The rising tide we’re not talking about: Why sea level rise is Britain’s silent climate crisis
As the UK grapples with heatwaves, floods, and storms grabbing headlines, one of the biggest climate threats is gathering under the radar: rising sea levels. According to the latest state of the UK climate report published by the Royal Meteorological Society, sea levels around the British coast are increasing faster than the global average – leading to a slow-moving crisis that will threaten millions of lives.
The UK’s climate has warmed by around 1.24°C since the 1961–1990 baseline. This warming is directly contributing to the rising seas through a combination of thermal expansion (as warmer water takes up more space) and the melting of glaciers and polar ice sheets.
But the standout figure is this: two-thirds of sea level rise recorded since 1900 around the UK has occurred in just the last 30 years.
A rising tide – with rising costs
Clear increases in sea levels have been shown by UK tide gauge records, now averaging at 3-5mm per year depending on location. And while a few millimetres might seem small, it adds up fast. Over time, that slow, steady rise makes a big difference.
What’s worrying is that higher sea levels don’t just make big storms worse — they make everyday tides more dangerous too. Even on calm, sunny days, we’re starting to see what scientists call “coastal inundation” — when a high tide alone is enough to flood low-lying areas. That’s already been spotted in parts of southeast England, and it's only going to become more common.
Rising seas also make storm damage worse. Between October 2023 and March 2024, England and Wales saw their wettest winter in over 250 years, with severe flooding in Derbyshire, the West Midlands and eastern Scotland. As sea levels rise, these kinds of disasters are becoming more common — and more costly.
The areas most at risk are low-lying parts of the UK, like East Anglia, the Thames Estuary, and parts of south Wales. A government report has warned that by 2080, over 1.5 million homes in England could be at risk from coastal flooding if we don’t act.
Why isn’t sea level rise getting more attention?
One reason: it doesn’t happen all at once. There’s no headline moment, nor any breaking news story about rising sea levels. But it’s at a constant, and permanent growth, especially now. If we ignore it, we’d be setting ourselves up for major damage in the decades ahead.
The government has talked about restoring nature and investing in clean energy — both important. But we also need serious investment in coastal defences, smarter planning laws, and long-term thinking to protect communities.
Most importantly, we have to tackle the root cause: cutting emissions. Every degree of global warming makes this worse. Sea level rise may be silent, but it’s relentless — and we can’t afford to ignore it any longer.