The U.S. Fish and Wildlife Service has created an Internet tool that simulates sea level rise. The Sea Level Affecting Marshes Model (SLAMM)-View (http://www.fws.gov/slamm/ and http://www.slammview.org) displays map pairs of the same area, each at different sea levels.

“Sea level rise is certainly one of the most pressing issues facing many coastal communities, as well as national wildlife refuges,” said Chincoteague National Wildlife Refuge Manager Lou Hinds. “SLAMM will be used by many coastal refuge managers to involve the public in discussions concerning sea level rise as part of the Comprehensive Conservation Planning process. This planning process must be undertaken every 15 years and unless something changes dramatically coastal refuges will be dealing with this issue over the next 100 years,” Hinds added.

The SLAMM predicts changes in coastal wetlands and shorelines.

What might not be clear to many users, however, is that the depictions are entirely dependent on assumptions about the severity of global warming and sea level rise. The FWS’s press release specified, “Users can select different scenarios by combining time, in 25-year intervals, at different severities, e.g., 0.5 meters to 1 meter increase in sea level.” What it didn’t mention is that 0.5 meters, the low end, is itself above the mid-range projections of the UN Intergovernmental Panel on Climate Change’s 2007 Assessment Report and more than double the high end of the more credible projection of 0 to 7.88 inches by the Sea Level Commission of the International Union for Quaternary Research.

Assumptions matter. Reality matters a lot more.