In this paper a suite of complementary methodologies are utilised to enable a comprehensive sustainability assessment of 2050 scenarios for 10 European cities. The aim is to compare a 2050 business as usual scenario (based on recent trends) with a 2050 post carbon (PC2050) scenario developed with city stakeholders. A key strength is that it applies both a production based approach and consumption (footprint) based accounting methodology to assess the impacts. A semi-quantitative/qualitative indicator approach shows that nearly all cities will improve under Business As Usual (BAU) for most indicators but the performance is significantly improved under PC2050.