Climate Change

Threat by monster waves to grow by 2100, coastline caution needs consideration, study suggests

Current estimates on climate change’s impacts on monster waves across 80% of the world’s oceans are unclear

By Rohini Krishnamurthy
Published: Friday 13 January 2023
Long-term data is needed to quantify extreme wave events for today’s climate, according to study authors. Photo: iStock_

Climate change could drive ocean waves to reach monstrous heights, growing by 5-8 per cent by 2100, a new study has warned. This could lead to widespread coastal flooding and erosion. 

The impact is likely to take a higher toll on India and a handful of countries affected by tropical cyclones, the study published in the journal Science Advances stressed.

Extreme or monster waves occur randomly. They are generated by extra-tropical and tropical storms and reach over 20 metres, equivalent to four double-decker buses stacked on top of each other, according to the University of Melbourne. Such events can also disrupt shipping.

Read more: US braces for the deadliest hurricane in 12 years; experts point to ocean warming

Understanding monster waves is also essential for offshore and coastal infrastructure such as natural gas and oil drilling platforms, aquaculture farms, renewable energy projects, and coastal defences, as they are expected to expand by up to roughly 50 per cent by this decade, the researchers wrote in their paper.

2020 study suggested the magnitude of extreme wave events in the Southern Ocean, for example, will increase by 5 to 15 per cent over the Southern Ocean by 2100, compared to the 1979–2005 period.

Current estimates of global warming’s impacts on extreme waves across 80 per cent of the world’s oceans and coastlines are highly uncertain, the study concluded.

These findings highlight that we need more long-term data to quantify extreme wave events for today’s climate completely, Joao Morim from the University of Central Florida (UCF) and the study’s lead author, told Down To Earth.

Morim and his colleagues used 12 global wave models with data from 1980 to 2014. They compared this data from 64 moored wave-buoy stations. Buoys are floating instruments that collect weather and ocean data. The researchers estimated the likelihood of witnessing a monster wave in a region once in 100 years.

The analysis showed that the height of extreme waves is estimated to increase by roughly 5 to 15 per cent across the Southern Ocean, eastern Pacific Ocean, and northeastern Pacific Ocean. The Arabian Sea, Gulf of Bengal, Aleutian Sea, and China Sea are projected to see similar impacts.

Read more: Climate emergency: Extreme weather events in Australia to get more frequent, intense

However, the northern and central Atlantic Ocean, northwestern Pacific Ocean, Indian Ocean, and southern Pacific Ocean are projected to see a decrease in wave height of up to 15 per cent.

These differences, according to Morim, are more severe in areas affected by tropical cyclones, such as Australia, Florida, the Caribbean, Mexico, Japan, India and China. 

The story will likely play out similarly in North Atlantic and Chile, which see extra-tropical cyclones.

“This means that coastal flood risk estimates that consider extreme wave events can differ by 1 metre, which is comparable to sea level rise by 2100,” he pointed out.

Read more: 

Maluku earthquake: Why do some ocean earthquakes cause tsunamis while others don’t?


Using the ocean to fight climate change raises serious environmental justice and technical questions

Oceans are warming twice as fast than the 1960s and it could get much worse

Subscribe to Daily Newsletter :
Related Stories

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.