Global Science Report is a feature from the Center for the Study of Science, where we highlight one or two important new items in the scientific literature or the popular media. For broader and more technical perspectives, consult our monthly “Current Wisdom.”
The Washington Post, yesterday, fanned the flames of a dispute over how much sea level rise the residents of the North Carolina Outer Banks should plan upon for this century.
The dispute arose when, a few years ago, politicians in Raleigh decided to get involved in the business of climate forecasting, and decreed that the Outer Banks region should expect a 39-inch sea level rise by the year 2100 and that people need to plan for a future based upon this number. Some of the rumored plans include abandonment of the region’s major roadways, stopping new construction, and re-zoning the land to declare all property at an elevation less than 39 inches to be uninhabitable. The state government under then-governor Beverly Perdue (D) was “helping” by preparing a website that showed all property that would be under water by the year 2100, deep-sixing the equity held in many beach houses.
It’s no surprise that there’s a pushback against the state’s 39-inch forecast, which was based on a selection of outdated science that foretold a much more alarming story than newer scientific studies.
For example, the latest (fifth) assessment report from the U.N.’s Intergovernmental Panel on Climate Change (IPCC) projects that the global average sea level rise over the course of the 21st century would be in the range of 10 to 32 inches, with a mean value of about 19 inches. This is only about 50% of the 39-inch projection.
And, the IPCC projection is probably too high because it was driven by a collection of climate models which new science indicates produce too much warming given a rise in atmospheric carbon dioxide levels. If the models were forced to run with a lower sensitivity to carbon dioxide emissions, their sea level rise projections would decline proportionally, down to about 13 inches. This arguably better value is only 1/3rd of the 39-inch value forwarded by the NC state government. No wonder the realtors and mortgage bankers were up in arms about Bev Purdue’s map.