One of the biggest concerns amongst coastal scientists and coastal managers alike is how our beaches will respond to future sea level rise. If you love beaches, you should also be concerned.
Sea level has always fluctuated up and down in relation to the volume of water in the oceans, which is intrinsically linked to the amount of ice on the planet, which in turn is linked to air and sea temperatures, both of which are presently increasing. We know that in the last 100 years or so, sea level has risen by about 20cm. What’s going to happen in the next 100 years is not as clear.
A recent study published in the prestigious scientific journal Nature Climate Change used various techniques to state that by the end of this century, sea level rise could result in the near disappearance of almost half of the world’s sandy beaches. This is a pretty gloomy finding!
But a group of coastal scientists wrote a reply refuting those findings based on how beaches fundamentally behave. Any natural beach and dune system faced with sea level rise will do what they’ve always done: they’ll just migrate landward. The beach and dune won’t disappear; they’ll just shift in position. Great! The problem is that in so many places, we’ve built roads and houses too close to the shoreline, which may not allow for that natural migration to happen.
What’s important is that we need to understand more about how our shorelines change over time – and now you can help! A colleague of mine, Dr Mitch Harley, is a coastal engineer at UNSW Sydney and came up with the CoastSnap program – a series of stations at selected beaches where you can insert your phone, take a picture, upload it to the internet where image analysis works out beach behaviour and shoreline change over time from all the pictures.
There’s now a free app so that anyone can do it by taking pictures of their local beach. Basically you find a location that overlooks a beach, preferably with a bit of elevation to get in as much of the beach as possible, and take pictures from the exact same spot as often as you can.
Try and find a fixed point that you can rest your phone on each time, like a handrail or a fence post. It helps to take pictures around low tide although it’s okay if you don’t.
It’s a great example of citizen science. I’m doing it at Coalcliff Beach (but the more the merrier) so why not choose your local beach and get involved? It’s easy to do.
Simply go to Apple’s App Store or Google Play and search for “CoastSnap”. You can also follow ‘CoastSnap’ on Facebook or Instagram.