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SD Scientist: 14 Measures To Slow Global Warming

January 17, 2012 1:20 p.m.


Dr. Ram Ramanathan is a Distinguished Professor of Atmospheric and Climate Sciences at the Scripps Institution of Oceanography, University of California, San Diego.

NASA Interactive Feature

Related Story: San Diego Climatologist Identifies 14 Measures To Slow Global Warming


This is a rush transcript created by a contractor for KPBS to improve accessibility for the deaf and hard-of-hearing. Please refer to the media file as the formal record of this interview. Opinions expressed by guests during interviews reflect the guest’s individual views and do not necessarily represent those of KPBS staff, members or its sponsors.

CAVANAUGH: This is KPBS Midday Edition. I'm Maureen Cavanaugh. For many years, scientists concerned about global warming have pointed to carbon dioxide emissions from the burning of fossil fuels as the major culprit. And carbon dioxide remains the biggest factor in global climate change. But other sources of air pollution have been identified as significant problems. Recently NASA used the research generated by a San Diego scientist to model how those secondary sources of pollution might be controlled.

I'd like to welcome my guest, doctor Ram Ramanathan, distinguished professor of atmospheric and climate sciences in Scripps institution of oceanography. Thank you so much for coming in.

RAMANATHAN:: I'm delighted to be here. Thank you.

CAVANAUGH: Now, the polluters the study focused on, if I'm correct, are methane and black carbon. If you could, give us some description of what methane is, and how it contributes to global warming.

RAMANATHAN:: Thank you. There are in fact four pollutants we are targets, first is methane. It's the dominant component of natural gas, which we use to cook. The important thing about methane is that once it's in the air, it's over 20 to 25 times stronger than carbon dioxide in its warming effect. Andup like carbon dioxide which stays in the air for centuries, methane stays only for ten years. So the beauty of that is, if you cut down methane emission now, they're gone about ten years from now.

CAVANAUGH: Now, where does methane come from? Where does most of it originate?

RAMANATHAN:: Varieties of sources. That's the challenge in reducing them. In producing coal for consumption and oil and gas, you release methane. So it's about a third of the total methane emissions comes from producing fuels. And there are ways to capture these gases from coal mines and natural gas, wells, and oil producing dilation facilities. Methane also leaks in the air through a transmission. So it's a question of tightening the pipes.

CAVANAUGH: Oh, okay.

RAMANATHAN:: Simple things. And other major sources of methane is live stock, cattle, in the digestion of food release a tremendous amount of methane, and the manure contains methane.


RAMANATHAN:: And the third major source-- these are all opportunities. They are problems but also opportunities. The third major source is landfill and base water treatment.

CAVANAUGH: Certainly. Is methane, is it related to the ozone lair in some way?

RAMANATHAN:: Not really. The ozone layer we think of is in the upper atmosphere.


RAMANATHAN:: But methane produces ozone close to where we live, smog, which we know in Southern California. The ozone there. But a third of it is produced by methane.

CAVANAUGH: So it's not the ozone layer but it produces OI don't know that's closer to the earth. I be.

RAMANATHAN:: Right. About 30 years ago, I discovered accidentally that this ozone is a major green house gas. So by cutting down methane, you cut down ozone, so you put down the ozone's green house effect. But the other thing is ozone is a major destroyer of crops. So we found cutting methane by about 30 to 50% in the next 20 to 30 years, you would save more than 25 to 130 million tons of crops in terms of maize, wheat, rice production. So that's only 1/3 of the story. The other pollutant we are targeting is black carbon.

CAVANAUGH: Otherwise known as soot?

RAMANATHAN:: Right. This is the black stuff which comes out of diesel trucks, when you have forest fires.

CAVANAUGH: Or out your chimney, right? If you're burning wood.

>> Exactly. I didn't want to make your viewers feel guilty for releasing black carbon. But yeah, and it's the strongest absorber of sunlight. That's why it's black. And it traps so much heat in the air, it's the cause of glacier melt, arctic sea ice retreat, and it's also a major health hazard. And about half the black carbon emissions happen in Asia. And these are all -- things come from cook stoves. So again, the black carbon is only a week, stays in the air. So if you cut down the emission of black carbon say, by diesel, putting filters in diesel trucks, they're anyone a week from now.


RAMANATHAN:: So we have a chance by targeting these compounds to get quick relief so that our leaders who are gridlocked in it trying to cut down CO2, you give them over 20, 25 years time to figure out how to -- we still don't know how to cut down carbon dioxide emissions. And it's estimated that to bring down the carbon dioxide emission by about 50%, which we have to, would cost about $45 trillion over the next 30 years. So we have to discover cheaper ways.


RAMANATHAN:: To get rid of CO2. And that's where our step of targeting this short-lived climate forces buys us some time to avoid this dangerous climate change, which we scientists know is imminent in the next 30 to 50 years.

CAVANAUGH: Do these other sources, these other climate forcers, as you say, methane and ozone and black carbon, do they have a significant enough effect on climate change so that reducing their output would actually forestall some of the most significant outcomes of climate change?

RAMANATHAN:: Terrific question. In fact, let me add one more, which is fluoro carbons. For example, 35 years ago, I accidentally discovered the CFCs, which is used as refrigerants and spray cans. One molecule of them traps as much heat as 15,000 molecules of carbon dioxide. So the we have -- if you add these four, methane, part of natural gas, black carbon, part of soot, ozone which is a pollutant, and these CFCs, they contribute as much as 40% of the global warming today. So all we're talking about is get rid of that 40%, and. We don't need new technologies. We have existing technologies.

CAVANAUGH: Now, this NASA study that used the research that you had compiled, did it also focus on immediate health benefits of reducing this output as well as the effects on global climate change?

