6 Minute English / Deep-sea mining: Good or bad for the planet?

Note: This is not a word-for-word transcript.

Hello. This is 6 Minute English from BBC Learning English. I m Neil.

And I m Sam. Here at Six Minute English, we often discuss the new inventions and ideas scientists dream up to fight climate change technologies like geo-engineering which could reduce global warming by reflecting sunlight back into space.

Often these ideas are controversial because scientists disagree over whether the technology is possible, and whether, in some cases, it could do more harm than good.

In this programme, we ll be finding out about a new idea to collect lumps of precious metals, called nodules, from the bottom of the ocean. The idea, known as deep-sea mining, could provide the metals like copper, nickel and cobalt which are needed for the green technology used in electric car batteries and other renewable energy. But could deep-sea mining actually damage delicate ocean ecosystems as well?

We ll be hearing from two experts and learning some new vocabulary soon, but first I have a question for you, Sam. Mammals like dolphins and whales represent a tiny amount of all marine biodiversity - the thousands of animal species living in the sea. Even all the different types of fish combined make up less than 3% of all living things in the ocean. So, according to recent estimates by Unesco oceanographers, how many different marine species have their home in the ocean? Is it:

a) 70,000?b) 170,000?c) 700,000?

I ll guess there are around 170,000 animal species living in the sea.

OK, Sam, I ll reveal the answer at the end of the programme. Deep-sea mining is supported by some scientists because it could provide the raw materials, especially metals, needed to power electric cars. Amongst them is, Bramley Murton, a professor of marine biology at Southampton s National Oceanographic Centre. Here he outlines the problem to BBC World Service s, Science in Action.

As in so many things in life, there's a real kind of paradox or a conundrum. The global grid capacity by 2050 will have to increase by three times. Electrical car ownership is set to increase by a factor of 25. Solar and wind generation is going to grow by a factor of a hundred. All of these things which we need to do to decarbonise are going to require raw materials and metals in particular. So, as a society we re faced with this conundrum. We need to decarbonise.