Close watchers of the climate scene will probably be familiar with the work of Kench et al., who put a big spanner in the works of the climate alarm community, by demonstrating that coral atolls, far from disappearing beneath the waves, had been getting bigger over the last few decades. Now, a new paper in Nature Scientific Reports looks as though it is going to add a fairly substantial hammer blow to those same works. The authors, Luijendijk et al., have surveyed sandy beaches around the world using current and historic satellite photographs – the same approach used by Kench – and have found that, in contrast to what a simple ‘global warming equals sea level rise’ approach might predict, more are getting larger rather are shrinking.
Coastal zones constitute one of the most heavily populated and developed land zones in the world. Despite the utility and economic benefits that coasts provide, there is no reliable global-scale assessment of historical shoreline change trends. Here, via the use of freely available optical satellite images captured since 1984, in conjunction with sophisticated image interrogation and analysis methods, we present a global-scale assessment of the occurrence of sandy beaches and rates of shoreline change therein. Applying pixel-based supervised classification, we found that 31% of the world’s ice-free shoreline are sandy. The application of an automated shoreline detection method to the sandy shorelines thus identified resulted in a global dataset of shoreline change rates for the 33 year period 1984–2016. Analysis of the satellite derived shoreline data indicates that 24% of the world’s sandy beaches are eroding at rates exceeding 0.5 m/yr, while 28% are accreting and 48% are stable. The majority of the sandy shorelines in marine protected areas are eroding, raising cause for serious concern.