Climate change may be breeding more powerful ocean waves

The power of ocean waves is getting a significant boost from human-made climate change, according to new study. Gaining a greater understanding of how Earth's wave climate is changing could help authorities mitigate some of the damaging predicted effects of global warming.

In 2019, numerous scientific studies and reports warned of the dangers posed by anthropogenic climate change, highlighting the devastation that will most likely befall us should we as a species fail to fundamentally alter almost every aspect of society.

In the coming decades, climate scientists are predicting food and water shortages, the easier spread of mosquito-borne diseases including malaria and dengue fever, and an increase in the occurrence of extreme weather events such as deadly heatwaves. These are just a few examples of the grim challenges humanity may be faced with on dry land, but the threats posed by climate change will resonate far beyond the shoreline.

Already, ocean acidity is on the rise, destroying coral reefs. At the same time global warming has accelerated the melting of Earth's polar ice caps and glaciers, which in turn is contributing to a rise in global sea level.

According to a new study, global warming could also be fuelling a gradual but constant increase in the power of ocean waves.

An international group of scientists set out to analyze the relationship between the rise in sea-surface temperature due to global warming over recent decades, and the amount of energy contained in surface waves. The latter is quantified using a metric known as wave power, which essentially measures the amount of energy transferred from winds interacting with the ocean, which is subsequently converted into wave motion.

This relationship is important, as the rising sea temperatures are thought to have influenced global wind patterns, and so altered how they interact with the ocean. The researchers analyzed historical wind-wave and sea-surface temperature data spanning the years between 1948 – 2017.

The results of the study revealed a direct association between ocean warming and wave power, the latter of which was found to have increased across the globe year on year at a rate of 0.4 percent since 1948.

"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," states director of research at the Environmental Hydraulics Institute at Spain's University of Cantabria, and co-author of the new study, Inigo J. Losada.

Wind-generated waves play a major role in sculpting coastlines. Alongside creating headlands, bays and numerous other features, they also have a significant influence over coastal flooding events. The authors of the new study hope that their research will help provide a more complete understanding of the dangers that will be faced by coastal communities in the coming decades. This in turn could help governments protect at risk populations and infrastructure such as ports and harbors by building coastal defences.

"Our results indicate that risk analysis neglecting the changes in wave power and having sea level rise as the only driver may underestimate the consequences of climate change and result in insufficient or maladaptation," comments co-author Fernando J. Méndez, associate professor at the Universidad de Cantabria

Wave power could potentially be used by climate scientists alongside other measures of climate change, such as atmospheric carbon dioxide concentration.

A paper detailing the findings has been published in the journal Nature Communications.

Source: University of California, Santa Cruz