How is tech helping to avert the climate crisis?

This week we mark 'Earth Hour' by focusing on investment into sustainable innovations and companies, as well as ideas to turn your home into a power station and using blockchain to save our oceans. David is joined by Olivia Sibony (Seedtribe), Laurent Schmitt (Dcbel), Ann Sofie Gade (the ReSea Project) and Amber Harrison (Harvey Nash Group).