on the deep ocean floor. of course, james cameron was inspired by deep sea animals for all of his movies. he says the impact of mining will be profound. it means humanity faces a difficult decision. it will be a dramatic shift in the ecology of that environment. and that's something that you just have to accept. some areas of the planet will have to be impacted if humans are going to move forward in a zero—carbon future. the decision about whether to allow mining will be taken by the un body that controls exploitation of the deep ocean. but, as sales of electric vehicles increase, pressure to allow mining in the deep oceans is also likely to grow. justin rowlatt, bbc news. as always, a lot more on a website. i'll be back very shortly. to get in touch, find us on social media. see you very soon.