Net Zero for Agriculture Within the City of Zurich: An Achievable Goal?

How can urban agriculture in Zurich move toward the net-zero target? A FiBL study shows that major restructuring would be necessary to reach the goal – although smaller measures can still help bring it closer.

The city of Zurich aims to achieve net-zero direct greenhouse gas emissions (GHG) by 2040, which also includes the city’s agricultural areas.

Participatory scenario development and modelling

For the study, Zurich’s urban agriculture was modelled as a single enterprise. Using the current status quo as a baseline, four exploratory scenarios were developed through a participatory process involving stakeholders. The goal was to combine known measures to present a range of options. These measures include reduced tillage, lower livestock numbers by adapting them to locally available roughage, and using biomass for biogas production. The scenarios were evaluated using four quantitative indicators (GHG, fossil energy consumption, income effect, and food production).

Net-zero through far-reaching measures

Zurich can achieve the net-zero target, but this would require giving up livestock farming and compensating for remaining emissions through tree planting and biochar. Other effective measures include grassland-based dual-purpose breeds with extended lifespan for meat and milk production, reduced mineral fertilizer and feed imports, electrification of farming processes, and widespread biomass use for biogas. However, these alone do not lead to net-zero.

Efficient use of local resources reduces emissions while increasing output

The study reveals significant trade-offs between climate protection, economic viability, and food production. Measures known today and necessary for net-zero cause significant costs and income losses, as well as a 16 % drop in food production. In contrast, efficient local resource use and the abandonment of fertilizer and feed imports increase net GHGE but boost protein output by 55 % and reduce GHG per kilogram of protein. Economically, these measures perform relatively well.

Feed imports drive high fossil energy use

Abandoning imported feed and mineral fertilizers reduces fossil energy consumption by up to 85 %. Especially non-ruminants, such as boarding horses or pigs, could then only be kept to a limited extent.

Net-zero hampered by multifunctionality

Agriculture, especially in urban contexts, serves various roles, including food supply, biodiversity, education, and recreation. Focusing solely on climate goals may lead to conflicts depending on the measures taken.

Methodology as example for others

The modelling approach, involving practitioners, can serve as a model for similar processes. It enables participatory scenario development and lays the foundation for broader consensus on feasible climate protection measures.