Proc. Natl Acad. Sci. USA http://doi.org/j65 (2012)

Sea-level rise is a potentially significant consequence of climate change. Accurately predicting the magnitude of change is difficult, however, because current climate models are unable to resolve the dynamic processes that govern ice-sheet changes.

To overcome these challenges, Gavin Foster and Eelco Rohling, of the National Oceanography Centre Southampton, UK, use reconstructions of atmospheric carbon dioxide concentrations and sea level over the last 40 million years to define the relationship between the two more clearly.

Their work identifies a clear correlation between atmospheric carbon dioxide and sea level over geological timescales, suggesting that other variables — such as ocean circulation and topography — play a secondary role in the evolution of Earth's climate. Although the work focuses on very long timescales it has implications for the present, as they report that limiting greenhouse-gas emissions to meet the 2 °C warming target might still result in over 9 m of sea-level rise in the long-term.