Public defence in Water and Environmental Engineering, MSc (Agr. For.) Johannes Piipponen

Title of the thesis: Sustainability and productivity in global livestock grazing: current challenges and future pathways

Thesis defender: Johannes Piipponen
Opponent: Dr. Adrian Müller, FiBL Research Institute, Switzerland
Custos: Prof. Matti Kummu, Aalto University School of Engineering, Department of Built Environment

As the world’s population expands, becomes more affluent, and increasingly consumes our planet's finite resources, the pressure on ecosystems grows. Reducing meat production and consumption has been identified as a key way to address environmental challenges, given that livestock production is highly resource intensive, especially since global livestock production has expanded nearly fivefold since the 1960s while the population has only tripled. So far, most discussion has focused on the necessity of reducing meat consumption without much thought on what should follow. If consumption declines, production will decrease as well. The question then is where to start and where such changes would bring the most benefits with the fewest downsides? Until now, this has remained unclear.

This dissertation focuses on the world’s grazing lands, examining where it might be reasonable to reduce or increase livestock production and where current land use remains justified. It identifies locations suitable for grazing, assesses carrying capacity, and highlights areas suffering from overgrazing or capable of supporting more animals. The dissertation also explores where livestock and crops do or do not compete and how changes in land use could increase food production potential, support biodiversity, and improve carbon sequestration.

Results show that nearly one-third of global grazing lands experience lowered carrying capacity or overgrazing. The research highlights regions where shifting grazing lands to croplands could most effectively benefit the food supply. It also underscores the complex trade-offs between production and biodiversity conservation, as achieving biodiversity goals requires reduced grazing pressure, impacting production levels of meat and milk. Restoring some previously forested grazing lands to their natural condition could notably increase carbon sequestration, surpassing total CO2 emissions from 2021 to 2023. In contrast, returning nonforested grazing lands to a natural state would yield smaller carbon gains.

There are strong grounds for changing land use and production methods, and this dissertation clarifies where such changes could be most effective from an environmental perspective. The author emphasizes that future studies should also account for social, economic, and cultural aspects when planning land use. 

Keywords: Livestock grazing, food production, land-use efficiency, global maps

Thesis available for public display 10 days prior to the defence at Aaltodoc. 

Contact information: https://www.linkedin.com/in/johannes-piipponen-2a45b0a0/; https://research.aalto.fi/en/persons/johannes-piipponen