NEW research “sounds a warning” on harmful emissions from rivers near the Arctic Circle, a Scots expert says.

Aberdeen University’s Professor Chris Soulsby was amongst an international team that has now reported the results of its work on the permafrost soils now thawing in western Siberia.

The changing conditions mean the high levels of carbon stored in the peatland river networks are now being released up into the atmosphere.

The rates are equivalent to emissions from major cities like Glasgow.

And because western Siberia is home to the world’s biggest store of permafrost carbon, the team believes this could have “far-reaching consequences”.

Soulsby said: “Up until now there has been very little data from rivers of this size, so this study sounds a warning in terms of the importance of these northern river peatland environments in accurately measuring carbon emissions.”

Permafrost soils play an important role in regulating the earth’s climate, but as it degrades frozen carbon can end up in streams and rivers, where it is processed and emitted as greenhouse gases directly into the atmosphere.

Western Siberia is home to the world’s largest store of permafrost carbon, and the study area -–which extends to approximately 350,000 square miles – contains 15% of the carbon stores in northern peatland areas.

It is also home to the Arctic’s largest watershed drained by the Ob River, which is the seventh longest in the world and a part of a vast network of streams and waterways that scientists have analysed.

Soulsby said: “Measuring carbon emissions from permafrost-affected areas is important to help us understand the role such areas play in the global carbon cycle, and in helping predict the impact of a changing climate on the Arctic.

“This is particularly important in western Siberia, where vast amounts of frozen carbon are stored, and where the river network covers a vast area.

“What is surprising about our results is that the level of carbon emissions coming directly from river surfaces is much bigger than we previously thought for this type of environment. Indeed, the average annual CO2 flux per square metre from the rivers is similar in magnitude to what you would get as an average per square metre for a city like Glasgow.

“It is vital that we continue to closely monitor these river environments close to the Arctic Circle.”

Lead author Svetlana Serikova, of Sweden’s Umeå University, added: “The large-scale changes that take place in the Arctic due to warming exert a strong influence on the climate system and have far-reaching consequences for the rest of the world.

“That is why it is important we focus on capturing how climate warming affects the Arctic now before these dramatic changes happen.”

Meanwhile, a separate study says rising temperatures are pushing Arctic plants to grow taller.

Work led by Edinburgh University recorded an increase in the abundance of plant species across the Arctic tundra over 30 years, with native varieties also growing in height.

More than 60,000 data observations from hundreds of sites across the Arctic and alpine tundra were analysed to produce the findings, which were published in the journal Nature.

The findings follow research headed by Edinburgh’s Dr Isla Myers-Smith and Dr Anne Bjorkman of the Senckenberg Biodiversity and Climate Research Centre in Frankfurt.

Bjorkman said: “Arctic regions have long been a focus for climate change research, as the permafrost lying under the northern latitudes contains 30 to 50% of the world’s soil carbon.

“Taller plants trap more snow, which insulates the underlying soil and prevents it from freezing as quickly in winter. An increase in taller plants could speed up the thawing of this frozen carbon bank, and lead to an increase in the release of greenhouse gases.

“The increase in height didn’t happen in just a few sites, it was nearly everywhere across the tundra. If taller plants continue to increase at the current rate, the plant community height could increase by 20 to 60% by the end of the century.”