Vidhi Singhal

Carol and Jon Epstein Fellow

McKelvey School of Engineering: Energy, Environmental, & Chemical Engineering | MS


Cohort 2008


Graduated 2010

Partner University:

Jawaharlal Nehru University


Career: Principal Air Quality Scientist | ESE Energy | Houston, Texas, USA

Scholar Highlights

From Kitchen Smoke to Global Warming

Every day Kamyani Devi cooks for her family on the chulha stove, and in the process inhales the equivalent in smoke of two packs of cigarettes. While she is coughing at the stove, her children are playing in the backyard and already suffer from tuberculosis and asthma, much to her dismay. The walls of her house have turned dark with black carbon over the years. Unfortunately, chulha stoves, unlike cigarettes, do not come with statutory warnings on them. Over the centuries, billions of women across the globe, like Kamyani Devi, have fallen victim to these poor cooking technologies.

Particles that are emitted from these cookstoves have created a death trap for over two million individuals annually. Apart from the health hazards, these cookstoves have adverse effects on the environment as well. In polar areas, these tiny heat-absorbing soot particles get deposited on the surface of glaciers, melting the snow and increasing the sea level, resulting in the frequency of floods. These particles have also been found to be responsible for the retreat of glaciers in the Himalayas, threatening the only major source of fresh water for the Indian subcontinent. Rural areas, especially in developing countries, are enveloped by black clouds from dawn to dusk due to the constant emissions of black soot from the traditional biomass cookstoves.

Wood, if harvested renewably, is assumed to be a greenhouse gas. It is viewed as neutral, releasing as much carbon dioxide as can be absorbed by the growing vegetation. However, this is usually not the case due to inefficiencies in the combustion process. Due to incomplete combustion of the fuel, products of incomplete combustion (PICs) are released into the environment. In a recent publication in Science, it was found that the contribution of biofuels to total black carbon emissions may be as high as 44 percent in India and 30 percent across all of Asia.

Introducing improved cooking technologies will not only improve the health of women and children, but will also decrease the environmental effects due to emissions of black carbon. Kirk Smith, a professor at the University of California, Berkeley, says that unless the production of PICs is lowered and fuel is harvested in a truly renewable way, we will keep emitting these tiny death particles into the environment in an unsustainable manner. Some climate experts claim that improved cooking technologies can be a cheap solution to all our global warming woes, at least in the short term.

One effective approach to solve this problem would be to replace the traditional stoves with new stoves. This would not only improve health conditions, but also help combat the problems of global warming to a certain extent. However, this is not an easy task to accomplish. Indeed, replacing hundreds of millions of stoves all over the world would be a mammoth feat. In addition, the new stoves would have to be designed with the local needs of the people in mind. In many communities, fire is considered as the center of the house and holds spiritual and religious significance. It would be essential that the stoves be designed accordingly and be economical to buy and use. It would also be imperative to reach out to rural areas to make people aware of the benefits of better cookstoves.

For most communities, these improved stoves involve unfamiliar technology and require high maintenance. Moreover, the traditional stoves impart a particular traditional flavor to the regional food, which is lost with many of the improved stoves. The improved stoves that have been introduced in developing countries, especially India, have been an utter failure due to their inability to cook roti, dosa, and other traditional Indian dishes. It has been found that households that use traditional stoves along with the new improved ones do not show a significant reduction in the total emissions of black carbon, implying that the improved stoves are not a success in these areas.

Despite the current strides made in improving the performance of cookstoves, the problem of finding the optimal cookstove–one that is efficient, clean and cheap and meets local needs– still stands.

A question that we need to ask oursevles is: Can we blame the developing countries for the increase in the global temperature from cooking their meals, when we sit in the comfort of our houses and SUVs, running on coal-fired power plants? Reducing emissions in the developed world is a grave problem that needs long-term efforts to solve. The cookstove problem, on the other hand, is a problem that can be solved in the short term, holding global warming at bay until we find long-term solutions to protect our environment.

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