RAMANATHAN: Yes. We had published two years ago that if you cut down these compounds, we can cut down the warming by about 25 to 30%. Well, they took that finding and estimated what are other benefits can society can accrue? It turned out on the black carbon measure alone, you can save close to one million to four million lives a year. And the cost of that alone, the benefit is about three + trillion dollars. So they estimated in detail. These deaths are rated to air pollution. They are from what it is called chronic obstructive pulmonary disease, childhood pneumonia. So the health benefits are huge.

CAVANAUGH: I'm speaking with doctor Ram Ramanathan, he's distinguished professor of climate sciences at the Scripps institution of oceanography, and vice chair of the NASA study we were just talking about. Now, why is that -- why is it that we haven't heard as much about these secondary climate effectors as we have about CO2? Where has this information been living? Because it all seems to be about reducing CO2 emissions.

RAMANATHAN:: Excellent. This information has been living in labs like mine, in scientists. We've been trying to hard to move it up. In fairness to these who pushed the CO2, since the CO2 molecule once released stays for centuries, by the end of the country, the CO2 becomes the most dominant, dangerous climate-warming gas. And because its lifetime is so long, we've got to do something now. So scientists like me, I was happy to watch on the sidelines, hoping we would get some disagreement on CO2. Now we feel we are losing time. And we are gridlocked in the current economic situation, it's going to prevent us from taking further action because carbon dioxide is intricately linked with everything the society does.

CAVANAUGH: And you have more wiggle room with these other factors?

RAMANATHAN:: I would to think it's a little bit more than wiggle room. That really, we can -- societies and leaders and scientists, we fear this onset of 2-degree global warming. And my own calculations show we'll be facing that in 30, 40 years from now. So we want to push that goalpost, the 2-degree goalpost. I think these short-lived climate forces, if you cut down by 30 to 50%, let me emphasize using existing technologies, we can push that goal post by about 25 years. And one of the -- it's maybe of interest to Californian, California is a leader in these technologies. For example, we released a study funded by the California research poll that California has cut down its black carbon emissions by 50% in the last 20, 25 years. So there is now a tremendous opportunity to export this technology.

CAVANAUGH: Would it be fair to say that most of the black carbon pollution comes from the area of the world where people do use cook stoves more than here? And what might be the solution there? What might those people use instead of what they're using now to cook their food?

RAMANATHAN:: Yeah, great question. Right now about a third of the black carbon emissions comes from industries and transportations that are diesel trucks, on-road and off-road, major source. Another 25%, surprisingly, comes from residential cooking with unprocessed biomass, firewood, cow dung. And prop residues. Your viewers might be surprised to know, over 3.5 billion people depend on this biomass. This is about 25 to 30%, a third. And at Scripps institution of oceanography, we have been issued a project in villages in India collecting data and showing that just simple technology, addag a fan to a tradition cook stove, still using biomass, you can bring down the black carbon emissions by 80%.

CAVANAUGH: That's amazing. Do you have any other of the 14 ways? I know that NASA did modeling on 14 ways these forms of air pollution could be controlled. Because that, the fan, that's amazing. Is there anything else that is almost that simple?

RAMANATHAN:: Yeah, for example in the US, one major source of methane is landfills. And we have the technology to extract methane. It's basically organic waste we throw into the landfill. You just compost the orbeganic part of it, then you capture the methane, and you can use that methane as fuel.

CAVANAUGH: Natural gas.

RAMANATHAN:: Yes, natural gas. So that's one thing we're proposing. The same thing, a lot of methane is released in waste-water treatment or sewage. That can be captured. There are in fact four hundred measures. We just highlighted 14. This is where actions can be taken locally. And the benefits would be accrued holily and globally.

CAVANAUGH: What kind of reaction have you gotten to this NASA study and your initial research? Are government entities moving in the direction of employing these sort of -- some of the low-tech technologies in order to change the amount of emissions from black carbon, methane, ozone, etc.?

RAMANATHAN:: Yeah, we have seen -- I must say, quite a bit of support for example borrow better at the Vatican other than. We lead this are the showing glaciers are melting how these nonshort-lived climate resources can give relief. Unionep has taken it as a major theme, and Sweden, the Swedish international development agency has gone into a major partnership between Sweden and Bangladesh. I myself am organizing a meeting in the maltese, where the president would be there to show how we can avoid dangerous sea level rise. You reduce the warming, you're going to reduce the sea level rise. As you know, one of the first things of global warming is going to be small island nations like maltese. So they have a tremendous vested interest. But as a scientist who wants to solve on the only the short term but the long-term problem, how do you do this without distracting attention from the CO2? The most dangerous thing I would end up doing is saying just cut down these climate forces, we have solved the climate problem.


RAMANATHAN: Not by a long shot. All I'm doing is to give ourselves about 20 years, to use your phrase, wiggle room.

CAVANAUGH: Now, here in California, you said we have these technologies in order to control these short term climate forces. Are we using them? Is there any policy underway to give us that time that we need in order to get a handle on a larger problem of CO2?

RAMANATHAN: Yes. As you know, our former governor was a leader in this. He started this AB32 program. So definitely they have to use these measures to get that reduction in the climate warming. Because it is not fair in knowing how to cut down CO2. The efficiency is important. Alternate energy is there, but they're not very scaleable. So these techniques, these measures could be used by our state, and they've done it. Not for the reasons we want. But it doesn't matter. They've cut down the soot emissions. But they cut down by 50%. I want them to cut some more.

CAVANAUGH: Well, I have to tell you this has been fascinating. I've been speaking with doctor Ram Ramanathan of Scripps institute of oceanography, and vice chair for the study. Thank you, and good luck with this message. Thank you.

RAMANATHAN: Thank you very much.