Natural gas releases fewer harmful air pollutants and greenhouse gases than other fossil fuels. That’s why it is often seen as a bridge technology to a low-carbon future. A new study by the Institute for Advanced Sustainability Studies (IASS) has estimated emissions from shale gas production through fracking in Germany and the UK.
It shows that CO2-eq. emissions would exceed the estimated current emissions from conventional gas production in Germany. The potential risks make strict adherence to environmental standards vital.
In the last ten years natural gas production has soared in the United States. This is mainly due to shale gas, which currently accounts for about 60 per cent of total US gas production. Shale, a fine-grained, laminated, sedimentary rock, has an extremely low permeability, which in the past made it difficult – and uneconomical – to extract.
However, recent advancements in horizontal drilling and hydraulic fracturing have opened up previously unrecoverable shale gas reserves to large-scale, commercial production.
In light of experiences in the US and dwindling conventional gas reserves, the debate on shale gas has also taken centre stage in Europe. The purported climate advantages of shale gas over coal and the implications for domestic energy security have made fracking in shale reservoirs an interesting prospect for many European countries.
What emissions is shale gas production in Europe likely to cause?
IASS researcher Lorenzo Cremonese led a study that investigated the greenhouse gas and air pollutant emissions (including carbon dioxide, methane, carbon monoxide, nitrogen oxides, particulates and other volatile organic compounds) expected to result from future shale gas production in Germany and the UK.
A team of researchers from the University of Potsdam, the TNO Utrecht, the Freie Universität Berlin, and the IASS determined the amount of these chemical compounds that would be released into the atmosphere through fracking activities, based on estimated reservoir productivities, local capacity, and the technologies used.
To quantify total emissions, the authors assigned gas losses to each stage of upstream gas production. In the process, they also generated two plausible emission scenarios: a ‘realistic’ and an ‘optimistic’ scenario.
While methane leakage rates for the optimistic scenario approximate official figures in national inventories, the rates for the realistic scenario exceed them by a large margin. The emission intensity of shale gas in electricity generation is up to 35 per cent higher than estimates of the current emission intensity of conventional gas in Germany. The study also questions the accuracy of methane leakage estimates for current conventional gas production.