Scientists warn that sea level rise will become unmanageable at just 1.5C of global heating, leading to “catastrophic inland migration”. This scenario may unfold even if the average level of heating over the last decade is maintained. The loss of ice from giant ice sheets has quadrupled since the 1990s due to climate change and is now driving sea level rise.
The world is on track for 2.5-2.9C of global heating, which would be beyond tipping points for ice sheet collapse. This would lead to a 12-metre sea level rise. Currently, 230 million people live within 1 metre above current sea levels, and 1 billion live within 10 metres.
Even 20cm of sea level rise by 2050 could cause $1 trillion in flood damages annually for the world’s 136 largest coastal cities. However, scientists emphasize that every fraction of a degree of global heating avoided through climate action matters, as it slows sea level rise and gives more time to prepare.
Research shows that sea level rise is occurring faster than previously estimated. The “safe limit” temperature for ice sheets was estimated to be around 1C or lower, with sea level rise inevitable at 1-2 metres. This would have devastating impacts on coastal cities like the UK’s Fens and Humberside.
Developing countries like Bangladesh would face much worse consequences than rich nations like the Netherlands. The lead author of the study said, “We’re starting to see some of the worst-case scenarios play out almost in front of us.” The international target to limit global temperature rise to 1.5C is already out of reach.
Source: https://www.theguardian.com/environment/2025/may/20/sea-level-rise-migration