Current European estimates likely underestimate fracking emissions

RESEARCHERS at the Institute for Advanced Sustainability Studies Potsdam (IASS) have concluded that European countries are likely underestimating emissions of greenhouse gases (GHGs) and air pollutants from current natural gas production as well as future shale gas exploitation (ie, by fracking).

Natural gas releases less GHGs and air pollutants than other fossil fuels, so it is often seen as bridge technology to a low-carbon future. In the US, production has rapidly increased over the past decade, mainly due to shale gas, which accounts for about 60% of total production.

Due to dwindling reserves of conventional gas, as well the alleged climate benefits and implications for energy security, European countries have started to consider shale gas production.

Led by Research Associate Lorenzo Cremonese, the IASS team investigated the potential GHG and air pollutant emissions from future shale gas production through fracking, in the UK and Germany. Its findings suggest that emissions recorded in national inventories are conservative and do not accurately reflect reality.

To study potential emissions from future shale gas production in the UK and Germany, the researchers developed three shale gas drilling projections in each country released under specific scenarios: realistic emission (REm) and optimistic emission (OEm) scenarios.

REm describes the potential emissions from “business-as-usual” activities, whilst OEm considers the lowest emissions technically possible under the study settings. Figures for the OEm scenarios are based on application of best available technologies and full compliance with stringent regulatory frameworks as described in the study.

The projected emissions were compared to national emissions inventories, for years in which similar volumes of natural gas were produced, but from conventional reservoirs.

The researchers found that the forecasted emissions intensity (EI) of the shale gas production in the UK and Germany could be 35% higher than emissions reported by national inventories. According to Cremonese, this discrepancy is caused by leaks in production stages common to natural gas and shale gas and is not related to fracking.

Additionally, the researchers found that existing emissions inventories of GHGs and air pollutants from current gas production more closely resemble OEm results than REm findings. Looking at potential future shale gas production, the researchers commented that “although OEm is technically achievable, it is very unlikely that all the conditions assumed in the optimistic scenario will be systematically met”.

Conversely, recent measurements on existing gas fields in the US mostly resemble results  from the REM scenarios.

The researchers concluded that national inventories likely show conservative estimates, which according to Cremonese and colleagues need to be updated by independent scientific bodies.

Therefore, the researchers believe that without strict adherence to environmental standards and best practices in place, emissions of the important GHG methane (CH₄) and air pollutants co-emitted with methane and naturally present in the raw gas are likely to increase compared to those expected by national authorities.

CH₄ is the main component of natural gas and it is a more potent GHG than CO₂. On a mass-to-mass basis CH₄ warms the planet 87 times more than carbon dioxide (CO₂) over a 20-year timescale, and over a 100-year time scale, it is 36 times more warming.

Unlike GHGs, air pollutants, such as volatile organic compounds, nitrous oxides, carbon monoxide, and particulate matter, can have a direct impact on health at local and regional levels. In a follow-up study, the researchers intend to investigate the potential impact of shale gas emissions on local and regional air quality in Europe.

The researchers believe that it is possible to avoid the potential emissions predicted by this study.

Cremonese said: “Ensuring best practices, constant monitoring and strict regulations to both conventional and unconventional gas is the way to keep emissions at minimum, so to ensure climate advantages when compared to coal for example. This depends on the financial investment that the industrial sector is willing to face, together with environmental regulation in place.

Elementa: Science of the Anthropocene: http://doi.org/c9px