Scientists Revive 40,000-Year-Old “Dormant Microbes”

Published on 10/21/2025 Last updated: 11:44 (Mecca Time)

In a scientific discovery that raises concern, an American research team, led by scientists from the Department of Geological Sciences at the University of Colorado Boulder, has managed to reactivate microbes that were frozen in permafrost in Alaska for about 40,000 years. These organisms have awakened from their deep sleep and returned to activity.

These microorganisms were not dead, but were in a state of dormancy or prolonged hibernation within the frozen soil, with the ability to return to life when suitable conditions are available, such as melting ice, the availability of water, and a relatively high temperature.

Hibernation is a temporary or near-complete cessation of vital activities such as breathing, cell division, and growth. This occurs when external conditions are unfavorable for life, such as extreme cold, lack of food, or drought. The living organism does not die, but enters an “emergency” mode to preserve itself until environmental conditions improve.

This discovery, published in the journal “Journal of Geophysical Research: Geosciences,” highlights an unexpected danger from the melting of permafrost in the Arctic. These ancient microbes can release greenhouse gases that contribute to accelerating global warming.

To understand the nature of this discovery, imagine that the earth has a “giant refrigerator” that keeps in its depths the remains of plants, animals, and microbes from ancient ice ages. This “refrigerator” is known as “permafrost,” which is a layer of soil or rock that has been permanently frozen for thousands of years in areas such as Alaska and Siberia.

Researchers feared that this layer would melt if the summer in the Arctic was prolonged and the Earth’s temperature rose. As it melts, microbes that have been dormant for tens of thousands of years could awaken and begin feeding on organic matter that has been frozen for thousands of years, producing greenhouse gases such as carbon dioxide and methane, leading to an acceleration of global warming.

To prove the possibility of this scenario, researchers led by Tristan Caro collected samples from the research tunnel in Fairbanks, Alaska, which extends 15 meters underground inside the “permafrost” and retains traces from the Pleistocene era, including mammoth and bison bones.

In the laboratory, the researchers exposed these samples to temperatures that simulate the current and future Alaskan summer, to monitor whether the ancient microbes would return to activity.

After six months of experiments, the microbes showed remarkable activity, and began to form sticky layers known as biofilms, confirming that they were not dead but were in a long hibernation. With their return to activity, these microorganisms began producing organic compounds and greenhouse gases.

Scientists warn that this phenomenon may release enormous amounts of carbon, as the frozen soil in the north of the Earth contains twice the amount of carbon currently present in the atmosphere.

If these microbes awaken on a large scale, the Earth may enter a vicious cycle of accelerated warming, where more melting leads to more gas emissions, and then more melting.

Tristan Caro says: “We have studied only one sample from Alaska, but there are vast areas of permafrost that extend across Siberia and other parts of the world.”

He adds: “We do not yet know how all those microbes will react to rising temperatures, but it is certain that the Earth has begun to open the door to its ancient refrigerator and the consequences could be catastrophic.”