The Second Revival of Gaia

January 11, 2020/David P. Turner

Gaia was originally a figure from Greek mythology: the mother goddess who gave birth to the sky, the mountains, and the sea.  Gaia was adopted by the Romans when they conquered the Mediterranean basin, but her myth was largely abandoned with the ascendency of Christianity by the third century CE.

The first revival of Gaia was a product of the nascent Earth system science community in the 1970s.  Atmospheric chemist James Lovelock was impressed by the finding of geologists that life had persisted on Earth for over 3 billion years despite a 25% increase in the strength of solar radiation (associated with an aging sun), and numerous catastrophic collisions with asteroids.  He also understood that the chemistry of the atmosphere − which provides oxygen for animal respiration, protection from toxic solar UV-B radiation, and influences the global climate − was maintained by the metabolism of the biosphere. 

These observations led him to suggest that the Earth as a whole was in a sense homeostatic, it was able to maintain certain life enhancing properties in the face of significant perturbations.    

In casting around for a name to give this organism-like version of the planet, he was inspired by author William Golding to revive the term Gaia.  Lovelock and microbiologist Lynn Margulis went on to write many influential peer-reviewed papers, and later books, on Gaia.

By the 1990s, the question of what regulated the functioning of the Earth system had become of more than academic interest.  Earth system scientists had observed that the Earth system was changing and begun to worry about possible impacts of those changes on the human enterprise.  Concentrations of greenhouse gases were rising, stratospheric ozone was declining, and a wave of extinctions was sweeping the planet. 

Geoscientists were initially intrigued by the Gaia Hypothesis about planetary homeostasis, hoping perhaps that Gaian homeostasis might save us from ourselves.  But by around 2000 they had largely rejected Gaia as an entity.  Many of the feedbacks in the Earth system (see my Teleological Feedback blog) were positive (amplifying climate change) rather than negative (damping), hence not contributing to homeostasis.

The second revival of Gaia came predominantly from scholars in the humanities.  Historians typically begin human history about 10,000 years ago when humans adopted an agricultural way of life.  However, the discovery that humans have recently begun to alter the global environment on a geologic scale changes everything (as activist Naomi Klein says).  The Earth system is no longer a benevolent background state that will provide a growing humanity with unlimited resources.  Earth has a Gaian history that is now imposed upon by human history.  The new field of Big History aims to juxtapose the geologic and anthropocentric time frames.

Historians needed a term to evoke an Earth system that in a sense has its own agency, and scholars like science historian Bruno Latour and philosopher Isabelle Stengers settled on Gaia.  They emphasized Gaia not as a nurturing mother, but rather a force that will smack humanity down if the current trajectory of global environmental change continues.

In a recent hybrid interpretation, geoscientist Tim Lenton and humanities scholar Bruno Latour have dubbed the newly revived Gaia as Gaia 2.0.  This version refers to an Earth system on which a sentient species has evolved and begun to alter the planet but has collectively taken on the project of developing an advanced technological civilization (a technosphere) that will live on the planet sustainably.  That means comprehensive renewable energy, nearly closed material cycling, conservation of biodiversity to support the background metabolism of Gaia 1.0, implementation of multiple strategies to moderate climate change, and forms of governance that facilitate self-regulation at multiple scales.

Gaia 2.0 is the combination of the pre-human Gaian Earth system and the recently emergent technosphere.

The Teleological Feedback

January 6, 2020/David P. Turner

Earth system scientists commonly refer to feedbacks in the climate system. 

A feedback loop within a system means that a change in one part or component of the system induces a change in another component that either amplifies (positive feedback) or dampens (negative feedback) the initial change. 

The classic positive feedback related to global climate change and the Earth system is that warming of the global climate caused by increasing greenhouse gas concentrations in the atmosphere results in reduction in snow cover and sea ice, which causes less reflectance of solar radiation, and hence more absorption of solar radiation by Earth’s surface, and more warming.  A potential negative feedback is if warming increases evaporation, which causes more clouds, which reflect more solar radiation, and hence cool the climate.  Most of the feedbacks in the climate system are positive.

By burning fossil fuels and pushing up the atmospheric CO2 concentration, humanity is unintentionally warming the global climate and inducing multiple climate system feedbacks.

