How will climate change affect waves?

If unchecked climate change is going to affect just about every aspect of our lives over the next century. But new research has shown that one thing that might seriously change is the size of waves in different parts of the world.

Big wave
In some parts of the world waves could become a lot more powerful over the next century

For many people the sight and sound of waves can be a soothing and relaxing constant, but in reality they can actually be one of the most powerful and unpredictable forces on our planet. Although climate change has been studied for decades and provided us with countless predictive models of how it will shape our future, its effects on wave patterns have remained one of the hardest things to predict. That is until now because new research has given us the most accurate and alarming look at how waves will change around the world over the next century. It warns us that if climate change remains unchecked the wave patterns in over half the world’s oceans could be changed forever. Whilst the effects of this will be different depending on where you are, as much as a 15% increase in the size of waves in some places could have some serious consequences.

Predicted changes

As avid surfers might tell you, accurately predicting the size of waves in a few days time can be hard enough. So just how do we know what they will be doing over the next century? The answers comes from a new collaborative project between 27 leading wave researchers from around the world. Known as the Coordinated Ocean Wave Climate Project (COWCLIP), the study combined more than 150 wave and climate models to create the first unified wave model covering the entire planet. This has allowed them for the first time to accurately predict where and how waves will break in the future, as our ocean systems are re-shaped by climate change. Their results, released in a recent paper for Nature Climate Change, show just how much wave patterns are likely to change if global warming isn’t kept below a 2oc increase.

Australia’s Southern coast is hugely popular among surfers, but the waves there could increase by 15% there and that’s not good news

It shows that approximately half of the world’s coastlines will experience significant and long lasting changes in wave size and intensity. For places like the East coast of the United States this will mean a serious reduction in size and power of waves, seriously altering the coastal ecosystems there. Whilst places like Australia’s Southern coast could see the opposite with waves potentially becoming 15% larger by 2100. This may seem like a small increase or even a good thing if you enjoy shredding gnarly waves. But it has the potential to drastically damage coastal communities and impact other things you wouldn’t normally consider.

Why will this happen?

So we know what is going to happen if the rate of climate change isn’t slowed down. But just how does a warming planet lead to changes in wave patterns? The answer lies with wind. Although tidal forces from the gravitational pull of the moon and the sun play a significant role in wave patterns, it is actually surface winds that are predominantly responsible for how and where they form. It is therefore changes to those winds from climate change that will create knock-on effects to waves. In particular the wind belt that circles the Antarctic Peninsula which is a big player in wave formation across the world. Increasing greenhouse gases are already increasing the number of annual low pressure systems over Antarctica, which in turn strengthens these wave-forming winds. But if climate change continues at its current pace the problem will get exponentially worse over time.

A zodiac boat transporting people towards a glacier
Researchers say the changes to the wind belt surrounding Antarctica will be the main reason for the changes in global wave patterns

Serious consequences

Now we know how and why wave patterns are likely to change in the future. So what are the effects for human populations likely to be? This is a little harder to accurately predict at the moment, but there is no way we escape unscathed. The main problem, according to COWCLIP lead researcher Joao Morim, will be coastal erosion. He told Hakai magazine that coupled with higher sea levels it could “lead to more wave energy being carried to shore, meaning faster erosion and dangerous storms”. Rising sea levels are already believed to be responsible for the erosion of 28,000 square kilometres of global coastline since the 1980’s. If we add bigger and stronger waves to that equation then it could lead to catastrophic damage that effects millions if not billions of people.

Coastal erosion
Coastal erosion is already a big problem in lots of places around the world, but bigger waves could make it even worse in the future

There are also the unforeseen impacts that will happen as a result to permanent oceanographic changes. For example, waves are an important factor in the types of marine habitats that have formed in tidal and coastal environments over millions of years. A change to that with either a decrease or increase in size and intensity will have knock-on impacts to marine life that we can’t even begin to predict. There is also wave and tidal energy production to think about. Because of its predictable and constant energy potential, tidal and wave energy is becoming a much bigger part of our renewable energy output for the future. But we are only just starting to harness these forces and if they significantly shift our ability to do so will be put in jeopardy. However hope is not lost if we can limit climate change to below a 2oc increase then we might still be able to escape the brunt of these problems.

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