Surf’s down dude! Gnarly Aussie waves hit by climate

BODACIOUS tubes on Australia’s east coast are being quashed by global warming. At current rates, by the end of the century, climate change will reduce the number of big waves by a third, according to the latest research. Andrew Dowdy and his colleagues from the Australian Bureau of Meteorology in Melbourne ran 18 climate models forwards and backwards to see how the changing climate influences big waves. They found that these waves were caused by storms in the west Pacific known as ”east coast lows”, driven by differences in air pressure. The models showed that climate change is pushing down the number of big waves and that trend will increase exponentially. Where there might have been waves taller than 6 metres on 36 days a year in the 1950s, now it happens on about 34 days a year. If we continue along a high-emissions path, that number will reduce by almost 30 per cent by the end of the century. They saw a similar trend for waves of between 4 and 6 metres high (Nature Climate Change, doi.org/rth). Surfers might take comfort in the thought that the biggest waves may get even bigger, Dowdy says, something his study didn’t examine. These changes could also affect beaches, says Mark Hemer from CSIRO, Australia’s national research organisation in Hobart. The amount of sand on a beach is determined by the balance between what gets washed in and out, “and waves are the primary driver of that".