Pupils of a two-teacher school in a corner of west Cork have written, recorded and released a rap song to deliver a message on climate change to a global audience.

Cappabue National School has just 23 pupils, but their YouTube video, which calls on everyone to make 'One Small Change' to help save the planet, has already been watched and shared over a million times.

Music producer, songwriter and rapper Garry McCarthy came to the school to help the pupils - some as young as five - have their voices heard.

The school lies in a valley between the Coosán Gap and the Pass of Keimaneigh, around 20km from Bantry.

The 23 pupils were appalled when they went on a recent beach clean-up, gathering sacks of discarded plastic and glass bottles, aluminium cans and other marine litter.

"The aerial shots are so good - they really display the landscape and all of that. It was quite fun making it. We really got our ideas out there. I don't think it's going to be the most viral thing, but it's definitely going viral."

They made a life-size model of a whale from the rubbish they collected and named it 'Moby Sick', which sits in the school yard as a daily reminder of the damage people can do to the environment, particularly the marine environment.

The beach clean-up had a huge impact on each of the pupils and they decided that it might be more effective send a message to people promoting a cleaner environment, rather than cleaning up after them.

But they also wanted their message to spread far wider than the little patch of west Cork that their two-teacher school occupies.

Their solution was 'One Small Change', a rap they they wrote themselves.

They recorded the song with McCarthy and shot a video for it with local videographer and past pupil of Cappabue, Elaine Lucey.

Now they have a YouTube hit on their hands and a very impressed music producer.

"I couldn't believe the quality and the energy from the kids in the video," McCarthy said.

"I love it. I get a great kick out of this, just seeing them turn something from an idea in their heads into something that is now possibly being watched by people all over the world is fantastic."

Fifth class pupil Archer Little, 11, said he thinks the video "turned out amazing".

"The aerial shots are so good - they really display the landscape and all of that. It was quite fun making it. We really got our ideas out there. I don't think it's going to be the most viral thing, but it's definitely going viral."

Chloe McCarthy is also aged 11 and said: "We hope people will learn not to throw their rubbish in the sea, and to help clean up beaches and help the environment, because if we don't do something about it soon, the whole world will be destroyed and there won't be anywhere to live."

Ibrahim Francis is eight and in second class.

"I learned that the environment is quite important and, if it gets destroyed, then we won't be able to survive," he said.

School principal Norma Healy and teacher Olive Creedon say they have had contact from as far away as Australia since the video went online and have been overwhelmed by the response.

"I'm not going to cry," said Ms Healy.

"We get emotional - they are brilliant," said Ms Creedon.

"They are like our own," said Ms Healy. "The video is part of us and part of them. They are like our own children and we are just so grateful to have them here. It's an honour to be working with fabulous, creative, wonderful children."

The pupils are now hoping their 'One Small Change' video will lead to one big change in saving the planet.