A Review of DEEP FUTURE:The Next 100,000 Years of Life on Earth

by Curt Stager, New York, St. Martin’s Press, 2011.

Climatologist Curt Stager speculates on the long-term prospects for Earth’s life forms, based on two scenarios—a moderate “path” if we limit CO2 levels to 600 ppm and a “Super-Greenhouse” situation if we “consume all our easily accessible coal,” reaching a peak of 2000 ppm around 2300 A. D.

Armed with a Ph. D. in biology and geology from Duke University, Stager explores the details of various life-threatening scenarios for both futures and notes that we will probably experience a warming similar to that of the early Cenozoic, 50 millions years ago. At that time “...global average temperatures were 18 to 22o F (10-12oC) or more above today’s mean for several million years. Life had moved north, as evidenced by dense Arctic forests. Many species survived the heat.

Stager introduces his detailed analysis of what might happen to polar bears and other currently familiar life forms by suggesting that our fate would be far worse if the next ice age were to make its expected (but poorly understood?) cyclical appearance on Earth. Such ice could wipe out everything in its path, a much worse scenario than what our CO2-induced long-term hot spell might inflict. We may do better if our long-term warming cancels the next ice age.

I recommend this book for general reading because the author is careful to present current findings with well-balanced, readable analyses. He presents the many facets of each complex situation that human cultures and animals will face. As a result of our current load of carbon dioxide in the atmosphere, he says, “Welcome to the Anthropocene...We’ve stopped the next ice age in its tracks.” It will take tens of thousands of years for current temperature levels to return to preindustrial conditions.

By understanding the details of our options, we could avoid arguments that oversimplify or exaggerate. In any case, we need to do our best to find a safer pass for life into its warm future. Then we might have a better chance of surviving the needed move north.