NEW evidence of the dramatic and destabilising impact of climate change on the world’s polar regions has prompted calls for the Scottish Government to toughen its climate targets.

Two scientific studies have highlighted the potentially disastrous impact of Arctic and Antarctic icecaps melting, raising sea levels and flooding the homes of as many as 150 million people around the globe.

In the polar regions, the air and water are getting warmer, the ice is getting thinner and the permafrost is thawing, scientists said. They warned that a “catastrophic runaway effect” could take hold, ice shelves could fracture and ice cliffs collapse.

The latest report from the US government’s National Oceanic and Atmospheric Administration (NOAA) said that the average surface air temperature in the Arctic in the year to September 2017 was the second warmest since 1900.

Sea ice was thinning with older, thicker ice shrinking from 45 per cent of ice cover in 1985 to 21 per cent in 2017. In August 2017, sea surface temperatures in the Barents and Chukchi seas were up to four degrees centigrade warmer than average.

Permafrost, which locks up huge amounts of carbon, is getting warmer, and the Arctic tundra is getting greener as more plants grow. We are seeing the “darkening” of the Arctic, according to NOAA’s Arctic research director, Dr Jeremy Mathis.

“Reflective, icy surfaces are melting to reveal darker surfaces that absorb more of the sun's energy. So it probably only took a little bit of human-induced change to start the Arctic down this cascading pathway,” he said.

“A little bit of ice melting led to a little bit of warming, which led to more ice melting, which led to more warming. And now we're seeing an acceleration - a runaway effect that may eventually be a catastrophic runaway effect starting to take hold in the Arctic.”

The Arctic has traditionally been the refrigerator of the planet, Mathis suggested. “But the door of the refrigerator has been left open.”

Another study published by scientists from five US universities suggested that the fracturing of ice shelves and the collapse of ice cliffs could rapidly diminish ice sheets in the Antarctic. With high carbon pollution, this could see average sea levels rise by 80 to 150 centimetres and “by 2100 submerge land currently home to more than 153 million people”.

Such extreme outcomes couldn’t be excluded after 2050, they concluded. Rain could start to fall on the ice sheets and they could “break up really suddenly”, said Rob DeConto from the University of Massachusetts.

Friends of the Earth Scotland warned that melting permafrost could release large amounts of climate changing gases. It pointed out that Iceland was now aiming for net-zero emissions by 2040 and MEPs were pressing for Europe to aim for the same by 2050 at the latest.

“Pressure is mounting on the Scottish Government to go further than their current proposal of a 90 per cent reduction by 2050,” said the environmental group’s director, Dr Richard Dixon.

“They say they are thinking about when Scotland can aim for net zero. They’ll need to significantly up their ambition for both short and long term targets in next year’s climate bill if they want to continue to be a climate leader.”

Dr Sam Gardner, acting director of WWF Scotland, argued that what was happening in the Arctic had serious implications for the whole world. “As the Arctic’s nearest neighbour, Scotland has a crucial role to play in preventing runaway climate change,” he said.

“If the Scottish Government is to strengthen its relationship with the Arctic and renew its position as a global leader on climate action, it must use next year’s climate change bill to set a net zero emissions target for 2050 at the latest, and spell out strong policy action to build a zero carbon economy.”

The Scottish Government stressed that it was a “world-leader on climate change” with among the most ambitious targets. “We have a commitment to strengthen these further with a new bill in response to the Paris agreement,” said a spokesperson.

“We are also committed to a transition to a low carbon economy that delivers sustainable economic growth and social justice here in Scotland, as well as tackling climate change globally.”