Global sea levels rose by an ‘unexpected’ amount last year, NASA warns – leaving hundreds of cities at risk of being plunged underwater

Global sea levels rose by an ‘unexpected’ amount last year, NASA has warned. 

The space agency had predicted the water level to rise by 0.17-inches (0.43cm) in 2024. 

But measurements show that last year’s rate of rise was actually much higher than this, with sea levels increasing by 0.23-inches (0.59cm). 

According to NASA, this ‘unexpected’ increase was due to an unusual amount of ocean warming, combined with meltwater from land-based ice such as glaciers. 

‘The rise we saw in 2024 was higher than we expected,’ said Josh Willis, a sea level researcher at NASA’s Jet Propulsion Laboratory in Southern California. 

‘Every year is a little bit different, but what’s clear is that the ocean continues to rise, and the rate of rise is getting faster and faster.’ 

Since 1993, global sea levels have risen by a staggering 3.97-inches (10.1cm). 

And if they continue to climb at this rate, hundreds of densely populated cities around the world could be plunged underwater. 

In recent years, about two-thirds of sea level rise has come from melting ice sheets and glaciers, while a third comes from ocean warming. 

However, in 2024, those contributions flipped, according to Nadya Vinogradova Shiffer, head of physical oceanography programs and the Integrated Earth System Observatory at NASA Headquarters in Washington.

‘With 2024 as the warmest year on record, Earth’s expanding oceans are following suit, reaching their highest levels in three decades,’ she explained. 

Using a series of ocean-observing satellites, NASA has been recording sea levels around the world since 1993. 

Since then, the rate of annual sea level rise has more than doubled – and things are only set to get even worse. 

Based on the current rate, NASA has also projected sea level rise over the next 15 years. 

Worryingly, their projections suggest that we could see another 2.7-inches (7cm) of sea level rise by the year 2040. 

Using Climate Central’s Coastal Risk Screening Tool, MailOnline set out to understand the impact this amount of sea level rise would have around the world. 

And it suggests that hundreds of towns and cities are at risk of being plunged underwater. 

Here in the UK, huge parts of London – including Canning Town, Canary Wharf, the Southbank, and Abbey Wood – would fall below the water line, along with Skegness, Hull, and Great Yarmouth. 

Over in Europe, much of the Netherlands would be plunged underwater, along with Venice in Italy. 

While most of the US would be safe, several parts of the south and east coasts would be at risk, impacted densely populated areas including Galveston, New Orleans, adn Charleston. 

Elsewhere, Bangkok in Thailand, Basra in Iraq, and Navi Mumbai in India, are also at risk of being submerged. 

Professor Richard Allan, Professor of Climate Science at the University of Reading, has described sea level rise as a ‘catastrophe’.

‘Sea level rise is a catastrophe emerging slowly and inexorably now that will worsen substantially into the far future,’ he said. 

‘Low lying coastal regions that including many populous cities such as Miami, Mumbai, Shanghai and Tokyo will be affected during this century and many centuries in the future. 

‘For the far future it seems inevitable that massive adaptation to rising seas will be essential and only by rapidly achieving net zero carbon emissions can the costs and scale of adaptation to the creeping ocean be tempered.’