The good news: Sea levels are, uh, where they are right now, meaning if you were thinking about purchasing beachfront property, that option is still on the table. The bad news? It shouldn’t be. According to researchers at the University of Florida, historical data suggests that at the present global temperature levels, sea levels ought to be a lot higher – as much as 20 feet higher.
Using computer models and geologic records, the researchers concluded that when temperatures were between 1 to 3 °C higher than at preindustrial levels, global sea levels where anywhere from 20 to 40 feet higher. That was due to the melting of the polar ice sheets, which isn’t happening now, for some reason.
“This evidence leads us to conclude that the polar ice sheets are out of equilibrium with the present climate,” said lead author Andrea Dutton.
According to the data, sea levels were about 20 feet higher 125,000 years ago, when the global average temperature was 1 °C higher than preindustrial levels – similar to today. Sea levels reached similar heights around 400,000 years ago, though temperature estimates aren’t as certain.
More disheartening – at the time atmospheric CO2 levels peaked at about 280 ppm, while today’s levels are somewhere around 400 ppm. On the one hand that number is atrocious, but on the other it’s somewhat comforting to know that things like sea levels and ice sheet retreat don’t have simple relationships with temperature and greenhouse gasses. Determining those relationships, the researchers say, will be the focus of further studies.