Tag Archives: Earth system science

The Anthropocene is Not Formally a Geological Epoch  ̶  So, What is It?

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David P. Turner / April 3, 2024

A surprising outcome emerged from the March meeting of the Subcommission on Quaternary Stratigraphy (within the International Union of Geological Sciences).  The surprise came in the form of a vote regarding the official status of the Anthropocene concept, with a majority of the subcommission members voting against a proposal to identify the Anthropocene as a new geological epoch.

The term Anthropocene was originally inspired by the observation that the impacts of the human enterprise on Earth’s environment  ̶  notably a rise in the atmospheric CO2 concentration  ̶  have begun to rival those of the background geologic forces.  Since divisions of the geologic time scale are generally associated with major changes in the global environment, naming a new epoch was a reasonable suggestion.

The formal proposal to do so came from the multidisciplinary Anthropocene Working Group (AWG), which has deliberated on the issue for the last 14 years.  The AWG proposal specified that the Anthropocene be named a new epoch, with a beginning point in the early 1950s.  Its stratigraphic marker was to be a layer of chemical residues from post-World War II nuclear weapons testing. 

The Vote

The vote against designating the Anthropocene as a new Epoch was a surprise because the proposal had been made with a strong scientific foundation and had a lot of support.  The decision against the proposal was not because the Anthropocene is geologically insignificant, but rather because the Anthropocene concept is highly significant to many disciplines besides geology.  In the last 20 years, the concept has received widespread attention in both academia and popular media.  Indeed, the term has taken on a life of its own, a life outside the staid world of Quaternary Stratigraphy.

The term Anthropocene has come to signify a rupture in human history  ̶  the end of a time when the biophysical environment was mostly a background to the march of human progress.  The rupture is evident from a suite of global indicators, ranging from oil consumption to the rate of deforestation, that all began rising dramatically in the last 100 years.  The word Anthropocene now has broad cultural significance; it implies that humanity has acquired a new responsibility to self-regulate, or face its own demise from a self-induced inhospitable environment. 

The negative vote within the subcommission was also based on a more technical issue about whether, considering that humans have been altering the environment at many scales for many thousands of years, the beginning of the Anthropocene Epoch could be narrowed down to the early 1950s.

An alternative proposal, with considerable cross-disciplinary support, is to designate the Anthropocene a geologic “event”.  This term is used in the geosciences to reference a wide variety of Earth system changes or transformations.  Designating something as an event does not require the kind of formal approval process associated with designating an epoch.

The Scope of the Anthropocene Event

Despite this quasi-downgrade to Event status, the Anthropocene has really just begun and will ultimately have a massive impact on the Earth system.  The Anthropocene Event, as we will call it here, will eventually push the global mean temperature up 2-3 oC or more, a range associated with the early Pliocene Epoch 3-5 million years ago (Figure 1).  Because of human influences on the atmosphere, Earth may well miss its next scheduled glacial period (as prescribed by the Milankovitch solar forcings).  

The graphic is a time series plot going back 5 million years ago showing the trend in global mean temperature.

Figure 1.  The geologic record of global mean temperature, with projections to 2100.  The x-axis units differ by panel.  The graphic is adapted from work by Glen Fergus.

What is also quite extraordinary is that the Anthropocene Event is concurrent with the origin of a whole new Earth system sphere – the technosphere.  This term refers to the accumulation of human artifacts  ̶  including buildings, transportation networks, and communication infrastructure  ̶  that now cloaks the surface of the Earth.

From an Earth system science perspective, the parts of the Earth system are its spheres, i.e. the lithosphere, atmosphere, hydrosphere, cryosphere and biosphere interact with each other over geological time to determine the state and dynamics of the Earth system.

The biosphere (defined by geochemists as the sum of all life on Earth) is of particular interest here.  The biosphere did not exist early in Earth’s history, but after the origin of life and its proliferation around the planet, the impacts of the biosphere on Earth’s energy flow and chemical cycling became profound (e.g. the oxygenation of the atmosphere).

