posed by climate change.

That's because rising seas,

stronger storms,

and heavier rainfall

could massively increase flooding

by the end of the century.

It's already starting to happen

and it's very likely to get worse.

Catastrophic flooding in Western Europe

after violent storms

and powerful flood waters destroying entire towns.

It's easy to feel overwhelmed

looking at footage like this.

It seems like no one has any idea

what to do about this problem.

So, we're just going to see more and more damaging floods,

year after year.

But there is one place where it's possible to imagine

a very different future.

When you look at the city of Rotterdam,

the water is in our genes,

you could say.

We are already working for 1,000 years on this topic.

Keeping the water out

isn't a new challenge for the Netherlands.

It's a battle they've been fighting for centuries.

So, when the effects of climate change

started to crop up,

they were like, yeah, let's do this.

We're ready.

We traveled to Rotterdam

to find out how this city is getting ready for the future

and whether the ingenious stuff they've come up with

will ultimately be enough to save them

and hopefully the rest of us, too.

When you look at Holland or the Netherlands,

the name, the Netherlands,

already says that we are a low-lying country.

One-third of this country

is below sea level

and two thirds is vulnerable to flooding.

Back in the day,

the only things keeping the water at bay

were the dikes,

which are basically just raised mounds of earth.

Once every few decades,

the water would overwhelm the dikes

and cause catastrophic flooding

and that was just the way things were,

until one day in 1953,

all that suddenly changed.

In '53, it was a disaster.

A powerful storm struck the Southern Coast,

overwhelming dikes that had been badly damaged

in the second World War.

On the morning of February 1st, 1953,

Koos' father and brother

woke him up and told him what had happened.

In 1953, almost 2,000 people died

and that was the moment for us,

we said, this can never happen again.

This is time we started making our first barrier.

The flood galvanized the Dutch government

to build the world's most powerful flood defense system,

the Delta Works.

It was a series of modernized dams

and storm surge barriers

that took more than 40 years to complete.

And the final act of the Delta Works

is the barrier over here,

the Maeslant Barrier,

made to protect Rotterdam.

We're looking at the biggest movable

storm surge barrier in the world.

This is the same size as the Eiffel Tower.

So, you're looking at the Eiffel Tower laying on its side.

Most of the time,

the barrier stays open,

so ships can pass through.

When a storm comes along,

it snaps shut,

preventing the storm surge from traveling up river

and flooding Rotterdam.

The moveable design was radical

when it was completed in 1997

and it's inspired similar structures

in flood-prone cities around the world.

If you look at St. Petersburg in Russia,

a small version of this barrier has been made over there

and maybe in the future,

in front of Manhattan,

they're thinking about a way to protect that, also.

So, this was the first one

and now smaller versions

are coming all over the world.

But the barrier on its own

isn't enough to keep Rotterdam from flooding.

Talking about climate change,

we see an increase of more intensive rainfall.

We already are facing now and then,

small-scale flooding.

So, we need more places

where we can store this water.

Arnoud Molenaar

is also working to keep Rotterdam dry,

not by keeping the water out,

but by giving it a place to go.

This is the water square

and it is actually, you could say,

a symbol for our approach,

how to become climate adaptive.

So, under normal circumstances,

this square can be used as,

for example, a basketball field.

But on days like this,

it stores excess rainwater

and keeps it from flooding the streets.

So, it's a multifunctional solution.

We want to add quality to the urban space,

but in this way,

we are also adding water storage.

This is the first water square

that we have been developing,

but it's part of a bigger package of measures.

An interesting one close by here is

what we call the dakpark

or the rooftop park,

which is a kind of a long levy

of one kilometer

and on top of it, a huge green park.

It's storing excessive rain water,

because of the green roof.

Looking at the challenges related to climate change,

a lot of people think it's going to cost us

a lot of space and money

and we try to show that you also can use it

to work on a better city.

In some ways,

the Dutch are just as baffled as the rest of us

about climate change.

For one thing,

there's the question of what happens when sea levels rise

beyond a certain point?

The Maeslant Barrier was built to withstand

one meter of sea level rise

and a redesigned barrier

could potentially handle even more than that,

but there's only so much that even Dutch engineering can do.

Beyond two meters,

it's difficult.

We are working on new scenarios,

suppose it will be more than two meters,

four meters, five meters,

then what?

People ask me,

will you be moving on a certain

moment in time

to the higher grounds in the Netherlands?

I can't imagine that that will be a decision.

For survivors like Koos,

on the other hand,

it's not so hard to imagine the worst.

I think in 300 years,

Rotterdam will still be here,

but when the sea level will rise four or five meters,

we will have to find additional solutions.

Any idea what those would be?

Maybe on a larger scale,

invest in floating districts,

floating cities.

And that brings us to our final

and most radical solution.

My name is Koen Olthuis.

I'm a water architect.

For the last 15 years,

We've been building floating homes

in cities that face climate change

and sea level rise.

So, we have the floating home,

which has a floating foundation

and it can move up and down

with the fluctuation of the river,

but to keep it on one spot,

we have these kind of stilts.

The water will come up

and you will see that the house will move up, up, up, up

and if the water goes down,

it just guides it back.

100 years ago,

you see cities start to grow up with high-rise buildings,

because they saw the space in the air.

Well, we see the city has to grow in the water.

It's not only about houses.

It's about floating apartment buildings,

floating roads,

floating parks,

all the kind of urban components you need

to make your city more waterproof.

Who knows,

maybe someday, we'll all live in floating houses

or maybe something entirely new will come along.

Preparing for climate change is a tough challenge,

but for the innovators of Rotterdam,

it's a process of adaptation that never ends.

It's not finished, our project.

It keeps on going.

It's an ongoing process.

I feel safe.

My children will feel safe

and my grandchildren will also feel safe,

but after that, you have to think again.