If you need one more reason to worry about warming global temperatures, you can add spontaneous land blowing to the list.

In 2014, a bizarre crater was discovered in Siberia on the Yamal Peninsula. Since then, several more similar holes have been located. Geologists studying these places concluded that they were created by an explosion.

There must have been some explosions, because these are not ordinary holes. Some craters are up to 50 meters deep. High levels of methane were detected in crater areas, leading scientists to believe that the flammable gas – large amounts of which are trapped beneath Siberia’s permafrost – was being released as the area’s average temperature rose. However, further research showed that melting permafrost alone would not have caused the outbreak.

Now, thanks to a team of chemical engineers, we finally know what probably happened. Publishing their findings in Geophysical Research Letters, the scientists wrote that rapid changes in pressure underground played a key role in making everything go kabooey.

“There are very, very specific conditions that allow this phenomenon to occur,” Ana Morgado, a chemical engineer at the University of Cambridge who worked on the study, said in a press release. “We’re talking about a very niche geological space.”

When Morgado and her colleagues began to study the composition of the soil in and around the craters, they realized that the explosion was not the result of chemical reactions and must have had a physical source.

They found the answer in the multi-layered substrate of the peninsula. At the top is soil that thaws and refreezes as the seasons change. Beneath it is permafrost, which, as the name suggests, remains permanently frozen. Something interesting and potentially explosive is happening underneath them.

During the last ice age, sea levels receded due to the formation of glaciers. The remaining salt formed cryopegs, a geological layer that does not freeze due to the high levels of salt left behind. On the Yamal Peninsula, cryopegs are about 1 meter thick and can reach up to 50 meters underground. Even deeper beneath the cryopegs is another layer filled with crystallized methane.

For thousands of years, the balance between these layers has been maintained, but higher temperatures have disrupted this cycle. Since the 1980s, water in the topsoil has become more meltable, causing it to flow deeper and deeper into the layers below. It finally started reaching the cryopegs.

Leaking water began to accumulate, but this led to an increase in pressure in the cryopeg. Cracks began to form on the surface, leading to a rapid drop in pressure. All this happens over explosive methane, so it’s like playing with matches in a fireworks factory. The gas came to the surface and then KABAM! You have a new, scary, mysterious hole in the ground.

Spontaneous explosions of odorless gas are bad. Worse still, methane is a potent greenhouse gas that traps much more heat than even CO2. Since explosions are primarily caused by climate change, it is essentially a downward spiral in which heating causes explosions, which in turn causes more heating. While it is unclear how often cratering explosions occur, Morgado said the process may occur “very rarely.”

So here you go. Climate change is turning the ground we walk on into a powder keg – at least if you live in the Siberian tundra.