An economist’s ode to the forests and the sea

The simple fact that we exist on a habitable planet contemplating our existence is an event of extraordinary improbability. According to physicist Dennis Sciama, if the fundamental constants that describe our universe, such as the strength of gravity or electromagnetism, were selected at random, the resulting universe would almost certainly have a negligible chance of supporting life. Our inhabited Earth is "barely possible."

Despite the unlikely outcome of our inhabited planet, we often labour under the delusion that we are the unshakeable masters of the world, the pinnacle of evolution standing atop a solid hierarchy of our own making. Yet, a more accurate assessment is that we are transient guests on a "Rare Earth." To truly understand our place in the universe, and our future, we must look away from our stock markets and GDP charts and turn our gaze toward the true architects of our existence: the oceans and the plants.

The ocean world

Our very language reveals a profound misunderstanding of our world. As the science fiction author Sir Arthur C. Clarke famously remarked: 

“How inappropriate to call this planet Earth when it is quite clearly Ocean”.

From space, we are a "pale blue dot," a world where 70% of the surface is water and where the ocean contains 95% of the planet's livable space. It is the womb of our existence. Abiogenesis - the event of life springing from non-life - occurred in the ancient oceans, likely around hydrothermal vents, approximately 4 billion years ago. To this day, we carry the legacy of that origin within us; our bodies contain saltwater with a mineral composition strikingly similar to the sea.

The ocean acts as the planet’s thermostat and shield. It is a  "Big Heat Bucket," absorbing over 90% of the excess heat trapped on the planet, stabilizing the climate system that allows civilization to exist. Without this "Blue Machine" and the life in it, planetary habitability would be in jeopardy. Partha Dasgupta states that, "if life in the oceans were to be extinguished, the changes would be so enormous that life on land itself ceases for the vast majority of organismal lineages." 

The empire of plants

If the ocean is the womb, plants are the engine. They are the architects of the habitable Earth. We live on a planet where most biomass is made up of plants. Global plant biomass is around 450 gigatons of carbon, dwarfing the approximately 2 gigatons of animal biomass, making the plant kingdom the dominant kingdom on Earth, dwarfing the 0.1% of biomass that constitutes humanity.

Plants possess the miraculous ability to "eat light." Through photosynthesis, they capture solar energy and convert it into the chemical energy that fuels the entire food web. They are the reason we can breathe and the reason we can think. As Zoë Schlanger poignantly observes:

 “Every thought that has ever passed through your brain was made possible by plants”.

This is literal, not metaphorical: the glucose powering the neurons in your brain right now was manufactured out of thin air by a plant using photons from the sun. Likewise, for the oxygen that your brain craves. The Earth’s atmosphere consists of 21% oxygen. This was not always the case. It is so high thanks to plants. Plants use chlorophyll to capture solar energy, converting water and carbon dioxide into glucose for growth, and releasing oxygen as a byproduct.  

Furthermore, plants are the great regulators, sequestering carbon and maintaining the atmosphere’s composition. They function as the primary engines for capturing energy and regulating the atmosphere through the terrestrial and marine biospheres. Terrestrial plants sequester approximately 4.8 Gt of carbon every year.  In the oceans, phytoplankton and algae drive the biological carbon pump.  Photosynthesis promotes the growth of phytoplankton, which consumes carbon, effectively removing it from the upper ocean and allowing the water to absorb more carbon from the atmosphere. When these organisms die, they sink. Once the carbon sinks below 500 meters, it is considered sequestered. This process currently sequesters about a quarter of all carbon emitted annually.

The realisation that we live in the Kingdom of the Plants, on an ocean world, fundamentally decenters us, revealing that we are not the masters of a world we created, but recent and minor participants in a complex system built by and for many other forms of life - an integrated system, sometimes called Gaia, on which our survival entirely depends.

Bulldozing the ocean and plant kingdom

Despite living in a world built by the ocean and plants and being animated by their water, energy, and oxygen, we have constructed an economic system based on human exceptionalism. We often think that we are some purpose or outcome towards which "nature" has been steering us towards. We often treat the planet as a warehouse of infinite resources to be bulldozed for utility. Mainstream economics tend to assume that the ocean and plants are only valuable if they can provide a monetary product or service, moreover that the services and products provided by the ocean and plants are infinite, that they can easily be substituted for by capital formation and technology, and that there to serve the consumption and production needs of humans, of which it is assumed that the more is the better. 

