Melting Arctic glaciers are releasing a new source of potent methane emissions

In the face of the warming Arctic, melting glaciers are revealing groundwater springs that bubble with potent and powerful methane emissions.

This surprising source could have a significant and overlooked impact on climate change, according to new research. A study published today in Nature Geoscience shares these startling findings.

The scientists, from the University of Cambridge and the University Centre in Svalbard, Norway, discovered extensive methane gas leaks. These leaks come from groundwater springs that are becoming visible as glaciers melt.

The researchers warn that as the Arctic glaciers continue to shrink, these methane emissions will likely rise. The methane not only comes from the springs but also from other melting ice and frozen ground in the Arctic. This could accelerate global warming.

Gabrielle Kleber, the lead author of the study from Cambridge’s Department of Earth Sciences, spoke about the research.

“These springs are a considerable, and potentially growing, source of methane emissions. One that has been missing from our estimations of the global methane budget until now,” she said.

Methane gas emissions will speed up global warming

The concern among scientists is that the extra methane emissions released by the Arctic thaw could speed up global warming caused by humans. The researchers believe these springs, previously unrecognized, could be a source of methane emissions.

For almost three years, Kleber has been keeping a close watch on the water chemistry of more than a hundred springs across Svalbard. This region has air temperatures rising two times faster than the average for the Arctic.

Kleber likens Svalbard to the canary in the coal mine of global warming, stating, “Since it is warming faster than the rest of the Arctic, we can get a preview of the potential methane release that could happen at a larger scale across this region.”

Professor Andrew Hodson from the University Centre in Svalbard, a study co-author, commented, “Living in Svalbard exposes you to the front-line of Arctic climate change. I can’t think of anything more stark than the sight of methane outgassing in the immediate forefield of a retreating glacier.”

Past research mainly focused on methane release from thawing permafrost (frozen ground). But co-author Professor Alexandra Turchyn from Cambridge’s Department of Earth Sciences said, “While the focus is often on permafrost, this new finding tells us that there are other pathways for methane emissions which could be even more significant in the global methane budget.”

Methane gas springs found under melting Arctic glaciers

The team identified methane-delivering springs fed by a hidden plumbing system beneath most glaciers. This system taps into extensive groundwater reserves in the underlying sediments and surrounding bedrock. Once the glaciers melt and recede, springs appear where this groundwater network breaks through to the surface.

In Svalbard, the team found methane emissions from glacial groundwater springs could exceed 2,000 tonnes over a year. This is around 10% of the methane emissions from Norway’s annual oil and gas energy industry.

“If global warming continues unchecked then methane release from glacial groundwater springs will probably become more extensive,” Kleber warned.

To find these springs, Kleber trained her eye to spot them on satellite images. She studied the lands revealed by the retreat of 78 glaciers across Svalbard. Kleber then looked for blue streaks of ice where groundwater leaked to the surface and froze.

She then traveled by snowmobile to each site. There, she took samples from places where the ice had blistered due to pressurized water and gas buildup.

What the research team learned

The team found that almost all of the spring sites contained water highly concentrated with dissolved methane. This means when spring water reaches the surface, plenty of excess methane can escape to the atmosphere.

The researchers also found that methane emissions hotspots were related to the type of rock from which the groundwater emerged. Some rocks like shale and coal, which contain natural gases including methane, contributed to the groundwater.

Kleber noted, “In Svalbard we are beginning to understand the complex and cascading feedbacks triggered by glacier melt. It seems likely that there are more outcomes like this which we have yet to uncover.”

Professor Hodson expressed a dire warning about the volume of trapped gas below these glaciers.

“The amount of methane leaking from the springs we measured will likely be dwarfed by the total volume of trapped gas lying below these glaciers, waiting to escape,” he said. “That means we urgently need to establish the risk of a sudden increase in methane leakage, because glaciers will only continue to retreat whilst we struggle to curb climate change.”

In conclusion, this research shows that the warming Arctic is revealing hidden springs that are a significant source of methane, a potent greenhouse gas. The continual shrinking of these glaciers will expose more springs and release more methane.

This finding reveals that methane emissions from the Arctic may be more significant than previously believed, posing a greater challenge to global warming efforts.

More about methane

Methane is a powerful greenhouse gas.One carbon atom and four hydrogen atoms make up methane, forming a chemical structure known as CH4. It is colorless and odorless, and you can find it both on Earth and in outer space.

Methane is a primary component of natural gas. It’s used as a fuel for heating and electricity generation. It’s also a raw material in chemical industries, where it’s transformed into a variety of products, from plastics to antifreeze.

Methane is produced by both natural and human activities. Natural sources include wetlands, volcanoes, and wildfires. In contrast, human activities such as fossil fuel extraction, agriculture (especially livestock farming), and waste treatment generate significant amounts of methane.

Potent greenhouse gas

Methane is potent in trapping heat in the atmosphere. While it’s less abundant than carbon dioxide (CO2), it’s 25 times more effective at trapping heat over a 100-year period. This makes it a significant contributor to global warming.

Methane doesn’t stay in the atmosphere as long as CO2, typically lasting about 12 years. However, when it breaks down, it turns into CO2 and water vapor, both of which are greenhouse gases.

Methane is also a potential health hazard. In large quantities, it can displace oxygen, leading to suffocation. It’s also highly flammable and can cause explosions.

Controlling methane emissions is a key part of tackling climate change. Strategies include improving the efficiency of fossil fuel extraction and distribution, reducing emissions from livestock and rice cultivation, and capturing methane emissions from landfills.

In recent years, researchers have also been exploring the use of methane-consuming bacteria and innovative technologies to mitigate methane emissions and convert them into useful products.