Ancient Microbes Revive in Thawing Permafrost, Raising Concerns About Accelerated Greenhouse Gas Emissions
FAIRBANKS, AK – Microbes trapped in Arctic permafrost for up to 40,000 years are showing signs of revival as temperatures rise, a new study reveals. Researchers from teh University of Colorado Boulder found that while initially sluggish, these ancient microorganisms become increasingly active over time, potentially releasing significant amounts of greenhouse gases and exacerbating climate change.
The study, published in the Journal of Geophysical Research: Biogeosciences, highlights a concerning lag effect. The microbes demonstrated a slow initial response to warming, with some strains replacing only one in every 100,000 cells daily – a stark contrast to the rapid growth of typical lab-grown bacteria.However, after six months, activity surged, indicating a delayed but substantial potential for emissions as permafrost continues to thaw. This suggests that the lengthening of warmer seasons, rather then single warm days, is the critical factor driving microbial activity.
“You might have a single hot day in the Alaskan summer, but what matters much more is the lengthening of the summer season to where these warm temperatures extend into the autumn and spring,” explains Tristan Caro, a researcher involved in the study.
permafrost,ground that remains frozen for at least two consecutive years,stores vast quantities of organic matter - including ancient microbes. As global temperatures increase, this permafrost thaws, releasing this previously frozen material. The revived microbes then decompose the organic matter, releasing carbon dioxide and methane, potent greenhouse gases, into the atmosphere.
Researchers collected samples from the Permafrost Tunnel in Alaska, a naturally exposed permafrost wall, allowing them to study microbes from different depths and ages. The findings are crucial for improving predictions of how thawing permafrost will contribute to a warming Arctic, “especially as thaw proceeds into deeper and more ancient permafrost horizons,” the researchers write. The delayed activation of these microbes underscores the potential for a hazardous feedback loop, where thawing permafrost releases greenhouse gases, further accelerating warming and leading to even more permafrost thaw.