Now the technosphere, a product of human history, has joined the biosphere as an active force on the surface of the planet.  Like the biosphere, it has mass and uses energy to maintain itself and grow.  It has become a significant factor in the global biogeochemical cycles.  Unlike the biosphere, the technosphere has not been around long enough to become well integrated with the rest of the Earth system, e.g. it largely does not recycle its own waste. 

During the Anthropocene Event, the technosphere could be destroyed or self-destruct by various mechanisms, or could come into a stable state of sorts with the rest of the Earth system, in which case it might last quite a long while. 

The Role of the Anthropocene Event in Cultural Evolution

Transition to global sustainability will require the emergence and evolution of a global culture, i.e. a globally shared set of beliefs and practices.  The Anthropocene Event is a concept that can help anchor a robust integration of human history and Earth history.

Transdisciplinary investigations covering a wide range of issues associated with managing the human enterprise on Earth  ̶  including  aspects of the social sciences, humanities, and biophysical sciences  ̶  may hinge on having this shared reference point. 

The Right Call

In light of the need for broadly unifying concepts related to global environmental change, I think the geologists made the right call.  The Anthropocene has become a politically potent idea and deserves the widest possible attention in the domains of scholarship, education, entertainment, and advocacy.

This post was featured on the Millennium Alliance for Humanity and the Biosphere (MAHB) web site.

Positive Feedback Loops to Propel the Sustainability Transition

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David P. Turner / March 8, 2024

In the jargon of systems theory, a positive feedback means that a change in a system initiates other changes within the system that amplify the original change.

A clear example in the Earth system is the water vapor feedback:  as the atmosphere warms (e.g. from increasing CO2) it can hold more water vapor (mostly evaporated from the ocean), and since water vapor itself is a greenhouse gas, the atmosphere warms further (Figure 1).

A box and arrow diagram shows the steps in the water vapor and snow/ice albedo feedbacks to climate warming.

Figure 1. The water vapor (blue loop) and snow/ice albedo (red loop) feedbacks. Climate warming induced by anthropogenic CO2 emissions drives changes in the hydrosphere and cryosphere that amplify the warming. A plus sign means causes to increase and a minus sign mean causes to decrease. Image Credit: David Turner and Monica Whipple.  Figure appeared originally in the Technosphere Respiration Feedback blog post.

Positive feedbacks are generally considered destabilizing to a system, potentially pushing it into a new state.  Negative feedbacks aremore familiar, e.g. the furnace/thermostat cycle in home heating; they tend to stabilize a system.

The Earth system has significant negative feedbacks that have helped keep global mean temperature in a habitable range over its 4-billion-year existence.  However, these feedbacks (e.g. the rock weathering thermostat) operate at a geologic time scale, and are thus not going to save humanity from the vast geophysical experiment that we began by burning fossil fuels and boosting atmospheric concentrations of greenhouse gases.

We need something faster.  Hence, it is worth identifying and perhaps cultivating various positive feedback mechanisms that could support global sustainability.  Here, I’ll consider three varieties of positive feedback loops that might help us.

Type 1.  Psycho-social Positive Feedback Loops.

Humans have various cognitive biases, meaning our decisions are sometimes subject to unconscious tweaking.  These tweaking tendencies have genetic as well as experiential origins, and may or may not be helpful in any given decision.  Prestige bias, under which we are drawn to believe and emulate individuals who have achieved high status in our society, is an example. 

A cognitive bias that might help the spread of sustainability principles and practices is the conformity bias.  As the name suggests, we tend to adopt ideas and practices that are already embraced by a significant proportion, or the majority, of our society.  The positive feedback comes in because converts increase the proportion of the society that are believers, which strengthens the pressure on nonbelievers to conform.

