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Interview With Jillian Gregg
Aired July 09, 2003 - 15:41 ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
MILES O'BRIEN, CNN ANCHOR: So where do you think a cottonwood tree has a better chance of thriving, in the cement jungle of the Bronx, say, or the more peaceful rural environment of Long Island? The answer surprised even the scientist doing the study.
On the phone from Corvallis, Oregon ecologist Jillian Gregg. Her study is published today in "Nature" magazine, was done jointly by Cornell University and the Institute of Ecosystem Studies in Millbrook, New York. Glad we got that all out. Jillian, good to have you with us.
JILLIAN GREGG, ECOLOGIST: Hello, can you hear me?
O'BRIEN: Yes, I sure can.
Now you planted trees, I think we have a little graphic to support this. You planted identical trees, same lineage, so forth. Mixed up the soil so the soil wasn't a factor. And the trees -- I don't know if you can see CNN, but you're towering above some trees here. Where were these trees planted?
GREGG: So you have a picture with urban trees, perhaps on the left that are larger...
O'BRIEN: Oh, yes. There you go, your right is the urban trees and then you see the other ones there. So what you're telling me is the urban trees are bigger.
GREGG: Right.
O'BRIEN: And that's quite surprising conclusion, isn't it?
GREGG: It is quite a surprising conclusion.
O'BRIEN: What is at work here?
GREGG: Well, I was expecting to start at the beginning of my story, not at the end. I have to tell you a little bit about the beginning.
O'BRIEN: Give me a little back story, Jillian. It's OK.
GREGG: A little bit about the beginning is that I was very interested in studying the effects of human cause changes on plant growth. And, you know, lots of researchers have looked at the effects individual factors, elevated temperature or CO2, ozone, acid rain, heavy metals.
But in the real world everything changes simultaneously. So the real question is what is the net growth response to multiple different, you know, multiple different changes.
So what I did is I went to the site where I found the highest concentration of the most pollutants and measured what is the net growth response. So I took those genetically identical cottonwood clones that you can see there in the photograph and I planted them in the city and the country to see where they grew the best.
O'BRIEN: And voila. The tree in Brooklyn thrived, to take a little poetic license there. And at the root of this is ozone. Here's the other counterintuitive part of this study. You discovered over time ozone, which is kind of related to emissions from vehicles, for example, and is a problem for people with respiratory issues.
GREGG: Yes.
O'BRIEN: Ozone is actually more concentrated over time in the country. Why is that?
GREGG: OK. So there's a couple different explanations you need to understand. First is that ozone is secondary pollutant. So the primary precursors are emitted in New York City and then they have to react in the presence of sunlight over time before the ozone is formed. By that time the ozone has moved to rural environments.
O'BRIEN: So, in other words, New York City is exporting among so many other things to so the rest of us, some ozone to the rural areas.
GREGG: Yes.
O'BRIEN: And that is hurting the trees there?
GREGG: Yes. But there is another thing you need to understand in regards to these ozone reactions. You do hear of ozone being high in the city and not to go outside. So why am I saying ozone is higher in the country?
O'BRIEN: You don't see smog alerts in the country. Right?
GREGG: It's because these reactions of ozone formation are cyclical. So when ozone concentrations are low these primary precursors react with oxygen to form ozone. As soon as ozone is high in concentration, those same precursors react with the ozone to remove it from the atmosphere.
O'BRIEN: So the stuff that makes the ozone also eats the ozone.
GREGG: Exactly.
O'BRIEN: Wow.
GREGG: So long as you're in the city you do have the high one- hour peak exposures, but they also will be depleted. O'BRIEN: Some big implications here if you talk about air quality as well as the whole issue of the trees here. Maybe there needs to be more study on the air quality in rural areas.
GREGG: Yes, it's, you know, certainly more rural ozone monitoring would be great. There is, you know, I was able to -- I grew my plants next to atmospheric pollutant monitoring stations and so I was at rural monitoring stations. So some ozone is monitored in the environment, currently. But it could be expanded.
O'BRIEN: You think perhaps there should be more of that?
GREGG: Sure.
O'BRIEN: All right. Jillian Gregg, Corvallis, Oregon. Thanks for checking in and trying to explain something rather complicated in the time and intelligence that is allotted in television which is minimal in both cases. Thank you very much.
