An unprecedented outbreak of wildfires in the Arctic has sent smoke across Eurasia and released more carbon dioxide in two months than the Czech Republic or Belgium does in a year.

As 44C heatwaves struck Europe, scientists observed more than 100 long-lasting, intense fires in the Arctic in June, the hottest month on record, and are seeing even more in July, according to Mark Parrington of the European Centre for Medium-Range Weather Forecasts.

Mostly in Alaska and Russia, the infernos have collectively released more than 120 million tonnes of CO2, more than the annual output of most countries. It is the most carbon emitted since satellite monitoring began in the early 2000s.

This will further exacerbate climate change and has sent smoke pouring toward more populated parts of the world. Pollutants can persist more than a month in the atmosphere and spread thousands of kilometres.

“You ask people about the Arctic, they think ice, polar bears, a clean environment, but clearly that's changing and that's no longer the case,” Mr Parrington said.

“It should be an alarm bell that something isn't right, but the way it could directly affect them is the long-range transfer of smoke pollution. I don't think it's getting as far as western Europe just yet but that could happen.”