Figure 2.  Conformity Bias Positive Feedback Loop.  Image Credit: David Turner and Monica Whipple.

The history of social norms and behaviors related to littering and paper recycling show evidence of conformity bias kicking in at some point.

Now that greater than 50% of Americans believe that climate change is for real, conformity bias may help enlarge the pool of believers, and hence the support for relevant policy changes. 

Type 2.  Technical-economic Positive Feedback Loops.

As new technologies become more widely adopted, the associated manufacturers begin to benefit from economies of scale, i.e. the marginal cost of production comes down as usage increases because larger production facilities are typically more efficient than smaller ones.  More efficient production means that the product can be offered at a lower price, and hence demand will likely increase.  This positive feedback loop can lead to rapid growth in product use.

An essential requirement for mitigating climate change will be conversion of the power sector from fossil fuel to renewable sources of energy.  This conversion is ongoing and is benefitting from economies of scale.  Installation of solar and wind power generators is expanding rapidly, in part because the economics are beginning to favor these sources over coal-fired plants.  The cost of installed solar panels and wind turbines has decreased over time because of economies of scale and rapid technical advances.  Hence, a virtuous cycle of more installations favors more decisions to go with renewables.

A second powerful technology-oriented positive feedback involves “network effects”.  Here, as a new technology becomes more widely utilized, its value to the user increases, and more users are recruited.  The spread of the telephone is the classic example. 

Figure 3.  Example of a Network Effect Positive Feedback Loop.  Image Credit: David Turner and Monica Whipple.

The network effect is readily applicable to the proliferation of electric vehicles (EVs).  The replacement of internal combustion engine powered vehicles with EVs is widely advocated to mitigate climate change.  This transition has started, and is fortunately accelerating because of positive feedbacks.  One feedback loop is that as more EVs enter the market, the economic incentives to build more charging stations has increased.  More charging stations makes it easier to take long trips, which reduces range anxiety and incentivizes drivers to purchase EVs rather that gas powered vehicles.

Type 3.  Socio-cultural Niche Construction Loops

Cultural evolution is the process by which the beliefs and practices of individuals and groups of various sizes change over time.  At the level of group selection, particular ideas and group practices may strengthen the group when faced with intergroup competition (e.g. intertribal warfare).

There are many group traits that are shaped by cultural group selection; for analytical purposes we can divide them into three types: sociological, technical, and ecological (Table 1, also below).  It is the constellation of these traits, including how they influence each other, that determines the success of a group.

Socio-cultural niche construction refers to the idea that human societies alter their physical environment (e.g. the vegetation, the energy infrastructure) in ways that reciprocally influence how the society is structured and functions.  Positive feedback loops among two or more of the group traits in Table 1 can result in rapid societal change.

If a group (e.g. a nation) invests (a sociological trait) in research and implementation of renewable energy technologies, the outcome may be a change in the mix of societal energy sources (a technical trait), which could result in cheaper and more reliable energy delivery to the society, which strengthens the society and encourages further investment in renewable energy sources.  The societal choice of energy source also influences the ecological trait of local air quality.  Improvement there would further strengthen the society and enhance group strength.

Figure 4.  Example of a Socio-cultural Niche Construction Positive Feedback Loop.  Image Credit: David Turner and Monica Whipple.

Conclusion

The various feedback loops reviewed here suggest that societal principles and policies are not simply top-down impositions on citizens.  Rather, they can be significantly strengthened or weakened by reciprocal interactions with features of the social, technological, and ecological environment.  To propel conformity bias regarding a particular value or technology, leaders and media can package it as a new social norm.  To propel sustainable technologies that benefit from economies of scale and network effects, societies can subsidize early stages of their development.  To foster revolutionary changes in technology (e.g. a renewable energy revolution), leaders must advocate for them based on the full range of their benefits to society.

These psychological and sociological considerations make the transdisciplinary aspects of Earth System Science ever more apparent.

Table 1. Examples of group traits that may interact to influence group selection.

