City level carbon mitigation strategies : What are their true impacts?

This paper addresses the problems associated with ambitious greenhouse gas (GHG) emission cut-off targets set for cities in recent years. Even though many cities have adopted an active approach to sustainability issues and climate change mitigation, they often lack appropriate and effective tools for achieving the cut-off targets. The primary purpose of this paper is to demonstrate the utilisation of a consumption based GHG emission assessment model in city level carbon management. The demonstration is executed by an evaluation of four different scenarios for city level carbon mitigation, including the construction of low-emission buildings, increasing the use of renewable energy sources, restricting urban sprawl and reducing private driving together with an increase in the share of public transportation. The study shows that a life cycle assessment (LCA) model like the one utilised here can be operated effectively in city level carbon management. Furthermore, the comprehensive, consumption based assessment model, even though used locally, provides a global view on a global issue. The results of the assessment suggest that the only way to significantly reduce the carbon emissions, within a short time period, on a city level is to change the carbon intensity of the local energy production. Other mitigation strategies might be of importance too, but the limitations and dimensions of the impacts should be understood