Ice

By Mark Pagani, John Wettlaufer, Jeffrey Park and David Bercovici

This week begins the United Nations Climate Change conference in Copenhagen, following the controversy of stolen emails from the University of East Anglia’s Climate Center. Both events have inspired a flood of news stories, editorials and blogs.

Although climate change remains one of our most urgent contemporary issues, it is wise to step back and view the big picture of what scientists do and do not understand about the Earth’s climate system and future climate change.

In his new book, A World Without Ice, geophysicist Henry Pollack explains the complex influences that Earth's ice has had on human survival, and that population growth and industrialization are now having on the survival of Earth's ice. Following is an excerpt.

By Henry Pollack

Just as the international financial system surprised the world with a major collapse in 2008, the global climate system, with its human component, is equally capable of serious surprises.

Lurking in the shadows of climate change is the possibility that the accelerations we now observe in the climate system are portends of approaching tipping points.