Changes to the Arctic tundra are not only a symptom of climate change but may fuel further warming, Scottish scientists have suggested.

One of the biggest studies to date of key vegetation provides strong evidence that dramatic changes in the region are being driven by climate warming.

Studies of tundra shrubs — which act as a barometer of the Arctic environment — show that they grow more when temperatures are warmer. Increased shrub growth, driven by warming in the Arctic, could cause more warming in tundra ecosystems and over the planet as a whole.

Scientists at 37 sites in nine countries, led by the University of Edinburgh, studied records of shrub growth spanning 60 years by analysing annual growth rings in the plant stems, to