Science Snippet: Rising Sea Level

Some climate scientists predict that by the year 2100, sea level will be three or more feet higher than today. If you live far from the ocean in Nebraska, or high above it in Boulder, Colo., you won’t worry too much about rising sea level.

However, the lives of millions of people in low-lying states (e.g., Florida) and coastal cities such as New York and Tokyo, will be changed forever. Sea level is now three inches higher than it was in 1992, but the rate at which it is rising is rapidly accelerating as global warming increases. Oceans absorb most of the excess heat trapped in the atmosphere, and as they warm their mass increases. This thermal expansion and the melting of land-based ice masses, such as glaciers and the Western Antarctic Ice Sheet, guarantee sea level rise.

The Western Sheet is in fact melting at an unusual rate, and if completely melted, sea level would rise more than 18 feet. Tom Wagner, a sea-level researcher at NASA, says: “People need to know that the planet is not only changing – it is changed.”

(2015, climate.gov/news-features; The Week, Sept. 25, 2015; Joughin et al, 2014, “Marine ice sheet collapse potentially underway for the Thwaites glacier basin, West Antarctica,”Science, July 9; Mouginot et al, 2014, “Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica,” Geophys. Res. Letters, July 9).