Vår SimaPro partner ESU Services i Schweiz och Tyskland, har gjort en analys av skillnaderna i miljöpåverkan, efter uppdateringen från 3.8. Det sker ju alltid förändringar beroende på uppdateringar i både LCI data och LCIA metoder. Men denna gången var det en avgörande förändring i LCI data för naturgas från t ex Libyen. Det påverkar många andra övergripande LCI data som baseras på det.
Niels Jungbluth, Christoph Meili, Maresa Bussa, ESU-services GmbH, Schaffhausen
Introduction
Reliable background data are an important prerequisite for life cycle assessment studies (LCA). ESU-services updated the life cycle inventory (LCI) data for more than 200 datasets for crude oil and natural gas extraction and transportation and evaluated the environmental impacts.
Methodology
Information for an update with the reference year 2019 was gathered from literature and statistics. The following stages were included, revised, and updated (the most relevant issues are listed):
Crude oil and natural gas extraction:
- LCI for onshore and offshore production in 16 countries of origin.
- Country-specific release of methane and flaring recorded for the first time.
- Harmonization of LCIs for gas and oil extraction.
- Update of direct energy uses and emissions including drilling, venting and flaring based on regular international statistics.
Transport of crude oil to refineries:
- Concrete market situation for supplies to Europe and Switzerland
- Distances and means of transport
Supply of natural gas in high- and low-pressure networks:
- Concrete market situation for supplies to Europe and Switzerland
- Distances and means of transport
- Energy demand and leakage rates of pipeline transport
- Offshore pipeline from RU (North Stream 1)
- Energy demand and emissions from liquefaction and evaporation
- Fuel consumption and emissions of LNG (liquefied natural gas) carriers
Results
The updated LCI data were published in EcoSpold v1 format as XML files. It is planned to integrate them in an updated version of the UVEK database. The reports and data can be downloaded free of charge at http://esu-services.ch/data/public-lci-reports/.
To verify the accuracy of the data and to detect differences compared with the previous data, 3 key indicators were used:
- Ecological scarcity method 2013
- Global warming potential
- Primary energy demand
The following figure shows the development of the environmental impacts of crude oil transported to Swiss and European refineries. The updated inventories have higher environmental impacts due to higher shares from high-emitters like Libya, Algeria and Iraq and the full inclusion of methane emissions.
The following figure shows the change in results compared to the former version of the UVEK data and the current ecoinvent v3 data. The consumption mix plays important role for the differentiation between Europe and Switzerland. It also makes a difference if natural gas can be transported by pipeline or if it is imported as LNG, which causes higher impacts. Impacts are also higher for natural gas than recorded in the previous versions of the background databases, mainly due to higher methane emissions.
Interpretation
The assessment by ESU-services shows a wide variety of environmental impacts depending on the origin of fossil resources. The main differences in overall impact according to the ecological scarcity method are due to global warming potential and the main air pollutants. Both depend mainly on flaring and natural gas emissions (e.g. venting, fugitive).
The greenhouse gas emissions are considerably higher than estimated in older inventories such as ecoinvent v3.7. This is mainly due to inclusion of unintentional methane release which now can be recorded using satellite measurements.
These findings have several implications for the discussion of the role of fossil-based products in climate change:
- Unintentional methane emissions need to be considered when discussing current emissions due to the use of fossil resources.
- The avoidance of such emissions is a low-hanging fruit and needs to be followed up and monitored by the companies active in the field of oil and gas extraction.
- So far, the carbon footprint of fossil-based products is underestimated in LCA databases such as ecoinvent, which has important implications for the comparison with non-fossil products (e.g. biofuels or biomaterials). The advantage of such materials in this regard becomes higher under consideration of these new findings.
- The full emissions are currently not recorded in environmental reports and LCA studies published by industries such the International Association of Oil & Gas Producers (IOGP), Eurobitume and Plastics Europe.