Global biodiversity impact spillovers of national transportation systems

Venla Aurora Leppilampi , Janne Kotiaho, Stefan Baumeisteri, Essi Järvinen, Sami El Geneidy

Transportation systems cause well-documented local biodiversity impacts and substantial greenhouse gas emissions, yet the global biodiversity impacts embedded in their value chains remain poorly understood. Here, we quantify the life cycle biodiversity and carbon footprints of Finland’s national transportation system, covering traffic, transport infrastructure, and vehicle production and maintenance, using detailed national data and the Biodiversity Equivalent Impact Assessment method (BIOVALENT). The transportation system generated a biodiversity footprint corresponding to an estimated potential extinction risk for approximately 0.1 percent of global species, and a carbon footprint of 677 megatons of carbon dioxide equivalents. Passenger car traffic and traffic lanes were the largest contributors to both footprints, and climate change was the dominant driver of biodiversity loss across most system components. Notably, for traffic lanes, life cycle biodiversity impacts were approximately 45 times larger than impacts from local land-use change alone, demonstrating substantial global biodiversity spillovers from national transport infrastructure. Scenario analysis showed that passenger car electrification can substantially reduce both biodiversity and carbon footprints, whereas biofuel adoption may reduce carbon impacts while increasing biodiversity loss. These findings highlight the need for transport policy to integrate life cycle biodiversity and climate impact assessment to avoid overlooking global impacts and unintended biodiversity-climate trade-offs.