Assessing the Climate Impact of the Gothenburg Cable Car -A Comparison of Two Alternatives Before and After Design Revision

Abstract

In 2019, the previously planned Gothenburg cable car, including towers and stations, was redesigned to cut costs since the project had proved more expensive than previously expected. This thesis compares the climate impact of the two designs before and after the design revision by investigating whether the revision had a positive effect on the climate impact and identifies which parameters of the current design that contributes the most to the climate impact. The materials and amounts in the bill of quantities of stations and towers were used as a basis for a life cycle assessment performed in the tool Klimatkalkyl, developed by the Swedish Transport Administration. A third objective was to see how well the tool Klimatkalkyl can be used for unusual constructions without all material being included in the tool. It was found that the second design alternative had a smaller climate impact than the first. During the redesign the climate impact of the assessed parameters decreased from 37 096 tCO2 eq. to 30 704 tCO2 eq. Not all parts of the stations could be included due to lack of data. Steel and concrete were the materials that contributed most to the climate impact. Important parameters included tower design, geotechnical conditions for foundations and amount of concrete in the stations. It was also found that Klimatkalkyl could be used for assessing the climate impact of the cable car when material quantities were known but that complementary data was needed in cases where specific material quantities were not known. This case study showed that an increased life cycle perspective in the design phase of buildings and infrastructure may help identify climate hotspots and serve as a basis for comparisons and selection between different design alternatives. However, missing or average data are an uncertainty that needs to be considered as project specific data is not always known or available in the design phase, especially for more unusual projects like the Gothenburg cable car.