Eawag - like all federal institutions - has been given a mandate by the federal government to become climate-neutral in the building sector and must therefore compensate for unavoidable CO₂ emissions. As this applies retroactively from 2020, Eawag has now purchased a corresponding certificate from the company Swiss Climate for a compensation project for the building sector’s CO₂ emissions in 2020. As part of this project, which was selected by the Directorate, the energy supply of several ceramics companies in north-eastern Brazil has been sustainably transformed. While previously the companies used wood from the surrounding rain forests, they are now using shells from cashew and coconut or from sustainable forest cultures. This saves the rainforest from further deforestation and thus also protects its rich biodiversity.

Different methods for calculating emissions

Eawag has purchased certificates for 170 tonnes of CO₂ emissions from this project. “This corresponds to Eawag’s emissions from the building sector in 2020 according to the calculation methods of the entire ETH Domain,” explains Dominik Scheibler, Eawag’s Environmental representative. It should be noted that Eawag’s internal calculation method has different system limits and therefore arrives at significantly higher values, namely 288 tonnes of CO₂. For example, in comparison to the ETH Domain’s method, Eawag also records emissions from process heat and electricity.

Mobility only more accurately recorded since 2021

“Not included are the high emissions from the mobility sector - around 1000 tonnes of CO₂”, Dominik adds. The basis for compensation in this area was still lacking, as Eawag’s mobility has only been roughly recorded so far. “Since 2021, however, the flight kilometres in particular have now been recorded much more precisely in the accounts,” says Dominik. “This will make it possible in future to calculate these CO₂ emissions more precisely and, if necessary, to offset or neutralise them if this is desired.”

The certificates for offsetting CO₂ emissions from Eawag’s building sector from 2021 - 197 t CO₂ according to the ETH Domain method - should be available soon. For 2022, the figures have yet to be calculated.