 Gettin' Down to the Core with Dr. Mike Bergin by Andrew Kerr October 2006 The gentleman I interviewed on October 5 bears little resemblance to the rugged, bearded fellow in the photo to the right. That's what spending quality time on Greenland's ice cap does to a man. Dr. Mike Bergin (School of Civil and Environmental Engineering, and the School of Earth and Atmospheric Sciences) has traveled around the world studying different aspects of particulate matter (the list includes Chamonix, Nepal, China, and, of course Greenland, where it gets down to -45 degress F). You've probably heard much about the effects CO2 has on global temperature; now get ready to meet aerosols, which also play a critical role in the global warming puzzle. The following interview was conducted October 5, 2006. On growing up in Minnesota... Minnesota, and the Dakotas, and Iowa, Wisconsin, are such fertile, beautiful places! For a long time I wouldn't listen to Garrison Keillor (host of the Minnesota-focused Prairie Home Companion). I thought he was kinda rippin' off Minnesota! And to tell you the truth, being a Minnesotan, I just never pictured it as the quaint, smug kinda place that Garrison Keilor pictured it as. I know when a bunch of my European friends that I work with saw Fargo [a movie set in Minnesota], Europeans are super super into that movie, and they were like, "Now I see why you're so strange, man! Cause you're from Minnesota!" Growin' up in Minnesota, I can't figure out if it was being from Minnesota, or if it was a time thing, that period in the 60's and 70's, but I think parents were a lot less uptight about where their kids were all the time. We lived by a park and we were always in the park, and our park had a hill on it, and you could go sledding and skiing on this little hill; you could walk up and go down. A lot of places in Minneapolis in the winter, they flooded the bottom area of this park and it was an ice rink. In the winter we would spend all of our time sledding and playing around in the park and skating and stuff like that, and in the summer we'd be running around in the park and running around the neighborhood. I think I was always just more interested in being outdoors.  My parents are middle class people. I never went to private schools or things like that. I just went to run-of-the-mill public schools which were solid but not totally engaging. So I kinda was into athletics and played sports and stuff. I was never that serious about it but that was what I liked to do.On getting into engineering... I was always sort of good at math but not great at math. I think my interest, kinda being good at math, translated into engineering. I'd read a little bit about it when I was a senior in high school and thought maybe I'd give it a try. It turns out engineering is a super-hard major! I went from this average run-of-the-mill high school, not studying (and not having to) to going to engineering school, which was super-duper hard! But it was really fun, I felt like I was learning a ton! When I was maybe 10, 12 years old I got into making model rockets and shooting them off, and I think any young boy would like that, because it's kinda like lighting off fireworks, but your parents don't yell at you for doing it. No one says you're going to blow your hand off doing it, although you probably could get hurt much worse! And then I liked physics in high school, and there was some aspect of this, rockets going up, how far they go up, based on the fundamental principles of science, and so I started studying aerospace engineering. I was really fascinated by shooting objects into the air and being able to calculate how high up they go and how fast they come down. I kinda made up my mind that I wanted to be an English major, and my dad said, "OK, you can be an English major, but I'm not paying for you to go to college if you're going to be an English major!" One thing that I liked about engineering was that it was really really challenging. I felt I was learning so much. It was incredibly challenging; it was really hard. In fact, my first year through I wasn't sure I was going to make it. In the big state schools like University of Minnesota, Wisconsin, Penn State, they tend to let in about twice as many people as are going to be able to graduate. On one hand that's really good because they give a lot of people a chance, but on the other hand unless you're really self-motivated you're not going to make it. So I was really super-determined to make it through. A little bit of it probably comes from being involved in sports and being competitive. I felt if it wasn't for my competitive edge I don't think I would have made it through. On changing direction...  I wanted to get some work experience of some kind, so I got into this co-op program. I worked for a small company that made little chips for computers. When you make the chips for computers you have to make them in super-clean-clean environments or else little particles will fall on them and mess them up. It used to be that when you made a computer chip there was about a fifty percent chance that it was not going to work. Part of the reason it wouldn't work was slight mess-ups in the manufacuring process, but another reason was if a little tiny piece of dust got on it, they were putting layer upon layer upon layer on this thing, so it would mess up the way it worked. So part of my job was to figure out how to make things cleaner during manufacturing.I had a randomly assigned advisor in the University of Minnesota and it just turned out that he studied particles in the atmosphere and how to detect them. He had done some work that had to do with my internship. So I started talking to him about that. It turns out University of Minnesota had this really famous, big research group that studies particles and characterized them and figured out what they were made of, where they were coming from, how to keep them from getting onto clean services. Then I went to get a master's degree. And then I got even more interested. At that time I wanted to do something different; I wanted to have an international experience. So I applied for a program to go to Japan to study combustion-generated particles from diesel engines. So I was a graduate student in Japan for a couple of years. And then I came back and I wasn't sure what I wanted to do. I worked at IBM in Rochester, Minnesota for a while doing micro-contamination research. In this case it was keeping computer hard drives clean because it was the same issue: little particles get into your hard drive and that messes it up. So I had taken environmental classes out of curiosity when I was an undergraduate and I'd been thinking a little bit about it. What I thought is that it's something that has a societal relevance to everybody. After working for a couple of years at IBM and kinda talking to my friends who had jobs and seeing what their jobs might be like, I thought it would be kinda fun to be more involved in academia doing research that I chose to do and doing something that was relevant to society. That's when I decided I think I'd like to try and be a professor. I was probably at that time 28, 29. On the cost of college, and being a "middle class" midwesterner in academia... When I went to the University of Minnesota, 1982, the