BBC: Changing the Earth's climate

It's hard to feel positive when you hear about climate change, don't you think, Neil?

Yes. According to the UN's conference, we're heading for a catastrophic global tempferature rise of three degrees by the end of this century... Fires are blazing from the Amazon to the Arctic...And even if we stopped burning all fossil fuels tomorrow, it would take decades to feel the effects. It's all very depressing!

I agree, but there is hope that catastrophes can be avoided thanks to some amazing ideas by some very imaginative scientists. In this programme, we'll be discussing geoengineering- the name for a collection of new scientific plans to remove carbon from the atmosphere and stop global warming. 

Also called 'climate repair', geoengineering is still in the experimental stages. Some technologies are controversial because they interfere with natural climate systems, and others may not even be possible.

One ingenious idea to cool the planet involves spraying diamond dust in the sky to deflect the Sun's rays. 

Amazing! But before we find out more, I have a question for you, Sam. Spraying diamond, dust in the sky sounds futuristic, but in the 1960s there was a band who wrote a song called 'Lucy in the Sky with Diamonds'. But which band? Was it:

a) The Rolling Stones   b) The Beach Boys   or c) The Beatles?

I think most people would say the answer is c) The Beatles. 

OK, we'll find out the answer later in the programme. Now, throwing diamonds in the sky might sound crazy, but it's far from the wildest idea scientists have thought up to decarbonise the planet. 

Oceans hold sixteen times more carbon than the Earth's atmosphere and could not even more if the fish and plankton living there had more available nutrients- food that animals and plants need to grow. 

But how to provide these nutrients? Believe or not, one answer involves- you guessed it- whale poo. 

David King chairs the Center for Climate Reparir at Cambridge University. He explained how his unusual idea would work to BBC World Service programme, Discovery:

Imagine now a pod of whales all coming up and pooing in the same area of the ocean. This could be in an eddy current,  and it could lead to somethisng like 10,000 to 20,000 square killometers being covered in nutrients, including iron. And as we know from observations today, within three moths that region is chock- a-block with fish. 

Whales live in groups called pods. They swim up to the ocean surface to poo, and this poo can be spread in an eddy- a large current of water moving in a circular motion, like a giant whirlpool. 

As a result, huge areas of the ocean are covered in nutrients, and becojme chock-a-block with fish- an informal way to say 'full of fish'.

Another orginal idea being explored in 'rock weathering'. Carbon is slowly locked into rocks and mountains over thousands of years by natural geological processes. This literally ground-breaking idea would speed up the process by locking carbon into rocks that have been dug up through industrial mining.

Listen as geochemist, Professor Rachael James, explains her ida to BBC World Service's, Discovery:

For every tonne of rock that's mined, only a very timy proportion, a couple of grams of that, is actually diamond. The rest of it is effectively waste. So, mine waste material is potentially a really great source of material that could be repurposed for enchanced rock weathering, and I think that's really good because it creates a circular economy. 

Mining for diamonds creates tonnes of waste rock which could be used to capture carbon. Professor James wants to repurpose this rock-to find a new use for it. 

Not only would this lock more carbon, it also creates a circular economy- an economic model which involves sharing, reusing and recycling products for as long as possible to avoid waste and to reduce levels of carbon. 

While these ideas might sound strange, they're all theoretically possible. And looking to science for positive solutions reminds some people of the early ecological movement, which started in the 1960s and now, fifty years later, is being taken seriously. 

Speaking of the 1960s, it's time to reveal the answer to my question, Sam.

Ah, yes, you asked me which sixties band wrote the song, Lucy in the Sky with Diamonds. I said, confidently,  c) The Beatles. 

Which was, of course... the correct answer!