Coastal Futures 2020 Conference: Sea Level Rise

Guest blog by Lee Walther

This last few days have seen the Climate Crisis more prominent in the news and online it seems.   However, it could just be the climate bubble I live in right now.  

I listened to the World at 1 on Radio 4 and was listening to the difference in the Davos speeches between Greta Thunberg and Donald Trump. One articulate and to-the-point the other rambling and quite frankly wrong on many levels. Trump was right on one thing though; there have been “Prophets of Doom” before.  But the different now is that the science is pointing in one direction only, if we carry on with Business as Usual that is. 

Recently I attended the Coastal Futures 2020 conference in London for work. It was held in the august surroundings of the Royal Geographic Society.  This is an annual event highlighting topical themes in the marine and coastal worlds.

The Main theme of day 1 was the “hot” topic of The Climate Emergency AND How We all Respond. The opening slot was given to the Chair of the Environment Agency, Emma Howard Boyd who drew attention to Australian film maker Damon Gameau’s documentary  2040.  This film allows us to see the best possible future we could be living in 20 years’ time. It offers practical solutions for a regenerative culture to help us adapt to and hopefully mitigate the climate and ecological emergency.  The EA as an organisation are committed to doing what it takes to achieve Net Carbon Zero by 2030; including what’s produced by the EA as well as through their supply chain.  An ambitious target for a non-departmental public body.  She said even if we manage to stick to 1.5C of warming the IPCC report expects about 26 to 77 centimeters of sea level rise by 2100.  And extreme, once-a-century sea level events will become annual events by 2050, in all future climate scenarios.  Being on the frontline of change, the coasts of England are very susceptible with 1.5million homes at risk to coastal flooding and 2000 homes vulnerable to erosion in the next 50 years.  People need to be at the heart of resilience planning as we cannot build our way out of this crisis but must adapt to it.  It’s not just houses but important inter-tidal habitats that will be lost (an estimated 3500 hectares of intertidal habitat is expected to be lost by the end of the century).  These habitats provide valuable flood defences and the beaches, cliffs, sand dunes and mud flats need space to move.

Medmerry in West Sussex was held up as an example of managed realignment that has protected 100’s of homes and created much needed intertidal habitat. If you haven’t been then do go and have a look for yourself. 

So, the IPCC say we are heading for 26-77cm of sea level rise, a pretty precise figure isn’t it?  Well, up came John Englander from the Rising Seas Institute to blow that prediction out of the water!  From 1900 to about 1990 sea levels rose by 1.1mm a year but from 1993-2010 it was rising by 3mm a year and this figure is forecasted to keep rising.  John said that the big unknown is the Greenland and Antarctic Ice Sheets with both possessing 98% of the worlds fresh water, or, to put it another way 98% of the world’s sea level rise. He highlighted how we are consistently under-estimating the potential impacts from the ice-sheets and that we should be preparing for maybe “meters” of rising water. 

Sea levels have been much higher and much lower in the past as the global ice sheets fluctuated. At the last glacial maximum 20,000 years ago, sea levels were 120m lower than the present. The rise in sea levels was not a gradual rise over 16,000 years, instead, a series of pulses lead to periods of accelerated rising.  John thinks that the melting of the Greenland and Antarctica Ice Sheets could become pulse events.  He finished his talk with a short film from Greenland and the sheer scale of glacier melt and iceberg calving was astonishing. You could feel the anguish in the room and I believe that there will not be any doubters out of the 350 academics, researchers, policy makers and land managers who were present.

What does this mean to me locally?  Well I live on the Downs about 8 miles from the coast at Worthing and a short walk up the hill allows me a view of the Arun Valley.  Before the River Arun flows through its gap in the South Downs it enters the vast flood plain known as the Wild Brooks – this area of low lying mostly grazing land is separated from its river by embankments on either side.  During times of heavy rain, the banks sometimes over-top and the brooks take on the appearance of an inland sea.  Is this the future we face in the Arun Valley and if so, where does the variety of grazing marsh, ditches, wet woodland and pools go?  The valley is home to RSPB Pulborough Brooks and Sussex Wildlife Trust’s Amberley Wild Brooks and Waltham Brooks reserves all important habitats and refuges for a vast amount of wildlife.  Adaptation will be key and there is an Arun Valley Vision which has recommended adaptive management as the preferred option for the valley.  It is an interesting read and I feel personally an open and honest account regarding the issues to be faced by the landowners, farmers and wildlife of the valley.  

I haven’t even touched on the coastal plain of Sussex which is extremely vulnerable.  A quick look at the interactive map on the Climate Central website makes for sobering viewing. I invite you to make up your own conclusions on the scale of the issue. The map below taken from the Climate Central website shows the areas (in red) at risk from sea level rise under the worst-case scenario emissions by 2100.

  

Therefore, to end, YES we must cut emissions to zero as quickly as possible to mitigate against further temperature rises but we must also adapt - and adapt quickly too.