Economists have historically failed to value these systems adequately, often arriving at conclusions that are nothing short of absurd. For example, the economist Colin Clark recommended, based on the logic of economic reasoning, that "depending on certain easily stated biological and economic conditions, extermination of the entire population may appear as the most attractive policy.” And the International Monetary Fund has infamously calculated the value of a great whale at $2 million. A World Bank study estimated that ecosystem collapse would reduce global GDP by a relatively small 2,3% annually by 2030. In the late 1990s, Robert Costanza and co-authors, in a much-quoted study, valued the ecosystem services provided by the planet at US$33 trillion. These attempts at valuation are cases of, as Partha Dasgupta called it,  “misplaced quantification”; if the biosphere collapses, there will be no one left to receive the trillions of dollars in supposed benefits.

Physicist Tom Murphy and co-authors provide a thought experiment of the terraforming of Mars to indicate the extent to which current economics far underestimates the economic value of ecosystem services when relating that "Images of a barren Mars from Perseverance remind us of what it would cost, monetarily, for humans to build such a system from scratch (i.e., starting with a sterile planet) -  assuming we had the intellectual standing and wherewithal to do so. The figure might well run into the quadrillions or quintillions of dollars, if not unimaginably more. Just how much value did humanity inherit in Earth’s abundant provision? Presumably, the amount absolutely dwarfs today’s trillion-dollar economic scales. Yet society continues to place essentially zero economic value on this foundation despite the fact that it took billions of years to produce.”

Given that economics undervalues plants and the ocean, and does not model these as a precondition for life on the planet, a global economy has emerged that is now bulldozing biodiversity in the ocean and on land. Extinction rates are currently around 1,000 times faster than natural background rates. Since 1970, there has been a ~50% reduction in plant biomass relative to pre-human times. The global economy’s demand for resources has reduced forest cover from 60 million to less than 40 million square kilometers. In 2024 alone, a record 6.7 million hectares of tropical rainforest were lost. Around 40% of plants are considered endangered. 

And the ocean is being over-commercialized by industrial fishing, which has been described  by Georg Monbiot as the "most destructive of all private industries." Roughly one-third of marine fish stocks are over-exploited, and marine populations have declined by 56% since 1970. Seafloor trawling is physically destroying deep-sea ecosystems and releasing carbon that took millennia to accumulate. Furthermore, new industries like deep-sea mining threaten to destroy species before they are even discovered. And on top of this, humans treat the ocean as a waste sink, burdening it with 8,000 megatonnes of plastic and creating noise pollution that disrupts marine life. Simultaneously, human carbon emissions are causing ocean acidification and warming, leading to the collapse of coral reefs- the "rainforests of the sea" - and the deoxygenation of the water.

Beyond sustainability

Facing the unfolding ecological crisis, the human solution is encapsulated by the concept "sustainability." But the very concept of sustainability may be a dangerous illusion that is preventing real change. The problem is that sustainability has been co-opted and redefined to mean sustaining economic growth with slightly less environmental damage. Even the recently popular notions of planetary boundaries and doughnut economics are deficient by maintaining the distinction between humans and nature - a distinction between human wants on the one hand, and the planet that creates "boundaries" on the other. It doesn't challenge the core assumption that the planet, the ocean, and the plants are a collection of resources for human use. Its worldview remains fundamentally human-centric, focused on tweaking our systems to ensure continued human convenience, consumption, and growth.

To move beyond being captives of a limited, anthropocentric, and ultimately failing concept, a necessary condition may be that sustainability makes place for the biocentric framework of Planetary Habitability. The point is that fixing a slow leak in a spaceship (sustainability) is insufficient when the ship’s entire life support system is collapsing due to a fundamental design flaw (anthropocentrism); instead, the focus must shift to ensuring the entire ship can support life (habitability), regardless of immediate human convenience. 

To read more, including what a move to embed economics in a framework of Planetary Habitability may entail, see my  IZA Discussion Paper: An economist’s ode to the forests and the sea.

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