Jungbluth, Niels; Meili, Christoph

Knowing the carbon footprint of one’s personal lifestyle is a prerequisite for reducing this impact in the right places. To reach a wide audience with varying degrees of knowledge about environmental issues, it is necessary to make compromises between level of detail, scientific robustness, and user-friendliness. The German office of the world wide fund for nature (WWF) recently updated such a carbon footprint calculator using data from ESU-services and the Global Footprint Network (GFN). For communication, the unit “planets necessary, if all people would have the same consumption pattern” is preferred. However, in the background, values in tonnes of CO2-equivalents released per person and year are calculated. For this decision, the following arguments were discussed: Pro: – Focus on a major problem that is globally not yet solved. – Statement becomes clearer: fossil fuels need to stay in the ground – Amount in tons and result in planets can be visualised and are both better understood by the public than values derived from aggregated LCIA-scores. Contra: – Less environmental impact categories are covered, e.g. impacts due to toxicity are neglected. – Disputable recommendations like to use electricity from nuclear energy instead of renewables result from this choice. Some lessons learned from user feedback: – Footprint calculators are an important vehicle for awareness rising. – The user shall not be left alone with the results. There is need for specific tips and an invitation to change and motivate others to follow. – Visualisation of results is key – Focus on relevant recommendations, instead of distracting with easy tasks that create ecological rebound effects. – Formulate recommendations positive Relevant recommendations for average German inhabitants are: – Enjoy commuting by train or bike. – Enjoy holidays in your country or nearby. – Motivate your landlord to change to renewable energy for heating. – Include more plant-based foods in your diet.