A world without beaches?

Having been reading various papers and reports on climate change for some time now, I thought I had a pretty good grasp on the range of negative effects associated with the unprecedented rate of change our actions are causing in the planet's atmosphere and oceans: higher temperatures, changing patterns of precipitation, more frequent heat waves and bushfires, more intense storms and floods, habitat destruction, biodiversity decline, cryosphere melt, reduced agricultural yields, increased water stress, increased area affected by drought at any one time, ocean acidification (which is not directly related to climate, but has the same cause: rising carbon dioxide levels), modified vector borne disease spread (such as dengue and malaria), exacerbation of respiratory health issues associated with ground-level ozone (smog), human migration patterns (refugees), desertification, shifting ocean currents, warming oceans, coral bleaching and mortality, poleward movement of the tropics, destabilisation of permafrost, shifts in the timing of annual events such as flowering, hibernations, migrations and peak river flows, sea level rise and the consequent threat to infrastructure during storm surges as well as salination of coastal water tables. All these I've read a fair bit about over the last couple of years. But only recently I have come across an implication that I hadn't heard before, one with a high visual and emotional impact for many people, but which, as far as I can tell, is not yet widely known.

Much has been said about sea level rise, and I don't intend to give a full account here. But quite apart from the risk of flooding, rising seas mean coastal erosion. I had not grasped how significant this could be. A rule of thumb used by some researchers is that, roughly speaking, for each centimetre of sea level rise, coasts will erode by one metre. When we are looking at a likely sea level rise between 50 and 200 centimetres by 2100 (and continuing thereafter for some time), you quickly get a sense of the scale of this particular issue. Sea defences can be built to minimise this impact, but they are only partially or temporarily effective (or extremely expensive), especially against the scale of change we are looking at.

Where the public at large are likely to particularly notice this, especially in Australia, is in its effect on beaches, many of which are likely to be progressively stripped of sand over the coming decades. The processes involved are complex and only partially understood, and there may be much local variation in how sea level rise affects coastal areas. Nonetheless, loss of sand is already a major (and costly) headache for many beaches and the best estimates are that this will generally get worse.

Many of us are likely to live to see a world virtually free of summer Arctic sea ice; our children may see the last of the great coral reefs die; our grandchildren may need an explanation of what a sandy beach was.