THE GAIA THEORY

Our Earth: One Self-Regulating Life System

The GAIA theory is a scientific theory that states that the Earth and all its biological, geological, atmospheric, and chemical components work together as one self-regulating system. This idea was introduced as a hypothesis in the 1970s by British scientist James Lovelock, with contributions from American microbiologist Lynn Margulis.

James Lovelock says about this:
"The Earth could be alive, not as a sentient goddess pursuing a goal and with a visionary outlook, but alive like a tree, existing in silence, never moving or changing place, but moving with the wind, communicating endlessly with the sunlight and the soil. It needs sunlight, water, and nutrients to grow and change. However, all this happens so unnoticed that the old oak tree in the meadow is the same to me as it was when I played under it as a child."

There has been a lot of understandable criticism of this theory (then still a hypothesis), but particularly in the 21st century, the GAIA theory has been further developed and reevaluated in light of climate change and environmental issues, all of which point to and can only be understood by assuming a total interaction, in which everything is connected to everything else (and therefore at all levels) and reacts to each other.

Many insights have grown in recent decades through newly developing sciences, such as earth system science, biogeochemistry, and systems ecology. 
Most scientists do not see the theory as a literal description of a “living” Earth, but rather as a useful framework for (increasingly) understanding the interactions between living organisms and their environment—leaving metaphysical and spiritual considerations aside.
We hope to return to these latter issues in a future blog, as I find them particularly fascinating, but they are beyond the scope of this post.
Let's start with some key questions:

First of all: What are LIVING BEINGS?

These can be described as: organized genetic units that undergo the following six processes: metabolism, reproduction, growth, and evolution, forming a self-functioning unit and at the same time being in continuous interaction with their environment. 

In other words: a self-existing system that maintains itself, that grows and develops, and that does so in interaction with its “living” and “dead” environment.

This description can be applied at all levels, from the smallest single-celled creatures to the most impressive plants and animals, including humans. 

CO-EVOLUTION

The Gaia hypothesis suggests that organisms co-evolve (simultaneously) with their environment. In other words, living organisms influence the non-living (abiotic) environment, and that environment in turn influences living organisms. They do not just co-exist, but interact, constantly influencing each other, working together, as it were. - That's what we can imagine, without thinking too deeply.

But it becomes realy complex when we look at it in the context of the entire geological and biological history of the Earth. At this point, Lovelock demonstrated how, over millions of years, bacteria that developed in a very hot and acidic environment, which ‘lived’ on sulfur compounds and produced methane gas,

gradually developed into other microorganisms (cyanobacteria), organisms that thrived in more moderate conditions and, with the help of carbon dioxide and water, now produced oxygen (instead of methane) – which ultimately resulted in a completely different atmosphere (with at least 20% oxygen) in which more complex life became possible and ultimately flourished: the very rich plant and animal life as we know it today.

AS A WHOLE?

That is a third important element in the hypothesis/theory: not only that there are living beings or that they develop together with their inorganic environment, but that this applies to our planet as a whole with all its very different elements.  Could you really call our Earth a single living being? Is everything organic and inorganic really connected in some way, and does it all contribute to life in all its dimensions?

Of course, we cannot check this piece by piece on our Earth.
But we can establish that there are literally global (i.e., affecting the entire globe) processes taking place, which, wonderfully enough, all contribute to optimal conditions for (higher forms of) life—of which we humans are perhaps one of the highest developments.

GLOBAL PROCESSES.

There are many different ways to view and determine this.
Here we select a few phenomena, all of which point in the same direction of coherence and interaction, all aimed at creating optimal conditions for life.

METEOROLOGY
Perhaps the first and most striking thing is what meteorology shows us: how the weather system truly encompasses the entire Earth and thus influences everything. The Earth is clearly one large coherent mechanism, in which the atmosphere, (large) water masses, and (large) land masses interact continuously in various ways (in terms of temperature, humidity, matter, etc.). The photo of the Earth, taken during a moon flight, clearly shows how winds, hurricanes, (sea) currents, lee areas, and all kinds of weather conditions interact around our globe.

Within and 'beneath' all these wheater phenomena many more processes are taking place. We will describe a few of these, mainly to clarify and confirm the overall picture, not to exhaustively demonstrate or prove everything.

After meteorology, we will discuss topics such as climate regulation, temperature regulation, the composition of the atmosphere, and the salinity of the seas. These are all crucial issues that together create the most optimal conditions for biological life—and which are also brought about by biological life. That is precisely what is so intriguing about the Gaia hypothesis/theory!

BIOLOGICAL?

Meteorology seems to be all about "ordinary matter" (air, water, sand, rock, heat, cold, etc.). But are living beings, the whole biosphere of the earth, also connected to each other and to so-called non-living matter? Let's dig deeper into this...

