Researchers warn that seven of our planet’s eight “safe and fair boundaries” have already been crossed. The consequences can be far-reaching, for current and future generations. Everything is based on a new concept that aims to make the soil load tangible.
Planet Earth is in danger, nobody should have missed it. But can’t people care if species die, air, soil and water are polluted by their actions? And how do you know when things are getting dangerous for us too? Researchers have come up with a new concept of “safe and just borders” that they believe should not be crossed. However, this has already happened in seven of the eight of these limits, warn the researchers in a study published in the journal “Nature”.
The researchers want to assess “the state of our planet not just in terms of Earth system stability and resilience, but also in terms of human well-being and justice,” as first author Johan Rockström of the Potsdam Institute for Climate Impact Research (PIK ) explained. This assessment is based on scientific discoveries of recent years and computer modeling.
Safely inside the donut
The Donut Concept: When the economy is moving green, people’s needs can be met without overburdening Earth’s systems.
(Photo: FutureEarth/Earth Commission/Lade et al., 2023)
The new concept offers the advantage of being comparatively clear: the team came up with a graphic that has a “donut” – that is, a wide ring – in the center. The basis is the so-called donut economy, developed by British economist Kate Raworth.
The middle of the donut, the empty space, represents the things people need to live: food, water, a home to live in, education and health. So that these needs are not lacking, the economy must be in the green of the donut. But the outer limits of the donut must not be exceeded. This is when so-called Earth systems are overwhelmed: climate change, loss of biological diversity, land-use changes, freshwater availability, phosphorus and nitrogen cycles, ocean acidification, stratospheric ozone depletion, aerosol pollution, and chemical pollution. .
Systems are already under pressure
What happens when limits are crossed? Biodiversity example: 50 to 60 percent of land area would have to be left in its natural state or sustainably managed for natural ecosystem services such as pollination, fresh water and fresh air to be preserved. According to researchers, this currently only applies to 45 to 50% of the land area.
Another example: according to the analysis, the water level of rivers and inland waterways should only vary by about 20% of the water volume to preserve the ecosystems involved. According to the researchers, however, this is not the case in about a third of the Earth’s area. Nitrogen and phosphorus values, which are introduced into the soil and water systems through artificial fertilizers, are also clearly too high. This leads to algal blooms, the death of fish stocks and ammonia particles in the air.
Consequences can be deadly
What are the possible consequences? According to the study, if the Earth’s balance system is permanently disturbed, there is a risk of considerable damage. Potential consequences include loss of life, livelihoods or income, displacement of people, loss of food, water or food security, and chronic illness, injury or malnutrition.
According to the researchers, only one earth system is not yet overloaded: the aerosols in the air. In particular, a large difference in aerosol levels in the northern and southern hemispheres could alter the monsoon, for example. According to the calculations of the researchers, however, this limit has not yet been reached – although the uncertainty about this question is particularly great.
“Other values for limits are also conceivable”
Independent experts such as Johannes Emmerling from the European Institute of Economics and Environment (EIEE) in Italy welcome the study: “Overall, the extremely complex approach of bringing these very different categories and data to a simple, comparable scale is very useful. .” , according to Emmerling. The study extends previous approaches. “Unification, in particular, could become a useful tool for assessing several key problem areas in the field of Earth system boundaries.”
Helmut Haberl, professor at the Institute of Social Ecology at the University of Natural Resources and Life Sciences in Vienna (BOKU), emphasized the importance of absolute limits in relation to the new concept, particularly in relation to global warming. However, he also points to the difficulties of drawing such boundaries in areas where important phenomena and relationships are less well understood, such as biodiversity and ecosystems.
Henrique Pereira, head of the Biodiversity and Conservation research group at the German Center for Research in Integrative Biodiversity (iDiv) Halle-Jena-Leipzig, points out that boundaries are not really defined by science, but influenced by science. , all limits are based on expert judgment of what constitutes an acceptable risk and consequences, but another group of experts may come up with different numerical values for the limits.”