Will we lose all our beaches underwater as sea levels rise? Won’t it take years for new beaches to form?


Will we lose all our beaches underwater as sea levels rise? Won’t it take years for new beaches to form?

In: Earth Science

Yes, but actually no. The rise will cover some current beaches. But it will take time, and much of the sand will be washed up on the new beach area. Eventually it will be so high that many miles of coastline will be underwater. Imagine the lower half of Florida underwater, so there will be much less actual beach

Yes and no. Or it’s complicated. It depends on the local geography and what humans do. Some areas will flood. Some areas will form new bays and estuaries. Take a look at how coastlines have changed in geologic time. A lot depends on what we do. We build sea walls and it changes the flow of water and sediments for large areas of coastline. We dredge rivers to make them deeper. Diapers an jetties all change the rate of sedimentation.

Your question implies that beaches as recreation are important to you.

In our lifetime “fun” beaches will remain with periodic issues of erosion, of more or less severity.

Our great-great-grandchildren will have an entirely different relationship with beach holidays.

So, yes, in the intermediate term [100 years], we are losing the typically understood holiday beach venues.

Yes, it will take millenia to re-draw the coast and establish beaches. This assumes we take explicit action to slow climate change.

If we don’t take action [and maybe if we do…the hour is late], we’re looking at inexorable Polar melt with a concomitant sea-level rise.

In this case, the loss of beach holidays is the smallest of our concerns.

You need to keep in mind that sea level rise isn’t an immediate process. The most extreme rates are currently millimeters to centimeters per year. Wave action can likely move the sand around quick enough that your favorite beach isn’t gonna be swallowed by the sea. However local geology is a massive factor in this, and the rate of inland advance depends highly on the angle of the beach.

Beaches will migrate uphill. Waves push sand up the slope, and then the draining water pulls some of it back. As the sea level increases, that’ll happen further inland than today.

And barrier islands will likewise migrate shoreward.