Invisibility Day: Lockdown effect on CO2 emissions unmissable

Invisible, odorless and weightless - carbon dioxide emissions cannot be perceived by the human senses, but they are easily measurable. This is shown by a new European-wide study in which the Environment Agency Austria and the University of Natural Resources and Applied Life Sciences Vienna (BOKU) played a major role and which was published in the journal "Science of The Total Environment". In doing so, international experts analyze the impact that measures to contain the COVID-19 pandemic have had on CO₂ emissions in European city districts. The authors estimated CO₂ emissions using the eddy-covariance technique at 13 sites in 11 European cities, including Vienna and Innsbruck, and compared them with pre-pandemic data. The eddy-covariance technique has been in use for measuring CO₂ emissions in Vienna since December 2017. It provides half-hourly results and also includes spatial and temporal information. This, for example, makes correlations with COVID-19 measures but also with traffic peaks or heating degree days apparent.

The analysis proves that CO₂ emissions at all urban monitoring sites studied during the initial 2020 lockdowns decreased noticeably compared to the same period in the previous year. This decrease is in a wide range depending on the transport contribution to local-measured emissions, and accounts for between 10% and 63%. The study authors attribute this decline primarily to limited mobility and the decrease in road traffic. It is also clear that the reduction of emissions only was of short duration. With restrictions lifted, CO₂ emissions quickly returned to pre-pandemic levels in most areas.

New method, fast results

The eddy-covariance technique has already proven itself many times in the context of agricultural land or forests. For the past five years, BOKU, Environment Agency Austria and A1 Telekom AG have been testing the method for quantifying CO₂ emissions in Vienna for the first time. The results from the Austrian capital, like the analysis of the lockdown effects, show that the innovative measurement method also has the potential to evaluate the effectiveness of local measures to mitigate climate change. This is a particular advantage in large cities, where there is a special need for action in terms of climate protection.

Links:

Article in Science of The Total Environment

Eddy-Covariance Measurements in Vienna (german)