I found the 2008 Presidential elections memorable for several reasons, not the least of which was the list of characters playing out the drama. One of the most interesting was the Republican vice-presidential nominee, a little-known, spunky governor from Alaska, Sarah Palin. Among Palin's more memorable and disturbing comments was her belief that global warming was not man-made, scientifically proven, or important. In an interview with Newsmax, Palin stated, "I'm not one though who would attribute [global warming] to being man-made.” Her spokesman was also quoted as saying that "she's not totally convinced one way or the other. Science will tell us ... She thinks the jury's still out."
I could not understand how anyone could possibly believe that our decades of disregard for the environment were not directly contributing to global warming. The evidence for global warming and man’s influence on global warming is overwhelming. I was also deeply concerned that millions of Americans were hearing this from a vice-presidential nominee and might actually believe it.
Reflecting on this impossibility, I came across a radio show transcript by Mark Levin, who cited research showing that the earth was heading for a new ice age, and that the greenhouse gases we are trying to control may prevent this disastrous global cooling. In the cited Nature paper from 2008, Thomas Crowley and William Hyde use data from geological core samples (samples of ice and rock bored from the earth that date back millions of years) and mathematical models to support their global cooling theory. The mathematical models use the geological core data and data on ice volume, ice movements, and global temperatures to simulate past global climate events and predict future events.
The Crowley and Hyde model accurately simulated the large variations observed in the global climate over the past million years. It also predicted that the global climate was approaching a crossroads that would lead to a more stable, cold climate with glacial ice covering large swaths of the Northern hemisphere. The authors briefly state that greenhouse gas emissions, which have resulted in global warming, may disrupt this process and block the invading ice. Naturally, this detail was not lost on all of the global warming naysayers and therefore became “evidence” for Palin, Levin, and others.
Global warming opponents misinterpret Crowley and Hyde's work, ignoring two key caveats in the model. First, the rapid shift to the glacial climate will not occur for another 10,000 to 100,000 years, which is rapid on the earth’s geological timescale, but extremely slow on the human timescale. Crowley has asserted that this time frame is certainly long enough for mankind to develop ways to deal with the encroaching ice age. Second, the model does not take into account the influence of man on the global climate. This is important, because the rate of global warming induced by man-made pollution may heat the earth to uninhabitable temperatures long before the ice age will begin.
So, while all the Palins and Levins out there still mistakenly believe that we should not worry about global warming, Crowley, Hyde, Gore, and many others continue the crusade to reduce the damage we inflict on the earth and its climate. If we do not solve this man-made global warming problem, Crowley warns that we will be “creating a situation at least as dangerous [as the Ice Age], only going in the opposite direction”. The question becomes would we rather ignore the data on global warming and rapidly fry ourselves into extinction or take the next 10,000 to 100,000 years to reduce our greenhouse gas emissions and carefully prepare for life in a colder climate? I think that the logical answer is as clear as ice.
Paper: Transient nature of late Pleistocene climate variability. Nature 2008.
Images: 1. Flickr/wili_hybrid 2. Flickr/Alaskan Dude