Tailoring Land Use, Land-Use Change, and Forestry (LULUCF) Impacts for Stakeholder-Centric Climate Policy

The land sector plays an important role in addressing global climate change: Land use, land-use change, and forestry (LULUCF) is currently responsible for about 10-15% of annual anthropogenic CO2 emissions, including the only notable origins of negative emissions to date; both emissions and removals aspects make LULUCF a key focus of future climate mitigation policies. However, LULUCF also acts via changing albedo, roughness and other surface properties and thus impacts the surface energy balance and water fluxes (the biogeophysical (BGP) effects). Through the BGP effects, LULUCF has a direct impact on local climate and may counteract global warming through local cooling and mitigate extreme weather events like heatwaves and droughts. LULUCF thus also plays a role in helping communities adapt to its effects.However, decision-makers often focus only on direct emissions and carbon storage from LULUCF. These are called local biogeochemical (BGC) effects. To make sound climate policies, it is important to consider other processes of LULUCF as well: (i) Local BGP effects, which are BGP effects acting at the site the LULUCF happens; (ii) nonlocal BGP effects, which are remote climate changes caused by advection and large-scale changes in atmospheric circulation; (iii) nonlocal BGC effects, which are remote changes in carbon storage driven by the climate changes from nonlocal BGP effects.The complexity of these LULUCF effects, with their different spatial scales and mechanisms, often prevents stakeholders from fully incorporating them into decision-making. In this study, we create a system that helps tailor the assessment of LULUCF effects to the specific concerns of different stakeholders. This system makes it possible to distinguish the combinations of LULUCF effects that should be considered in decision-making of different purposes: For example, the interest of a farmer will focus more on the local changes in climate (predominantly influenced by BGP effects) and additionally, if farmers get credits for emission reductions or CO2 removals, on local BGC effects. International negotiations under the UNFCCC, by contrast, focus predominantly on the combined local and nonlocal BGC effects.In our study, we carefully identify different combinations of LULUCF effects exemplarily for 5 key stakeholders’ perspectives. We analyze model results from three advanced Earth system models to give an idea of how important the negligence or incorporation of one or the other LULUCF effect is. We do so for stylized large-scale scenarios of three common forms of LULUCF: global cropland expansion, global cropland expansion with irrigation, and global afforestation. We show that the answer to whether or not a LULUCF change brings desirable effects to climate and may help mitigation and/or adaptation is very much dependent on the perspective, with our system providing a tool to translate between the different perspectives.This study gives a detailed look at how LULUCF affects both climate and the carbon cycle, providing a foundation for incorporating these impacts into policy at different levels. It helps guide climate action that balances land use with the Sustainable Development Goals, especially considering the growing interest in nature-based solutions for future climate strategies.