Sociological Traits

Laws
Customs
Policies
Belief system (e.g. religion)
Type of political organization (e.g. tribe vs. nation state)
Type of military organization
Civic institutions

Technological Traits

Type of fuel for energy production
Form of transportation
Form of electronic communication

Ecological Traits

Local species composition
Local net primary production
Local air quality

More Blows to Humanity’s Self-image

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heliocentric universe
Cellarius’s chart (1661) illustrating a heliocentric model of the universe, as proposed by Nicolaus Copernicus.  Image Credit.

David P. Turner / October 2, 2022

Copernicus, Darwin, and Freud are credited with delivering major blows to humanity’s self-image. They didn’t do it on their own of course, but their ideas were notably illuminating.  Here, I revisit their insights and discuss two additional blows of that type rendered in more recent years.  Awareness of the human limitations implied by these blows may help save us from our present environmental predicament.

Copernicus (1473 -1543) established that – contrary to Church dogma – Earth rotated on its axis and revolved around the sun.  Humans could no longer maintain that we are living at the center of the universe.  The scientific discipline of astronomy has gone on to reveal how remarkably tiny this planet really is in the context of an immense universe.  Knowing that we live on a small planet points to biophysical limits on our current demands for natural resources.

Darwin (1809 – 1882) elucidated the theory of biological evolution, and the corresponding fact that Homo sapiens originated the same way every other animal species on this planet did – through natural processes.  We were no longer a special creation of an omnipotent, benevolent god who dictates our aspirations and values.  Ironically, though, humanity is coming to have a kind of dominion over the Earth even without the hand of god.

Freud (1856 – 1939) suggested that unconscious processes within our brains have a substantial influence on our thoughts and emotions.  He turned out to be wrong in many respects, but his primary insight had merit.  We are not even in full control of our own minds.  Contemporary cognitive science aims to understand (1) the function (adaptive significance) of specific mental processes, (2) the representations and algorithms by which those processes are implemented, and (3) the underlying neurobiological mechanisms.  Insights along those lines may help modify our destructive impulses.

The two recent blows to our self-image come from a biologist and an atmospheric chemist.

In the 1970s, Harvard professor E.O. Wilson (1929 – 2021) fostered the development of the new discipline of sociobiology – the study of animal social behavior.  He applied its concepts to Homo sapiens, as well as to ants (his favorite object of study).  What he asserted (albeit in the face of raging controversy) is that humans have significant genetic influences on our thinking and behavior.  Our capacity for altruism (self-sacrifice) and jealousy are notable example of traits which evolution has likely shaped.  As with the first three blows, this realization forces us to question our spontaneous motivations and actions (e.g. our acquisitiveness).

The fifth blow is truly aimed at the whole of humanity.  Around 2000, atmospheric chemist Paul Crutzen (1933 – 2021) helped consolidate a wide array of observations by Earth System Scientists concerning the baleful influences of humanity on the biosphere and the global environment.  He suggested that we have entered a new geologic epoch – the Anthropocene. 

In the scientific Anthropocene narrative, humanity has become the equivalent of a geologic force; we are now capable of significantly altering the global biogeochemical cycles.  This shocking realization and consequent shift in worldview have been characterized as the “second Copernican revolution”.

Unfortunately, we are altering the global environment in a way that may ultimately be self-destructive (e.g. by inducing rapid global climate change).  Our self-image must therefore include the conclusion that we are an existential threat to ourselves.

Recognition of the Anthropocene epoch places a new responsibility on each of us as individuals, and a new responsibility on our species as a whole, to begin managing ourselves – and to some degree begin managing the Earth system – in support of global sustainability.

The prescription for better integration of the human enterprise (the technosphere) with the Earth system requires that humanity become aware of itself as a social entity, having agency at the global scale, before it can learn to self-regulate and reintegrate with the Earth system.  Awareness of the five blows covered here introduces an element of humility to this project of understanding ourselves as a planetary phenomenon.

