Planetary Boundaries: Understanding the Nine Thresholds for Sustainable Human Development and Survival
After the Industrial Revolution, excessive human use of natural resources has deteriorated the earth’s environment. Ever since, human activity has a profound impact on the Earth’s environment. Therefore, it is vital to respect certain thresholds to ensure sustainable development.
The 9 Planetary Boundaries
In 2009, a team of environmental scientists led by Johan Rockstrom and Will Steffen suggested a framework that consisted of 9 Planetary Boundaries.
Johan Rockström
Will Steffen
These boundaries are known as Planetary Boundaries. They are thresholds within which humanity can survive, develop, and thrive for generations to come. Or in other words, these boundaries must not be crossed to ensure our existence on earth.
Crossing these boundaries can lead to irreversible environmental damage and disastrous consequences for life on Earth. Let’s find out what those 9 thresholds are.
- Climate change
- Ozone depletion in the stratosphere
- Increase of aerosols in the atmosphere
- Ocean Acidification
- Biochemical flows of nitrogen (N) and phosphorus (P)
- Freshwater use
- Land use change
- Biodiversity loss
- Introduction of new entities by humans
Unfortunately, three of these Planetary Boundaries were already crossed by 2015. And they are climate change, biodiversity loss, and biochemical flows of nitrogen and phosphorus.
Climate Change
Recent evidence show that the levels of CO2 in the Earth’s atmosphere has passed the safety level (under 350ppm) and is not over 400ppm.
It means that we have crossed the planetary boundary and entered the increasing danger zone (350~450ppm) and may transgress to the high risk zone when the level becomes higher than 450ppm.
Biodiversity Loss
Biodiversity loss involves an increased rate of species extinction, including living species and ecosystems. Destruction of natural environmentsdue to human activities, pollution of the habitats, and climate change are some of the reasons.
The threshold number not to be exceeded was 10 out of a million species, But the limit was crossed in 2009 by tenfold, with 100 extinctions out of a million.
Biochemical flows of Nitrogen and Phosphorus
Nitrogen and Phosphorus are naturally occurring elements in plant growth. They have been used to make chemical fertilizers and greatly helped to increase crop yields to ensure food security.
However, the excessive use of these fertilizers has led to negative environmental impacts, including soil and water pollution. When nitrogen and phosphorus fertilizers are applied to fields, they can leach into groundwater and surface water, eventually making their way into lakes and oceans. This can lead to an overgrowth of algae and other plants, leading to phenomena such as red tide or blue-green algae that turn the water red or green.
The nitrogen limit was exceeded in 2015, and natural phosphorus reserves will be exhausted in less than 100 years at the current rate.
Final Thoughts
In 2022, two new thresholds were crossed, chemical pollution and novel entities; and freshwater use. If we keep at this pace, scenes from the movie Interstellar may become a reality one day.
Planetary boundaries provide a powerful yet simple visual of what we should be doing, indicating that there is a limit that we must not cross to ensure our existence on Earth. The consequences of exceeding these thresholds may not result in an immediate large-scale catastrophe but will lead to small consequences that appear little by little and ultimately disrupt the entire ecosystem.
These boundaries are interdependent and caused by human activities. Therefore, it is important to remember that we must adhere to these nine limits collectively, rather than focusing our efforts on only a few choices. – in order to keep the Earth habitable for future generations.
Learn more about each of the Planetary Boundaries What are Planetary Boundaries?
“Endless greed for material possessions has brought about
serious air and water pollution that is destroying nature,
including the ozone layer that protects us.
If present trends continue,
humanity will find itself destroyed by the traps of material civilization.”
-Dr. Sun Myung Moon, As a Peace-Loving Global Citizen–
