Scientists say there is growing evidence that rising temperatures were catalyst for massive unexplained holes in ground.
Global warming could leave parts of Siberia exposed to a wave of underground explosions like those behind the recent unexplained giant craters phenomenon.
Scientists studying one of the massive holes on the Yamal Peninsula say there is growing evidence that rising temperatures is the main catalyst triggering the blasts.
They believe warming air is melting the thick permafrost, leading to the accumulation and release of volatile 'fire ice' gases which then explodes to create the giant funnels.
Overall temperatures in Yamal, in northwest Siberia, in the past 14 years alone have risen by at least two degrees Celsius.
Any continued increase – as is predicted by meteorologists – could create the ideal conditions for more craters to be formed across the icy region, and other parts of Siberia.
July 2014, the first scientific expedition has just returned from the site with first probes. Pictures: Marya Zulinova, Yamal regional government's press service
There is already speculation that Lake Baikal, the largest and oldest freshwater lake in the world, could also be sitting on a 'time bomb' ready to explode. The scenic stretch of water, which snakes for 400 miles through south-east Siberia, has massive reserves of the volatile 'fire ice' buried under ground.
A number of craters have appeared across Siberia over the past few years, with the first spotted in 2013 by helicopter pilots 20 miles from a gas extraction plant at Bovanenkov. The second was in the same permafrost region of northern Russia, and the third on the Taymyr Peninsula, to the east, in the Krasnoyarsk region.
Their emergence has baffled scientists, who have carried out extensive tests including taking ice probes, sampling gas levels and examining the crater walls.
A number of expeditions have taken place to the Yamal hole, the latest of which was at the beginning of November. Since then several conferences, seminars and meetings have been held by scientists and other experts to share their opinions about what caused it.
This new crater near the village of Nosok on Taimyr and in the Taz district, near the village of Antipayuta. Pictures: Local residents, Yamal regional government's press service
The latest data suggests the crater was formed at some point between October 9 and November 1, 2013.
A consensus is beginning to grow that elevated levels of the crystallised ‘fire ice’ gas is causing the explosions in the same way as eruptions below the Atlantic may be behind the Bermuda Triangle phenomenon.
It is thought permafrost at the sites could have one million times more methane hydrates locked inside than ordinary gas.
But what is causing this gas to erupt has caused great divide, although many scientists now believe there is a link to the rising temperatures in the region.
One of the first to view the site was Marina Leibman, a senior researcher at the Institute of the Earth’s Cryosphere, of the Siberian Branch of the Russian Academy of Sciences.
She is convinced global warming is to blame, and told this to delegates at the recent Scientific Conference on Arctic Exploration.
Dr Leibman told the Siberian Times: 'We have agreed that in the area of Bovanenkovo there was an emission of gas and gas hydrates caused by the heating of the earth’s surface and geological features of the site. These phenomena caused the formation of crater.
'In the last 14 years, the overall temperature in the depths of the Yamal has increased by at least two degrees Celsius.
'In some areas of the region seasonal thawing of permafrost may affect the upper layers of ice and, under certain circumstances, cause thawing and dissociation of gas hydrates.'
She added: 'I would argue this is a new process, which was not observed previously. It can be seen as a reaction to changes in the temperature, which releases gas, possibly hidden in the form of relic hydrate, from the upper layers of permafrost.'
Marina Leibman and Andrey Plekhanov making measurments at the site. Pictures: Marya Zulinova, Yamal regional government's press service
One expert said more eruptions could prove deadly, with estimates that the total explosive power of the craters has been the equivalent of about 11 tonnes of TNT.
Larissa Kozhina, the head of the laboratory centre of hydrocarbon resources and reserves at energy firm Gazprom, said: 'The crater at Bovanenkovo is above the gas trap, where prospective reserves are estimated at 17 billion cubic meters. What does this mean? All fields, all pipelines and railway tracks could be affected by such dangerous objects behind them and should be monitored.'
Formed in a near-perfect cylinder, the Yamal crater is slightly wider at the surface and has smooth walls, with a frozen lake at the bottom. During recent examinations of the site, thawed out permafrost was found 200metres from the top of the crater.
About a third of the crater is filled with water because of its melting walls and rain, and it is thought that within three years it will be almost full. Initially it was thought that by 2024 it will be difficult to see the 40 metres wide and 50 metres deep crater at all as it will be completely submerged by a lake.
But Dr Leibman told the Siberian Times that the crater may already be under water from the melting ice by next year. She said: 'Judging by the pace, by the end of next summer it may turn into a lake.
'I once heard a theory that deep Yamal lakes were mostly the result of emissions of gas. Then I just laughed at it. Now I take back my laughter: I think that a lot of deep lakes on Yamal were formed in this way.'
Scientists from 'Gazprom VNIIGAZ' and the Trofimuk Petroleum-Gas Geology and Geophysics Institute study the crater in September. Pictures: Gazprom
Other scientists disagree with that theory, however, and say that the permafrost is being melted by underground heat from tectonic plates.
'The Yamal crater is located at the intersection of tectonic faults,' said Vladimir Olenchenko, a senior researcher in the Laboratory of Geo-electrics at the Institute of Petroleum Geology and Geophysics in Novosibirsk.
'Despite the fact the region itself is seismically quiet area, there is an active tectonic life. Of course, it says the following: there was a slightly higher temperature, simply because heat rises from the centre of our planet via these cracks in the earth's crust. It warmed the permafrost.
'Or the warm stream could come from the oil and gas deposits lying under the funnel.'
There are two tectonic fault lines across the Yamal Peninsula, with one possibility being that the blow-out was caused by a deadly combination of heat leaving these rifts, a higher than normal air temperature, and the ‘fire ice’ melting.
In November the Siberian Times told how scientists have been carrying out tests in the funnel to see if it could harness a new, highly efficient, gas energy source of the future.
Japan, Canada and the United States have all ploughed millions of dollars into research projects to uncover and utilise global reserves of methane hydrate, as oil and coal dwindle.
But now the discovery of the compound within the Siberian craters could give Russia the lead in the race to dominate the market over the next century.
The latest expedition to Yamal crater was initiated by the Russian Centre of Arctic Exploration in early November 2014. Pictures: Vladimir Pushkarev/Russian Centre of Arctic Exploration
A research team from the Trofimuk Petroleum-Gas Geology and Geophysics Institute said there is evidence all the craters could be linked to the Bermuda Triangle.
Explosions under the Atlantic Ocean caused by high gas hydrate emissions are thought to explain part of the mystery of ships and aircraft disappearing. Ironically the name Yamal means 'the end of the world', the same description applied to the Bermuda Triangle, off the Florida coastline.
Further tests at the site will take place in April, if there is sufficient funding in place.
Dr Leibman said: 'To understand and describe this phenomena fully, we need to do it seriously and not in a hurry.
'I hope that we will have opportunity to go to the funnel next year. Now we have more information and we know better about which measurements we need and which equipment we need to take.'
Eaten by an ancient cave lion or bear, only the tail was left, preserved by the Siberian permafrost.
At least five species of ancient animals will walk again in Siberia, predicts South Korean cloning expert.
Tantalising studies now underway to establish if one of two carcases preserved by permafrost has traces of world's oldest mother's milk.
Virtual reality diagnosis using a new mathematical model linked to balance can detect first signs of these disorders, it is claimed.
Over thousands of years, the giant beasts came to die in the same place - but the older ones were twice the size of the final mammoth generations.