Making a Difference: Climate Scientist

Dr. Susan Solomon

The ozone hole can be seen in this satellite image. The hole is the pale blue and black region immediately above Solomon’s shoulder

Susan Solomon will not soon forget crawling across the roof of an Antarctic field station in windchill temperatures of –62°C (–80°F), moving heavy equipment, and adjusting mirrors while the winds howled and whipped about her. Sounds like an adventure, right? It sure was! But it is just part of what Solomon has done to establish herself as one of the world’s leading authorities on ozone destruction.

Q: What is the significance of discoveries regarding the ozone hole?
A: Before British scientists discovered the ozone hole in Antarctica, no one was sure about ozone changes in the atmosphere. The popular belief was that in 100 years there might be 5 percent less ozone. So there were questions about whether it was a serious environmental problem. But when the British researchers released data that showed 50 percent less ozone over Antarctica in 1985 than was present 20 years earlier, the research raised our awareness that the problem was far more serious than previously thought.

Q: How have you contributed to the study of ozone?
A: Well, when the British data was first released, no one had much of an explanation about what was causing the destruction of the ozone layer. I”thought about the problem a lot. I got to thinking about types of clouds called polar stratospheric clouds. These are beautifully colored clouds that are known for their iridescence. While I was looking at these clouds, which are common in the Ant arctic but rare elsewhere, it occurred to me that they may have something to do with ozone depletion. Perhaps they provide a surface for chemical reactions that activate reactive chlorine from CFCs (human-made chlorofluorocarbons). If so, once activated, the chlorine could contribute to”reactions that destroy ozone.

Q: Did you get the chance to test your hypothesis?
A: Yes, the next year the National Science Foundation chose me to lead a group of 16 scientists for a nine-week expedition in Antarctica. We were the first team of scientists from the United States sent to the Antarctic to study the ozone hole. Within one month we could see that unnaturally high levels of chlorine dioxide did occur in the stratosphere during ozone depletion. This discovery was very exciting because it seemed that we were on the right track. We kept collecting data that year and collected more data during a second trip the next year. Pretty soon, the evidence seemed to support my hypothesis that CFCs and ozone depletion are linked.

Q: How has your research helped to make a difference in our world?
A: Since our findings and others were announced, the world’s countries decided to stop making CFCs. As a result, the ozone hole will eventually go away, but it will take a very long time. So although we aren’t adding CFCs to the atmosphere anymore, the CFCs from years past will still be hanging around in our atmosphere for the next 50 to 100 years. But I think our work has led in a small way to the realization that our actions do have consequences, and this realization should bring positive change.

Dr. Solomon has received international recognition for her work on the ozone hole over the Antarctic. She is a member of the U.S. National Academy of Sciences, the European Academy of Sciences, the Académie des Sciences de France, and the Royal Society in the United Kingdom. In 2000, Dr. Solomon was awarded the National Medal of Science and the American Meteorological Society’s Carl-Gustav Rossby Medal. She was co-chair of the science panel of the United Nations Intergovernmental Panel on Climate Change, which won the Nobel Peace Prize in 2007.

climate research

Solomon has braved freezing polar temperatures to gather data about the ozone hole.

Q: What kinds of research projects are you working on today?
A: One of the main things I do is to study how a broad range of chemicals contributes to climate change—not just carbon dioxide, although carbon dioxide too, of course. To me it’s one of the most interesting chemicals, but it’s not the only one that is actually contributing to the way our climate is changing. So I’m doing work on everything from aerosol particles in the stratosphere to water vapor to different kinds of industrial chemicals like hydrofluorocarbons and perfluorocarbons. I’m a chemist by training and I’m absolutely fascinated by anything that affects the chemistry of our atmosphere or its climate. I’m also continuing to work on stratospheric ozone. There’s a number of different issues there that from a scientific point of view remain tremendously fascinating and are still interesting questions for the community to address.

Q: Why would a young scientist want to study climate change?
A: Climate science is certainly one of the most important challenges that humanity has ever faced. Climate change, whichever way it comes out, whether it turns out to be something that we manage wisely or unwisely or whatever, I think it’s quite clear that the planet in the next 20 to 40 years is going to change in ways that we haven’t even really thought about. We’re constantly turning the corner and being confronted with new ways in which climate change is manifesting itself, whether that’s acidification of the ocean and what it may do to various different kinds of organisms or what it does to insects and the way that they interact with forests, things like the mountain pine beetle, which is ravaging the forests of the west and Canada, all those sorts of questions. How much are these things changing? How much of that change is human-induced? What is it going to do in the future? These are epic questions. I find it very exciting from a scientific point of view that we’re standing on the threshold of a different planet. It’s going to happen in our lifetime. So what better thing for a young scientist to pick than an area of science that is about to explode? It’s just a great time to be doing climate science in my opinion.

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