State of Fear the Day After Tomorrow?

(A Geological Perspective on Global Warming)

George Philander

Knox Taylor Professor of Geosciences
Director, AOS Program
Princeton University

The recent Michael Chrichton novel contradicts the Hollywood movie "Day after tomorrow", thus giving the impression that the debate about global warming is at a stalemate. The geological record of climate changes over the past 3 million years (3 Ma) provides a more compelling perspective, even stranger than the fiction in the movie and novel. The present is seen to be a precarious moment in the history of an exceptional planet, Earth. Even though the Milankovitch forcing (modest, perfectly periodic variations in sunlight) has been practically constant, the response to that forcing has amplified enormously over the past 3 Ma, culminating in dramatic oscillations between prolonged Ice Ages and brief, warm interglacial periods such as the present one. In the absence of other perturbations, the Milankovitch Cycle will, any millennium now, initiate a new Ice Age. Will the rise in the atmospheric concentration of greenhouse gases prevent that and, instead, return us to the warm world of 3 Ma? How did that world differ from ours?

About the Lecturer

For more information about George Philander, visit www.aos.princeton.edu/faculty/Philanderweb-3.html.

George Philander