Ends of the Earth: Journeys to the Polar Regions in Search of Life, the Cosmos, and Our Future

by Neil Shubin

As temperatures ranged over 6 degrees Celsius for the past 400,000 years, sea levels varied by almost 360 feet. When scientists plot temperature against sea-level rise over the last 400,000 years, they get a straight line—for every 1 degree Celsius of temperature rise, there was nearly 60 feet of sea-level rise. But if we look at the current situation on that graph, there is a disconnect: For our current global temperature, we sit at a relatively low level of ocean, based on data from the past. The position of this point on the graph means that as the globe adjusts to the very recent increases in temperature, sea levels will inevitably rise over time. Studies of the past predict that if we do nothing to lower temperatures, sea levels will rise by 120 feet in coming centuries. How fast this rise happens is anybody’s guess, but change in coastlines and the oceans is, to pardon the pun, already baked in.