both squinted through a steady stream of heavy smoke. The fumes quickly become too thick for me. “Don’t you find it hard to breathe?” I asked, coughing.

“Yes, my eyes feel it,” Zangmo said matter-of-factly, as she placed another circle of dough near the flames. “I feel the smoke.” (The Zanskari word for “smell” is the same as the word meaning “to feel” or “to sense.”) She sized me up with a concerned glance. “Go have some tea. The smoke isn’t good for you."

It wasn't good for her, either. And it’s not good for almost three billion people worldwide – the 40 percent of humanity that burns wood, dung, coal, or agricultural waste in open hearths or simple stoves to make their meals - pretty much the same way people have cooked since before the invention of the alphabet.

In India, over two-thirds of all households burn cow dung and wood in their chulhas, simple mud stoves. In many countries of sub-Saharan Africa, 80 to 90 percent of the population burns biomass. In many of those kitchens, the cooks (the vast majority of whom are women) are exposed to concentrations of dangerous fine particulates as high as 40 times the World Health Organization’s recommended limits. It’s a huge, largely overlooked epidemic.

“It’s incredibly easy to say how awful this is in a sentence and a half," Jacob Moss, the director of Cookstove Initiatives at the U.S. State Department, told me. "It’s incredibly hard to solve it."

The awful part: the Global Burden of Disease study released in 2012 estimated that 3.5 million people die prematurely from respiratory illness, cardiac disease, cancer, and other illnesses due to exposure to indoor air pollution, while another half a million die every year from exposure to smoke that escapes kitchens into the outside ambient air. In China, those particles kill 1.2 million people every year; in India, at least 1 million prematurely.

To solve it would mean helping those three billion who cook with solid fuels in simple stoves get access to truly clean cooking technologies. It’s much easier said than done. Cooking practices vary as widely as the people who practice them. Designing, manufacturing, distributing, selling and then maintaining clean biomass stoves across many different cultures and economic contexts, from Zanskar to Zambia, is a “wicked problem.”

But it’s one worth tackling. When I visited Dr. Stenzin Namgyal, one of Zanskar’s three doctors, he told me that respiratory problems caused by exposure to indoor smoke was the number one problem among the patients he saw. Cases of child pneumonia were a particular concern.

“In Zanskar the chronic diseases, the chronic pulmonary diseases, they are because of smoke,” he explained. “I see more women with obstructive problems, more women than men with these problems."

If he had a bigger budget, he told me, he “would try to improve the ventilation condition of the kitchen in every household. We would do some evaluation of how to ventilate the kitchen, how you can get a better chulha, so it can be more effective, less smoke and more combustion.”

Less smoke and more combustion – it could be a succinct mission statement for the creators of BioLite’s HomeStove, which uses similar technology as its CampStove. It’s still being tested in a variety of settings, including eastern India. A few years ago I asked Jonathan Cedar, the co-inventor of the stove, if it could burn yak dung for high-altitude communities. "I don't know," he replied, "but why not? You should try it."

So I took a BioLite CampStove to Ladakh and Zanskar, in the Indian Himalaya. I showed it to Zangmo one evening in her kitchen. We loaded it up with willow twigs, burtse (a local kind of sage), and yak dung and set it alight. It smoked a bit at first, but once it got going it boiled water for tea quickly. “It cooks very fast,” Zangmo said. “And it looks nice.” Then she got down to brass tacks: “But how much does it cost?”

When I told her she whistled in surprise: "Too much!" (The CampStove is designed and priced for the recreation market in industrialized countries, so it’s not an entirely fair comparison.) So I asked what she would pay for a similar device. 1,500 rupees, max, she said. About thirty dollars (at the time). [editor's note: The BioLite HomeStove is a larger format cookstove designed for Emerging Markets and, thanks to BioLite's Parallel Innovation model, is offered at a much lower price point, helping get this clean cooking technology to households that need it most.]

I later went to visit my old friend, an engineer, solar designer, and inveterate tinkerer named Wangchuk, near the city of Leh in Ladakh. We set it up in the kitchen of the school he founded, where giant solar reflectors cook most of the meals. We dropped some pieces of dried cow dung down on top of a few burning sticks. It lit immediately, and the flames turned from yellow to greenish blue. We boiled water for milk tea in about a minute. Wangchuk’s eyes lit up.

“Amazing!” he exclaimed. The elegant, simple genius of the thermoelectric generator— using the fire’s own excess heat to power a fan to improve combustion in a feedback loop that burns off all the dark particles and turns them to current, then light in another form— appealed to his practical engineer’s mindset, and aligned with his aversion to waste in all its incarnations. He wanted to figure out how the stove worked and make a bigger version of his own for the campus. He cradled the device in his hands like a child on Christmas morning.

“This is development that I like!”

I also showed the stove to my friend Urgain, in Zanskar, another veteran tinkerer and jack-of-all-trades. He was impressed enough to deploy his trademark, all-purpose exclamation for approval and surprise: “Oh ho!”

“Wood gas! Very interesting - and you can find wood everywhere,” he said, unwittingly echoing BioLite’s slogan (“Energy everywhere”).

My Ladakh and Zanskari friends’ reactions demonstrate that there are opportunities – there really is energy, and interest in harnessing it, everywhere - and there are obstacles – e.g., understanding the cultural context of how people cook and the different fuels they depend on, figuring out how to balance the sometimes competing values of convenience, durability, aesthetics and cost.

I don’t know if BioLite’s stoves will be the answer to this wicked problem in remote places like Zanskar, where the thin high-altitude air, relative scarcity of energy dense fuel, and need for space heating during extremely cold winters combine to demand a very tailored solution. It will be instructive to watch what happens when the HomeStove finally reaches the market in India. The proof of its viability as a clean cooking solution will boil down (pardon the pun) to two key metrics: whether it dramatically reduces dangerous smoke emissions, and whether many customers like Zangmo want to buy one, and keep using it.

But more broadly, I’m confident that approaches like BioLite’s – that seek to upgrade the primeval hearth by harnessing modern technology and design principles that puts the user’s needs first – are a critical piece of the solution to the global scourge of household air pollution. We need to accelerate and multiply our these kinds of efforts to help the three billion people who still burn coal, dung and wood every day - just to survive - finally breathe easier.