Weathered

- By the end of the century, we're likely to see around one meter of sea level rise.

Coastal cities and towns all over the world will be impacted, but perhaps nowhere more than the low-lying atoll islands of the Pacific and Indian Ocean.

Many of these islands could be uninhabitable.

By 2050 or so, scientists thought a shocking 2010 paper showed the opposite.

The vast majority of the 27 actual study remained stable or had even grown.

But is this story really that simple?

- It doesn't tell the whole story.

That was not the story at all that I wanted to go out.

- The actual story it turns out, is much more interesting.

- Our hypothesis is that the problem is the solution, - And that solution could actually help us understand how some coastal areas all over the world might adapt to the rising tide.

And stay tuned because we're gonna take a look at how one of the most destructive forces on earth might actually play a vital role in the survival of atoll islands.

Atoll islands are a wild cork of geology.

They're ring shaped islands formed atop coral reefs surrounding a lagoon.

They're essentially burial sites for ancient volcanoes formed when a volcanoes slowly erodes and sinks into the sea.

Most of the world's atolls are in the Pacific Ocean and they're truly magical places, but they're also incredibly vulnerable to climate change.

The average elevation of atoll islands is less than two meters above sea level.

And sea levels aren't just rising.

They're rising faster and faster.

- There's not too much variation in projections out in the next 30 years.

Beyond that, though, the real elephant in the room is what are the world's major ice sheets going to do it in Antarctica, in Greenland, - By 2100, we're on track to see about two to three feet of sea level rise.

- But it's plausible that global seas could rise upwards of six feet by the end of the century.

- For people living on low lying islands, sea level rise is truly existential.

So when a series of studies came out showing that some atoll islands were in fact growing, there must have been a collective sigh of relief or was there In 2018, Paul Kench used aerial photography and satellite imagery to see how the atoll and reef islands of Tuvalu had changed between 1971 and 2014, and the results were pretty astounding.

Eight of nine atolls and almost three fourths of the islands grew increasing the overall land by 2.9%.

- And that work has been repeated many, many times in other areas as well.

In the Maldives, it was shown that more islands would've got bigger than smaller, - But the residents were having a different experience.

- That's saying that we are not affected because our islands are, are growing big.

But from our daily lives, we are experiencing the impact of climate change.

- Lamese was fired up by these conflicting stories of his nation's demise and resilience.

He wanted to study it himself, which eventually led him to pursue a Masters and PhD.

He zeroed in on a small island on the rim of Funafuti, the capital of Tuvalu, and he collected data by drone to assess changes and not only the circumference of the island, but also its volume.

He confirmed that the island was indeed growing, but he found something else too.

- Results suggests that you know, Tepuka is expanding, but in terms of the volume is losing out, - The circumference had grown, but its elevation had decreased.

So why is this happening?

- The reason the islands got bigger is because there's also sand being added to the island by waves and currents.

So you're losing a lot of sand from one side and then you're smearing it out on the other side.

That's a possibility.

So the island looks bigger, the circumference of the islands got bigger, but has the island become more resilient?

- The original studies had shown that atolls are dynamic.

They're able to shift, reshape, and even grow.

But if the islands are expanding by essentially spreading out their sediment, they might also be getting lower, which means more exposure to flooding and sea level rise.

And with an average elevation of less than two meters, these atolls don't have height to lose.

So can island nations like Tuvalu be saved?

- At the moment, there's two options.

One option is build a a sea wall around every atoll island.

We're talking millions, tens of millions of dollars.

You could also say that's not really a sustainable solution in the long run because there'll be a point where the water will just basically come through the floorboards.

Now the other alternative is, okay, the flooding is gonna become unbearable in 10, 20 years.

Before that happens, we'll relocate you.

It's after generations of living on an island.

You basically take everyone and tell people to move.

Now I, I don't see either of these as viable solutions, - But there may be a third option, one that takes into account how these islands were formed in the first place.

- Our hypothesis is that the problem is the solution.

So the the problem is the flooding, but the flooding is also the solution.

- When the islands flood, the water brings with its sediment and deposits this sediment on top of the island, - That's how the islands formed in the first place.

Now, that's not actually going to increase the circumference or the size of the island.

It actually might even even slightly decrease the size of the island, but it will increase the elevation of the island.

- And a higher island is more resilient to the rising seas.

This natural process relies on healthy coral, which creates the sediment that washes up on shore.

And we know that coral bleaching is impacting reefs everywhere.

And human infrastructure like sea walls, buildings and roads prevents floods from depositing the sediment, which means some islands may be shifting but not growing taller as they have the potential to do.

But there's a lot more research needed.

Lamese has been trying to understand this dynamic process to better support his nation's survival.

- I am bringing in the wind and the waves data to really understand how those are affecting the island dynamics.

- Scientists are also looking into the role of buffer zones, and these are areas with no human development, where floods can be allowed to deposit sediment.

- Always just keep a vegetative buffer zone around your island that is at least 25 or 30 meters wide.

When we, we think the islands, if they're left as natural as possible, that they are able to move up and back with the rising sea level.

So the islands will not drown.

They will evolve.

- For this process to work though, the island has to remain in a relatively natural state.

Sea walls, for instance, block flood waters and with them the sediments that build the island.

So while they may protect against short-term flooding, they could also make the island more vulnerable In the long run, floods can be devastating to human communities, especially hurricanes.

But from the island's perspective, they're essential.

Hurricanes churn up the ocean carrying with them coral sand and sediment.

And when the hurricanes make landfall, all of that sediment piles on top of the land.

Without flooding from major storms, a lot of the world's islands could disappear.

So what does this all mean for coastal areas around the world?

- The human environment doesn't adapt that well because it's not like these sediment or things flung up onto the the coast during hurricanes.

It doesn't go underneath our stuff and elevate it.

It's not like it's jacking up our foundation of our house.

It's over washing and it's damaging and it's corroding.

- If you wanna prevent London from being affected by storm surge, well you're not gonna make space for water.

You're just gonna build a massive storm surge barrier to keep out.

- Our developed cities like Miami and New York aren't going to be able to accommodate flooding in the same way that these atoll islands might.

But there are many places that can, - All sorts of coastal environments that are made of sand or gravel or loose material have the ability to adapt.

You make space for the sand to move into by avoiding critical infrastructure, by moving infrastructure, by, you know, getting out of harm's way, you will maintain your beaches and your dunes and your valuable ecosystems only they will slowly move back.

- But how much sea level rise can these low-lying coastal environments take?

Sea level rise projections typically only go out to 2150, but we'll still be around after that and there's a lot more sea level rise already baked in.

- We do know 125,000 years ago when we've had temperatures and carbon dioxide levels not too different than today, seas were on the order of 10 to 30 feet higher, whether that's in a few hundred years or a few thousand years.

Sea level is rising and it's going to continue to rise for some time.

- 30 feet of sea level rise would completely rewrite our coastlines.

The adaptations we're doing now from sea walls to more natural solutions are all just buying us time.

If we slow the impacts, we give communities time to adapt when possible and to move when necessary.

- We we're going to have to fundamentally change our footprint at the coast in the long run, for sure, at these higher amounts of sea level rise.

- And as scientists help inform the best adaptation strategies, it's critical that the lived experiences of locals are taken into account.

- It's not just like whether we appear or disappear in the next a hundred years, but like right now, as I'm speaking, we already experienced those impacts of climate change.

- Hurricanes and floods have been around longer than humans, and even these destructive forces have a critical role in shaping our ecosystems.

And as seas rise and hurricanes grow stronger, more and more of our cities will be forced to contend with these realities.

And there are a lot of creative ways that cities around the world have learned.