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What are the 9 Planetary Boundaries and how do they apply to Sustainable Development?

What are the 9 Planetary Boundaries and how do they apply to Sustainable Development?


As our planet’s population continues to grow, we are using resources at a much higher rate than in previous times in our history. At the same time, our economy has continued to grow at the highest rate in history also. This began with the advent of the industrial revolution, which allowed humans to have a higher standard of living. As a result, there has been an increase in carbon emissions, high usage of natural resources which might lead to depletion, increase of pollution, and loss of biodiversity resulting in the sixth major extinction event.

While economists want to continue to increase the global economy, allowing for the least developed countries (LDCs) to catch up to the most developed nations, environmental scientists are worried that this is not sustainable because we live in a finite world. So, the question is, can economic growth be reconciled with environmental sustainability?

We should all aim for a planet that is more prosperous, socially inclusive, and environmentally sustainable. Can all these objectives really be reached? Would gains in living standards prove to be illusory as the world ran short of primary resources? Would scarcity lead to poverty in the long-term? Are gains in living standards merely a temporary overshooting with, with humanity to its comeuppance in the form of a future environmental crisis? These worries are increasingly heard, as the multiple crises of climate change, land degradation, water scarcity, and loss of biodiversity continue to deepen.

By very careful and science-based attention to the real and growing environmental threats, we can indeed find ways to harmonize growth. This is done by implementing the tools of sustainable development, which should be the normative idea that every individual, corporation, and government should abide by. This requires taking precautions, respecting resource constraints, and recognizing the dangerous environmental destruction that our day-to-day practices bring.

Humanity has the ability to achieve its objectives of ending poverty; raising living standards; ensuring social inclusion; and protecting the environment for ourselves, other species, and future generations. To do so we need to understand the real natural boundaries – the planetary boundaries – that we must observe as planetary stewards of the planet.

Planetary Boundaries

Economic growth is complicated but sustainable development is even more complicated. To achieve sustainable development, countries need to achieve three goals simultaneously: economic growth, broad-based social inclusion, and environmental sustainability. While many countries have solved the “growth” aspect, few have succeeded in achieving all three aspects of sustainable development, if at all. No country is really on a path to sustainable development because every country feels the impacts of climate change, ocean acidification, and the extinction of species on a global scale. We live in a global economy that requires everyone, every business, and every country to do their part.

The problems keep getting more difficult to solve. The main problem is one of scale. The world economy is getting very large compared to the planetary finite resources. We are pushing against the limits of the environment; we are exceeding the planetary boundaries in several critical areas. The main culprit is population increase and the ever-expanding economy which is necessary for humans to live comfortable lives. We are crossing boundaries f Earth’s carrying capacity, thereby threatening nature and even our species’ survival in the future. That is why it was necessary to come up with the concept of planetary boundaries. There are nine planetary boundaries that we will discuss.

  1. Human-Induced Climate Change

Human-induced climate change is the result of rising greenhouse gases (GHGs) in the atmosphere. These GHGs include carbon dioxide, methane, nitrous oxide, and a few other industrial gases. Also, petroleum-based vehicles release 8 recognized gases with carbon dioxide being the main culprit.

Greenhouse gases allow incoming solar radiation, in the form of ultraviolet radiation, to pass through the atmosphere of Earth, in turn, reradiates the heat as infrared radiation. The Earth warms to the point that the incoming (ultraviolet) radiation is exactly balanced by the outgoing infrared radiation. The GHGs trap some of the outgoing, resulting in making the Earth warmer. The Earth has been consistently getting warmer since the industrial revolution at a much faster rate than at any time in Earth’s history. This is pushing the Earth to a new climate crisis, one that is different than supported human life during the entire time of human civilization.

This results in threatening the global food supply; the survival of other species; causes much more intense storms; and the possibility of a significant rise in ocean levels, perhaps by as much as a meter, by the end of the 21st century, which would disrupt life in many parts of the world.