A Positive Narrative for the Anthropocene

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David P. Turner / July 16, 2020

Humans are story-telling animals.  Our brains are wired to assimilate information in terms of temporal sequences of significant events.  We are likewise cultural animals.  Within a society, we share images, words, rituals, and stories.  Indigenous societies often have myths about their origin and history.  Religious mythologies remain prevalent in contemporary societies.

The discipline of Earth System Science has revealed the necessity for a global society that can address emerging planetary scale environmental change issues – notably climate change.  A shared narrative about the relationship of humanity to the biosphere, and more broadly to the Earth system, is highly desirable in that context. 

The most prevalent narrative about humanity’s relationship to the Earth system emphasizes the growing magnitude of our deleterious impacts on the global environment (think ozone hole, climate change, biodiversity loss).  The future of humanity is then portrayed as more of the same, unless radical changes are made in fossil fuel emissions and natural resource management.

In the process of writing a book for use in Global Environmental Change courses, I developed an elaborated narrative for humanity − still based on an Earth system science perspective but somewhat more upbeat.  I used the designation Anthropocene Narrative to describe it because Earth system scientists have begun to broadly adopt the term Anthropocene to evoke humanity’s collective impact on the environment. 

There are of course many possible narratives evoked by the Anthropocene concept (e.g. the historical role of capitalism in degrading the environment), all worthy of study.  But for the purposes of integrating the wide range of material covered in global environmental change classes, I identified a six stage sequence in the relationship of humanity to the rest of the Earth system that serves to link geologic history with human history, and with a speculative vision of humanity’s future (Figure 1).  The stages are essentially chapters in the story of humanity’s origin, current challenges, and future.  The tone is more hopeful than dystopian because our emerging global society needs a positive model of the future.  

Figure 1.  An Earth system science inspired Anthropocene narrative with six stages.  Image credits below.

The chapters in this Anthropocene narrative are as follows.

Chapter 1.  The Pre-human Biosphere

The biosphere (i.e. the sum of all living organisms) self-organized relatively quickly after the coalescence of Earth as a planet.  It is fueled mostly by solar energy.  The biosphere drives the global biogeochemical cycles of carbon, nitrogen, and other elements essential to life, and plays a significant role in regulating Earth’s climate, as well as the chemistry of the atmosphere and oceans. The biosphere augments a key geochemical feedback in the Earth system (the rock weathering thermostat) that has helped keep the planet’s climate in the habitable range for 4 billion years.  By way of collisions with comets or asteroids, or because of its own internal dynamics, the Earth system occasionally reverts to conditions that are harsh for many life forms (i.e. mass extinction events).  Nevertheless, the biosphere has always recovered − by way of biological evolution − and a mammalian primate species recently evolved that is qualitatively different from any previous species. 

Figure 2.  The pre-human biosphere was a precondition for the biological evolution of humans.  Image Credit: NASA image by Robert Simmon and Reto Stöckli.

Chapter 2.  The Primal Separation

Nervous systems in animals have obvious adaptive significance in term of sensing the environment and coordinating behavior.  The brain of a human being appears to be a rather hypertrophied organ of the nervous system that has evolved in support of a capacity for language and self-awareness.  These capabilities are quite distinctive among animal species, and they set the stage for human conquest of the planet.  The most recent ice age receded about 12,000 year ago and a favorable Holocene climate supported the discovery and expansion of agriculture.  With agriculture, and gradual elaboration of toolmaking, humanity ceased waiting for Nature to provide it sustenance.  Rather, Nature became an object to be managed.  This change is captured in the Christian myth of Adam and Eve’s expulsion from the Garden of Eden (Figure 3).  They lived like all other animals in the biosphere until they became self-aware and began to consciously organize their environment.

Figure 3.  The story of Adam and Eve symbolizes the separation of early humans from the background natural world.  Image Credit: Adam and Eve expelled from Eden by an angel with a flaming sword. Line engraving by R. Sadeler after M. de Vos, 1583. Wellcome Trust.

Chapter 3.  The Build-out of the Technosphere

The next phase in this narrative is characterized by the gradual evolution and spread of technology.  An important driving force was likely cultural group selection, especially with respect to weapons technology and hierarchical social structure.  The ascent of the scientific worldview and the global establishment of the market system were key features.  Human population rose to the range of billions, and the technosphere began to cloak Earth (Figure 4).  The Industrial Revolution vastly increased the rate of energy flow and materials cycling by the human enterprise.  Telecommunications and transportation infrastructures expanded, and humanity began to get a sense of itself as a global entity.  Evidence that humans could locally overexploit natural resources (e.g. the runs of anadromous salmon in the Pacific Northwest U.S.) began to accumulate.

Figure 4.  The Earth at night based on satellite imagery displays the global distribution of technology dependent humans.  Image Credit: NASA/GSFC/Visualization Analysis Laboratory.

Chapter 4.  The Great Acceleration

Between World War II and the present, the global population grew from 2.5 billion to 7.8 billion people.  Scientific advances in the medical field reduced human mortality rates and technical advances in agriculture, forestry, and fish harvesting largely kept pace with the growing need for food and fiber.  The extent and density of the technosphere increased rapidly.  At the same time, we began to see evidence of technosphere impacts on the environment at the global scale – notably changes in atmospheric chemistry (Figure 5) and losses in global biodiversity.

Figure 5.  The impacts of the global human enterprise on various indicators of Earth system function take on an exponential trajectory after World War II.  Image Credit: Adapted from Steffen et al. 2015.

Chapter 5.  The Great Transition

This phase is just beginning.  Its dominant signal will be the bending of the exponentially rising curves for the Earth system and socio-economic indicators that define the Great Acceleration (Figure 5 above).  Global population will peak and decline, along with the atmospheric CO2 concentration.  Surviving the aftermath of the Great Acceleration with be challenging, but the Great Transition is envisioned to occur within the framework of a high technology infrastructure (Figure 6) and a healthy global economy.  To successfully accomplish this multigenerational task, humanity must begin to function as a global scale collective, capable of self-regulating.  Neither hyper-individualism nor populist tribal truth will get us there.  It will take psychologically mature global citizens, visionary political leaders, and new institutions for global governance.

Figure 6.  A critical feature of the Great Transition will be a renewable energy revolution.  Image Credit: Grunden Wind Farm

Chapter 6.  Equilibration

Human-induced global environmental change will continue for the foreseeable future.  The assumption for an Equilibration phase is that humanity will gain sufficient understanding of the Earth system – including the climate subsystem and the global biogeochemical cycles – and develop sufficiently advanced technology to begin using the technosphere and managing the biosphere to purposefully shape the biophysical environment from the scale of ecosystems and landscapes (Figure 7) to the scale of the entire planet.  Humanity is a part of the Earth system, meaning it must gain sufficient understanding of the social sciences to produce successive generations of global citizens who value environmental quality and will cooperate to manage and maintain it.  The challenges to education will be profound.

Figure 7.  An idealized landscape in which the biosphere and technosphere are sustainably integrated.  Image Credit: Paul Cézanne, Mont Sainte-Victoire, 1882–1885, Metropolitan Museum of Art.

As noted, this Anthropocene Narrative is largely from the perspective of Earth system science.  In the interests of coherence, humanity is viewed in aggregate form.  Humanities scholars reasonably argue that in the interests of understanding climate justice, “humanity” must be disaggregated (e.g. by geographic region or socioeconomic class).  This perspective helps highlight the disproportionate responsibility of the developed world for driving up concentrations of the greenhouse gases.  The aggregated and disaggregated perspectives on humanity are complementary; both are needed to understand and address global environmental change issues.

