A heat wave of 2020 during summer in Siberia increased limestone methane emissions, an event that could hit Earth’s atmosphere with a “methane bomb”.

A new study, led by researchers at Bonn University, found that an extreme heat wave in Siberia led to a “temperature anomaly” of 6°C over the base time period 1979-2000.

Since June 2020, there has been an increase in methane concentrations in two areas: the Taymyr Fold belt and the Siberian platform edge.

The researchers found that in early 2021, methane spread throughout the region. What is troubling about both areas is that the bedrock was formed from limestone formations from the Paleozoic era, dating back 541 million years.

“Methane is particularly dangerous here because the potential for warming is several times higher than that of carbon dioxide,” study lead author Dr Nicholas Fruitzheim, a professor at Bonn University, said in a statement.

According to the Environmental Defense Fund, methane has 80 times the warming power of carbon dioxide over the first 20 years it hits the atmosphere.

The researchers compared the spatio-temporal distribution of methane concentrations in the air of northern Siberia with geological maps to reach their findings. About 15% of the Northern Hemisphere or 11% of the entire globe is covered in permafrost, according to a study conducted in April 2021.

And if this part of the Earth were to thaw due to climate change, that could be particularly worrying, given the effects of rising temperatures.

Previous research suggested that thawing permafrost would only contribute to a 0.2°C rise by 2100, and not lead to a ‘methane bomb’, but the new study challenges that assumption.

Soil composition in these areas is “too thin to nonexistent,” Fruitzheim notes, so you don’t have to worry about methane from decomposing soil.

However, fracture and cave systems in limestone are likely to become porous with higher temperatures.

As a result, he explained, natural gas consisting mainly of methane from reservoirs within and under permafrost can reach the Earth’s surface.

“The estimated amounts of underground natural gas for northern Siberia are huge. And when parts of this are added to the atmosphere when the permafrost thaws, it can have dramatic effects on an already overheated global climate,” Fruitzheim said.

The study was published in the Proceedings of the National Academy of Sciences.

Several groups of scientists have expressed concerns about what would happen if the Earth’s permafrost thaws.

And in July 2020, a separate group of experts found that increased thawing of permafrost could result in microbes releasing 40 billion tons more carbon dioxide into the atmosphere than previously thought.

Other studies, including one published in September 2017, have expressed concerns about revealing ancient diseases trapped in permafrost.