KEY IDEAS

As already mentioned, the core of the GAIA theory is that the earth functions as a single, living organism that maintains its own balance. This means that biological processes and non-living elements (such as oceans, the atmosphere, and rocks) work together to create a stable environment that supports life and contributes to the habitability and livability of the earth. This requires a lot. We mention here five factors:

1. Climate regulation: Microorganisms and plants influence the oxigen and carbondioxide levels in the atmosphere, which in turn influences the climate.

2. Temperature stabilization: Reflection of sunlight by clouds and large ice masses contributes greatly to stable temperatures. This (decreasing) albedo effect is currently a matter of great concern.

3. Presence of liquid water. Closely related to the previous is the preservation of liquid water in the hydrosphere (everything related to water): Liquid water is probably the most important element of and for life at all levels, from the simplest cells to the most highly developed organisms (plants and animals, including humans).

4. Stable salinity of seawater, which enables and sustains the continued life of marine animals.

5. Oxygen balance: The oxygen content in the atmosphere remains within a range suitable for life, thanks to photosynthesis by plants, which absorb carbon dioxide and produce oxygen.

CLIMATE REGULATION AND TEMPERATURE STABILITY

The energy of the sun, and therefore also the radiation reaching the earth, has increased by 25 to 30 percent since the sun was formed. However, the entire earth system has adapted well to this and has not become “overheated.” Fluctuating between higher and lower limits, the whole has remained “habitable.”

    Unfortunately, after millions of years of nature maintaining its own balance, we have now reached a point (especially in the last two centuries) where humans are

producing excessive amounts of carbon dioxide and releasing methane from the earth's crust (e.g. thawing permafrost  because of global warming), and nature is no longer able to keep up. Hence all the actions now being taken to reduce carbon dioxide production and develop procedures to use new ‘inexhaustible’ and non-polluting forms energy sources, such as wind, water, sunlight, and geothermal energy: the so-called energy transition. 

SALINITY OF THE OCEANS

The salinity of water, in which virtually all life has developed and continues to develop, is crucially important for biological life. It is therefore striking that the salinity of the oceans has remained constant for hundreds of millions of years, at around 3.5%.

This is astonishing, because ‘salt’ is constantly being added, for example through the erosion or weathering of mountains, causing more and more ‘salt’ to enter the seas via rivers. Yet the salt content of the oceans remains roughly the same.
It has been discovered that there are several (micro)organisms that react to an increase or decrease in salt content and (ingeniously) correct this. It is also known that (coral) reefs absorb salt from their environment and release it again according to the ‘need’ for their own viability and that of other animal and plant organisms.
Lagoons (into which the sea ‘overflows’ from time to time) also play a role, because seawater stands still and evaporates there, causing the salt to precipitate on the spot and thus be extracted from the ocean. 
In this way, the conditions for a well-functioning ecosystem are apparently maintained.

OXYGEN CONTENT OF THE ATMOSPHERE

Oxygen molecule

There is also a stabilizing mechanism that keeps the oxygen content in the atmosphere constant. For millions of years, this content has remained stable at around 20 percent, with 79 percent nitrogen and small amounts of other gaseous components such as carbon dioxide, water vapor, nitrogen oxides, and the noble gas argon.Due to various forms of oxidation, i.e. reactions with oxygen, such as rusting, forest fires, etc., one would expect this oxygen content to decrease. But that is not the case. Mainly through the process of photosynthesis in green plants (see a previous contribution), nature has been adjusting ‘as needed’ for millions of years, allowing all animal life in particular to flourish. For at least a billion years, the oxygen content has remained essentially the same, albeit with some fluctuations.

FINALLY

As a preliminary conclusion, we can say, perhaps with surprise, that after all the turbulence of the long process that created stars, clusters, spiral nebulae, milky ways, the (our) sun, and finally the planets around that sun, over a period of about 8 billion years, one planet has emerged on which—again, after a great deal of turbulence on that planet itself—a beautifully stabilized state has emerged. A state in which biological life has emerged and developed in unimaginable richness and beauty, and in which that life continues to thrive, even through several phases of mass extinction (the extinction of life forms).

Perhaps even more amazingly, it has been discovered that ‘life’ is not simply passive, but constantly plays an active and purposeful role in this entire balanced process, a phenomenon known as co-evolution. Biological ‘partners’ are constantly involved in all the stabilisation processes described above (temperature, salinity and oxygen content). It is one large dynamic system in which the biotic and abiotic continuously work together.
Apparently, as numerous scientists and admirers of nature have observed, the entire creation has been designed for life from the beginning; it is biophilic, life-loving.
For those who experience life and death, and who does not? Those who live through the ‘harshness’ of nature, this life-loving character is not an obvious conclusion. It gives many of us reason to investigate further and to think more deeply about all this.... The paradox of life: birth - growth - flourishing - fertility - decrease - death - new beginning ...

Johan Muijtjens
July 20215