The UK Department of Energy and Climate Change (DECC) has published a report called “Potential Greenhouse Gas Emissions Associated with Shale Gas Extraction and Use,” which presents the outcome of a study on this subject and provides recommendations to mitigate the climate change impacts of shale gas production in the UK.
The study examined local greenhouse gas (GHG) emissions associated with shale gas exploration and production. It also studies the effect of shale gas use on overall GHG emission rates and cumulative emissions.
The report states that, if adequately regulated, local GHG emissions from shale gas operations should represent only a small proportion of the total carbon footprint of shale gas, which is likely to be dominated by CO2 emissions associated with its combustion. Furthermore, if the carbon budgets impose a binding constraint, any increase in emissions associated with shale gas production in the UK would have to be offset by emissions cuts elsewhere in the economy.
According to the report, the carbon footprint (emissions intensity) of shale gas extraction and use is likely to be in the range 200 – 253 g CO2e per kW·h of chemical energy, which makes shale gas’s overall carbon footprint comparable to gas extracted from conventional sources (199 – 207 g CO2e/kW·h(th)), and lower than the carbon footprint of liquefied natural gas (233 – 270g CO2e/kW·h(th)). When shale gas is used for electricity generation, its carbon footprint is likely to be in the range 423 – 535 g CO2e/kW·h(e), which is significantly lower than the carbon footprint of coal, 837 – 1130 g CO2e/kW·h(e).
As to the impact of the shale gas production on national GNG rates, the study concludes that if shale gas production is demonstrated by industry to be economic in the UK, some of the UK’s reserve may be used nationally. Because the UK is well connected to the Western European gas market, the effect of UK shale gas production on gas prices is likely to be small, and the principal effect of shale gas production in the UK will be that it displaces imported LNG, or possibly piped gas from outside Europe. The net effect on total UK GHG emission rates is likely to be small.