Cities puzzled by greenhouse gas measurements


Many regional initiatives are already taking place in the EU to tackle climate change, but the array of different tools for measuring global warming gases make the results difficult to compare, a recent study showed.

The European Commission has acknowledged that the battle against climate change will be fought in cities, which are home to 80% of Europeans and consume most of the continent’s energy (see EURACTIV LinksDossier on ‘Cities and climate change’).

The role of cities is thus seen as crucial for meeting the EU’s target of cutting greenhouse gas emissions by 20% below 1990 levels by 2020.

European regions and cities have already started to share experiences on the best way to fight climate change by means of initiatives like the Covenant of Mayors, which brings together hundreds of cities in a pledge to exceed the EU’s climate objectives.

A joint report by the College of Europe and Institut Veolia Environnement recently argued that any action to reduce greenhouse gas emissions at local level will require local governments to be aware of local sources of emissions and their potential to reduce them. But in order to carry out the required “greenhouse gas emissions inventory,” cities are confronted with a maze of different tools to construct and implement mitigation and adaptation policies, the report warned.

Policymakers use greenhouse gas inventories as a basis for developing strategies to cut emissions and track progress. When calculating the amount of global warming emissions cities spew into the atmosphere, local authorities need to decide on whose emissions are measured, which greenhouse gases are included and which method is used.

“Already small methodological differences can greatly complicate the comparison of results obtained with different tools,” the report warned. For instance, measuring only CO2 as opposed to all greenhouse gases, or including only public sector operations in the scope of the exercise instead of all the city’s polluting activities, have a major impact on the result, it stated.

Room for harmonisation

The researchers found that a number of advanced calculating tools for creating local greenhouse gas inventories already exist, but that the awareness of these is low.

“Surprisingly, many tool developers contacted during the compilation of this study were not aware of the work currently undertaken on this topic and sometimes did not know of the existence of other tools,” they wrote. They thus concluded that if the different cities’ inventories are to produce comparable results, interoperability between the methods used to calculate greenhouse gas emissions will be essential.

If the cities want to keep their existing reporting guidelines, compatibility can be ensured by creating a protocol within which the different tools could “dialogue” with each other, the College of Europe study argued.

Another option would be to develop an international reporting standard, possibly converging around the guidelines of the Intergovernmental Panel on Climate Change, a UN scientific body, the researchers suggested. The standard could cover only the most important greenhouse gases and a limited number of emitting sectors at first, they envisage.

Finally, the most radical approach would be to adopt a common tool with common standards, guidance documents and administrators, the report suggested. It acknowledged that this would require significant harmonisation and replacement of existing tools, and may therefore represent the final step in the convergence process.

The urgent need for decisive action to fight climate change in European cities will become even more imperative if the UN climate conference in Copenhagen yields an ambitious post-Kyoto treaty. Under this scenario, the EU has promised to up its 2020 target to 30%, which would require upgrading its efforts in all areas.

This could merit looking into introducing an EU-level tool to help cities carry out greenhouse gas inventories and exchange best practices, the College of Europe study concluded. In any case, a harmonised protocol could be developed in the context of the Covenant of Mayors, the authors suggested.

The European Commission considers cities to be at the heart of the EU's sustainable development efforts. In January 2006, it launched a Thematic Strategy on the Urban Environment.

But the strategy is limited in scope, since the Union has no direct competence on urban affairs. Meanwhile, EU sectoral policies in the areas of transport, environment and social affairs significantly impact upon cities.

EU ministers responsible for urban and spatial development also attempted to lay the foundations for a European urban policy by signing the Leipzig Charter on Sustainable European Cities in May 2007.  

In January 2008, nearly 100 mayors from across Europe signed up to the Commission-backed Covenant of Mayors, a commitment by city leaders to go beyond the EU's own stated aim of slashing CO2 emissions by 20% by 2020 (EURACTIV 11/02/09). 

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