Clean burning cook stoves can reduce air pollution and save lives in the developing world. (NASA Goddard Space Flight Center)
Reducing short-lived air pollutants like methane and soot could limit global temperature increase by as much as 25 percent. Johan Kuylenstierna coordinated two UN reports on the topic. He tells host Bruce Gellerman that the US State Department will begin working with other countries to implement change.
GELLERMAN: From the Jennifer and Ted Stanley Studios in Somerville, Massachusetts, it’s Living on Earth, I’m Bruce Gellerman. Carbon dioxide gets most of the attention when it comes to climate change, but scientists say as much as 40% of the increase in global temperature can be attributed to short-lived, but powerful, pollutants like methane and soot, or black carbon.
Secretary of State Hillary Clinton recently announced a new, multinational plan to implement simple strategies aimed at reducing these planet-warming pollutants.
[CLIP OF HILLARY CLINTON SPEAKING: We know that in the principle effort necessary to reduce the effects of carbon dioxide the world has not yet done enough. So, when we discover effective and affordable ways to reduce global warming not just a little, but a lot, it is a call to action for all of us.]
GELERMAN: The UN will implement the 6-nation program. Johan Kuylenstierna is coordinator of two UN reports on the benefits of reducing methane and soot.
KUYLENSTIERNA: What we're trying to do here is look at ways by which we can reduce the amount of global warming over the next few decades by addressing these so-called short-lived climate pollutants. And if you were to take these measures and implement them, we can reduce climate warming by about half a degree C by mid-century.
GELLERMAN: Half a degree being half a degree Celsius.
GELLERMAN: That doesn’t sound like much, but it’s pretty significant.
KUYLENSTIERNA: Yeah, it is significant because at the moment we have a warming… an estimate of about point eight degrees C above pre-industrial levels. So point five degree C is significant, and it would significantly reduce the rate of temperature increase over the next few decades, giving more of a chance for societies and ecosystems to adapt to a new climate.
GELLERMAN: So these things - methane, soot, hydrofluorocarbons - they’re short-lived, they stay in the atmosphere for a short period of time, but they’re very potent in terms of global warming gasses?
KUYLENSTIERNA: That’s right. And what’s very interesting about the methane and the black carbon reductions is that there will be some very substantial co-benefits in terms of air quality. We’ve estimated that the black carbon measures would reduce the number of premature deaths by about two million every year, if these measures were fully implemented globally.
GELLERMAN: So, specifically, what are the measures you’re taking to reduce these global warming gasses?
KUYLENSTIERNA: The measures we’re looking at, they’re divided into two categories: one are methane measures, and the other are black carbon or soot measures. And the methane measures are really related to capturing the methane when you extract oil or gas or coal, or if you transport the gas on long distance pipelines - making sure you don’t have leakages and so forth.
And the agricultural sector it's trying to reduce the amount of methane from rice paddies and also by better handling of manure from cattle and pigs for example on farms, and capturing the methane as well. In terms of the black carbon measures, we have a large emission from the residential sector - one of the major sources in the world of black carbon is cooking indoors using fuel wood or other biomass.
So the black carbon is emitted when you get incomplete burning of the wood. So you need to burn it more completely, which will also mean that you use less wood to do the cooking. And, also, there’s an increasing amount of heating by wood in Europe and North America. And so it’s a question of getting better technology that gives you the heat but low emission.
GELLERMAN: So, you’ve got the United States, Canada, Sweden, Mexico, Ghana and Bangladesh - kind of a strange collection of countries if you ask me!
KUYLENSTIERNA: Well, to some extent these countries - several countries - have been focusing on it independently for awhile. Some of the impacts of black carbon are particularly high in the arctic. The black carbon, when it deposits on snow and ice, makes it darker and therefore absorbs more of the sun’s heat and melting the snow and also heating the air above it.
So there’s some real benefits of reducing these emissions in the arctic, so Sweden is very interested, another reason why Canada’s interested. And then countries like Ghana, the Minister says: ‘You know, this is a development issue.’ So people are coming at it from different angles and different reasons, but finding common ground and a desire to do something about it.
GELLERMAN: So is your project an acknowledgement that our attempts to reduce CO2 emissions, which is the big greenhouse gas, is that an admission that the climate summits just aren’t working?
KUYLENSTIERNA: Well, reducing carbon dioxide is very important, particularly for the long-term climate. What we’re talking about here is no alternative to CO2 emissions, because these will help us in the near term - say in the next few decades, if we implement them we’ll get a benefit - but then the CO2 will kick in and we will have severe global warming if we don’t do anything in the future. That’s why these are complimentary strategies, they’re not alternatives. For the long term you have to address CO2.
GELLERMAN: Johan Kuylenstierna is the Director of the Stockholm Environment Institute Center at York and coordinator of two UN reports on the benefits of reducing methane and soot. Well Mr. Kuylenstierna, thanks so much.
KUYLENSTIERNA:Yeah, thank you very much.
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