As the frost melts off the creatures that were stuck under the ice for thousands of years, they’re ready to enter the present-day world.

The premise seems out of a horror film but there is some truth to it — especially in the cases of viruses that are frozen in glaciers. Considering the melting ice caps, which are a direct product of climate change, what threats do these ancient viruses pose to human life?

Climate change and viruses

A new study published in the journal Proceedings of the Royal Society B found that frozen ancient viruses that exist in glaciers may be a cause for concern, as the melting icebergs will allow the pathogen to escape, according to Salon.

Researchers analyzed the soil and lake sediments of Lake Hazen, a freshwater lake in Canada, north of the Arctic Circle, to study the “spillover risk” where a virus is able to continue infecting and transmitting sustainably, per the study.

The samples were then analyzed for their DNA and RNA to match them to known living organisms.

According to The Guardian, the research found that the risk of spillover is higher in areas where glacial meltwater usually leaks in, but the current levels of global warming may make this a common occurrence.

The work is still ongoing as known viruses and their capabilities are identified.

“Melting will not only lead to the loss of those ancient, archived microbes and viruses, but also release them to the environments in the future,” another study from last year, led by author and microbiologist Zhi-Ping Zhong, from Ohio State University, concluded.

Climate change and virus science

Does that mean climate change could invite another pandemic? Not exactly. As the study notes, “assessing spillover risk” is not the same as predicting a pandemic.

“As long as viruses and their ‘bridge vectors’ are not simultaneously present in the environment, the likelihood of dramatic events probably remains low,” the research stated.

“But as climate change leads to shifts in species ranges and distributions, new associations can emerge, bringing in vectors that can mediate viral spillovers.”

What does other research say?

Last year, research identified 33 viruses that are 15,000 years old and originate from the Guliya ice cap of the Tibetan Plateau.

“These glaciers were formed gradually, and along with dust and gases, many, many viruses were also deposited in that ice,” said Zhi-Ping in a press release.

Meanwhile, Ohio State University microbiologist Matthew Sullivan noted that these viruses, which “would have thrived in extreme environments,” have “genes that help them infect cells in cold environments — just surreal genetic signatures for how a virus is able to survive in extreme conditions.”

Another study from 2014 managed to revive a virus, which had not been active for 30,000 years and originated in Siberia.