Climate change is making ocean waves stronger

Climate change is set to wreak havoc worldwide with dramatic changes in weather patterns. Droughts will become more common and prolonged. Storms will get more frequent and severe. Sea levels will rise.

Ocean waves, too, will get more destructive, say the authors of a new study.

Waves have been increasing measurably in intensity as a result of warming surface water temperatures. The researchers say they have found “long-term correlations and statistical dependency with sea surface temperatures, globally and by ocean sub-basins, particularly between the tropical Atlantic temperatures and the wave power in high south latitudes, the most energetic region globally.”

Their results, they add, “indicate the upper-ocean warming, a consequence of anthropogenic global warming, is changing the global wave climate, making waves stronger. This identifies wave power as a potentially valuable climate change indicator.”

Various phenomena account for the size and intensity of waves, including wind speeds and water surface temperatures. In their study, the team of scientists focused on the energy contained in ocean waves, which is transmitted from the wind and transformed into wave motion in the water. This so-called wave power increases as surface water temperatures increase. As a result, waves will become stronger across much of the world.

“For the first time, we have identified a global signal of the effect of global warming in wave climate,” says the study’s lead author Borja G. Reguero, a researcher at the Institute of Marine Sciences at the University of California, Santa Cruz. “In fact, wave power has increased globally by 0.4 percent per year since 1948, and this increase is correlated with the increasing sea-surface temperatures, both globally and by ocean regions.”

Coastal communities, especially vulnerable ones, will need to get better prepared for battering waves in coming years so as to mitigate the  ocean’s impacts on local infrastructure. “Ocean waves determine where people build infrastructure, such as ports and harbors, or require protection through coastal defenses such as breakwaters and levees,” the authors explain.

“Indeed, wave action is one of the main drivers of coastal change and flooding, and as wave energy increases, its effects can become more profound,” they add. “Sea level rise will further aggravate these effects by allowing more wave energy to reach shoreward.”