Researchers have warned surfers that climate change will significantly reduce the number of large waves off Australia’s east coast in the coming decades.
The research found that an increase in greenhouses gases will cut the number of days with large ocean waves more than four metres high. The frequency of large waves is expected to drop by 40% by the end of the century, with roughly half of this decline happening over the next 30 years.
Researchers looked at 18 different climate change models and found that even in a scenario where greenhouse gas emissions were rapidly slowed, there would be a 25% reduction in large waves.
The study, published by Nature, analysed buoy data along the NSW coast, from Coffs Harbour to Eden, to show that large waves in the region are primarily caused by storms called east coast lows.
As heat-trapping gases are released into the atmosphere, fewer of these storms are created, resulting in a reduction in large waves.
This is in contrast to tropical areas further north, where storms are not such a key driver of wave intensity.
“If you like to surf the large waves, in the future you might have to pick your days to go out a bit better,” report co-author Andrew Dowdy of the Bureau of Meteorology told Guardian Australia.
“Storms aren’t surface events, they are three dimensional. We found that storms about 5km up are good representations of how large waves occur.
“This level is good to look at in terms of climate models. Our results show that some change may have already started.”
The loss of large waves may also have an impact upon marine creatures that depend on tidal motions.
Additionally, while large wave frequency may decrease, sea levels are predicted to rise, meaning that waves will still cause a problem for coasts susceptible to erosion and inundation.
“There are lots of different pieces in the jigsaw puzzle of our oceans,” said Dowdy. “We hope our results will be taken up by future studies on how they all interact.”
Read article at The Guardian