Energy-related GHG emissions balances: IPCC versus LCA

Abstract

Addressing climate change is one of the greatest environmental challenges. Due to the impact of cities to energy consumption, the involvement of the local authorities in environmental policies is rapidly increasing. The Covenant of Mayors (CoM), launched by the European Commission, is an urban initiative aimed at reducing CO2 emissions. The signatories have to compile the greenhouse gas emissions (GHG) balance of their territory and, to do so, they can use the Intergovernmental Panel on Climate Change (IPCC) or the Life Cycle Assessment (LCA). Moreover, the signatories have to define strategies to reduce the GHG emissions. In this context, authors estimate the GHG balance of an Italian municipality using both methodologies in order to compare the results. In detail, the first application is the IPCC, the second one is the LCA approach for which two cases are analysed: i) LCA with fossil fuels and electricity GHG emission factors based on the European Reference Life Cycle Database, LCA (I); and ii) LCA with a site – specific GHG emissions for electricity generation, LCA (II). They propose energy strategies in order to quantify the achievable GHG emissions reduction by the exploitation of the renewable energy resources. The study shows that the GHG emissions results obtained with the LCA approach are higher by 20% than those calculated with the IPCC approach. This difference is relevant and it could be significant in identifying effective climate strategies. The LCA methodology ensures a systemic accounting of emissions, then, it can be more effective in order to achieve GHG emissions reduction at global level. The examined energy strategies allow for reducing the GHG emissions of about 7% of the total reduction required by the CoM. This confirms that a preliminary evaluation of the strategies is useful for the allocation of the financial resources to the environmental policies.