How we'll address planetary limits

25 of May of 2023

Planet Earth is a system in complex equilibrium. Elements like the atmosphere, water bodies, and the biosphere help regulate this balance and keep it within certain limits. But what happens when humanity pushes those limits, even a little? Do we have the technology to address planetary limits? Are planetary limits a problem of technological misapplication? The ozone layer closing gives us hope for a greener future through innovation.

What are planetary limits?

Planetary limits are thresholds of nine global processes that, if crossed, would lead to a global system that would be unpredictable by scientific methods and, in high probability, not kind to life as we know it. They were proposed in 2009 and accepted worldwide by 2016. The latest report from 2022 shows that we need urgent changes in our ways of life.

The easiest way to understand planetary limits is by keeping in mind that the current climate crisis is one of those limits. This is probably the limit with the most social awareness and the most studies on it since we have been monitoring it for several decades.

Why are planetary limits important?

If one of these limits is broken, the rest of the global systems will try to correct it and compensate for the damage. This is what happens when one species goes extinct – another usually occupies its ecological niche. But if a few do so in parallel, that balance could break down abruptly and unpredictably. That’s no good for us.

The nine planetary limits and how to address them

There is a general consensus that there are nine major planetary limits. While some authors group them into fewer categories and others break them down into more, the factors behind them remain the same. For example, the current loss of biodiversity has sub-elements such as the “insect apocalypse” (the name for this massive worldwide loss) and the loss of megafauna. Grouped or not, the problem is the same.

Limit 1. The hole in the ozone layer, a story of techno-hope

clouds and mountains Lightscape,

Discovered in the 1980s, the hole in the ozone layer can be considered one of the first boundaries. The ozone layer is essential for life, as it filters out dangerous ultraviolet radiation so that it does not reach Earth’s surface. In 1987, the Montreal Protocol was adopted, and it was launched in 1989. The prohibition of CFCs and other gases pushed the industry to work with other molecules that are less harmful to the environment; if we continue on this path, the hole will be restored completely by 2066.

Limit 2. The well-known climate crisis and CO2

The climate crisis is a boundary that includes increased CO2 in the atmosphere, rising temperatures, and climate change as all its associated consequences. Obviously, the solution lies in starting to reduce carbon emissions, along with the use of carbon capture technology to clean up the atmosphere and oceans faster than nature alone would.

Limit 3. Particulate pollution of the atmosphere

This is probably one of the most complicated to measure, so much so that in June  2022 final figures were not yet available. Considering that it covers plastic and microplastic pollution, among other things, most of the projections are rather pessimistic. And how is this solved?

It is immediately necessary to eliminate all processes with single-use plastics, as well as avoiding plastics that cannot be 100% recycled (which are almost all of them) or manufacturing methods that do not allow recycling, such as the tetra-brick or disposable electronic cigarettes, as much as possible. Making more durable objects is a basic point for this planetary limit. For example, metal bottles instead of PET.

We are also going to need to clean up rivers, lakes, and seas through direct actions ranging from collecting waste from beaches to capturing plastics in the high seas. The good news is that there is the technology to do it and that the waste can then be used for other projects, such as making toys or bricks for building.

Limit 4. Ocean acidification

Ocean acidification is the reduction of the water’s pH. The bad news is that, from 1950 to 2020, it dropped from 8.15 to 8.05. The good news is that its main cause is CO2, so we are already designing technology capable of emitting less and even capturing the surplus. Of course, the faster we move towards decarbonization, the less damage the oceans will suffer.

It is very important to reverse the damage as soon as possible, and not only for life in the oceans. Human activities such as fishing or whaling tourism depend on this balance. There are some promising technologies for adding bases to the ocean to neutralize their acidity, although they should be understood as complements to decarbonization.

Limit 5. Erosion of the biosphere and biodiversity

For more than 60,000 years, humans have been struggling with biodiversity. Wherever we show up, megafauna disappear. But now, we have a key tool to prevent this: knowledge. Never before have we had so much information or so many protected areas. And they are in the process of expansion. The goal is to protect 30% of the planet’s surface by 2030 and 50% by 2050.

Polar Bear Hans-Jurgen Mager,

Protecting natural environments, like creating green bridges for wildlife, is a priority in the agenda for protecting biodiversity. There is a large set of technologies that will help us. Vertical cultivation allows large areas of cultivation to be freed up for reforestation, citizen science helps locate species, and satellite technology enables better measurements of the recovery of the environment.

Limit 6. The nitrogen imbalance

The nitrogen cycle is little known but governs balances in nature, just like the water or carbon cycle. In order to feed the population cheaply, humankind has added a lot of nitrogen to the fields in the form of fertilizers, and this has resulted in a very serious imbalance. Luckily, there is technology to solve this.

Among the most interesting technologies is the use of nitrogen-fixing bacteria that is naturally present in sugar cane and which eliminates the need to add fertilizers. Crop rotation, which is not exactly a new technology, also makes it possible to regenerate soils. Other measures involve polyculture so that plants work together, complementing their chemistry.

Limit 7. Can we take fresh water that’s available out of the atmosphere?

 Water stress (using more water than is available) is unfortunately a global practice. The solution includes adapting crops to the environment instead of forcing the environment to hydrate foreign crops, using water resources more efficiently, or identifying food chains that require less water.

It is also possible to make use of cultivation technologies in controlled environments that use a tenth of the water, to reduce meat consumption, and even to ‘harvest clouds.’ The atmosphere contains a huge amount of water that can be used for irrigation – if it can be trapped. There are already prototypes that allow condensing mineral water from the air with hydropanels designed for places with drought.

Limit 8. Changes in land use

The Amazon is probably the region of the planet that gets the most attention when its jungles are cut down to develop crop fields, one of the most damaging soil changes. This comes with urban dispersion and the abandonment of agricultural fields. Is there a solution? There actually is, and the technological solutions are the same as those for the limits of the biosphere or nitrogen because they are related problems.

Limit 9. Atmospheric aerosol ‘load:’ everyday pollution

Despite its very technical name, this limit refers to atmospheric pollution, and addressing it requires the use of clean technologies that do not emit particles into the air. Electrifying to decarbonize is an indispensable step especially within cities, which are environments where gases are concentrated.

Planetary limits have partial technological solutions

Technology will be essential when it comes to respecting planetary limits. It can help us reduce greenhouse gas emissions, mitigate ocean acidification, restore the ozone layer, manage water and nutrient use, curb deforestation and biodiversity loss, and minimize atmospheric and chemical pollution. Technology can also allow us to adapt to environmental changes that are already inevitable and develop innovative, sustainable solutions for the future. Though not all solutions are technological, some are as simple as not building a golf course in a rain-fed area.

Main imagen: dan carlson,

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