A big question is whether humanity can collectively begin to purposefully impact the Earth system in the form of a negative feedback to climate change, i.e. begin to slow down the rise in greenhouse gas concentrations and even begin to draw down those concentrations.  This willful action would be a teleological feedback to our unintended warming of the Earth system by way of greenhouse gas emissions.

Teleological feedback. The segmented line indicates the potential for a deliberate societal influence on the Earth system.

A disturbing paradox about current climate change is that by increasing the atmospheric CO2 concentration, humanity has shown that we are the equivalent of a geological force.  But humanity thus far is not organized enough to purposefully shape the Earth system. 

What we don’t have is much political will to reduce greenhouse gas emissions, nor the right international institutions to manage a global scale response. 

Political will comes from lots of sources, but maybe the most likely source is that as more and more people experience extreme weather events, sea level rise, and the other impacts of climate change, they will support mitigation efforts (e.g. a carbon tax).  Australia in 2020 appears to be a test case for this proposition.

Also, we might hope for political leaders who understand the situation and are committed to doing something about it.

Regarding global environmental governance, the size and strength of relevant international institutions are incommensurate with the challenge of global environmental change.  At the very least, a stronger United Nations Environmental Program or a new U.N. World Environmental Organization is needed.

Recommended Reading

Lenton, T. 2016. Earth System Science: A very short introduction. Oxford University Press.

Recommended Audio/Video

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Discovery of the Technosphere

Earth System Science Discovery of the Technosphere

January 5, 2020/David P. Turner

The field of Earth System Science is a relatively young and is still working out how best to characterize Earth’s parts.  A key difficulty is with including the human dimension in a comprehensive description of the contemporary Earth system.  Earth scientists like to think in terms of the Earthly spheres and their interactions, e.g. the geosphere, atmosphere, hydrosphere, and biosphere.  By way of its industrial might, the global human enterprise recently has begun to exert an influence on the Earth system that is the equivalent to one of these spheres – effectively we have become a “geologic force”.  One proposal for characterizing this newly evolved global scale presence is to call it the “technosphere”.

To gain an appreciation for the meaning of technosphere, it helps to draw an analogy to the term biosphere.  We consider the biosphere to consist of all life on Earth.  It lives on energy, mostly in the form of solar radiation that is converted to biomass by photosynthesis, and it has a throughput or cycling of mass, mostly in the form of carbon and essential nutrients.

The Earth system existed before the origin of life and the evolution of the biosphere.  But once in place, the biosphere began exerting a strong influence on the chemistry of the atmosphere and the ocean, as well as on the global climate. 

Likewise, the technosphere is a globe-girdling network of artifacts −including all machines, buildings, and electronic devices – that lives on energy, mostly derived from fossil fuels, and has a throughput of mass (food, fiber, minerals).  The technosphere is growing rather irrepressibly, and like the biosphere before it, has begun to alter the global climate.

In a systems-oriented worldview, we try to differentiate parts and wholes, and to understand their relationship.  Generally, a part does not control the whole.  Thus, a critical feature of the technosphere is that humans are only a part of it, and correspondingly humanity cannot fully control it.  The technosphere is said to have agency, its own agenda.  It thrives on ever greater flows of energy and mass, which is not surprising when you realize that capitalism is its operating system.

Now that Earth system science has “discovered” the technosphere, we can study its structure, properties, dynamics, and how it interacts with the rest of the Earth system.  An awareness that we serve the technosphere as much as it serves us may help us redesign and rebuild it in a way that makes a human-occupied Earth system more sustainable.

Recommended Reading

Earth’s ‘technosphere’ now weighs 30 trillion tons

Zalasiewicz, J., et al. 2017. Scale and diversity of the physical technosphere: A geological perspective. Anthropocene Review. 4:9-22.

Will Steffen , Katherine Richardson, Johan Rockström, Hans Joachim Schellnhuber, Opha Pauline Dube, Sébastien Dutreuil, Timothy M. Lenton and Jane Lubchenco. 2020. The emergence and evolution of Earth System Science. Nature Reviews, Earth and Environment, January 2020).

Haff, P. 2014. Humans and technology in the Anthropocene: Six rules. Anthropocene Review. 1:126-136.

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