´óÏó´«Ã½

Until now climate-related terms like "greenhouse gas" and "carbon footprint", didn't have official signs in British Sign Language (BSL).

That meant children, teachers and scientists would often have to finger-spell long, complex, scientific terms - which not only took a long time, but could be very tiring and frustrating too.

But that's now changing. Deaf scientists and sign language experts have created 200 new signs, including many for climate-related terms.

The signs have been created to support deaf children in schools.

Dr Audrey Cameron, who helped come up with the new signs, said: "We're trying to create the perfect signs that visualise scientific concepts."

She is profoundly deaf and leads the sign language project at Edinburgh University.

The science glossary project, funded in part by the Royal Society, has been running since 2007 and has added about 7,000 new signs to BSL.

To develop the new signs Dr Cameron said they had taken a list of terms from the school curriculum and then worked together to come up with "something accurate" but that also had visual meaning.

The newest signs are themed around biodiversity, ecosystems, the physical environment and pollution.

There is also an online video glossary that people can watch to see how the new sign words are demonstrated.

Melissa, 13, a deaf student at a mainstream school in Glasgow, said she was already seeing the difference between having to finger-spell a long word like greenhouse gases (G-R-E-E-N-H-O-U-S-E G-A-S-E-S), compared to using the new sign.

It involves moving her closed fists around like gas molecules in the air.

"With the sign I can see something is happening with the gas," she said.

Her biology teacher is Liam McMulkin, who has also been involved in the sign-creation workshops, hosted by the Scottish Sensory Centre.

He is profoundly deaf and said that hearing people were "constantly learning and acquiring knowledge" wherever they go, "but deaf people miss out on so much information".

"That's why it's so important to use sign language in science lessons in schools," he said. "It allows deaf children to learn in their natural language."

Dr Cameron said showing scientific concepts in hand movements could help both hearing and deaf children think about and understand the meaning of the words more easily.

She remembered seeing a class of five-year-olds learning about how things float or sink.

"They were learning about how things that are less dense will float, which is quite complex," she explained. "And the teacher was using the sign for density."

The sign illustrates the concept by using one closed fist and wrapping the other hand around it - squeezing and releasing to represent different densities.

"I thought - these five-year-olds are not going to get this. But some time after the end of the lesson, they were asked a question about why things float or sink and they all used the sign for density," Dr Cameron said.

"So I've seen how much of an impact this can have. And my passion has just grown as the glossary has grown."

Mr McMulkin agrees. He said: "The beauty of sign language - particularly for science - is that it's a visual language.

"Some of the concepts are abstract, but sign language can really help children to understand them."

Mr McMulkin used the sign for "photosynthesis" as an example, which uses one flat hand-shape to represent a leaf, while projecting the fingers - like the sun's rays - from other hand.

"When I do this [move the sun hand towards the leaf hand], you can see that the energy is being absorbed by the leaf," he explained.

Dr Cameron said during her own scientific career, a lack of vocabulary meant she was often excluded from important meetings and conversations.

She told ´óÏó´«Ã½ News, "I was involved in research for 11 years and went to numerous meetings but was never was truly involved because I couldn't understand what people were saying.

"I wanted to talk with people about chemistry and I just wasn't able to."

It is hoped these new signs will mean children can avoid a similar experience in the future.

Prof Jeremy Sanders, chair of the Royal Society diversity and inclusion committee, said: "We hope these new signs will inspire and empower the next generation of BSL-using students and allow practising scientists to share their vital work with the world."