Air quality in Austria: Implications from changing biomass burning patterns

To mitigate anthropogenic global warming, a gradual phase-out of fossil fuel use is necessary. Therefore, Austria supports biomass heating, which, however, leads to higher particulate matter emissions. In this project, we investigate the effects of the increased combustion of biomass on particulate matter concentration in Austria.

The greenhouse gas emissions associated with the combustion of fossil fuels are primarily responsible for anthropogenic global warming. In 2023, supply of space heating contributed to approximately 16 % of greenhouse gas emissions in Austria. To promote the gradual phase-out of fossil fuel use, Austria is relying on the combustion of biomass. This increased from 15 % in 2005 to 19 % in 2023. Furthermore, about 50 % of district heating is already generated through the combustion of biomass.

While the transition to renewable energy through the combustion of biomass advances the decarbonization of Austria, it also leads to higher particulate matter emissions: in 2023, 47 % of PM2.5 emissions and 24 % of PM10 emissions were caused by the combustion of biomass. However, high concentrations of particulate matter can also lead to serious health problems, which are directly related to particle size. Particles smaller than 10 μm can get deep into the humans’ lungs, and smaller particles may even get into the bloodstream. According to estimates from the European Environment Agency (EEA), 3200 people died in 2021 in Austria due to high PM2.5 concentrations. For this reason, the member states of the European Union agreed in 2024 to revise the limits for particulate matter concentrations. According to this directive, for example, the daily average of PM2.5 concentration must not exceed 25 μg/m3. These limits may be difficult to comply with in Austria with the increased use of biomass heating.

The investigation of this very relationship is the aim of this project. In the first step, regions in Austria will be identified where there is a risk of exceeding PM2.5 and PM10 limits. For these regions, current emission data with high spatial resolution for the building sector and district heating will be collected, and future emissions for 2030 to 2050 will be estimated. Using chemical transport modeling, the relationship between changing emissions and the resulting concentrations, as well as their uncertainties, will be analyzed. The resulting findings will be made accessible to (political) decision-makers to enable sustainable, science-based decisions.