  • Ocean Acidification

Ocean Acidification is very close to human-induced climate change in that the CO₂ concentrates in the atmosphere, and then dissolves in the ocean, increasing the acidity of the ocean. The more CO2 gets trapped in the atmosphere, the more it gets concentrated in our oceans. This in turn threatens marine life, including corals, shellfish, lobsters, and very small plankton, by  making it difficult for these species to form their protective shells.

  • Ozone Depletion

In the late 970s NASA discovered a hole in the ozone over Antarctica. It was found that CFCs were the main source of this disaster. This disaster was mitigated by a universal treaty, eliminating the use of CFCs. Now new chemicals are being used and it remains to be seen if there is any environmental detrimental use of these new chemicals. If this problem would not have been mitigated, it would have led to major problems such as an increase in skin cancers and other disorders. This would have been a dire threat to human survival.

  • Pollution that is caused by excessive flows of nitrogen and phosphorus.

The major culprit of this type of pollution is the heavy use of fertilizers by the world’s farmers.  Fertilizers have the profound benefit of increasing food yield that is produced in farming but has detrimental effects on the environment caused excess fertilizer not taken up by crops.

Much of it enters the atmosphere, being carried to other parts of the planet through down winds. Also, it enters the groundwater and rivers, with heavy concentrations of nitrogen and phosphorous reaching the estuaries where rivers meet the oceans. In turn, the heavy influx of nitrogen and phosphorous leads to heavy ecological changes in the estuaries resulting in the rise of algal blooms, which are massive increases in algae in the estuaries. When the algae die, they are consumed by bacteria, which in turn depletes the oxygen in the water creating dead zones which kills fish and other marine life.

  • Overuse of freshwater resources

Humans and other species need freshwater every day to survive. Of the total amount of freshwater that humans use, 70% is used for agricultural production; about 20% is used for industry; and the remaining 10% is for household use such as cooking, hygiene, and other household uses. Humanity is using so much water, especially for food production, that in many parts of the world, societies are depleting their most critical sources of water supplies. Farmers are tapping into groundwater aquifers, taking water out of the ground faster than it is being recharged by rainwater. When they are depleted, the farmers depending on this groundwater will suffer massive losses of food production, and food scarcity will result.

Freshwater scarcity is being exacerbated by countless other problems: growing populations, industrial use of water, changing rainfall and soil moisture conditions due to human-induced climate change, and the loss of meltwater from glaciers, and glaciers retreat and eventually are eliminated because of global warming. This is a major problem, and many political scientists believe that major conflicts and even a third world war could be caused over the loss of freshwater resources.

  • Land use

Humanity uses a massive amount of land to grow food, graze animals, and produce timber and cities and creating new cities. Many regions of the world that were once dense forests are now farmlands or cities. The resulting deforestation not only adds CO to the atmosphere, thus adding to human-created climate change, but it also destroys the habitats of other species. This is causing massive disruption to ecosystems and species survival in many parts of the world.

  • Biodiversity (biological diversity)

Our planet has a remarkable diversity of life with anywhere between 10 million and 100 million species, most of which have not as of yet, been catalogued. That biodiversity not only defines life on the planet, but also contributes in fundamental ways to the functions of ecosystems, the productivity of crops, and ultimately to the health and survival of humanity. We depend on biodiversity for our food supply, safety from natural hazards, countless construction and industrial materials, our freshwater, and our ability to resist pests and pathogens. When biodiversity is disrupted, ecosystem functions change remarkably, usually in adverse ways.

Countless species face the risk of complete extinction, and we are currently in the sixth mass-extinction event, which is man-caused.  The previous five were mostly naturally caused when the comet hit the Earth, whereas this one is not. Since humankind depends on these other species, we are gravely endangering humanity as well.

