Sea Levels Could Rise By 25 Metres… From Today’s Carbon Dioxide Levels

Posted on 23. Jun, 2009 by Ross in Climate Change

Forget all those predictions of climate change-fuelled sea level rises of 1-5 feet: research from the UK’s National Oceanographic Centre and the universities of Bristol and Tubingen (Germany) has concluded that sea levels are set to rise by 25m, and that’s before we add a single molecule more of carbon dioxide into the atmosphere!

Such a rise in sea levels would leave substantial swathes of most of the world’s largest cities - characteristically sited by the sea or by tidal sections of rivers - abandoned to the fishes.

Most sea level rise predictions are based on calculating quantities of ice melting from the polar regions, along with estimates from the thermal expansion of water under higher global temperature conditions. This study mapped historical changes in atmospheric carbon dioxide with changes in sea level across the last five glacial cycles.

The researchers found a systematic equilibrium between the two factors, based upon which they predict that sea levels are set to rise by 25 metres should carbon dioxide levels remain at their current concentrations. Researchers Michal Kucera and Mark Siddall wrote:

We emphasise that such equilibration of sea level would take several thousands of years, but one still has to worry about the large difference between the inferred high equilibrium sea level and the level where sea level actually stands today. Recent geological history shows that times with similarly strong disequilibria commonly saw pulses of very rapid sea-level adjustment, at rates of 1 to 2 metres per century or higher.

The implications of the study are inescapable. As well as taking efforts to start achieving absolute cuts in global carbon dioxide levels, countries are going to have to invest massive levels of funding to try to mitigate the expected results of such sea level rises.

Image by wonderferret @ Flickr