Interactive flood risk map: See how rising sea levels could impact your area of Cambridgeshire by 2030
An updated version of Climate Central’s Coastal Risk Screening tool has revealed that large parts of the east coast of England could be below sea level by 2030 – bringing flood risks to the Cambridge region.
Climate Central is a US-based non-profit news organisation that analyses and reports on climate science. In 2017 the Cambridge Independent reported on its ‘Surging Seas Risk Zone’ map, which showed how a rise of 3°C would impact East Anglia, with sea levels rising, breaking through The Wash which, without proper defences, would potentially flood the region from King’s Lynn to Cambridge.
Since 2017 global temperatures have risen relentlessly. The global average mean surface temperature for the period from 2017 to 2021 (based on data until July) is among the warmest on record, estimated at 1.06°C to 1.26°C above pre-industrial (1850–1900) levels, according to the World Meteorological Organisation.
Climate Central has now upgraded the elevation data and the sea level projections it uses to determine outcomes, with results that can be seen in this interactive map – rises that could leave Waterbeach, Ely, Fen Ditton and Chesterton below the annual flood level by 2030, far before reaching a 3°C rise.
“There’s a lot to this tool,” said Rob Larter, a marine geophysicist at British Antarctic Survey. “What it’s showing is what areas would be affected given a certain sea level rise.
“It’s very interesting to see what it implies regarding different dates and warming scenarios, but it’s not the full picture – it depends on what we do, especially with sea defences, and what happens with the weather systems which affect tidal surges.
“The last big tidal surge in East Anglia was in 2013, when lots of coastal defences were close to being overrun. The one previous to that was in 2007. The surge events are little understood and are crucial, because even a relatively small rise in sea level can be critical if you don’t have sea defences.
“We are currently seeing 3 or 4mm of sea level rise every year. By 2030 we can expect sea-level to have risen 3 or 4cm, perhaps a bit more if the rate of rise continues to increase as it has done over the past quarter century.
“This amount of rise won’t actually make a huge difference to the areas that would flood if there were no sea defences, waterway controls or pumps. You can see this if you open the tool and choose the ‘water level’ map, then move the slider to 0 change.
“When we look forward over long periods the rate is likely to increase through the rest of this century, so the latest IPCC report considers that the likely range of sea-level rise is greater than a simple linear projection would give. Changes to ice flow in West Antarctica could push the rise higher still – that is the subject of current research.”
East Anglia’s fate may actually rest on the quality of the work of Dutch engineers in the Fens 300 years ago, says Dr Larter.
“The area in red on the map is presently below the high tide level, and that area would be pumped out anyway because we’ve had pumps in the region since the 17th century, so you shouldn’t take it as read that it’ll flood – it’s the area at risk if we do nothing.
“Sea levels will rise, but we have our hand on the controls for how much it rises – ‘really bad’ or ‘catastrophic’ are the choices at this point.”
Dr Larter added: “Investment in sea defences is a question for each nation individually. By 2050 global temperatures will be 1.5 or 2°C above pre-industrial levels. It will take a long time for the world’s glaciers to recover – we’ll be losing ice for many centuries to come.
“Global topographic data on coastlines show that 1 billion people live within 10m of the sea, and with coastal tide surges and low pressure even people quite a few metres above the the high tide line could get their feet wet.”
Haydn Belfield, research associate at the University of Cambridge’s Centre for the Study of Existential Risk, said: “This map illustrates the risk to all of us from climate change.
“More extreme weather events, worse floods and sea level rise put our region – our home – at risk.
“That’s why it’s so important that we make progress at COP to move quickly to net zero and keep global warming below 1.5°C.”
Meanwhile, as the COP26 climate change conference began in Glasgow, Extinction Rebellion Cambridge hung banners on bridges over the M11 near Cambridge as part of a ‘Code Red for Humanity’ action.
A Climate Justice march, part of a UK-wide day of action during COP26, takes place on Saturday (November 6), starting at Great St Mary’s Church at 1pm.
November 4: This story was updated to stress that the tool indicates areas that would be below the annual flood level, rather than underwater.
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