How rocks on the ocean floor could be key to the transition to electric cars. Justin Rowlatt speaks to Gerard Barron, boss of DeepGreen, a company that wants to gather rocks from the ocean floors rich in the metals essential for making electric car batteries. He tells us why this kind of mining is crucial to transitioning away from fossil fuels. Louisa Casson, senior campaigner with Greenpeace, warns of the environmental devastation this could cause. And zoologist Adrian Glover tells us how mining could take place alongside conservation of the deep seabed.

(Photo: A sunset over an ocean, Credit: Getty Images)