The Arctic is warming at an unprecedented rate, happening twice as fast in the region that anywhere else in the world. Another banner report from NOAA this month puts Arctic temperatures at its warmest since record keeping began in 1900. If global temperatures continue to rise, scientists warn that it’ll threaten the permafrost, a type of soil that exists below freezing for two or more years and covers a quarter of the Northern Hemisphere. The permafrost is a sleeping carbon giant, and if it thaws, it’ll release an enormous amount of greenhouse gases into the atmosphere. Rising temperatures in the Arctic are giving way to another new fear factor in the Alaska interior: forest fires, which destroy the organic vegetation and could pick up the pace of permafrost thaw. Continuing our coverage in the Arctic, TechKnow traveled to Fairbanks, Alaska to report on the state of permafrost in a unique laboratory constructed by the US Army Corps of Engineers in the 1960s, the Permafrost Tunnel.

Walking inside the permafrost tunnel.

Vladimir Romanovsky, a geophysicist with the University of Alaska Fairbanks who uses the tunnel for his research and has been studying permafrost globally for over forty years, tells TechKnow that a thaw below ground can have a huge influence above. Here are some examples of what’s hidden within the frozen layer. A carbon time bomb

The first thing you notice when walking through the permafrost tunnel is the smell: it’s a mossy scent from the twigs, sticks, and mud that make up permafrost. Nearly 1,600 gigatons of carbon are stored in the frozen organic matter, and that’s a mega source of greenhouse gases. More than twice that amount is already in the atmosphere. You can see why scientists would be worried about the feedback loop from a thaw: warming begets more warming. This is how it works: as the permafrost heats up, the ice turns to water and the permafrost turns to thawed mud. The mud is full of dense biomass, like plants and mossy peat, that have been locked in the soil for thousands of years. The decomposition of the biomass releases CO2 and methane into the atmosphere. The thawing process will flip the switch from permafrost carbon sink, meaning it absorbs and locks the CO2, to greenhouse gas spigot. Vladimir Romanovsky tells TechKnow that when that happens, there’s no going back: “As soon as permafrost starts thawing, it will continue for a long period of time, and it’s practically impossible to control it.” Scientists are still trying to pinpoint when it will happen. According to a study co-authored by Romanovsky, 15% of the carbon stored in permafrost could be released by 2100. Ancient viruses

Mollivirus sibericum, Courtesy: IGS CNRS/AMU

Another consequence to an Arctic thaw is waking up dormant viruses that have been frozen for thousands of years. Earlier this year, scientists unearthed a 30,00 year old virus, Mollivirus sibericum, a pre-historic “frankenvirus” found in Siberia. Further study into these viruses will help clarify the risk, but rest assured, this virus isn’t a danger to humanity and won’t unleash a major public health crisis. Still as the permafrost thaws, more viruses could rise to the surface. Wooly mammoth bones Walking through the Permafrost Tunnel is like going through a frozen time machine. The permafrost inside has been frozen for tens of thousands of years. A fun historic feature are the fossil bones from mammoths and bison protruding from the tunnel walls.

US Army Corps engineer Quentin Gehring and TechKnow host Phil Torres inspecting a 14,000 wooly mammoth bone.