In fact, analysed cities haven been found to engage actively in measuring their greenhouse gas emissions: 75% of cities have already done emission inventories, the rest of them is currently about to develop their first emission inventory. However, cities use a variety of different methodologies to measure their emissions. An example from the transport sector illustrates this: While city A includes emissions from all transport taking place inside its geographic boundaries, city B estimates transport emissions that its citizens produce (including emissions produced outside city B’s boundaries). City C chooses not to include emissions from the transport sector at all. Maike Sippel concludes: “Emission data from different cities is hardly comparable”.
A large part of cities has also adopted targets for the reduction of greenhouse gas emissions – and these targets are mostly very ambitious. However, it remains unclear, if targets are based on a proper analysis of local emission patterns, and realistic, city-specific reduction pathways. Frequently targets are externally influenced. For example cities often adopted a target suggested by the city network Climate Alliance. Other cities have targets equalling the national German or the European Union emission targets. “Almost half of all city targets may rather be symbolic, as cities do not publish emissions from the base year of their target” says Maike Sippel. Without such reference data, one cannot analyse whether and how much emissions have actually dropped, and it is thus impossible to control for target achievement.
A closer look at actual emission development in individual cities reveals a mixed picture. Interestingly, cities in the new “laender” seem to be far more successful in their climate protection activities: Their emissions have dropped significantly – on average by about 3% per year. Cities in the old “laender” have only reached average reductions of 0.65%. The explanation may be simple: East German / new laender have benefitted from so-called wall-fall profits. These are emission reductions resulting from structural changes and the close down of numerous industrial sites after the German Reunification.
The Intergovernmental Panel on Climate Change (IPCC) states that emission reductions by industrialized countries have to be around -1.33 to -1.58% annually to avoid dangerous climate change. If cities continue on their current emission trends, only seven cities will reach their emission targets for 2020, 2030 or 2050 – all seven of them are located in East Germany. Cities in West Germany are not on course: Though most of them would reach their targets at some point in time, target achievement in some cities will be more than 100 years later than intended.
The study concludes that a uniform methodology for emission measurement would be essential to allow for comparability of cities’ emission reductions. City networks and national policy can play an important role: They could establish a common standard for urban emission inventories, and Climate Alliance and ICLEI are already active in this field. The national government could also make emission measurement obligatory, e.g. starting with cities of more than 100,000 inhabitants. A nation-wide, public database with cities’ emission data would make cities’ climate performance comparable. If cities would critically review their emission targets, they could use their revised targets as a real tool for municipal climate policy evaluation. Such an approach would need cities to set realistic targets which are based on city-specific reduction potentials.
However, external factors such as national energy or climate policies also strongly influence the potential contribution of any city to climate protection. Therefore, a double strategy may be necessary: Cities could set a realistic and city-specific target A, which each city can achieve by its own. In parallel, cities could adopt a very ambitious target B – but make clear, that target B achievement is conditional on a supporting overall climate policy environment. Cities’ call for effective national and international climate policy would gain credibility by such an approach.
*) Michael Bradt collected data for this study in the course of his diploma thesis.
**) Sippel, Maike: „Urban GHG inventories, target setting and mitigation achievements: how German cities fail to outperform their country”, in: Greenhouse Gas Measurement & Management 1/1, Earthscan Verlag 2011, Seite 55-63. Kostenloser Zugang unter:
