Shale gas could play an important role in reducing Denmark’s climate emissions, but only if it offsets the burning of coal, the environmental think-tank Concito wrote in a report released this week.

Extracting gas from shale deposits has grown from an obscurity to a globally-significant energy source in just over a decade, especially in the US where it has dampened demand on oil.

Burning shale gas for energy produces less CO2 than burning coal, and is therefore seen as a potential tool for reducing global climate emissions and slowing catastrophic climate change. But with coal still much cheaper than shale gas, Concito argues that swapping coal with gas would either require prices for CO2 quotas to rise, or for shale gas prices to fall.

It added that even if this were the case, it is more likely that shale gas would offset the consumption of imported natural gas, rather than coal, thus minimising its climate benefits.

“In the current situation, the question of whether to exploit shale gas remains a political decision on potential income and energy security, rather than a decision on the impact on climate change,” the report concludes.

Concito adds that even if there were a political consensus to move ahead with extracting shale gas, there are technical challenges that need to be overcome before it can be deemed safe to those living near the drill sites.

Shale gas is extracted by drilling down into, and then horizontally through, rock formations containing gas. The gas is released through a process called ‘fracking’ in which small explosions are triggered under high pressure inside the rock.

As a result, there are concerns that the escaping gas could pollute the water table and drinking water. Leaking methane gas would also counteract any gains made in reducing carbon emissions as a result of burning gas rather than coal.

Shale gas, like conventional natural gas, is mostly made up of methane, a greenhouse gas that is far more effective than CO2 at trapping heat. The same mass of methane would trap 72 times more heat than carbon dioxide over 20 years.

French energy company Total is currently carrying out test drills at locations in northern Zealand and northern Jutland, which have the correct geological conditions for extracting shale gas about four kilometres below the surface.

Total argues that Denmark will cease to have self-sufficient reserves of natural gas reserves in the next ten years and that there is a need to plug the gap while the country continues its switch-over to renewable energy.

“The prices will change once the US begins to export shale gas, and right now coal prices are at their lowest level,” Total spokesperson Henrik Nicolaisen told Ritzau. “But it’s incredibly difficult to predict future prices, especially when we are only in the exploration phase.”

Regardless of the current economics of shale gas, the International Energy Agency has forecasted that gas use will rise by 50 percent by 2035, at which point it will account for 25 percent of world energy demand.