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And I'm Sam. It's hard to feel positive when you hear about climae change, don't you think, Neil?

Yes. According to the UN's COP26 conference, we're heading for a catastrophic global temperature rise of three degrees by the end of this century... Fires are blazing from the Amazon to the Arctic...And even if we stopped bruning all fossil fuels tomorrow, it would take decades to feel teh effects. It's all very derepssing!

I agree, but there is hope that catastrophes can be avoided thanks to some amazing ideas by some very imaginative geoengineering-the name for a collection of new scientific plans to remove car bon 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 climat 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 1960's 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 programe. 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 hold 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 it or not, one answer involves- you guessed it-whale poo

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

Image 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 somethin glike 10.000 to 20,000 square killometers being covered in nutrients, including iron. And as we know from observaions today, within three months 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 overed in nutrients, and become chock-a-block with fish-an informal way to say 'full of fish'.

Another original being explored is '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 indeustrial mining. 

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

For every tonne of rock that's mined, only a very tiny proportin, 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 enhanced 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 produts for as long as possible to avoid waste and to reduce levels of carbon. 

While these ideas might sound strange, they're all theoretically possibe. 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.