By Kathryn O’Neill
Civil & Environmental Engineering Correspondent

CEE Professor Sallie (Penny) Chisholm has been awarded the National Medal of Science, the nation’s highest honor in science and engineering. President Obama presented her with the award in a White House ceremony on February 1, 2013.

“Winning this award is without a doubt the high point of my career,” said Chisholm, who is the Lee and Geraldine Martin Professor of Environmental Studies in the Department of Civil and Environmental Engineering and the Department of Biology. “The White House ceremony was much more thrilling than I had imagined. It is difficult to describe, but it was an incredible privilege to be there and to have the medal put around my neck by the president.”

Chisholm was one of just 12 researchers across the country to receive the Medal of Science for 2011. The ceremony also honored the 11 winners of the National Medal of Technology and Innovation, including Robert Langer, the David H. Koch Institute Professor at MIT.

“We are so grateful to all of you,” Obama said. “The incredible contributions that you’ve made have enhanced our lives in immeasurable ways, in ways that are practical but also inspirational. And so we know that you are going to continue to inspire and in many cases teach the next generation of inventors and scientists who will discover things that we can’t even dream of at this point.”

Chisholm is best known for her research on the ocean phytoplankton Prochlorococcus — the world’s smallest, yet most abundant, photosynthetic organism. Chisholm led the team that discovered it in 1988.  Using this cyanobacterium as a model system, she has focused her research on how marine microbes shape the chemical composition of the Earth’s oceans and atmosphere. Her medal citation reads: “For contributions to the discovery and understanding of the dominant photosynthetic organisms in the ocean, promotion of the field of microbial oceanography, and influence on marine policy and management.”

A passionate advocate for public science education, Chisholm is also the co-author (with illustrator Molly Bang) of two books for children: Living Sunlight: How Plants Bring the Earth to Life (The Blue Sky Press, 2009) and Ocean Sunlight: How Tiny Plants Feed the Seas (The Blue Sky Press, 2012), both of which have been awarded the American Association for the Advancement of Science/Subaru SB&F Prize for Excellence in Science Books, which celebrates outstanding science writing and illustration for children and young adults.

A Fellow of the American Association for the Advancement of Science and Member of the National Academy of Sciences, Chisholm also shared the Ruth Patrick Award last year from the Association for the Sciences of Limnology and Oceanography (ASLO) for her “effective efforts in addressing the environmental impacts of ocean iron fertilization.”

Iron fertilization has been proposed as a method for removing carbon dioxide from the atmosphere. Seeding the ocean with iron will promote the growth of phytoplankton in certain areas, which in turn could potentially take in carbon dioxide from the atmosphere. However, Chisholm and others have argued that the plan would significantly alter oceanic food webs and biogeochemical cycles.

“Our joint awardees have steadfastly and clearly communicated the issues, pitfalls, and dangers of ocean iron fertilization for twenty years,” the ASLO wrote.

“I have always felt extremely lucky to have chosen science as my career path and to be able to follow that path at MIT. where the advantages are many and the students are fantastic,” Chisholm said. “For all this, and for the Medal of Science, I am extremely grateful.”

Awarded annually, the National Medal of Science honors outstanding contributions in chemistry, engineering, computing, mathematics, and the biological, behavioral/social, and physical sciences. The National Medal of Technology and Innovation recognizes achievement in the innovation, development, commercialization, and management of technology.

“I am proud to honor these inspiring American innovators,” Obama said in announcing the medalists in December. “They represent the ingenuity and imagination that has long made this nation great.”