Bacteria found living in polar ice prompts rethink on climate, alien life

NEW YORK: A new study from the University of York has now directly observed bacteria living in ice in both the Arctic and Antarctic regions. That discovery has implications for our understanding of the planet’s past climate, as well as where we might hope to find life elsewhere in the universe, according to New Atlas.

In areas like Greenland and the poles, permafrost is thought to do a great job of preserving a detailed time capsule of the climate from Earth’s deep history, by locking gases from the atmosphere into snow as it compresses into ice. Ice cores have been used to measure things like air pollution and carbon levels in the atmosphere at different points in time. They usually stretch back hundreds of thousands of years but have been sampled as far back as 2.7 million years.

These calculations are usually based on the fact that bacteria can’t survive in those conditions, so their biological processes won’t mess up the readings. But that assumption might not hold true, as scientists have now seen bacteria alive and well in that hostile environment.

Working at carefully quarantined sites in both the Arctic and Antarctic, the York researchers sterilized samples of snow with UV light and compared them to untreated samples. In doing so, they found that the natural snow contained traces of methyl iodide, a by-product of certain bacteria. Their presence could affect the CO2 levels detected in ice cores, altering our understanding of the Earth’s past climate.

Although the researchers took great care to ensure that the testing sites remained uncontaminated, curious wildlife.

The implications of that are not good news. If the pre-Industrial era CO2 levels were lower than earlier estimates that mean human activity is having an even bigger impact on the climate now than we thought.

On the other hand, there is some potentially good news to the find as well. The fact that bacteria can survive in this harsh environment bodes well for life on other planets, which we might have previously dismissed as too cold. Liquid water might not be a necessity for a planet to be deemed habitable after all – water ice could suffice.

In future, the researchers plan to look deeper into the ice caps to see if they can find signs of active bacteria further down.

The research was originally published in the Journal of the Royal Society Interface.