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Abstract

Background:
Ambitious climate change (CC) mitigation in all economic sectors is crucial to limit global warming. Cost-effective mitigation pathways limiting global average temperature decreases to below 1.5°C by the end of the century in line with the Paris Agreement often rely on land-based greenhouse gas (GHG)reductions, increased land-based carbon uptake and biomass supply to other sectors (e.g. energy, transport) as well as a demand-side changes in the food system. Assessing the consequences of these land-system interventions and their interactions, not only for the climate but also for other environmental dimensions is important for evaluating the broader sustainability of CC mitigation action. -
Methods:
Using the dynamic land-system modeling framework MAgPIE, we assess the consequences of land-based GHG reductions, increased land-based carbon uptake and biomass supply to other sectors and a food-system transformation towards the planetary health diet (PHD) on five planetary boundaries (PBs). -

Findings:
A food-system transformation together with ambitious land- and energy system CC mitigation can limit global warming to below 1·5 ° by 2100 while reducing PB transgression, particularly for the Climate, Land, Biosphere and Nitrogen PBs. Yet, a safe operating space is not achieved as all PBs are transgressed by the end of the century. Increased bioenergy supply alone worsens PB transgression when only looking at land system impacts, but in combination with GHG pricing in the land sector, adverse effects are alleviated. Food waste reductions and dietary shifts towards the PHD ease land-system pressures and reduce the PB transgression of all assessed PBs. -

Interpretation:
This research highlights the importance of considering multiple PBs and the interactions between various mitigation strategies when assessing climate action in the land-system to avoid negative consequences for other environmental aspects.