Of the nine planetary limits, we have already crossed four, there are three within the safe zone (for now) and two that are still a great unknown.
Some 11,000 years ago, something unprecedented in the last 100,000 years of Earth’s history happened: the planet’s climate became stable.
This geological era with predictable temperatures was dubbed Holocene and it allowed humanity to develop agriculture, domesticate animals, and basically create today’s modern world.
However, in this process we also extinguish species and damage ecosystems, pollute the air, water and soil, and unleash the crisis of climate change.
In other words, we forced entry into the Anthropocene, the current geological era where humans are primarily responsible for changes on the planet.
It is in this context that an international group of scientists led by the Swedish Johan Rockström from the Stockholm Resilience Center began to investigate what risk we run of breaking the natural balance and resilience capacity of the Earth.
Their influential study, published in 2009, defined nine interconnected limits or parameters that are determinants to maintain the stability of the planet.
“Each of these aspects is very important individually, but also it is very important to see them with the set”, Arne Tobian, a researcher at the center, tells BBC Mundo.
In addition to identifying these nine processes, the experts defined very specific quantitative measures for each of them, which delimit a safe area of action and one of risk, which in turn is growing in danger.
If we don’t cross those borders traced, they say, humanity will be able to continue to prosper for generations.
But in case of spending only one of them, we expose ourselves to generating irreversible environmental changes throughout the system and trigger the collapse of our society.
The results of this colossal study were brought to the screen in a recent Netflix documentary entitled “Breaking the Boundaries: The Science of Our Planet” and has become especially relevant in the framework of the 26th United Nations Conference on Climate Change (COP26), whose objective is to make the world act quickly in the face of a crisis that has been known for decades and whose margin of action is decreasing.
THE 9 PLANETARY LIMITS
Of the nine planetary limits, We have already crossed four, there are three within the safe zone (for now) and two that are still a great unknown.
1. Climate change
One of the four limits that we have already exceeded is perhaps the best known of all: climate change.
Since the Industrial Revolution, global temperature has risen 1.1 ° C. This increase is responsible for the extreme weather events that occur with increasing frequency throughout the world, such as droughts and floods.
According to the United Nations (UN), today we have five times more meteorological disasters than in 1970 and seven times more expensive. The consequences are more devastation and more deaths.
The scientific community affirms that, to prevent the consequences of climate change from being even worse, it is necessary that the increase in temperature remains around 1.5ºC.
However, if we continue as we are today, by the end of this century the increase can reach 4.4 ° C, which would be catastrophic.
“The drama is that the climate change challenge may be the easiest (to solve) if you consider the challenge of sustainable development together, ”Rockström said when presenting his study at a TED talk in 2010.
As if that were not enough, climate change is one of the two planetary limits considered central due to its influence on the entire system.
2. Integrity of the biosphere
The integrity of the biosphere, that is, the loss of biodiversity and the extinction of species, is the other of the central limits. And we’ve been through it too.
However, unlike climate change, this process has already passed the growing risk zone and is directly in the high risk zone, increasing the chances of generate large-scale irreversible environmental changes.
We have exceeded this threshold so much that some researchers believe that we are in the middle of the sixth mass extinction in the history of the planet.
To get an idea, mass extinctions were periods where 60 to 95% of species were wiped out.
In the Netflix documentary, Rockström claims that we should lose zero biodiversity and species from next year.
The challenge is monumental if one takes into account that currently of the 8 million animal and plant species that inhabit the planet, 1 million is in danger of extinction.
However, it is a necessary effort: having healthy ecosystems provides us with clean air, fertile soils, fresh water, pollinated crops, raw materials for new drugs and much more.
3. Land use change
Land use is another of the limits that we have crossed and consists of the transformation of forests, grasslands, wetlands, tundra and other types of vegetation, mainly in land for agriculture and livestock.
Deforestation, for example, has a huge impact on the ability of the climate to regulate itself, something that specialists repeat every time there are fires in the Amazon.
But land use change is also one of the drivers of severe declines in biodiversity, not least because of the growing demand for land to produce food.
In fact, one of today’s sustainability challenges is how to feed the nearly 8 billion people living on the planet (and the 2 billion more that will be in 2050) without taking more ground from nature.
4. Biochemical flows
The fourth and last frontier, already surpassed, is that of biochemical fluxes, which encompasses above all phosphorus and nitrogen cycles.
