The material that's been trapped in the ice for years is being released as the world warms up. There are a lot of microbes that have been dead for hundreds of thousands of years.

Scientists have revived a number of zombie viruses from Siberia, including one that is thought to be nearly 50,000 years old.

These reanimating viruses are potentially a significant threat to public health, and further study needs to be done to assess the danger that these infectious agents could pose.

The researchers wrote that one quarter of the Northern Hemisphere is underlain by frozen ground.

Due to climate warming, irreversibly thaw permafrost is releasing organic matter frozen for up to a million years, most of which degrade into carbon dioxide and methane, further enhancing the greenhouse effect

The 48,500-year-old amoeba virus is one of 13 outlined in a new study which is thought to be tens of thousands of years old. The researchers were able to establish that each one was different from the others.

While the record-breaking virus was found beneath a lake, other areas included mammoth wool and the guts of a wolf. The team used live single-cell amoeba cultures to show that the viruses could be infectious.

As the world warms up, we're seeing huge numbers ofbacteria released into the environment, but given the antibiotics at our disposal, they might be less threatening. There is a chance that a novel virus could be a bigger problem for public health as more people move to the northern part of the country.

In the case of plant, animal, or human diseases caused by the revival of an ancient unknown virus, the situation would be much more dire.

The risk of ancient viral particles getting back into circulation is legitimate.

There is a previous study detailing the discovery of a 30,000-year-old Viruses in Siberia. The new record holder was able to be seen using light microscopy.

The name of the resurrected virus was given to it by acknowledging its size and the type of soil it was found in. The researchers believe there are many more viruses to be found.

Many of the viruses that will be released as the ice thaws will be completely unknown to us, but it remains to be seen how infectious these viruses will be once they're exposed to the light, heat and oxygen of the outdoors. There are many areas that could be studied in the future.

Eric Delwart is a researcher at the University of California, San Francisco. Delwart has a lot of experience reuscitating ancient plant viruses.

"If the authors are isolating live viruses from ancient permafrost, it is likely that the even smaller, simpler mammals would also survive for a long time," Delwart said.

The research has not yet been peer reviewed.