Sea Level Rise Unstoppable, say Scientists

Even if nations manage to mitigate carbon emission levels, oceans will continue to rise throughout 21st century

Rising sea levels threaten about a tenth of the world's population who live in low-lying areas and islands which are at risk of flooding, including the Caribbean, Maldives and Asia-Pacific island groups. (Photo: Daily Mail)

Even if nations across the globe can agree on effective schemes to mitigate their carbon emissions in significant ways, the world's ocean levels will continue to rise far into the future, according to a new scientific study released on Sunday.

Scientists at the New Jersey-based Climate Central, the US National Center for Atmospheric Research, and the Center for Australian Weather and Climate Research in Melbourne claim that even if the most "aggressive" efforts are made to curb atmospheric global warming, ocean levels would continue to rise even as global surface temperatures stabilize.

The report includes a variety of variable scenarios under which average global temperatures could be stabilized and each scenario received a corresponding fluctuation in the expected behavior of ocean levels. But because deeper ocean waters store and transfer the warmer water that contributes to glacial melting, the impact of future stabilization of surface temperatures would be too late to halt the ocean warming that has already occurred.

Slower sea level increases that allow more time for those living in low-lying coastal areas to adapt, according to the report, is the best that can be hoped for. If carbon-reduction efforts are not successful, the rate of sea level increases will be faster, larger, and significantly more damaging.

"With little mitigation, future sea-level rise would be large and continue unabated for centuries," the scientists said. "Though sea-level rise cannot be stopped for at least the next several hundred years, with aggressive mitigation it can be slowed down, and this would buy time for adaptation measures to be adopted."

 

a, Globally averaged annual mean sea-level rise anomaly (relative to 1986–2005) due only to thermal expansion from CCSM4 for the three RCP scenarios. b, Globally averaged annual mean upper 300 m ocean-temperature anomaly (relative to 1986–2005) for the three scenarios. c, Globally averaged annual mean upper 3 km ocean-temperature anomaly (relative to 1986–2005) for the three scenarios. Note different vertical scales in middle and lower panels.