cost was $550 per trimester. So that's pretty cheap. And then I lived on campus and I lived pretty cheaply, and my folks footed me money. The first two years I had summer jobs. First couple years my parents probably paid for my education, and the last couple years I had this internship and I would make enough each semester that I worked that it would be enough for next semester, and then I'd be right back to even and just start working again. I probably do not fit the stereotype of someone who is a professor. My dad went to college; my mom didn't. We don't have any doctors or lawyers or people with PhD's in my family. I think that [back then] it wasn't the normal thing do do. I was working at IBM and I said, I really want to go back to school, and they were like, "What are you talking about, man! How long is that going to take you? Five years? And you're not sure what you want to do when you get out?" On the perils of giving career advice... Undergrads come and ask us for advice all the time about what they should with their lives, and I kinda hold that we're just about the worst people to ask! Because we don't have any experiences other than the intense race to try to become a professor. I usually tell the undergrads that, well, here are my experiences, but listen, you know, you either got to seek out other people or you gotta think deeply within yourself about what you want to do. You come and ask people like me and all we're going to say is you should go to graduate school and become a professor! [laughs] On his PhD, coming to Tech, and visiting the dirtiest and cleanest places on earth... So I started my PhD in 1990. I went on purpose to Carnegie Mellon University. What they were doing was really cool. The Greenland ice sheet has about 200,000 years of snow accumulation to the tip top. And every year when snow falls it catches more or less what is in the air, and so there's a 200,000 year chronology of atmospheric chemistry and composition in the ice core. But it's not exactly clear how you would take the stuff that's in the ice and figure out how much was in the air and how much was being emitted, so it was a non-trivial couple of steps there. So my PhD thesis was to go to Greenland. I spent like six months on top of the Greenland ice sheet to try to figure out how what's in the air gets in the snow. Every so often soot blows over, a diesel truck here from Atlanta blows soot into the air and it gets blown over the Greenland ice sheet, and we're trying to figure out how those things transfer so that if you have a soot concentration in the snow what does that mean was in the air and what does that mean for emissions and how does that affect climate and how are all these climatogical things linked with soot emissions? (Part of the reason I think I was interested was because I grew up in Minnesota and I like cold weather, I like adventures, and it sounded right up my alley. I don't get cold very easy.) After I got done, I thought these little particles have the potential to mess up climate. If there were no particles in the air you should be able to see about 200, 300 miles. Often in Atlanta you can only see 10 miles. All these particles getting into the air from power plants and cars and stuff, they're scattering light. And they look kinda white, so they're scattering light back to space. Because that light is being scattered back into space it's not heating up the ground, so you're getting this cooling effect. So we have this global warming because of CO2, and we have this cooling affect from these particles. My big push [at Georgia Tech] was to go somewhere where the particles are at their worst. We wanted to go somewhere where it's so hazy that if there's an effect, if there's less radiation getting to the surface because of this scattering and absorption of particles, you'd see it there. So I spent the first five years here in China and Nepal. It was so bad in those places that we saw huge, huge effects. So we go to some of the dirtiest places in the world, but we also go to some of the cleanest, like Greenland. The positive aspect of these jobs is that you get to travel, go to cool places, and meet people from different cultures and stuff. On what ice cores tell us about the history of temperature...  So you get in Greenland, like a half meter to a meter of snow falls. And then more snow falls on it, then more snow, then more snow and more snow and more snow, and then after having about 70 to a hundred meters of stuff piled on it it gets squished into ice. The air that was in that ice gets squished into little ice bubbles, and so what scientists do is cut pieces of the ice core. There's many different ways to date it. You can date it to a very high precision. You can go back 150,000 years, plus or minus hundreds of years, thousands at most. And you look at those bubbles and those bubbles trap the CO2 from the atmosphere at that time.The part that I'm looking at is particles, and that's actually much more difficult to get out for various reasons, because little shifts in the different properties of the particles can make it deposit at different rates... The main things [ice cores] give us is temperature from the oxygen isotopes. It turns out that water, H2O, there's different flavors of oxygen. Oxygen is mostly 8 protons and 8 neutrons, so that it has a molecular weight of 16. But every so often the isotopes have more or less neutrons. So it turns out you have heavier and lighter water, and it turns out when it's warmer you get more of the heavy water with respect to the light water, and when it's colder you get more of the light with respect to heavy. And you can actually look at the water molecules. So from that we can get an approximate temperature, which is fairly trustworthy; even the skeptics believe that. (It seems there are fewer and fewer climate skeptics all the time.) On aerosols... An aerosol by definition is a solid or liquid particle in a gas. So right now in this room per cubic meter there's probably about a million particles per cubic meter in this room. The ones in this room right now are probably 50% sulfate, which comes from sulfuric acid, which is from power plants, and probably 30% of it is carbon from burning stuff, primarily (in this state) from cars. And then another 5 to 10% is kicked up dust from the roads. You can't see them, so you have to use some relatively high tech means to determine what they are. We don't really completely understand where they're coming from. The sulfur we know is coming from power plants, but all these carbon compounds, we don't know if they're coming more from diesel or gasoline vehicles, or to what extent they're coming from burning across the state. There's all sorts of other issues about sulfur here; are they coming from power plants in Georgia, or are they coming from power plants outside of Georgia? In the U.S. in general in the grand scheme, the particle concentrations are going down. Worldwide that's not exactly the case, because India is industrializing and so is China, so their emissions are going way up. The EPA sets concentrations to protect human health, and the concentrations, even though they are going down, still exceed the EPA standard. So for health impacts they're still too high. Georgia Performance Standards (-- Show --) |