I was surprised by Spencer Weart’s comments on my previous letter. I had explained that when floating sea ice melts, the sea level would actually go down and not up, as the general public has been led to believe. I further stated that the Vostok and Dome-C ice cores from Antarctica show that the main Antarctic ice mass has not melted in the past 730 000 years. That evidence would seem to remove most of the planet’s ice as a possible factor in coastal flooding in the event of global warming.
Instead of addressing those statements, Weart chose to introduce a completely different situation, namely what happens when the ocean’s mean temperature rises—something I never mentioned.
Of course, warming the ocean could raise the sea level due to expansion, as evidently happens during El Niño events, but no one suggests that ocean warming could raise ocean levels by tens of meters and flood low-lying areas. Increased evaporation has apparently lowered ocean levels in some warmed areas.
