Buried deep beneath Alaska’s wild terrain lies permafrost, a giant slab of earth that’s been frozen solid for millions of years.
This icy layer in central Alaska, just below the Arctic Circle, can stretch hundreds of feet down through the tundra.
Recent climate changes are beginning to melt this permafrost, releasing dangerous amounts of carbon dioxide into our atmosphere—and it’s happening fast.
You might expect scientists to focus on preserving this permafrost, but a forward-thinking team at the Permafrost Research Tunnel has set out to do the exact opposite.
As permafrost thaws, it revives ancient microbes that devour organic matter, thereby pumping even more carbon dioxide into the air, according to a revealing study released on September 23 in JGR Biogeosciences.
However, researchers are currently stumped about how quickly these microbes spring back to life once temperatures rise.
“It’s one of the biggest unknowns in climate issues,” claims Sebastian Kopf, one of the study authors, in a press release dated October 2 from the University of Colorado Boulder. “How the melting of these significant carbon stores will alter both the ecology in these areas and the pace of climate change is still unclear.”
To tackle this pressing question, Kopf and his international colleagues traveled to the Permafrost Research Tunnel in Fox, Alaska, which descends about 350 feet underground.
This extensive tunnel, similar in size to a mine shaft, had its curiosity piqued when researcher Tristan Caro first stepped inside and spotted fossilized remains of prehistoric creatures embedded in the walls.
“As soon as you enter, there’s a terrible smell—think of a musty basement that’s been neglected for ages,” Caro explained. “For microbiologists like us, such odors are thrilling, as they often signal microbial activity.”
Donning protective Tyvek suits and N95 masks, the team extracted long-core samples from the permafrost layer.
Once back at the lab, these cores were saturated with water and heated to between 39 and 54 degrees Fahrenheit for analysis.
Caro pointed out that while these ancient microbes pose no direct threats to human health, they’re kept in sealed environments for precaution.
They monitored the growth rates of these revived microbes to see how quickly they thrived.
Initially, microbial growth rates were excruciatingly slow—with significant increases only noticed after periods of 7 and 30 days post-thaw. However, after incubating for a whopping 180 days, they noted the microbes showed remarkable growth, particularly due to nutrients sourced from water.
Initially, the microbes were only able to replicate about one in every 100,000 cells daily—a sluggish pace compared to how fast organic cultures can evolve in controlled lab conditions.
As the heating period extended, the microbes picked up their pace—suggesting that prolonged warm temps would boost their chances of becoming “resurrected” and active.
Looks like just a warm spell in the Arctic isn’t enough for these microbes, but an entire warm season could be game-changing.
As Caro wisely noted, “A single hot day during Alaskan summers won’t do much. The critical factor is the duration of warm spells, especially as they stretch into autumn and spring.” He added, “There’s an enormous expanse of permafrost globally—spanning Alaska, Siberia, and other frigid areas—meaning we’ve only scratched the surface with our limited samples.”
Fox itself is conveniently located about ten miles from Fairbanks in central Alaska.
The research group consisted of Caro, Kopf, J.M. McFarlin, A.E. Maloney, S.D. Jech, A.J. Barker, T.A. Douglas, and R.A. Barbato.
