But methane and CO2 are not the only things being released from the once frozen ground. In the summer of 2016, a group of nomadic reindeer herders began falling sick from a mysterious illness. Rumours began circling of the “Siberian plague”, last seen in the region in 1941. When a young boy and 2,500 reindeer died, the disease was identified: anthrax. Its origin was a defrosting reindeer carcass, a victim of an anthrax outbreak 75 years previously. The 2018 Arctic report card speculates that, “diseases like the Spanish flu, smallpox or the plague that have been wiped out might be frozen in the permafrost.” A French study in 2014 took a 30,000 year-old virus frozen within permafrost, and warmed it back up in the lab. It promptly came back to life, 300 centuries later. (To read more, see BBC Earth’s piece on the diseases hidden in ice.)

Adding to this apocalyptic vision, in 2016 the Doomsday Vault – a sub-permafrost facility in Arctic Norway, which safeguards millions of crop seeds for perpetuity – was breached with meltwater. And listed amongst the membership of The Global Terrestrial Network for Permafrost, is Swedish Nuclear Waste Management who presumably also rely on a permanently frozen permafrost (when BBC Future approached them for comment on this point, they did not respond).

Long-preserved human archaeology may also be emerging, but just as quickly lost. A frozen Palaeo-Eskimo site in Greenland, preserved for some 4,000 years, is at risk of being washed away. This is just one of an estimated 180,000 archaeological sites preserved in the permafrost, often with soft tissues and clothing that uniquely remain intact but would rot quickly if exposed. Adam Markham, of the Union of Concerned Scientists has said, “with rapid, human-caused climate change, many sites or the artefacts they contain, will be lost before they have been discovered.”

More modern (and unwanted) human detritus will, however, not rot away: marine microplastics. Due to circular global marine currents, much plastic waste ends up in the Arctic, where it becomes frozen in sea ice or permafrost. A recent study of marine micro-particles demonstrated that concentrations were higher in the Arctic Basin than all other ocean basins in the world. Microplastic concentrations in the Greenland Sea doubled between 2004 and 2015. “Scientists are finding that those microplastics are accumulating across the entire ocean and being dumped into the Arctic”, explains Osborne. “This is something we didn’t [previously] realise was a problem. What scientists are trying to find out now is the composition of these microplastics, what sort of fish are feeding on these… and whether we are essentially eating microplastics through eating these fish.”