Sea level rise will cause ‘catastrophic inland migration’, scientists warn
Sea level rise will become unmanageable at just 1.5C of global heating and lead to “catastrophic inland migration”, the scientists behind a new study have warned. This scenario may unfold even if the average level of heating over the last decade of 1.2C continues into the future.
The loss of ice from the giant Greenland and Antarctic ice sheets has quadrupled since the 1990s due to the climate crisis and is now the principal driver of sea level rise.
The international target to keep global temperature rise below 1.5C is already almost out of reach. But the new analysis found that even if fossil fuel emissions were rapidly slashed to meet it, sea levels would be rising by 1cm a year by the end of the century, faster than the speed at which nations could build coastal defences.
The world is on track for 2.5C-2.9C of global heating, which would almost certainly be beyond tipping points for the collapse of the Greenland and west Antarctic ice sheets. The melting of those ice sheets would lead to a “really dire” 12 metres of sea level rise.
Today, about 230 million people live within 1 metre above current sea level, and 1 billion live within 10 metres above sea level. Even just 20cm of sea level rise by 2050 would lead to global flood damages of at least $1tn a year for the world’s 136 largest coastal cities and huge impacts on people’s lives and livelihoods.
However, the scientists emphasised that every fraction of a degree of global heating avoided by climate action still matters, because it slows sea level rise and gives more time to prepare, reducing human suffering.
Sea level rise is the biggest long-term impact of the climate crisis, and research in recent years has shown it is occurring far faster than previously estimated. The 1.5C limit was seen as a way to avoid the worst consequences of global heating, but the new research shows this is not the case for sea level rise.
The researchers said the “safe limit” temperature for ice sheets was hard to estimate but was likely to be 1C or lower. Sea level rise of at least 1-2 metres was now inevitable, the scientists said. [Continue reading…]