Almost 1,000 bacteria species – hundreds new to science – have been found in the glaciers of the Tibetan Plateau, yet another indication that we’ve barely scratched the surface of the microbial world.

However, with climate change threatening this precious environment, these new discoveries also raise new concerns about the release of potential pathogens toward the world's two most populated countries.

As reported in the journal Nature Biotechnology, scientists from the University of Chinese Academy of Science collected surface snow, ice, and other samples from 21 Tibetan glaciers between 2016 and 2020 and discovered 968 species of bacteria – around 82 percent of which have never been documented before. 

It was once assumed that glaciers were too extreme to harbor a rich diversity of life, but recent studies have shown that’s far from true. Last year, researchers described a number of viruses found in 15,000-year-old glacier ice that were like nothing they’ve ever seen before. 

Glaciers and ice sheets cover about 10 percent of the Earth’s surface and are the largest reservoir of fresh water on the planet. Beyond scientific curiosity, there’s a much more pressing need to understand the microbes that dwell here. 

The researchers on the new study express concern that the glaciers of the Tibetan Plateau are becoming increasingly melted by warming temperatures caused by climate change. Their fear is that the plethora of bacteria that have been held high in the Tibetan Plateau for millennia could soon find themselves in new environments after being washed downstream in melted glacier water. 

“Ice-entrapped modern and ancient pathogenic microbes could lead to local epidemics and even pandemics […] These microorganisms may carry novel virulence factors that make plants, animals, and humans vulnerable,” the study reads. 

“In addition, virulence factors can be transferred horizontally within a microbial community via mobile genetic elements [...] The interaction between glaciers and modern microorganisms could be particularly dangerous, and potential health risks need to be evaluated.”

To make matters even more grave, the Tibetan Platea sits in a very important but precarious place in the world. Known as the "water tower of Asia," it is the source of several of the world’s largest rivers surrounded by densely populated areas, including the Yangtze, the Yellow River, the Ganges River, and the Brahmaputra River. If a pathogenic bacteria were to take root here, it has the potential to be devastating. 

“The release of potentially hazardous bacteria could affect the two most populated countries in the world: China and India,” the study authors add.

These are very preliminary warnings for now, but the researchers suggest that their new work stresses the urgent need to evaluate the potential health risks of glacier melting.