Greenhouse-gas emissions associated with drilling and burning shale gas are similar to conventional gas and shouldn't endanger the UK's climate change goals, according to the energy department's scientists
In a new study on the potential impacts of exploiting the UK’s shale gas reserves, Decc’s chief scientific advisor, Professor David Mackay, and the energy secretary’s senior advisor, Dr Timothy Stone, conclude that the carbon footprint of the unconventionally sourced gas is comparable to that of liquefied natural gas (LNG) and conventional gas piped to the UK from outside the EU.
If hydraulic fracturing – or fracking – sites are properly regulated, releases of carbon dioxide and methane will result in a carbon footprint of 200–253g of CO2e per kWh of energy generated, estimates the report. This compares with 199–207gCO2e/kWh produced in extracting conventional gas, and 233–270gCO2e/kWh from LNG operations.
However, the emissions figures assume that 90% of the methane released during fracking will be captured and flared. Also, the authors acknowledge their is undertainty around their assessments as very little research has been conducted into methane emissions from shale gas exploration and production.
The scientists stress that operators should adopt the principle of reducing methane emissions to “as low a level as reasonably practicable” and recommend that reduced emissions completions - an example of best practice in the industry where gas is recovered from flowback fluids - should be adopted at all stages of shale gas exploration.
“The government should discuss with regulators appropriate mandatory requirements to be applied at each stage to ensure that the best technology is implemented in all cases,” states the report.
Operators must also monitor greenhouse-gas emissions from the exploration, pre-production and production phases, to ensure early warning of any leakages. They are also advised to work to reduce the amount of lower water use in the fracking process.
“Our study indicates that shale gas, if properly regulated, is likely to have a GHG footprint no worse than the other fossil fuels that society currently depends on,” confirmed Mackay.
However, he also cautioned: “To ensure that shale gas exploitation doesn’t increase cumulative GHGs it is crucial that society maintains efforts to drive down the costs of low- carbon technologies, including carbon capture and storage.”
Ed Davey welcomed the report, claiming it bust many of the myths surrounding fracking.
“If you took at face value some of the claims made about fracking, such has been the exaggeration and misunderstanding, you would be forgiven for thinking that it represents one of the gravest threats that has ever existed to the environment… on the other side of the coin, you could have been led to believe that shale gas is the sole answer to all our energy problems. Both of these positions are just plain wrong.
“This report concludes that with the right safeguards in place the net effect on national emissions from UK shale gas production will be relatively small when compared to the use of other sources of gas.”
Continuing to use gas-fired power stations was “perfectly consistent” with the UK’s carbon budgets over the next couple of decades, he told the Royal Society in discussing the report, while acknowledging that the country must continue to take action to mitigate and abate carbon emissions.
“[The report] should help reassure environmentalists like myself, that we can safely pursue UK shale gas production and meet our national emissions reductions targets designed to help tackle climate change,” Davey concluded.