TO ORDER A VIDEO OF THIS TRANSCRIPT, PLEASE CALL 800-CNN-NEWS OR USE OUR SECURE ONLINE ORDER FORM LOCATED AT www.fdch.com
Aired July 9, 2003 - 15:41 ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
MILES O'BRIEN, CNN ANCHOR: So where do you think a cottonwood tree has a better chance of thriving, in the cement jungle of the Bronx, say, or the more peaceful rural environment of Long Island? The answer surprised even the scientist doing the study.
On the phone from Corvallis, Oregon ecologist Jillian Gregg. Her study is published today in "Nature" magazine, was done jointly by Cornell University and the Institute of Ecosystem Studies in Millbrook, New York. Glad we got that all out. Jillian, good to have you with us.
JILLIAN GREGG, ECOLOGIST: Hello, can you hear me?
O'BRIEN: Yes, I sure can.
Now you planted trees, I think we have a little graphic to support this. You planted identical trees, same lineage, so forth. Mixed up the soil so the soil wasn't a factor. And the trees -- I don't know if you can see CNN, but you're towering above some trees here. Where were these trees planted?
GREGG: So you have a picture with urban trees, perhaps on the left that are larger...
O'BRIEN: Oh, yes. There you go, your right is the urban trees and then you see the other ones there. So what you're telling me is the urban trees are bigger.
GREGG: Right.
O'BRIEN: And that's quite surprising conclusion, isn't it?
GREGG: It is quite a surprising conclusion.
O'BRIEN: What is at work here?
GREGG: Well, I was expecting to start at the beginning of my story, not at the end. I have to tell you a little bit about the beginning.
O'BRIEN: Give me a little back story, Jillian. It's OK.
GREGG: A little bit about the beginning is that I was very interested in studying the effects of human cause changes on plant growth. And, you know, lots of researchers have looked at the effects individual factors, elevated temperature or CO2, ozone, acid rain, heavy metals.
But in the real world everything changes simultaneously. So the real question is what is the net growth response to multiple different, you know, multiple different changes.
So what I did is I went to the site where I found the highest concentration of the most pollutants and measured what is the net growth response. So I took those genetically identical cottonwood clones that you can see there in the photograph and I planted them in the city and the country to see where they grew the best.
O'BRIEN: And voila. The tree in Brooklyn thrived, to take a little poetic license there. And at the root of this is ozone. Here's the other counterintuitive part of this study. You discovered over time ozone, which is kind of related to emissions from vehicles, for example, and is a problem for people with respiratory issues.
GREGG: Yes.
O'BRIEN: Ozone is actually more concentrated over time in the country. Why is that?
GREGG: OK. So there's a couple different explanations you need to understand. First is that ozone is secondary pollutant. So the primary precursors are emitted in New York City and then they have to react in the presence of sunlight over time before the ozone is formed. By that time the ozone has moved to rural environments.
O'BRIEN: So, in other words, New York City is exporting among so many other things to so the rest of us, some ozone to the rural areas.
GREGG: Yes.
O'BRIEN: And that is hurting the trees there?
GREGG: Yes. But there is another thing you need to understand in regards to these ozone reactions. You do hear of ozone being high in the city and not to go outside. So why am I saying ozone is higher in the country?
O'BRIEN: You don't see smog alerts in the country. Right?
GREGG: It's because these reactions of ozone formation are cyclical. So when ozone concentrations are low these primary precursors react with oxygen to form ozone. As soon as ozone is high in concentration, those same precursors react with the ozone to remove it from the atmosphere.
O'BRIEN: So the stuff that makes the ozone also eats the ozone.
GREGG: Exactly.
O'BRIEN: Wow.
GREGG: So long as you're in the city you do have the high one- hour peak exposures, but they also will be depleted. O'BRIEN: Some big implications here if you talk about air quality as well as the whole issue of the trees here. Maybe there needs to be more study on the air quality in rural areas.
GREGG: Yes, it's, you know, certainly more rural ozone monitoring would be great. There is, you know, I was able to -- I grew my plants next to atmospheric pollutant monitoring stations and so I was at rural monitoring stations. So some ozone is monitored in the environment, currently. But it could be expanded.
O'BRIEN: You think perhaps there should be more of that?
GREGG: Sure.
O'BRIEN: All right. Jillian Gregg, Corvallis, Oregon. Thanks for checking in and trying to explain something rather complicated in the time and intelligence that is allotted in television which is minimal in both cases. Thank you very much.
TO ORDER A VIDEO OF THIS TRANSCRIPT, PLEASE CALL 800-CNN-NEWS OR USE OUR SECURE ONLINE ORDER FORM LOCATED AT www.fdch.com
