Climate change impacts and Coastal Change Management Areas

Dr. Tim Poate

In this guest blog from January 2021, Dr Tim Poate from the University of Plymouth looks at the impacts of climate change on sea levels and coasts, and how Coastal Change Management Areas can be used to plan for the future. 

I would like nothing more than to gaze from my house across the beach to see what the surf is doing and decide which surfboard to use. Owning a property with a sea-view is a popular aspiration for many but sadly out of reach for most of us. Such locations are picturesque and in demand and, as such, usually expensive. With the expected impacts of climate change including a rise in sea-levels, properties that were once further from the beach, may soon find they have sand in their gardens.

While for some, sea-level rise may bring the beach closer to their door, there are many areas where changes to our coastlines will mean significant property loss and more coastal flooding. It is very difficult to be certain about how our coastline will change in the future; many factors control erosion of cliffs and beaches, such as how hard or soft the cliffs are, and whether storms are going to get bigger and more energetic.

Storm waves hit sea defences at Chesil Beach Dorset

The best tool we have for predicting what the future may bring is to look at past trends. Coasts are dynamic and always changing and over time sea-levels also change. By looking at how a section of coast has moved in the last 10, 50 or 100 years we can then explore how it might continue to respond as our climate changes.

If we can identify a historic trend in shoreline behaviour, then we can use that to project where a cliff might be in 50 or 100 years or how a beach might change as sea-levels rise. To do this we measure our coasts using a range of techniques from GPS to satellites. This data allows us to re-draw the likely position of our coastline and plan for the probable impacts.  This information is vital for local councils to decide what should and should not be built in certain areas. We call these ‘Coastal Change Management Areas’ or CCMAs. They are an essential management tool for our coasts.

So what do we do with a CCMA? How does it help protect against climate-change impacts? These questions can be answered in two different ways; we can prevent housing or infrastructure (e.g., roads) being built somewhere that may experience erosion in the future, and we can consider moving people away from coastal that may already be a risk. The council use a CCMA to ensure any new buildings such as houses, hospitals and sewage treatment sites are not going to be built in a location that is not safe over the next 100 years. This means that money is not wasted or lost to sea! And if someone is lucky enough to have a beach view already, but is worried about the future, the council can help them move inland- although they may lose their sea-view!

Storm waves at Porthleven, Cornwall

The problem is that predicting how the coast may change is not straightforward. There are broad trends for different coast types e.g. sandy beaches, gravel beaches, hard cliffs and estuaries but they all vary slightly. This is where my research is so important. At the University of Plymouth, we are monitoring coastal behaviour and looking at past trends to help develop a universal ‘method’, which can allow a council to map how their coast may change. This is challenging work, and it is unlikely to ever be finished, I am not sure it will ever pay for my house, with a view across the beach to the surf, but maybe that’s not such a wise investment!

Coastal erosion at Slapton, Devon - how will this be managed in the future?

Useful references - Coastal Change Management Areas:

https://sweep.ac.uk/portfolios/coastal-change/

https://sweep.ac.uk/coastal_change_management_areas_ccmas_methodology_and_adoption/

Read more about coastal erosion and the work being done at the University of Plymouth

Coastal Processes Research group:  http://www.coastalprocesses.org/

Coastal Marine Applied Research: https://www.plymouth.ac.uk/research/cmar

About the author:

Tim Poate is a Coastal Scientist at the University of Plymouth. He divides his time between active research on coastal processes, focussing on storm response and beach behaviour, and providing consultancy services through the Coastal Processes Research Group. When not studying the beach he can be found searching for wind and waves to entertain him.