Cookstoves and the climate

A promising area of change for the better

May 14, 2015 06:18 pm | Updated May 23, 2016 05:33 pm IST - MADURAI

Millions of Indians cook with stoves fuelled with wood, dung or some other form of biofuel.

Millions of Indians cook with stoves fuelled with wood, dung or some other form of biofuel.

In the last article, we considered the climate impact of India’s love for milk (short summary: not good). This time we will consider another aspect of our food: how we cook it. Most readers of this newspaper will perhaps not have more than the slightest acquaintance with wood-fired stoves. Most of us are still wondering whether or not to voluntarily give up our LPG subsidies (more than 3 lakh of us have).

But millions of Indians cook with stoves fuelled with wood, dung or some other form of biofuel. That’s not a good thing. Why?

For several reasons. We'll deal with three here: the warming impact of the black carbon in the smoke generated from using these stoves; the negative health impacts of the smoke, and third, the negative consequences of the smoke on agricultural yield.

"Biofuel” or wood stoves are quite inefficient: they don’t allow the biofuel (for simplicity, let us call this wood) to burn fully: witness the telltale blackish smoke that emanates from them. The primary constituent of this smoke is what scientists call “black carbon” and it warms the world. Black carbon, or soot, absorbs the sunlight directly in the air and releases the trapped energy as heat, warming the air (I'll pass now on the albedo and cloud formation effects). Many leading scientists believe black carbon to be the most potent warming agent after CO2. While the climate benefits of reducing black carbon are clear, there is some uncertainty on how much benefit we will get. Why? Because the smoke that emanates from a cookstove is a complex cocktail of chemicals, some of the which (like soot) warm the climate while others cool it down. This means that cutting smoke may not slow down warming by as much as some models predict.

The second reason: Health. According to the World Health Organisation, 4.3 million people die globally each year due to indoor air pollution (the small particles in the sooty smoke travel deep within the lungs causing many ailments including heart disease and cancer). A million die every year in India from indoor air pollution, and the primary cause of this pollution is the use of biofuel cookstoves. While there is so much attention on outdoor pollution from vehicles, very little popular attention is directed towards indoor air pollution and its causes. The burden hits hardest on women (the primary cooks) and the very young children (who stay by the women). Moreover, the health burden is being transmitted to the next generation because even the unborn children are affected by the smoke. We also need to consider the effort and time taken to gather firewood. This again falls hardest on the women of the household, often on the girls. Lest you say development will take care of this, even in a relatively developed state like Tamil Nadu, more than eight million of a total 16 million households use firewood to cook some of the time.

The third significant negative impact of cookstoves is the creation of tropospheric (or ground level) ozone. While ozone in the upper atmosphere is a good thing - absorbing ultraviolet rays and preventing cancer, it is not good at the ground level. Why? Because it lowers crop yields. In a context of so much farmer pain from crop damages, this is an under-appreciated reason why agriculture may be suffering.

To sum up: most Indians cook with wood fires (technical name: solid fuel cookstoves). This is bad from at least three perspectives: health, the climate and agriculture. The negative impact falls hardest on those least able to cope with it: the poor women and children.

So why is the use of wood-stoves continuing? First and foremost, due to lack of awareness. Many users of wood fired stoves do not know the negative impacts of using those stoves. Second are financial barriers to adoption of more efficient cookstoves. Often, in rural situations men make the financial decisions of the household and they are less enthused than women (who bear the brunt, especially in terms of health) in investing in efficient cookstoves. Third, the design of cookstoves needs to ensure the efficient burning of a diverse variety of fuels and generate enough heat to cook what people are used to eating. Doing this while keeping the stoves cheap and sturdy is a significant challenge. This is an exciting area where many NGOs and startups are taking action. Many startups are experimenting with cookstove design; others with providing microfinance and marketing to help more households adopt cleaner cookstoves. And as awareness builds up that efficient cookstoves save health and money in the medium term, increasing numbers of households are transitioning to using more efficient stoves. There is hope.

Climaction is a fortnightly column that is published in MetroPlus Weekend on alternate Fridays. The views expressed in the articles are those of the author.

The next article in this series will appear on May 29.

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