Have you heard of Earth's Forgotten forests that can help combat climate change? 

They are underwater and cover a third of our coast lines, and are worth more than $500 billion globally. But they're disappearing worldwide and in some places they have vanished entirely. 

These vibrant underwater jungles play a vital role in capturing carbon from the atmosphere, and in fact, they capture millions of tons of CO2 each and every year.

Kelp forests are also incredible hubs of biodiversity here in Australia. They are home to hundreds of species that can't be found anywhere else on earth. Kelp forests are vanishing at a frightening rate all over the world due to rising ocean temperatures, overfishing water pollution, and an explosion in the number of sea urchins, which feast on the kelp.

At UNSW, we are at the forefront of a worldwide movement to protect and restore 4 million hectares of kelp by 2040 to ensure the health of these incredibly important underwater forests. 

SDG 14 is all about preserving life underwater. And in the places where we have kelp forest, which is a third of our world's coastlines, they're critical to life underwater.

The Kelp Forest Alliance is working to create a global home for our kelp forest, and we're doing this by bringing together all different parts of society. 

We're providing the best available science to guide their management. We're consulting with communities to understand how they need and interact with Kelp Forest.

We're creating awareness and we're building government support to really create this unified global effort to save these underwater ecosystems. 

In this project we are re-establishing forests of kelp that went missing, we think because of pollution back in the eighties. But they went missing just from the Sydney metropolitan coastline.

And in the last 11 years, we've managed to bring those forests back and re wild a substantial portion of the metropolitan coastline. 

All the methods that we use in Operation Crayweed can be used for other kelp species. 

Achieving the kelp forest challenge is a really, really big task because so far we've only achieved a very small proportion of that 4 million hectares. 

However, we do have a lot of the science that we need. 

What we don't have is global action on climate change, which is absolutely essential.