Reindeers in Svalbard are shrinking in size due to the effects of climate change that is causing winter rain to ice up their pastures – leaving them struggling to survive.

Scientists are predicting there will be more smaller reindeers in the Artic in the coming decades, even possible extinction because of the "increased ice on the ground".

Over the past 16 years, the weight of adult deer in Svalbard, Norway, has fallen by 12% to 48kg. They are going hungry and aborting their young which is born much lighter. Another reason behind their reduced size is the number of reindeer searching for food has doubled in the past 20 years.

Lead researcher Professor Steve Albon, of Scotland's James Hutton Institute, said: "There is a risk of catastrophic die-offs."

It follows an Arctic Council report last month that identified the Arctic as one of the so-called tipping points or regime changes affected by global warming. Other areas included Greenland and hypoxia – loss of oxygen in the oceans – and the collapse of fisheries.

In the past six to 12 months, report co-editor Marcus Carson of the Stockholm Environment Institute has heard more "warning bells ringing about the Arctic and the significant rebound effects to the rest of the world.

He told the Thomson Reuters Foundation: "Because the Arctic is so connected to the rest of the planet in terms of climate regulation ... the change that we're sending to the Arctic is likely to be amplified and come back to us."