A new study has found a correlation between warming oceans and wave size and strength, suggesting that the more things heat up, the more destructive our oceans will become.
Ocean waves are built by the wind from an invisible handshake between the atmosphere and the ocean. It should, therefore, come as no surprise that these spectacular and at times intimidating undulations are impacted by changes in the global climate.
Yet despite this recognised relationship, there has never actually been a global methodical, long-term study on how climate change and the behaviour of waves are linked.
And while we know that wind speeds and wave heights are increasing in some parts of the ocean, the local causes have so far gone unexamined.
For the first time, researchers have now managed to connect all of these phenomena.
To be clear, this study only showed a correlation, so we can’t say that climate change is directly causing waves to get larger. But the data shows that the two are closely linked and could even be used to monitor each other.
“This study shows that the global wave power can be a potentially valuable indicator of global warming, similarly to carbon dioxide concentration, the global sea level rise, or the global surface atmospheric temperature,” says co-author Inigo Losada, a civil engineer at the University of Cantabria, where the study was developed.
So what’s going on?
As climate change has gradually heated up the surface of our oceans, it appears to have also influenced global wind patterns, and this, in turn, is making ocean waves stronger.
In other words, the warming of our oceans seems to have exacerbated the strength of local winds, allowing them to whip up even greater waves – a transfer of energy known to scientists as global wave power.
Using historical wind-wave and sea surface temperature data between 1948 and 2017, the researchers have shown an increase in wave power that corresponds to sea-surface temperatures.
Between 1948 and 2008, the findings reveal that wave power has increased globally by 0.47 percent per year, speeding up to a 2.3 percent annual average after 1994.
And while this may not sound like much, in some parts of the world, the changes are even more dramatic.
Surface warming in the tropical Pacific, for instance, is predicted to be especially great, increasing wave heights and wave energy levels over certain parts of the central North Pacific and the Southern Ocean, which surrounds Antarctica.
The danger of even larger waves will not only have an impact on coastal areas, including exacerbated flooding and erosion, it will also likely impact ocean transport, like fishing and cargo transport.
Again, this study didn’t look into whether climate change was directly increasing wave size, but with ocean warming increasing much faster than we once thought, figuring this out will be crucial if we want to accurately predict and limit the impact of climate change in and around coastal areas.
This study has been published in Nature Communications.