Ocean waves may be getting stronger

A new study has found a direct correlation between ocean warming and an increase in wave strength

“This is a new signal of climate change that was previously unknown. It has a great impact on our adaptation and future planning in coastal regions.” — Borja Reguero, a researcher at UC Santa Cruz

Many of us have heard that climate change is causing a rise in sea levels, higher ocean temperatures and a decline in sea ice. But stronger waves?

According to a new study from the UC Santa Cruz Institute of Marine Sciences, waves are crashing onto the coastline with more force than ever before — and this increase in wave strength is directly correlated to ocean warming.

Published in Nature Communications last month, the study found that wave power, which is the transfer of wind energy into wave motion, has increased globally by 0.4 percent per year from 1948 to 2017.

This may seem like an insignificant number, but it can mean big changes when it comes to coastal damage and flooding.

“This is a new signal of climate change that was previously unknown,” said Borja Reguero, a researcher at UC Santa Cruz and lead author on the study. “It has a great impact on our adaptation and future planning in coastal regions.”

The energy in most ocean waves comes from the wind. When wind hits the ocean’s surface, it creates a ripple effect that eventually forms a wave. The stronger the wind, the bigger the wave.

Previous research has found that wave height has grown in recent decades, particularly near the North and South poles. Furthermore, scientists have discovered that wave periods, or the time it takes for a wave to complete one full cycle, have increased in speed. The direction of waves has also shifted in certain areas of the ocean. But scientists have paid far less attention to changes in global wave power.

With this new study, researchers uncovered that the rise in sea-surface temperature has

caused wind patterns to change, resulting in stronger waves. This increase in wave power is seen both

globally and in distinct ocean basins, including the Indian, Pacific and Atlantic oceans.

Although the team noted a long-term trend of increasing wave power, the rise is particularly evident during storm seasons,

such as the winter of 20132014 in the North Atlantic that severely damaged the west coast of Europe, and the catastrophic 2017 hurricane season in the Caribbean.

Understanding this rising trend in wave power is

very important for coastal communities. With stronger waves, coastal cities and towns risk losing key parts of their infrastructure. Breakwaters may no longer be able to fully protect ports and harbors and water will be able to

move further inland, increasing the chance of flooding.

Along with providing new information on the effects of climate change, Reguero hopes this research highlights the importance of considering wave power when planning future coastal infrastructures.

“If we don’t take this into account, we might be underestimating the effects (of the waves) and the needed adaptations,” he said.