Breaking point Is the world ready for bigger waves?

In some seas, swells are growing noticeably larger. Scientists say coastal communities should be prepared for damaging consequences-but also potential opportunities

- James Bradley

The idea of duality is difficult to avoid when thinking about waves. In them we see energy and matter collapse into each other, find fluidity with structure and form and apprehend beauty and symmetry and violence and terror. Likewise, the physics of waves are simultaneously very simple and impossibly complex, the non-linear nature of fluid dynamics meaning they can remain relatively regular or combine without warning into rogue waves capable of sweeping people off rocks and sinking ships.

Waves are a vital part of the ocean system, helping to control the rate at which the ocean absorbs heat and carbon dioxide and shaping and sustaining coastlines. And as ocean temperatures rise and weather patterns shift, they are changing, in some oceans growing bigger and more powerful.

This has frightening implications for coastlines and the coastal communities that bear the brunt of the ocean's fury. But if harnessed effectively waves and the energy they transmit may play a part in tackling the climate crisis.

The waves we see on the ocean's surface are mostly wind waves. Because wind pressure is never uniform, it creates tiny fluctuations in the water's surface. As the wind pushes against these fluctuations they grow, creating larger and larger surfaces and transferring more and more kinetic energy from the air into the ocean. As they move across the water's surface these fluctuations interact and combine, first forming ripples, then longer and larger waves. Out on the open ocean, where powerful winds can blow on the water for hundreds or even thousands of kilometres without interruption, these eventually become the massive swells that crash on to shores in higher latitudes.

Waves can also be created by seismic events such as earthquakes and volcanic eruptions.