Cities account for almost 75 % of global human-induced CO2, mostly coming from transport and heating. But annual emission estimates may be imprecise and outdated – that is where the ICOS Cities monitoring network can offer reliable data for cities like Zurich.
Recently, the ICOS Cities Zurich crew was interviewed by both swissinfo.ch and immo-invest.ch – this is a compilation of these news stories.
Read the full news stories here:
Hi-tech CO2 sensors help Zurich track 2040 net-zero goal (swissinfo.ch)
Zurich as a pilot city for CO₂ measurements (immo-invest.ch)
Switzerland has a national net-zero goal of 2050 – but Zurich wants to speed up the process and reach net-zero by 2040. Achieving this ambitious target requires accurate, reliable data – and that’s why the ICOS Cities project is particularly interesting to local media outlets.
“Zurich, for example, currently counts all its cars and heating systems and multiplies that by emission factors to calculate a bottom-up inventory. What we are doing is observation based: we look at the atmosphere and the concentrations of CO2 in the city and we combine that with models to get an independent estimate of the emissions,” explains ICOS Cities lead in Zurich, Lukas Emmenegger at the Swiss Federal Laboratories for Materials Science and Technology (Empa), to SWI swissinfo.ch.
Zurich is one of the three ICOS Cities pilot cities, together with Paris and Munich, setting up innovative monitoring networks for greenhouse gas emissions in urban environments. Emmenegger and his team have expanded the existing CO₂ measurement network to 60 locations in the city of Zurich, using inexpensive sensors to record data on streetlamps and trees. In addition, more complex instruments have been installed on mobile phone antennas and precise measurements have been carried out on a high tower site. 
“There is no diet without scales,” says Emmenegger to another local media outlet, immo-invest.ch, emphasizing the importance of reliable data. “We hope that our findings will help Zurich to achieve its climate targets,” Emmenegger concludes.
Emmenegger and his team at EMPA are trying to find out where the CO2 in urban areas originates, whether it is from traffic, heating, natural sources or elsewhere, and the influence of factors like winds, forests and parks on CO2 concentrations. This knowledge will ‘help the city of Zurich accelerate its’ own climate action progress and can also serve as a model for other cities in Europe’, explains immo-invest.ch.
Services advising cities
After two years measuring CO2 concentrations, the Empa team is currently finalising the integration of the data into high-resolution models. Some of the most surprising results of the project data, ‘suggest that the current CO2 inventory method may overestimate annual emissions by around 20 %’, reports swissinfo.ch.
Going forward, the monitoring stations, currently used only for research purposes, should offer better transparency, eventually allowing policymakers, and the public, to monitor fluctuating emissions levels and see whether the city is on the right track, say the Empa scientists to swissinfo.ch.
Based on the monitoring techniques and services being trialed in Zurich, Paris and Munich, the project team aims to develop services for cities on a more general level:
“We plan to develop services to advise cities on how to set up and operate an urban greenhouse gas monitoring network,” says ICOS ERIC Director General and ICOS Cities Coordinator Werner Kutsch to swissinfo.ch.
The ICOS Cities project is set to officially end in December 2025 when final reports and conclusions are published.