Short-lived greenhouse gases cause centuries of sea-level rise

Warming from short-lived compounds - greenhouse gases such as methane and chlorofluorocarbons - can cause sea levels to rise for hundreds of years after the pollutants have been cleared from the atmosphere, a new study has warned.

Even if there comes a day when the world completely stops emitting greenhouse gases into the atmosphere, coastal regions and island nations will continue to experience rising sea levels for centuries afterward, according to researchers at Massachusetts Institute of Technology (MIT) and Simon Fraser University in the US. The greenhouse gases such as methane, chlorofluorocarbons or hydrofluorocarbons linger in the atmosphere for just a year to a few decades.

Recent studies by many groups have shown that even if human-caused emissions of carbon dioxide were to stop entirely, their associated atmospheric warming and sea-level rise would continue for more than 1,000 years.

These effects - essentially irreversible on human timescales - are due in part to carbon dioxide’s residence time.

The greenhouse gas can stay in the atmosphere for centuries after it is been emitted from smokestacks and tailpipes. In contrast to carbon dioxide, other greenhouse gases such as methane and chlorofluorocarbons have much shorter lifetimes.