Although both elements are essential for plant growth, their excessive use in fertilizers places them in a risk zone.
One of the problems that this generates is that part of the phosphorus and nitrogen applied to crops is washed into the sea, where they push aquatic systems to cross their own ecological thresholds.
5. Stratospheric ozone depletion
Of the nine processes, there are a single one that humanity successfully acted upon by seeing the red flags: ozone depletion in the stratosphere.
More than 30 years ago the whole world agreed on ban chlorofluorocarbons (CFC), chemicals that were causing a “hole” in the ozone layer.
The consequences of losing this layer of protection ranged from the multiplication of skin cancer cases to irreversible environmental damage.
After the famous Montreal Protocol, stratospheric ozone has been recovering, which today allows us to be calm within the safe zone for this process.
6. Use of fresh water
While the use of fresh water is currently within the safe action area, we are moving rapidly towards the risk zone, says Rockström in the documentary.
It is that the Earth can be seen as a blue point from space, but only 2.5% is fresh water. This percentage is decreasing mainly due to the already mentioned growing pressure from agriculture to produce more and more food.
It should be noted that although desalination is possible, it consumes a lot of energy that, in general, comes from the same fossil fuels that contribute to climate change. As if this were not enough, this process is a source of contamination of coastal ecosystems.
7. Ocean acidification
Something similar happens with ocean acidification as with fresh water: the boundary hasn’t been crossed yet, but we’re dangerously close.
The problem is that its effects are precisely hidden under water, for example, with the death of corals.
This particular process presents an extra layer of risk, as several of the mass extinctions in history had the acidification of the oceans as a trigger.
In the last 200 years, ocean water has become 30% more acidic, a rate of chemical transformation 100 times faster than that recorded there in the last 55 million years.
This limit is so closely linked to climate change that it is often called its “Evil twin”.
The good news is that if the climate change goals ratified at COP26 are met, the ocean’s pH will be kept in check.
8. Loading of atmospheric aerosols
There are still two limits to mention that are not on either side of the border. And is that scientists don’t know how to measure them.
“There is no baseline of the last 11,000 years for these processes, because they are new,” explains Tobian.
One of them is the pollution of the atmosphere with aerosols of human origin, that is, microscopic particles generated mostly by burning fossil fuels, but also for other activities such as forest fires.
These aerosols affect both climate (for example, causing changes in monsoon systems in tropical regions) and living organisms (some 800,000 people die prematurely each year from breathing highly polluted air).
9. Incorporation of new entities
The ninth and last process is the incorporation of the so-called “new entities”.
These are elements or organisms modified by humans, as well as entirely new substances. This includes a list of hundreds of thousands of entities ranging from radioactive materials to microplastics.
But perhaps the best example is CFCs, that is, those chemicals that were banned to save the stratospheric ozone layer.
Hope as action
The work of the Stockholm Resilience Center not only warns about the core issues affecting the planet. Too gives hope.
“We know what the problem is and we know that we have a problem and also at the same time we know what the possible solutions would be. We have it at hand”Tobian tells BBC Mundo.
The challenge is great and pressing: In this decade ending in 2030, humanity must undergo a massive transformation to stay in line.
However, scientists say it is possible.
Quick and bold action required on behalf of each and every one of the world’s governments, starting with the use of renewable energy.
“Our addiction to fossil fuels is driving humanity to the brink”Said UN Secretary General António Guterres this week at COP26.
“Enough burning, drilling and digging deeper. We are digging our own grave, “he added.
He also assured that “the G20 countries have a special responsibility, since they represent around 80% of emissions”, reminding developed countries of their commitment (so far unfulfilled) to contribute “US $ 100 billion a year in climate finance in support of developing countries”.
However, achieving a sustainable world also requires changes in the lifestyle of individuals.
Eating more vegetables, saving energy, planting trees and choosing to walk, cycle or use public transport are concrete measures that, according to specialists, make a difference.
In other words, achieving sustainable development is possible and necessary, but not easy. As Swedish activist Greta Thunberg put it in a pre-COP26 speech that went viral: “Hope is not blah blah blah. Hope is telling the truth. Hope is to act”. (I)
Paul is a talented author and journalist with a passion for entertainment and general news. He currently works as a writer at the 247 News Agency, where he has established herself as a respected voice in the industry.