  • Aerosol Loading

When we burn coal, biomass, diesel fuels, and other sources of pollution, small particles called aerosols are put into the air. A tremendous amount of air pollution is created that is very damaging to the lungs, claims any lives each year, and has a significant impact on changing climate dynamics. Wery fine particles less than 2.5 micrometers in diameter can cause life-threatening lung disease. Some cities are experiencing such catastrophic levels of aerosol pollution, leading to urban smog so think that on some days it is dangerous to venture outside. This is a common occurrence in China for example.

  • Chemical Pollution

Industries such as petrochemicals, steel production, and mining not only use a huge amount of land and water for their processing but also add a tremendous amount of pollutants back into the environment, many of which accumulate. Hey can be very deadly for humans as well as other species.

Biggest contributors affecting Planetary Boundaries

Population Growth

Humanity is already pushing against the limits of Earth’s planetary boundaries and carrying capacity. Yet the environmental pressures are likely to increase not decrease due to Earth’s growing population and the increase of gross domestic product (GDP). It is important that we are interested in the success of poor countries raising their standards of living. We are therefore faced with the most important challenge of sustainable development: how to reconcile the continued growth of the world economy and the sustainability of the Earth’s ecosystems and biodiversity.

This challenge is both profoundly significant and profoundly challenging. We want economic development, and we need environmental sustainability. The two might seem contradictory, but they are in fact compatible if we follow smart policies based upon the current data and technology available, while focusing on the creation of new technologies. We need to learn to achieve economic growth that remains within planetary boundaries.

Energy Consumption

One of the problems of reconciling growth with the planetary boundaries, probably none is more urgent and yet more complicated than the challenge of the world’s energy system. Our planet’s economy was jumpstarted on the basis of fossil fuels, starting in the eighteenth century with the creation of the steam engine, and the nineteenth centuries creation of the combustion engine, and then the twentieth centuries gas turbine. Fossil fuels have allowed for the breakthrough of modern economic growth. Now the challenge is to move away from fossil fuels in the twenty-first century. These energy sources have been central to global economic development for more than two centuries and are now known as a clear and present danger to the world, because of the CO₂ they emit.

It is therefore useful to quantify how much energy we use, how much CO₂ we emit into the atmosphere, and what that implies for how much climate change that we are causing. On average, for every $1,000 USD of total production tends to be 0.19 tons of oil-equivalent energy. One metric ton is 1,000 Kilograms, so 0.19 pf a metric ton is 190 Kilograms; therefore for each $1,000 USD of production we use approximately 190 kilograms of oil or its equivalent in energy content.

Every ton of oil-equivalent energy use din the world releases 2.4 tons of CO₂ emissions. The exact amount of CO₂ depends on the energy source. Coal, which is almost all carbon, produces the most CO₂ emissions per unit of any fuel, about 4 tons of CO₂ for an amount of coal equal in energy units to 1 ton of oil. One ton of oil itself creates about 3.1 tons of CO₂. The amount of natural equivalent to one ton of oil creates about 2.4 tons of CO₂.

If we took the world’s total economy from 2015 of $91 Trillion would result in over 41 billion tons of CO₂ released into the air in just 2015 alone. CO₂ is also added into the air when we cut down trees by releasing biologically sequestered carbon that was stored in the trees. Approximately 46% of every tone of CO₂ stays in the air. The other 54% are stored in what are called “natural sinks”, the oceans, lands, and vegetation. This means that roughly 18 billion tons of CO₂ remained in the air from the year of 2015 alone. Keep in mind that as the world’s population grows, and production grows as we grow the economy, the amount of CO₂ emitted each year grows as well, necessitating the need for alternative clean energy sources.


Agriculture is an economic sector with comparable or even greater environmental impact than the energy sector. This is not surprising since agriculture is the key to our very survival, we have to eat. The extent of agriculture’s environmental impact is even greater than it appears. Think of the planetary boundaries, almost every single one of them is related to agriculture. This topic will require its own article.

