We Can’t Engineer Our Way Out Of This: Sea Levels and Wave Heights Continue To Rise

Climate change is here, and it’s only been getting worse.

This is one of many new realities that we as a species have to face in the 21st century and beyond. We’ve all heard about the consequences: The planet is warming, sea levels are rising, species are dying—it’s hard to keep track of all the effects at this point.

But for every aspect of climate change that gets widely talked about, there are many more that barely see any recognition. Among these more obscure effects of climate change is an increase in wave heights in the ocean—an unprecedented change with unprecedented consequences.

Since global warming began rapidly accelerating around 1970, ocean wave heights have also seen a great increase. According to research by UCSD Professor Peter Bromirski, ocean wave heights since 1970 have been about 13% higher on average than those between 1930 and 1969. Furthermore, projections suggest that wave heights could increase by a further 15% if global temperatures were to rise by 3 degrees Celsius above pre-industrial levels.

This growth in wave heights spells all sorts of trouble, especially for maritime and coastal communities. Increases in wave height also increase the energy delivered by waves, which could lead to more erosion, property damage, and ecosystem disruption, to name a few effects.

But to understand where these wave height increases are coming from and what we can do about them, we first need to understand the weather conditions that drive waves around the ocean in the first place.

A Warming Planet

As we continue to burn fossil fuels, emit greenhouse gases, and disrupt ecosystems across the globe, the planet has warmed significantly over the past 150 years. Earth’s oceans have seen a disproportionate amount of this warming, having absorbed more than 80% of the heat gained by the planet in the latter half of the 20th century.

As the ocean has absorbed this heat, its surface temperature has risen by about 1.5 degrees Celsius from 1955 to 1998. This rise in surface temperature causes the air directly above the ocean to heat up as well. This warm air then rises, and cooler air sinks in order to take its place. This cycle of heating and cooling leads to currents of air moving over the ocean surface.

This cycle of heating and cooling is what causes wind to form over the ocean. As these winds blow over the ocean, they drag across the surface of the water and cause the water to bunch up into waves. Depending on how fast and far these winds blow, waves can range from small ripples on the ocean surface to beasts capable of sinking ships.

But the warming of Earth’s oceans has intensified every step in this process, leading to stronger winds and stronger waves.

With all that being said, this is just one of many factors that has been driving increases in wave heights. Research has shown that there may be many other factors at play, and we have yet to uncover everything behind these changes.

But even with all these unknowns, we know one thing for certain: these changes are happening, and the consequences are soon to follow.

It’s Not Just the Waves

“So what”, you might say. “So what if waves get a bit higher? It shouldn’t affect me. It’s not like there’s that many people living right on the coast, so what does it matter?”

As the climate continues to change across the world, we’ve seen alarm bells ringing for all sorts of consequences: sea levels are rising, temperatures are going up, glaciers are melting, and natural disasters are becoming ever more commonplace, just to name a few. But as bad as the individual effects of climate change are shaping up to be, there’s still much to be said about the interplay between all these different effects.

Sure, a 15 percent increase in wave heights on its own probably won’t affect your day-to-day life very much. But it’s not just an increase in wave heights that we’ll have to worry about.

In fact, the main concern with increased wave heights is the potential that they have to exacerbate other facets of the climate crisis.

To start, taller waves also carry more energy with them, which allows them to displace more sand when they come into contact with coasts, leading to increased erosion. We’re already losing land to sea level rise, but erosion is another major contributor to coastal land loss—including right here in Isla Vista, where the bluffs have been eroding away at an alarming rate.

Combined with the loss of coastal ecosystems that have traditionally protected shores from erosion, this situation poses major risks to coastal communities across the world, from coastal cities to low-lying island nations. These effects, too, can be seen here in Isla Vista, where houses on Del Playa Drive might become uninhabitable in a matter of years.

Bigger waves are especially dangerous when combined with the projected sea level rises that we’re expected to see in coming decades. Projections show that flooding and damages considered extreme today could become commonplace by the end of the century due to both sea level rise and increased wave intensity.

Make no mistake: the projections above could very well be the reality we have to deal with in the near future.

It’s easy to think that we might be able to mitigate these effects by building dams and barriers. After all, humans have always found a way around these problems. From huge projects like the Hoover Dam to truly impressive land reclamation efforts across the globe, we as a species have time and time again exerted our dominance and control over the forces of nature.

So what’s stopping us from just building our own defenses against these waves?

We Can’t Engineer Our Way Out of This

First of all, saying that we can just build more defenses against climate change presupposes that we have the resources and infrastructure to do so. For many of the places that will be the most affected by climate change, this simply isn’t a reality. Countries in the Global South, and especially low-lying island nations in the Pacific often don’t have the resources or means to implement these defenses, even as climate change poses an existential threat to their land.

But even for nations with the means to build seawalls, revetments, bulkheads, and the like, it’s simply not a sustainable strategy to keep building bigger defenses. 

For one, the bigger waves get, the faster they wear down at coastal defenses. Coastal engineers do take erosion into account, but faster rates of erosion would mean not only that structures would have to be replaced more often, but also that existing structures might see levels of damage that they weren’t built to handle and thus fail.

Furthermore, increases in wave height affect the intensity of large waves more than they do to small waves. That is to say, we can expect to see storms that come more often, more intensely, and that last longer. 

These more intense storms are especially difficult for engineers to deal with. Stronger winds and waves are more damaging to coastlines, but one of the most worrying changes is that storms could last longer before dying down. With longer storms, there’s a much higher chance that high tide could strike while a storm is occurring, which allows the winds and waves to batter structures that are much further inland.

This isn’t to say that we shouldn’t invest in coastal defenses, but rather that this isn’t a problem that we can just fight the symptoms of—we have to tackle it at the root.

So, What Can We Do?

With all the bleak news these days about climate change, it’s easy to think that there’s nothing that we can do about it at this point. But it’s not entirely too late.

If we’re able to keep emissions down, and keep temperatures from rising by more than 2 degrees, we could keep changes in wave climate relatively manageable.

It won’t be easy; there’s still much work to be done in reducing our reliance on fossil fuels, and curbing the amount of emissions we put out. We need to divest from unsustainable practices, invest into renewable energy and sustainability, and pressure those in power to work towards a future that’s better for us and the world we live in.

We may not be able to engineer our way out of this, but if we’re able to act fast enough and strongly enough, there may still be hope for our oceans and our future.