Mapping functional biosphere integrity via human appropriated NPP and ecosystem change

A stable Earth system requires a healthy biosphere, but many ecosystems are being pushed beyond safe limits due to human activities such as land-use change, resource extraction, or climatic changes. Functional biosphere integrity is at the core of global assessments demarcating the limits to this human interference with our planet (Richardson et al. 2023, Rockström et al. 2023, te Wierik et al. 2025).

Studying the biosphere can happen through field observations, remote sensing, or computer models. Modelling has the advantage of obtaining global scale data, and the opportunity to also study past and future states of the Earth System.

We utilize the dynamic global vegetation model LPJmL to map the pressures of climate change and land use on ecosystems via the two indicators human appropriation of net primary productivity (HANPP) and the risk for ecosystem destabilization (EcoRisk) spatially explicitly for each year since 1600 (Stenzel et al. 2025). HANPP acts as a metric for human pressure on the environment, while EcoRisk is more of a response metric measuring changes in biogeochemical conditions and thus risk for degradation.

Since such indicators ideally also require thresholds that define when local boundaries are breached, we developed a method using 10 independent indicators for biosphere integrity (e.g. human footprint index, biodiversity intactness index, forest landscape integrity index) informing where local transgressions have already occurred. This helped us to map regions with intermediate and high risk of degradation and allowed us to aggregate the local status to the area globally transgressing the local boundaries.

Both metrics show strongly increasing values since 1600, and combined are current transgressed on 60% of the land area, with 38% already at high risk.

A preliminary assessment of the future status according to simulations from ISIMIP3b scenarios indicates that climatic pressures will keep rising, while pressures due to land use change strongly vary with scenario, based on projected productivity changes on agricultural areas and the demand for bioenergy plantations as a negative emissions technology.