Planet in Peril: 60% of Earth’s Land Now Outside “Safe Zone”

Sixty percent of global land is outside safe biosphere limits, with human use of biomass driving widespread ecological strain.

A new study provides the first detailed mapping of the planetary boundary known as “functional biosphere integrity,” tracing its status across centuries and in specific regions. The analysis shows that 60 percent of the world’s land surface has already moved beyond the safe operating range, with 38 percent falling into the category of high risk. The research was conducted by the Potsdam Institute for Climate Impact Research (PIK) in collaboration with BOKU University in Vienna and published in the journal One Earth.

Functional biosphere integrity describes the capacity of the plant world to help regulate the stability of the Earth system. To do so, vegetation must generate sufficient energy through photosynthesis to sustain the circulation of carbon, water, and nitrogen that underpins ecosystems and their interconnected processes, even under conditions of intense human disturbance.

Alongside biodiversity loss and climate change, this measure of integrity forms one of the central elements of the Planetary Boundaries framework, which defines the conditions necessary for a safe operating space for humanity.

“There is an enormous need for civilization to utilize the biosphere – for food, raw materials and, in the future, also for climate protection,” says Fabian Stenzel, lead author of the study and member of the PIK research group Terrestrial Safe Operating Space. “After all, human demand for biomass continues to grow – and on top of that, the cultivation of fast-growing grasses or trees for producing bioenergy with carbon capture and storage is considered by many to be an important supporting strategy for stabilizing the climate. It is therefore becoming even more important to quantify the strain we’re already putting on the biosphere – in a regionally differentiated manner and over time – to identify overloads. Our research is paving the way for this.”

Two indicators to measure the strain and the risk

The research builds on the most recent update of the Planetary Boundaries framework, released in 2023. “The framework now squarely puts energy flows from photosynthesis in the world’s vegetation at the center of those processes that co-regulate planetary stability,” explained Wolfgang Lucht, head of PIK’s Earth System Analysis department and coordinator of the study. “These energy flows drive all of life – but humans are now diverting a sizeable fraction of them to their own purposes, disturbing nature’s dynamic processes.”

The resulting strain on the Earth system can be assessed by examining how much of natural biomass productivity is redirected for human use—such as harvested crops, timber, and plant residues—as well as by the decline in photosynthetic activity caused by land conversion and soil sealing. To complement this, the study also introduced a second key measure of biosphere integrity: an indicator of ecosystem destabilization risk, which tracks large-scale structural shifts in vegetation along with imbalances in the water, carbon, and nitrogen cycles.

Europe, Asia, and North America are particularly affected

Based on the global biosphere model LPJmL, which simulates water, carbon, and nitrogen flows on a daily basis at a resolution of half a degree of longitude/latitude, the study provides a detailed inventory for each individual year since 1600, based on changes in climate and human land use.

The research team not only computed, mapped, and compared the two indicators for functional integrity of the biosphere, but also evaluated them by conducting a mathematical comparison with other measures from the literature for which “critical thresholds” are known. This resulted in each area being assigned a status based on local tolerance limits of ecosystem change: Safe Operating Space, Zone of Increasing Risk, or High Risk Zone.

The model calculation indicates that worrying developments began as early as 1600 in the mid-latitudes. By 1900, the proportion of global land area where ecosystem changes went beyond the locally defined safe zone, or were even in the high-risk zone, was 37 percent and 14 percent, respectively, compared to the 60 percent and 38 percent we see today. Industrialization was beginning to take its toll; land use affected the state of the Earth system much earlier than climate warming. At present, this biosphere boundary has been transgressed on almost all land surface – primarily in Europe, Asia, and North America – that underwent strong land cover conversion, mainly due to agriculture.

PIK Director Rockström: Impetus for international climate policy

“This first world map showing the overshoot of the boundary for functional integrity of the biosphere, depicting both human appropriation of biomass and ecological disruption, is a breakthrough from a scientific perspective, offering a better overall understanding of planetary boundaries,” says Johan Rockström, PIK Director and one of the co-authors of the study. “It also provides an important impetus for the further development of international climate policy. This is because it points to the link between biomass and natural carbon sinks, and how they can contribute to mitigating climate change. Governments must treat it as a single overarching issue: comprehensive biosphere protection together with strong climate action.”

Reference: “Breaching planetary boundaries: Over half of global land area suffers critical losses in functional biosphere integrity” by Fabian Stenzel, Liad Ben Uri, Johanna Braun, Jannes Breier, Karlheinz Erb, Dieter Gerten, Helmut Haberl, Sarah Matej, Ron Milo, Sebastian Ostberg, Johan Rockström, Nicolas Roux, Sibyll Schaphoff and Wolfgang Lucht, 15 August 2025, One Earth.
DOI: 10.1016/j.oneear.2025.101393

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