The importance of urban environmental policy and its influence on climate change is beyond doubt. Urban areas have a fundamental role to play in reducing greenhouse gas emissions, in Europe and around the world. Cities need the right tools to establish an inventory of GHG emissions, but the results of existing analyses are not always commensurable.
How can we compare greehouse gas impact measurements?
European cities are not subject to any general community-wide restrictions in terms of greenhouse gas emissions, and yet their role in the fight against climate change is widely recognized by the European institutions, and involves a host of initiatives centering on strategic thinking, financial incentives, and the spread of best practices.
In recent years, local citizens’ groups, energy agencies and research institutes have developed a range of software tools to assess each city’s carbon footprint. However, the methods they use for measuring the impact are, for the most part, specific to each nation or even city. It is becoming clear that we need a shared framework and set of criteria for measuring the climate impact of cities.
The aim of this project was to understand what it was that differentiated these methodologies from the outset, and to what extent the results obtained from the various tools could be compared.
« By analyzing and comparing selected carbon inventories, the study highlights the sources of significant methodological differences, and offers lines of action for achieving greater comparability. »
All too often, the measurements are not comparable
The study identified the different variables and discussed the requirements for creating a unified methodological framework to measure the greenhouse gas emissions of European cities. The results showed that the methodologies used for these inventories differed in important respects, such as the calculation of CO2 equivalents, the scope of measurement, or the actual greenhouse gases measured. Consequently, the inventories are often not comparable.
This work was presented to the European Commission at a workshop in May 2009, and—on two occasions—at the HQ of the World Bank in Washington. Following these meetings, the Veolia Institute took part in an international working group made up of members of the Institute for Sustainable Development and International Relations (IDDRI), the World Bank, UNEP and UN-Habitat, tasked with formulating recommendations on how to achieve convergence between existing carbon inventory methodologies for cities.