When you think about all the habitat types on Earth that are sensitive to climate change.

Obviously, ice comes to mind.

But the other thing that comes to mind is coral reefs.

Healthy reefs are vital for marine wildlife.

Over a million species depend on them to survive.

From the tiniest fish, to flocks of seabirds and gigantic manta rays.

Around the world, 500 million people rely on reefs for food and to protect coastlines from storms and rising sea levels.

They're also crucial for humanity as a whole.

Coral reefs are the cornerstone of a well-functioning ocean ecosystem.

They create habitat for seagrass beds and mangroves, which in turn absorb carbon and store it, helping to stabilize the climate, but the future of coral reefs is hanging in the balance.

They are really sensitive to lots of things sea water rise, sea water temperature, acidification of the oceans, pollution.

...and that's why they are really one of the most endangered habitats on earth.

We are at a tipping point.

Half of all coral reefs have already been lost or severely damaged and experts predict that without action, nearly all reefs could die off in the next few decades.

Now, groundbreaking scientific collaborations are offering a beacon of hope.

If they work.

For the past two years, this ambitious project has been following the pioneering work of scientists and conservationists at key places around the world.

But this year, I'm focusing on a habitat that's facing the most urgent threat, coral reefs.

I'm taking a special in-depth look at the crucial efforts to save coral and innovative techniques that could bring reefs back to life.

Reefs around the world are literally collapsing because they don't have enough corals on them.

Everything we do today has to focus on saving what we have and rebuilding what we've lost.

My search for practical, scalable solutions has brought me here to the Maldives because this is the epicenter of climate change, coral reefs and practical science.