Climate Change: What We Know and What We Don’t Know

Professor David Helfand in conversation with NY Times science reporter Claudia Dreifus.

When it comes to climate change, public debate is conducted primarily with misinformation and irrational exuberance. This two hour presentation will be something completely different: a dispassionate analysis of what we actually know and what we don’t yet know about climate change. Columbia Professor Helfand will carefully distinguish facts from fictions, and physics certainties from feedback uncertainties.

The fact is, every planet’s temperature is controlled by a simple balance between the energy it receives and the energy it radiates back into space. We will examine each of the main factors affecting this balance, beginning by exploring the astronomical phenomena that have driven climate change in the past. This list includes  solar variability, changes in the Earth’s orbit and other factors over which we have absolutely no control. Professor Helfand  will then go on to show how the composition of the Earth’s atmosphere has changed in the past and is changing today using measurements of prehistoric climate derived numerous ways, including tree rings and ice cores! Examining the current energy balance and what we can expect over the next few decades, we will conclude by exploding a few myths and providing a rational basis for decisions about our future.

David Helfand is a Professor of Astronomy at Columbia University where he served as chair of the Department and co-Director of the Astrophysics Laboratory for 15 years. He is President Emeritus of the American Astronomical Society and of Quest University Canada. He has received the Columbia Presidential Teaching Award and the Great Teacher Award from the Society of Columbia Graduates. His latest book, “A Survival Guide to the Misinformation Age” was just published.

Claudia Dreifus is an American journalist, educator, lecturer, and producer of the feature “Conversation with…” of the Science Section of the New York Times. She is known for her interviews with leading figures in world politics and science. She is also an adjunct associate professor of international affairs and media at the School of International and Public Affairs at Columbia University.