Sea Level Rise, Way Worse than We Thought (Again)

BY LAURA TAM, SUSTAINABLE DEVELOPMENT POLICY DIRECTOR
December 18, 2009

A paper this week in what is arguably the world's most prestigious scientific journal, Nature, says that the last time the Earth warmed up as much as it will under climate change, sea levels rose about 8 meters. This means that global sea level rise over the coming decades may be about twice as worse as we thought. When we published two articles in the Urbanist last month on the topic of sea level rise, we reported that sea level rise might possibly be 5-7 m higher in 300 years, and very likely 1.5 m by 2100. (these were the most well-documented worst-case scenario numbers I could find).

This new paper - a great analysis here - says sea level rise is very likely going to rise 20-30 feet (6-9 m) if we hold temperature to about 3.6 degrees F higher than today. We don't know when we'll get these levels.  We only know we'll be committed to them even if we somehow manage to slow down climate change.

As of today's proposals in Copenhagen, the temperature in 2100 is going to be 7 degrees F hotter.