Adding to the River of Knowledge

“I wanted to go after things that were important to our planet ... it’s a feeling that if I can contribute in some way, then I should try.”

As a senior scientist at the National Oceanic and Atmospheric Administration, Susan Solomon (CHEM ’77) spends hours consulting the Internet, analyzing atmospheric chemistry observations and models, and studying columns of data about Earth. While she admits that the computer is an indispensable tool, Solomon also says that a perhaps more dated object holds timeless appeal for her.

“I love going to a library and just looking at the books,” she told a group of IIT students who had the opportunity to meet with her before she delivered the Darsh T. Wasan Lecture in October.

“One of the things I started doing early in my career, and still do to some extent, is when I become interested in a particular scientific problem, I go to the library and trace it back to find out who was the first person who actually thought about this issue. I find it difficult just working on the Internet to see what I call the flow of the river of knowledge. To me, being a scientist is all about contributing to that flow, putting a couple of drops into the river. I want to understand the river, and in order to do that, I really want to see the original books.”

Solomon’s immersion into her chosen career took place at IIT’s Paul V. Galvin Library. Her interest in quantitative chemistry led her to do a senior project with the late IIT Professor David Gutman, an expert in reaction kinetics. His work on the rate of a chemical reaction that was significant to the atmosphere of Jupiter inspired her to dig through Galvin’s books and journals to further research the chemistry of planetary atmospherics. This research further fueled a passion Solomon had begun to develop earlier in her life.

“I wanted to go after things that were important to our planet,” she says. “It’s a feeling that if I can contribute in some way, then I should try.”

After graduating from IIT and earning her doctorate from the University of California, Berkeley, where she specialized in atmospheric chemistry, Solomon started working for the NOAA. She became adept at computer modeling, and using that technique she surmised that a unique chemical reaction was occurring on the surfaces of clouds in the lower Antarctic stratosphere, contributing to the destruction of the protective ozone layer in that part of the world. In 1986, she was tapped to lead a team to the McMurdo Station to get direct measurements to test all the possibilities. Light measurements she and her team took onsite supported her hypothesis that chlorofluorocarbons, organic compounds used at that time in personal care products and coolant systems, were the main driver of the reaction.

The following year, the Montreal Protocol was established, with representatives from 24 nations signing the treaty to limit the production of CFCs; by September 2009, all member countries of the United Nations ratified the original protocol.

During the more than three decades that she has been with the NOAA, Solomon has expanded her research to include climate change, and is considered one of the world’s leading experts in the field. She was named co-chair of Working Group One of the Intergovernmental Panel on Climate Change and helped to compile a landmark report on global warming. In 2007, the IPCC and former Vice President Al Gore shared in the Nobel Peace Prize for their efforts. In the Wasan Lecture, “A Tale for Our Times: Something for Everyone About Climate Change and the Reasons for Climate Gridlock,” Solomon noted that the climate change issue differs from the CFC issue on several levels. While it was easy for everyone to understand that skin cancer cases would likely rise if the protective ozone layer continued to be eroded, it may be a lot more difficult to imagine the varying predicted effects of global warming—from increased heavy rainfall in the Midwestern United States to 10-20 percent drier conditions in Mediterranean countries—and their repercussions.

The amount of the greenhouse gas carbon dioxide that Americans alone emit is now approximately 25 tons per person per year. “On average, the 5.5 billion people in the developing world emit about five times less carbon dioxide per person than the 1 billion people in the developed world,” she says, adding that the problem is not so much a function of the number of people as much as it is that lifestyles have become increasingly prosperous.

While the ozone layer is expected to recover by the middle of the twenty-first century, at today’s emission rates 20 percent of the carbon dioxide added by people today will still be circulating in the Earth’s atmosphere 1,000 years from now. Trees, the soil, and the upper levels of the oceans—normal carbon dioxide sinks—become saturated with the gas so that only the deep ocean remains as a long-term reservoir, but the rate of uptake there is very slow. According to Solomon, the only way to increase that rate is by altering the carbonate-bicarbonate equilibrium of the sea water, which takes many thousands of years.

She is hopeful that considerations being taken now in the development of future infrastructure and alternative energy forms, along with public discussion on climate change issues, will lead to the best direction for society. Solomon is adamant, however, that policymaking decisions be left to elected leaders.

“Our job as scientists is simply to state the science as we know it and to avoid political advocacy,” she says.

A recipient of the President’s National Medal of Science in 1999 for her ozone discoveries, Solomon continues to conduct ongoing investigations of the ozone hole, looking at recent changes that are further influencing the air circulation and meteorology of Antarctica. She is also performing computer modeling on the persistence of climate change, investigating such topics as how long it would take for the climate to return to the state it was before various chemicals began to be regularly emitted into the atmosphere by people.

It is a way for her to build upon the work of those researchers who came before her and to add to the river of knowledge.