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Know your planetary boundaries

Do you remember the eye-opening documentary ‘Breaking Boundaries: The Science of Our Planet‘? Well, Prof. Johan Rockström, Director of the Potsdam Institute for Climate Impact Research, has won the 2024 The Tyler Prize for Environmental Achievement! 🏅

Prof. Rockström is recognised for his pioneering work on the Planetary Boundaries framework, which defines the safe operating space in which human societies can continue to develop and thrive without pushing the Earth’s systems out of balance.

What is the Planetary Boundaries Framework?

The Earth’s climate stabilised about 10,000 years ago after the last major ice age ended. This was the beginning of the Holocene, in which humanity flourished unprecedentedly. The favourable environmental conditions and climatic stability allowed us to quickly develop and expand our civilisations. But since the start of the industrial revolution, we have been putting so much pressure on Earth systems that we are now seriously affecting the stability of the entire planet.

Throughout the Holocene, Earth’s self-regulatory systems have kept the planet in a state with permanent icecaps, flowing rivers, a cloak of forests, reliable weather, and an abundance of life. But because we have heavily depended on fossil fuels and industrial (animal) agriculture, human activities have pushed the planet outside the desirable Holocene state. According to scientists, the Earth is now “well outside the safe operating space for humanity”.

The systems that have kept the planet in a Holocene state have been successfully quantified and are described by the so-called ‘Planetary Boundaries Framework’. The framework, initially proposed by Johan Rockström and a group of 28 internationally renowned scientists in 2009. In September 2023, the framework received its latest update, which was the first to map all nine boundary processes that define the safe operating space for humanity. 

The message of the study is clear: through pollution and destruction of the natural world, we’re seriously affecting the stability of the entire planet. We’re placing unprecedented pressure on Earth systems, have already transgressed six of the nine planetary boundaries, and are close to crossing two more. But the most worrying is that all biosphere-related boundaries, which cover the living world and provide the resilience of Earth systems, are at, or close to, the highest risk level.

It is a very gloomy picture, but it is not too late. Let’s briefly discuss the different planetary boundaries – we’ll discuss them in more depth in the near future.

The 2023 update to the Planetary boundaries - version 3.0

Climate change & Biosphere integrity

Scientists consider ‘climate change’ and ‘biosphere integrity’ the two core planetary boundaries because either one could drive the Earth system to a new state.

Climate change is measured through the concentration of carbon dioxide in the atmosphere and the amount of heat the Earth absorbs. Biosphere integrity rests on its genetic diversity – the diversity in living species on Earth – and its functional integrity – the intactness of Earth system services (e.g. pollination and carbon sequestration). But with the combustion of fossil fuels and the destruction of the natural world through deforestation, we have crossed all four sub-boundaries.

Land-system change, freshwater change & biogeochemical flows

‘Land-system change’, freshwater change’ and ‘biogeochemical flows’ are three other biosphere-related boundaries that regulate the stability of our planet.

From biome composition, freshwater availability, the hydrological regulation of ecosystems, and the nitrogen and phosphorus flows (the building blocks of the living biosphere), all boundaries are crossed and are at, or close to, the highest risk level. Agriculture, especially animal agriculture, is driving these boundary transgressions and is effectively destabilising the Earth system at a planetary scale.

Ocean acidification and atmospheric aerosol loading:

As long as we keep burning fossil fuels, the oceans will continue absorbing excess carbon from the atmosphere and become more acidic over time. This process is sometimes called “marine osteoporosis” because it effectively eats away the minerals that marine life depends on. If left unchecked, it could ultimately lead to an ecological collapse.

For the first time, ‘atmospheric aerosol loading’ was assessed, and researchers found that besides being a health hazard, air pollution negatively affects plant growth and monsoon rains.

Both systems are still within the safe space, but the first cracks are becoming visible.

  • Read: Ocean acidification (coming soon)
  • Read: Atmospheric aerosol loading (coming soon)

Novel entities:

We have been releasing a dangerous cocktail of synthetic chemicals in the water, air and soil for many decades. From plastics to pesticides and antibiotics to nuclear waste, ‘Novel entities’ are likely to have irreversible effects on living organisms, the physical environment, atmospheric processes and the climate. With most pollutants being released into the environment without ever being tested, we have clearly overstepped this boundary.

  • Read: Novel entities (coming soon)

Stratospheric ozone depletion:

‘Stratospheric ozone depletion’ is a case closely related to novel entities, and it’s the only boundary where we’re moving in the right direction.

The ozone layer plays a vital role in our atmosphere by shielding us from the sun’s harmful ultraviolet radiation. Concerned about ozone layer depletion in the 1980s, world governments ratified the Montreal Protocol in 1987 to phase out 99% of ozone-depleting substances.

  • Read: Stratospheric ozone depletion (coming soon)

This success story proves that we can also get into safe operating space with other planetary boundaries if we act collectively and decisively. So… What are we waiting for?

“It will be the decisive decade for humanity’s future on Earth. The future is not determined. The future is in our hands. What happens over the next centuries will be determined by how we play our cards this decade.”

Johan Rockström in Breaking Boundaries.

In the upcoming months we’ll discuss them one by one. Here is the entire list:

Don’t forget to scroll through our Instagram slider below!

Resources:

  • Richardson, K., Steffen, W. et al. (2023). Earth beyond six of nine planetary boundaries.

  • Stockholm Resilience Centre – Planetary boundaries (for updates, publications and related news articles).

  • Satellite imagery in slider by the European Space Agency (ESA)

  • Even though the documentary “Breaking Boundaries: The Science of Our Planet” does not examine the latest framework, it’s still relevant today. If you haven’t already watched it, please do. Check out the trailer below, or go to our resources page.
Elise & Joy

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