The seaweed farms that could feed us all, at a cost.

It looks like a large ring from which innumerable star-shaped lines branch out. They are seaweed, glowing in the sunlight.

This is Brian von Herzen's plan to 'save the Earth'. Founder and director of the Climate Foundation, Von Herzen wants to use highly-engineered platforms to 'reforest' the oceans with algae, thus solving everything at once: feeding mankind, restoring ecosystems, extracting carbon dioxide (CO2) from the atmosphere and ending the climate crisis.

Algae have been called the 'elephant in the blue carbon room' because they grow very fast: Climate Foundation algae in fact grow up to three times faster than algae growing on the surface.

'We could change humanity's relationship with the ocean, from extraction to regeneration,' says Von Herzen.

But there is a problem, algae, like corals, cannot withstand high water temperatures and the sea is now becoming warmer than the algae can handle.