Princeton Engineering

Engineers, scientists and policy experts tackle energy and climate problems

Practically every activity of every human being every day contributes to perhaps the most dramatic experiment ever conducted—what happens to life on Earth if the atmospheric concentration of carbon dioxide gas triples?

Any action that consumes fossil fuels or changes land use plays a role in the current human pattern of transferring billions of tons of carbon from plants and the ground into the atmosphere each year. At the current rate, the percentage of atmospheric carbon dioxide gas will triple during this century from pre-industrial levels.

The general effect of this change appears to be that the planet gets warmer because carbon dioxide traps the sun’s heat. The specific consequences still are being determined but appear to include loss of polar ice, coastal land areas, coral reefs and biodiversity, changes in ocean circulation and weather patterns, and increases in disease propagation.

The complexity of understanding, monitoring and, ultimately, controlling this experiment is staggering. Each aspect requires close interaction among scientists, policy-makers, engineers and business leaders. Building on these connections forms the basis of Princeton Engineering’s strategy for helping to manage the carbon experiment.

“We are taking a big-picture approach to this problem,” said H. Vincent Poor *77, dean of engineering. “We are working ever more closely with our colleagues in the natural sciences and public policy to develop a coordinated approach and go after the big questions, including the fundamental technologies that need to be in place to move forward.”

This approach already is making a difference. In 2004, Stephen Pacala, professor of ecology and evolutionary biology, and Robert Socolow, professor of mechanical and aerospace engineering, teamed up to publish a landmark paper in the journal Science outlining what could be done to hold global carbon emissions steady for the next 50 years, thus keeping the atmospheric concentration of carbon dioxide on track, with further effort, to stay just below double pre-industrial levels. Their paper, which divides possible solutions into easy-to-understand “wedges,” quickly became a standard way of describing the problem and is referred to at practically all climate conferences.

“The wedges concept has become the iPod of climate policy,” said David Hawkins, director of the Climate Center at the National Resources Defense Council. “By designing an attractive and recognizable package, Pacala and Socolow have provided the climate community with a versatile and accessible tool that helps clarify the murky subject of reducing greenhouse gas pollution. Like the iPod, the wedges image is a versatile container that different users can fill with their favorite ideas on how to fight global warming.”

Former vice president Al Gore featured the wedges concept in “An Inconvenient Truth,” his film about climate change.

Pacala and Socolow are co-directors of the Princeton Environmental Institute’s Carbon Mitigation Initiative, a 10-year venture funded in 2000 by BP and Ford. The initiative, which exemplifies Princeton’s multidisciplinary approach, seeks to understand and develop solutions for the carbon problem.

In the following brief articles, EQuad News presents three examples of research projects within Princeton Engineering, each of which could contribute a wedge or more of climate solutions. Much of this research receives funding through the Carbon Mitigation Initiative as well as from the National Science Foundation, the Department of Energy and other sources. A fourth project presented here improves the prospects of nuclear fusion, a safe and clean energy source that may become crucial in the second half of the century.

In addition to contributing to these technological solutions, Princeton engineers are advancing the techniques and devices needed to improve fundamental climate science. Civil and environmental engineer Professor Eric Wood, for example, is developing hydrological models that feed into scientists’ overall understanding of how water, land and air interact. In the same department, Professor James Smith is part of Princeton’s newly established MIRTHE center for mid-infrared sensors and is developing technology that could better monitor greenhouse gasses in the atmosphere.

This rich collection of expertise positions Princeton to be the leading institution in the world for dealing with the overall climate problem, said Pacala, who directs the Princeton Environmental Institute. Strong programs in engineering, science and public policy combine with the presence at Princeton of two important national labs: the Princeton Plasma Physics Lab, which is the nation’s first research center for nuclear fusion, and the Geophysical Fluid Dynamics Lab, which is one of the most important climate modeling centers in the world.

The payoff for reducing carbon emissions goes beyond slowing climate change. Pacala and Socolow noted that a technology designed to solve that one problem often will eliminate other forms of pollution, including smog and acid rain, and increase U.S. energy independence, thereby improving national security and easing global tensions.

“It’s an example where you solve multiple societal problems by inventing a technological solution to solve one,” Pacala said.