Black carbon emerges as climate villain

Written by adam


Last week, a $6 solar cooker took top prize in a contest for best climate change innovation. It seems the award couldn’t have come at a better time. This week brought an increasing amount of scrutiny to the climate chaos wreaked by “black carbon.”

Black carbon, better known as soot, is produced in large quantities by the cookstoves traditionally used by the world’s poor. Some of these cookstoves burn wood, others burn dung, but all have in common that they produce thick clouds of smoke that coat nearby buildings, ravage the lungs of the people who use them — and attack glaciers thousands of miles away.

> Like tiny heat-absorbing black sweaters, soot particles warm the air and melt the ice by absorbing the sun’s heat when they settle on glaciers. One recent study estimated that black carbon might account for as much as half of Arctic warming. While the particles tend to settle over time and do not have the global reach of greenhouse gases, they do travel, scientists now realize. Soot from India has been found in the Maldive Islands and on the Tibetan Plateau; from the United States, it travels to the Arctic. The environmental and geopolitical implications of soot emissions are enormous. Himalayan glaciers are expected to lose 75 percent of their ice by 2020.

The idea that black carbon is a major contributor to climate change is so new that soot isn’t even mentioned in the 2007 IPCC report that declared evidence of global warming unequivocal. Although carbon dioxide is still the chief climate change culprit, soot may be responsible for about half as much warming as CO2 — an enormous amount.

Solar ovens are a cheap and emissions-free alternative to traditional cookstoves, one that promise great health and economic benefits to their users alongside the environmental dividends. But solar ovens aren’t a cure-all. For one thing, many types of food, such as flatbreads, can’t be prepared in a solar oven. So researchers are developing other types of cheap stoves that still burn fuel, but do so much more cleanly and efficiently. Ultimately, such ovens may be like any other consumer item, with different models for different needs.

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  1. Ed Heath

    It seems like so many people (not me) express their concern for the environment in spiritual terms, and revere the idea of returning to a simpler time and simpler ways. Others (like me) see technology, carefully applied and with constant scrutiny for unintended side effects, as more likely to help nine billion people survive on this planet at one time. Of course, neither approach is really being tried at the moment.
    But this post is a reminder of the frustration of trying to get things right, of trying to help the 6.7 billion people live on the planet in a sustainable manner, so that 9 billion can live on the planet in 40 years, and some number can live on the planet in 100 years. Obviously we need billions of electric ovens, at least some hardy enough to be used by people with crude shelter, and we need huge numbers of solar arrays and wind turbines (the kind that are bird friendly). We apparently need to get away from burning almost anything (maybe vegetable oil is ok as an intermediate step), we need to convert all our lights to the latest low mercury cfls or LED

  2. Anonymous

    Oh Ed: You neglected something. And everyone needs to get adequate sleep so that their faculties are not diminished. What are you doing posting this at 3:45 AM????

  3. Ed Heath

    Much the same as you posting at 4:07AM, Anon. Terra Pass, being a West Coast company, converts to Pacific time (or as Jillian said on “Family Guy” Specific time) from my EST.
    Not that I couldn’t do with some more sleep.

  4. RS

    As a follow-up to my earlier comment (which is stuck in the spam filters), the contribution of BC to climate change may not be explicitly spelled out in the 2007 *summary*, but it is lumped in with the net aerosol effect (in addition to the BC-in-ice/land albedo effect.) The specific contributions are broken out here:
    See Figures 2.21 and 2.22.

  5. veeek

    –For an alternative view see The Economist 4-11-09 page 81.
    –The article indicates N20, indirectly associated with fertilizer use and said to be about 300 times more potent than C02 as a greenhouse gas, is potentially a huge and overlooked contributor to Warming. Unlike black carbon, N20 is associated with the kind of lifestyle we live in developed world (and will increase if crops are grown for biofuels).
    –The article reminds us the goal is not to get rid of CO2 as much as it is to examine and get rid of contributors to Warming. It is important,IMHO, to keep focused on that.

  6. Tom

    veeek brought up a good point about land management. We continue to buy food at the store and forget where it came from, both as the source and as a cause for env concern.
    NC has 9 million people and 4 million acres farmland in row crops requiring fertilizer. This land impacts air & water quality. The impact of this management has gone untreated in public policy and funding, while autos, home construction, appliances and saving cans and bottles precludes meaningful improvement in our fields and landscapes.
    The only viable replacement, compost, can not be furnished in enough quantity to cover those acres. Composting ALL biodegradable, safe waste in NC would only cover about 7 % of cropland a year. At least that much would be converted each year, improving food quality, pollution and reducing inputs.
    Our govt, policy makers and public are drawn to shinier, more dramatic publicity makers in recycling than something so basic and common sense as composting. And home composting is a waste of resource, though a popular practice. It closes neither the gap of land management need nor the proper use of clean waste.
    “An rind is a terrible thing to waste.”

  7. Lorne Craig

    Particulate soot from diesel engines, then, must also be a factor. Clean up Big Transportation (shipping, trucking) in our own backyard.

  8. hwickline

    Thanks for posting on this important topic, Adam,
    My colleagues and I just produced a viral video on the topic of Black Carbon for Earthjustice, and I thought you and your readers might find it interesting. You can check it out at Hope you like it!