In addition to crossing these planetary boundaries, the global agricultural system has other adverse environmental impacts. One issue is that the food system is also giving rise to new pathogens. For example. The industrial breeding of poultry causes recombination of genes, bacteria, and viruses. When poultry and livestock mix with wild species, there are further viral recombinations. The interaction of the food industry with wild-type pathogens has probably given rise to several emerging infectious diseases, most likely including SARS and COVID.

We are going to need to find new farm systems, adapted to local ecological conditions and causing much less ecological damage. What is common to all of the world’s major farm regions is that the farm systems are still not sustainable.

Ways to ethically reduce population growth.

I want to make this point very clear; I do not want to see population reduction through nefarious means, in other words, I do not want people to subscribe what I am seeing to conspiracies that I am advocating for a large reduction in the world’s population. I believe in sustainable growth and the ability for people to choose how many children they want without government interference.

With that said, it is important to note that the more rapidly a population is growing in a particular country, the more difficult it will be to combine economic growth, social inclusion, and environmental sustainability in that place.

Reducing the fertility rates voluntarily, while respecting human rights and family desires, is therefore essential to sustainable development and ending poverty. The world’s governments have enshrined sexual and reproductive rights as core human rights for women, yet often these rights are not realized because many countries are too poor to implement programs to implement programs for safe pregnancy and family planning. Other times governments just do not implement programs that they have committed to provide.

If current fertility rates persist, then in the year 2100, there will be 31 billion people, this is unsustainable. If fertility rates are decreased by just .5 per woman, then the population would be roughly 10.1 billion in the year 2100. This is the rate that the United Nations foresees as the most likely scenario. This is where a mother has two children, one male, and one female. At this rate reproduction is about replacement for the next generation.

Ethical Voluntary Fertility Reduction

Least-developed countries have the highest population growth rates. A major factor of this is girls as young as twelve being married off, starting to have babies soon afterwards. They are prevented from getting an education, are not able to obtain birth control, are prevented from the work force, and also have more babies due to higher child mortality rates.

Countries should pass legislation to make the minimum age for marriage at 18, allow for girls to obtain education including high education, have access to family planning and birth control in all forms, and improve health care standards that will lower child mortality rates, so that families do not feel the need to have more children.

Clean Energy Technologies

Countries should implement programs that focus on green energy such as solar, wind, water, and any other new technologies that might not have been developed yet. These green power sources emit no carbon and are completely green.


When humanity trespasses on these planetary boundaries, meaning that the human pressures on the environment become greater than the ability of the Earth’s natural systems to absorb those human pressures, the result is a major change in the function of the Earth’s ecosystems. Those changes, in turn, threaten human well-being and even human survival when the shocks occur in places where populations are very poor and do not have the buffers of wealth and infrastructure to protect them. When fisheries die, fishing communities die with them. When groundwater is depleted, farming collapses. When the climate changes, regions can be thrown into turmoil and even war, as had increasingly occurred in the dryland regions of Africa, the Middle East, and Western Asia.

Human induced climate change is already having such dire affects in many parts of the world. The most direct manifestation of human-induced climate change has been the steady rise of temperature. This is not only in land, but seas as well. The summer of 2023 has reached record levels in land and sea temperatures globally, even in the Southern Hemisphere during their winter months have been warming up. Fish, crabs, coral, and other marine life have been dying by the millions, washing up on shores. Between 2021-2022 there was an 80% loss of Alaskan Crab because of rising ocean temperatures.

By respecting the planetary boundaries, creating new technologies, supporting ethical and voluntary fertility reduction, such as supporting girls and women to obtain their education and be part of the workforce, while allowing them access to birth control and family planning, and developing farming techniques, we can be successful in not only growing our economy but doing it in a sustainably and ethical way.

Pearce Sustainability Consulting Group (PSCG) is an Award-Winning Boutique Consulting Firm based out of Redding, California, with offices in the State of Georgia, the country of Tunisia, and plans to expand into Dubai and Qatar. Wealth & Finance International’s 2023 Business Management Awards named PSCG as the Best Sustainability Consulting Firm – California 2023.

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