Snow of Tomorrow | The Theory of Planetary Boundaries

People have limits, so does the earth

We often want to test our limits in winter sports. We boast about having pushed ourselves to our limits or perhaps even beyond them. We want to grow and develop in our sport. To do this, it is necessary to question, explore and redefine our limits from time to time. But there are also other areas where it might not be so good for us to always be at our own limits. Then, at some point, enough is enough. Enough is enough. And we just want to press pause. Our reserves are depleted, our supplies empty. We are not alone in this: our planet also has its limits. And unfortunately, it cannot use the exploration of its limits to continue growing, as we do in sport. When the planetary boundaries are exhausted or exhausted, the Earth tends to go in the other direction. But where are its limits and what exactly does that mean?

The idea behind the theory

The theory of planetary boundaries basically deals with the question of how stressed the Earth is or whether the Earth is already overloaded. And, above all, to what extent humans are contributing to this. We are no longer in the Holocene, but have arrived in the Anthropocene - the age in which humans have a significant influence on our planet.

The impetus for a more specific examination of the topic came in 2008 at a science forum in Sweden, where scientists and various interest groups considered the interactions between human activity and ecological processes. According to the scientists, humanity can continue to develop and progress within the limits of these ecological processes. However, if the limits are exceeded, this can lead to changes in the ecological framework. This in turn means a risk for future generations.

"Planetary boundaries" was then established as a term in 2009. 29 international scientists came together in a working group led by Johan Rockström, Director of the Stockholm Resilience Center, and initially identified nine areas in which the limits of our planet's resilience can be quantified. These areas are referred to as planetary boundaries or critical planetary boundaries.

In sport, we sometimes like to push the boundaries, but if we exceed them, things can go wrong. — When it comes to sport, we sometimes like to push the boundaries, but if we cross them, things can go wrong.

LH

Nine areas of planetary boundaries

Nine processes were defined that can be used to determine the planet's resilience and stress limits:

1. Biodiversity loss

2. Climate change

3. Biogeochemical cycles

4. Ozone layer depletion

5. Deforestation and land use change

6. Ocean acidification

7. Freshwater use

8. Pollution of the atmosphere with aerosols

9. Release of novel substances

The defined processes are shown on the graphic above by Steffen et al.. The load range is shown on the outside. If these load limits are reached or, as can be seen above, exceeded, there is a risk of irreversible damage to nature and thus to the basis of human life.

Some processes have tipping points in the Earth system. If these tipping points are exceeded, irreversible changes can occur. The limits are defined in such a way that the "safe scope for action" is followed by a "zone of uncertainty". This uncertainty exists because the complex interrelationships in the system cannot be determined one hundred percent. Humanity should also still have the opportunity to act accordingly. In addition, some earth system processes are very inert, such as the climate system. This means that changes only occur after a certain period of time. This is followed by the dangerous zone, in which there is a high probability of the system being impaired.

Different parameters were defined for each process. In the case of climate change, for example, the CO2 concentration in the atmosphere. The limit here is 350 ppm and we have already clearly exceeded it at 405 ppm. In the case of biodiversity loss, the metric is the extinction rate in number of species per million per year (E/MSY). The limit here is defined as 10 E/MSY and, according to Steffen et. al, we were at 100-1000 E/MSY in 2015.

Originally, the concept was only applied on a global scale. However, it did not take into account that some processes occur very differently from region to region. As a result, limit values were exceeded in some regions without having a global impact. In 2015, the theory was revised and sub-global limits were defined. Although these regional boundaries do not necessarily have the same units as the global boundaries and are not included in the graph above, they do offer the opportunity to assess the extent of the use of our Earth systems at a regional level.

From a global perspective, the agriculture and food sectors are responsible for exceeding four of the nine pollution limits. These include, in particular, excessive nutrient inputs into terrestrial and aquatic ecosystems as well as excessive land use change and biodiversity loss.

The planetary boundaries model only includes the ecological dimension. The social dimension is completely ignored. The economist Kate Raworth criticized this and in 2012 added an inwardly open circle to the classic representation, which is reminiscent of a donut and reflects the social level.

Application in practice

After its first publication in 2009, the model attracted a great deal of attention and thus also found its first fields of application. Among other things, the planetary boundaries were used to define the two-degree target as a climate protection guard rail. However, many scientists no longer consider this target to be sufficient to prevent tipping points from being exceeded. The planetary boundaries have even reached the outdoor industry. Swedish manufacturer Houdini, for example, has based its own sustainability strategy on the planetary boundaries model.