Methane is one of the most potent greenhouse gases and scientists have found the chemical is being created on a monumental scale by an Icelandic glacier.
Sólheimajökull glacier flows from the active, ice-covered volcano Katla and released up to 41 tonnes of methane every day during during the summer.
This is equivalent to the production of more than 136,000 cows – another offender for methane emissions.
Katla creates the perfect environment for methane-producing microbes to thrive and is also top-five in the world for overall production of CO2.
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Sólheimajökull glacier flows from the active, ice-covered volcano Katla (pictured)and released up to 41 tonnes of methane every day during during the summer. This is equivalent to the production of more than 136,000 cows – another leader of methane emissions
The Lancaster university-led research, published in the journal Scientific Reports, is the first to show such large-scale release of methane from glaciers.
Study author Dr Peter Wynn, of the Lancaster Environment Centre, said: ‘This is a huge amount of methane lost from the glacial meltwater stream into the atmosphere.
‘Methane has a global warming potential 28 times that of carbon dioxide.
‘It is therefore important that we know about different sources of methane being released to the atmosphere and how they might change in the future.
‘There has been a lot of speculation about whether or not glaciers can release methane.
‘The beds of glaciers contain the perfect cocktail of conditions for methane production – microbes, low oxygen, organic matter and water – along with an impermeable cap of ice on the surface trapping the methane beneath.
The study comes out of PhD research carried out by Dr Rebecca Burns when she was at Lancaster University.
Researchers took water samples from the edge of the melt water lake in front of the Sólheimajökull glacier and measured the methane concentrations.
These were compared with methane levels in nearby sediments and other rivers, to make sure that the methane wasn’t being released from the surrounding landscape.
Dr Wynn said: ‘The highest concentrations were found at the point where the river emerges from underneath the glacier and enters the lake.
‘This demonstrates the methane must be sourced from beneath the glacier.’
Using a mass spectrometer, which identifies the unique ‘fingerprint’ of the chemical, the researchers discovered the methane is coming from microbiological activity at the bed of the glacier.
Researchers took water samples from the edge of the melt water lake in front of the Sólheimajökull glacier and measured the methane concentrations. Study author Dr Peter Wynn (pictured), said: ‘This is a huge amount of methane lost from the glacial meltwater stream into the atmosphere’
They also discovered that although the volcano is not directly producing methane it is creating the perfect conditions for methane-producing microbes to thrive.
Normally when methane comes into contact with oxygen it combines to form carbon dioxide but this is different on a glacier.
Meltwaters rich in dissolved oxygen access the bed of the ice mass and convert any methane present into carbon dioxide.
Study co-author Professor Fiona Tweed, an expert in glacier hydrology at Staffordshire University, said: ‘Understanding the seasonal evolution of Sólheimajökull’s subglacial drainage system and how it interacts with the Katla geothermal area formed part of this work.’
At Sólheimajökull when the meltwater reaches the glacier bed, it comes into contact with gases produced by the Katla volcano.
The study comes out of PhD research carried out by Dr Rebecca Burns (pictured) when she was at Lancaster University. Researchers took water samples from the edge of the melt water lake in front of the Sólheimajökull glacier and measured the methane concentrations
These gases lower the oxygen content of the water, meaning some of the methane produced by the microbes can be dissolved into the water and transported out of the glacier without being converted to CO2.
Study co-author Dr Hugh Tuffen, a volcanologist at Lancaster University, said: ‘The heat from Katla volcano may greatly accelerate the generation of microbial methane, so in fact you could see Katla as a giant microbial incubator.
‘Scientists have also recently discovered that Katla emits vast amounts of CO2 – it’s in the top five globally in terms of CO2 emissions from volcanoes – so Katla is certainly a very interesting, very gassy volcano.’
Dr Burns added: ‘Both Iceland and Antarctica have many ice-covered, active volcanoes and geothermal systems.
‘The recent International Panel on Climate Change (IPCC) report highlights that current trajectories indicate global warming is likely to reach 1.5C between 2030 and 2052, with greatest perceived climate sensitivity at higher latitudes.
‘If methane produced under these ice caps has a means of escaping as the ice thins, there is the chance we may see short term increases in the release of methane from ice masses into the future.’
HOW IS GLOBAL WARMING AFFECTING GLACIAL RETREAT?
Global warming is causing the temperatures all around the world to increase.
This is particularly prominent at latitudes nearer the poles.
Rising temperatures, permafrost, glaciers and ice sheets are all struggling to stay in tact in the face of the warmer climate.
As temperatures have risen to more than a degree above pre-industrial levels, ice continues melt.
For example, melting ice on the Greenland ice sheet is producing ‘meltwater lakes’, which then contribute further to the melting.
This positive feedback loop is also found on glaciers atop mountains.
Many of these have been frozen since the last ice age and researchers are seeing considerable retreat.
Some animal and plant species rely heavily on the cold conditions that the glaciers provide and are migrating to higher altitudes to find suitable habitat.
This is putting severe strain on the ecosystems as more animals and more species are living in an ever-shrinking region.
On top of the environmental pressure, the lack of ice on mountains is vastly increasing the risks of landslides and volcanic eruptions.
The phenomena is found in several mountain ranges around the world.
It has also been seen in regions of Antarctica.