Our world is getting wavier—and not in a good way.
New findings published in Science this week suggest that in the Southern Ocean, the world’s tallest waves are now nearly a foot taller than they were in 1985. Towering walls of water have seen similar height increases in parts of other oceans as well, riding on the back of faster winds. The new results don’t directly link the gustier winds and wild waves to climate change, but there’s evidence it could be playing a role.
Analyzing the world’s waves would have been a near-impossible endeavor before satellites came online in the 1970s and 1980s. Sparse buoys and ship records were all scientists had to go on, and data was especially lacking in the Southern Ocean where some of the most violent gales on the planet make travel a very risky proposition.
But the satellite record has opened up a host of ways to analyze both the winds that roar across the high seas and how, uh, high the seas are. Researchers from Australia and Indonesia used 31 different satellite records covering 1985-2018 that measured wave height and wind speed and direction. The results shows that the Southern Ocean has seen winds speed up about 2 centimeters per second each year on average. But the strongest winds have increased at twice that rate. The North Pacific and Indian oceans have also both seen increases in the gustiest winds, though at slightly slower rates.
These small changes in wind speed each year have also helped waves swell to new heights. That may bring surfers joy when they come ashore, but taller waves can also make navigating the seas more challenging and create more damage so it’s not all hanging ten, brah. And as if on queue, the Southern Ocean saw the tallest wave ever recorded last year. A swell pushed along by a powerful storm lifted a buoy to a height of 78 feet.
Because the study juggles so many variables and satellite datasets, there is still some room for error in the trends it teases out. But the initial results seem robust. The data has been calibrated against buoy measurements, and fits with trends in wave height in other studies.
The research doesn’t get into what’s causing the stiffer winds and taller waves, but the study authors think climate change could be playing a role, though they don’t really have a causal mechanism outlined according to the Guardian. That said, other recent research shows that wave power has increased due to rising ocean temperatures and shifts in wind patterns.