Sea level rise could cause Britain’s coastline to recede by up to 22 meters (72ft) by 2100, a new study has found.
Researchers from Imperial College London have modeled the consequences that different future scenarios of climate change will have on the country’s cliffs.
They found that by the end of the century the rocky coasts of North Yorkshire and Devon could be retreating ten times faster than they are today.
Lead author Dr Dylan Rood said: ‘The erosion of rocky coastlines is irreversible: now is the time to limit future sea level rise before it is too late.
“Humanity can directly control the fate of our coasts by reducing greenhouse gas emissions – the future of our coasts is in our hands.”
Sea level rise could push Britain’s coastline back up to 22 meters (72ft) by 2100, new study finds
The rate of erosion is likely to be between three and ten times the present rate, a rate not seen for 3,000 to 5,000 years, and is much faster than previously thought. Pictured: Cliff retreat predictions based on future sea level scenarios at Bideford (a) and Scalby (b)
To build their model, the researchers collected rock samples from study sites near Scalby in Yorkshire and Bideford in Devon, and measured the concentration of special atoms called ‘cosmogenic radionuclides’ (CRNs). Pictured: Coastline near Bideford, Devon
Global climate change has been repeatedly linked to sea level rise by reputable scientists.
This is due to the 1.8°F (1°C) temperature rise we have experienced since pre-industrial times, the melting of ice caps and glaciers, such as those in Greenland and Antarctica.
A Met Office report released in July found sea levels are rising up to three times faster than a century ago.
The rate of increase has reached up to 0.2 inches (5.2 mm) per year in some parts of the country.
Researchers from the University of East Anglia revealed in June that the UK could see sea levels rise by almost a meter (3ft) by the end of the century.
As a result, nearly 200,000 homes and businesses in England are at risk of being lost to sea level rise by the 2050s unless greenhouse gas emissions are reduced.
For the new study, published today in Nature Communications, the researchers wanted to look at what effect this will have on UK cliffs.
They collected rock samples from study sites near Scalby in Yorkshire and Bideford in Devon, and measured the concentration of special atoms called ‘cosmogenic radionuclides’ (CRN).
These accumulate in rocks that have been bombarded by cosmic rays, revealing how long they have been exposed, and therefore the past rate of erosion.
This data was combined with recorded changes in cliff shape and sea level to build a model that tracked coastal erosion over the past 8,000 years.
It revealed that the historical rate of erosion at both sites closely matched that of sea level rise and that there is a definite cause and effect relationship.
The model revealed that the historical rate of erosion at both sites closely matched that of sea level rise and that there is a well-defined causal relationship. Pictured: past and future relative sea level for the years 1900 to 2100 for Bideford (dotted line) and Scalby (solid line) for different climate change scenarios (RCP)
This means that the model could be used to reliably predict the impact that different greenhouse gas scenarios, and therefore sea level changes, will have on the coastline in the future.
He revealed that Scalby could see between 43 feet (13 m) and 72 feet (22 m) of coastal retreat by 2100, and between 33 feet (10 m) and 46 feet (14 m) at Bideford.
The upper end of these ranges is thought to be the result if the current trajectory of our greenhouse gas emissions remains unchanged.
The rate of erosion is likely to be between three and ten times the present rate, a rate not seen for 3,000 to 5,000 years, and is much faster than previously thought.
This is because past erosion was driven by waves, and these are likely to become more powerful as sea levels rise and storms become more frequent due to climate change.
Lead author Dr Jennifer Shadrick said: “Sea level rise is accelerating and our results confirm that rocky coastline retreat will accelerate accordingly.” It’s not a question of if, but when.
“The most positive news is that, now that we have a better idea of the sizes and the deadlines, we can adapt accordingly.”
Past, present and future cliff positions by 2100 at Bideford (a) and Scalby (b). RCP 8 (red line) represents the current trajectory of greenhouse gas emissions. BP = Years before 2000
The researchers say this is the first model that assesses the expected erosion of hard rock coastlines, which make up more than half of the world’s coastlines. Pictured: Scalby Coast
The researchers say this is the first model that assesses the expected erosion of hard rock coastlines, which make up more than half of the world’s coastlines.
His findings could be applied to other coastal sites around the world with the same type of rock, as they will respond similarly to accelerating sea level rise.
The researchers hope their study will inform policymakers, planners and insurers, leading them to take action to protect coastlines and achieve Net Zero.
Dr Shadrick said: “The findings are a stark warning that we need to adapt better to coastal retreat or deal with the loss of the people, homes and infrastructure that inhabit coastal areas.”
Future research will aim to adapt the model to make predictions on coasts composed of softer rock types, such as chalk.
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