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posted 04/05/02

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Pioneers in Global Climate Change Share 2002 Tyler Environmental Prize
USC Prize Carries $200,000 Award

Two scientists who study geological clues from the past for insight into the environmental problems of the present have been selected to share the 2002 Tyler Prize for Environmental Achievement.

The award, which includes a $200,000 cash prize and gold medallions, will go to Wallace S. Broecker of Columbia University and Tungsheng Liu of the Chinese Academy of Sciences.

The men will be honored by the international environmental community at the University of Southern California -- which administers the prize -- on April 11 during a private luncheon and public lecture. They will accept their prize on April 12 during a ceremony at the Four Seasons Hotel in Beverly Hills.

Broecker, 70, is the Newberry Professor of Earth and Environmental Sciences at Columbia's Lamont-Doherty Earth Observatory and has spent decades studying the ocean's role in global climate change.

The geochemist may be best known for his discovery of a great "conveyor belt" of ocean currents that transports heat around the globe and is tied to abrupt shifts of the earth's climate.

He has repeatedly warned of the danger of releasing greenhouse gases into the atmosphere, often referring to the climate system as an "angry beast" that may lash out if provoked.

An unchecked buildup of greenhouse gases in the atmosphere could alter the oceans' delicately balanced circulation patterns and cause a radical and abrupt reconfiguration of earth's climate, Broecker contends.

"As I sometimes tell my students, the folks in the back room who designed our planet were pretty clever," Broecker wrote in his Columbia faculty biography.

"We have clear evidence that different parts of the earth's climate system are linked in very subtle yet dramatic ways. The climate system has jumped from one mode of operation to another in the past.

"We are trying to understand how the earth's climate system is engineered so we can understand what it takes to trigger mode switches. Until we do, we cannot make precise predictions about future climate change."

Broecker also pioneered new approaches to the study of the earth's climate, using isotopes to date marine sediments and focusing on the demise of the "Little Ice Age," a global cooling event that occurred between 1350 and 1880.

He has also largely shaped scientists' understanding of oceanic carbon dioxide and how it interacts with the atmosphere.

Broecker, who was awarded the National Medal of Science in 1996, led efforts to use Columbia's Biosphere 2 Center as a laboratory to test the impact of carbon dioxide on plant life.

Liu, 84, is a research professor with the Institute of Geology and Geophysics at Beijing's Chinese Academy of Sciences.

He is a trailblazer in developing ways to measure global climate patterns by studying loess, a windblown silt that formed thick deposits in central China and elsewhere.

Starting in the 1940s, Liu demonstrated that loess provided a complete and accurate record of environmental change. The fine-grained dust is now widely considered one of three reliable sources of past environmental information -- the other two are deep-sea sediments and arctic ice cores.

Liu's work has led to a greater understanding of monsoon systems and their variability through time, and has also shown the effect of dust depositions on marine life.

Liu was also instrumental in discovering the cause of Keshan disease, which affected thousands of people in China. He linked the disease to deficiencies of trace elements in soil and water, a problem now countered by supplements of selenium and other nutrients.

Liu, a member of the National Academy of Sciences in China, established the Xi'an Laboratory for Loess Research and the Guiyang Laboratory of Environmental Geochemistry.

He has also helped government officials there improve environmental quality through urban construction reform and encouraged the exchange of scientific knowledge across borders by participating in international conferences.

The Tyler Prize for Environmental Achievement is one of the premier awards for environmental science, energy and medicine.

It was established by the late John and Alice Tyler in 1973 and is awarded annually to those who have made world-class environmental accomplishments.

For more information about the Tyler Prize, go to

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About The Earth Institute
The Earth Institute at Columbia University is the world's leading academic center for the integrated study of Earth, its environment and society. The Earth Institute builds upon excellence in the core disciplines — earth sciences, biological sciences, engineering sciences, social sciences and health sciences — and stresses cross-disciplinary approaches to complex problems. Through research, training and global partnerships, it mobilizes science and technology to advance sustainable development, while placing special emphasis on the needs of the world's poor. For more information, visit