The Anthropocene Narrative developed here is broadly consistent with scientific observations and theories, which gives it a chance for wide acceptance.  The forward-looking part is admittedly aspirational; other more dire pathways are possible if not probable.  However, this narrative provides a solid rationale for building a global community of all human beings.  We are all faced with the challenge of living together on a crowded and rapidly changing planet.  The unambiguous arrival of global pandemics and climate change serve as compelling reminders of that fact.  A narrative of hope helps frame the process of waking up to the perils and possibilities of our times.

Recommended Video:  Welcome to the Anthropocene (~ 3 minutes)

This blog post was featured as a guest blog at the web site for The Millennium Alliance for Humanity and the Biosphere (MAHB).

https://mahb.stanford.edu/blog/a-positive-narrative-for-the-anthropocene/

Redesigning Technosphere Metabolism

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David P. Turner / April 7, 2020

When I was 20 years old, I picked up a paperback version of “Life and Energy” by Isaac Asimov.  This lucid scientific description of the chemical basis for life was very compelling, indeed, it helped inspire me to pursue a career in biology and ecology.  The time around its publication in the mid 1960s was quite exciting in biology because the fields of biochemistry and cell biology were in full flower; scientists had worked out the role of DNA in regulating cellular metabolism and had achieved a good understanding of the chemistry of photosynthesis and respiration.

Metabolism is broadly defined as the chemical machinery of life, the networked sequences of chemical reactions that build and maintain living matter.  Biologists think of living matter in terms of levels of organization – from cells, through organisms, communities, and the biosphere.

In Asimov’s days, the concept of metabolism was mostly applied at the level of the cell or organism.  However, ecologists in recent years have also applied it in the context of ecosystems and the Earth system as a whole.  Here I would like to consider metabolism at the scale of the technosphere. 

An ecosystem is a biogeochemical cycling entity, e.g. a pond or a patch of forest.  Like an organism, it requires a source of energy and it cycles nutrients such as nitrogen from one chemical form to another.  Strictly speaking, it is the biota (the set of all organisms) that in a sense has a metabolism.  Component organisms are classified into nutrient cycling guilds — most simply as producers (photosynthesizes), consumers, and decomposers. 

Ecosystem metabolism can be described in terms of energy fluxes, as well as the stocks and fluxes of key chemical elements. The element carbon plays a central role in ecosystem metabolism.  Its cycle extends from the atmosphere, through plants, to animals, and to decomposers, then back to the atmosphere.

The ecosystem carbon cycle. Image credit, Figure 4.1, The Green Marble, David Turner, 2018, Columbia University Press.

At the scale of the Earth system, we can likewise talk about biogeochemical cycling guilds and the associated biogeochemical cycles.  Biosphere metabolism is based on photosynthesis on the land and in the ocean.  Biosphere driven element fluxes help regulate the atmospheric chemistry, ocean chemistry, and global climate. 

Despite repeated intervals in the geologic record of Hothouse Earth and Icehouse Earth, the metabolism of the biosphere has run steadily for over 3 billion years.  

Quite recently in geologic time, a new sphere has emerged within the Earth system.  This “technosphere” is the cloak of technological devices and associated human constructs that has come to cover the Earth.  Like the biosphere, it has a metabolism.

We can think about technosphere metabolism in terms of three key factors: energy flows, materials cycling, and information processing. 

Humans are a part of the technosphere and mostly benefit from its metabolism.  The technosphere produces a vast array of goods and services that support billions of people.  However, the metabolism of the technosphere has begun to disrupt the formerly background global biogeochemical cycles.  It is effectively now a geological force and the changes it has precipitated are not necessarily favorable to advanced technological civilization.  Notably, the delivery of vast amounts of CO2 into the atmosphere is destabilizing the global climate.  A course correction in the evolution of the technosphere is required.

Energy flow into the technosphere is predominantly from the combustion of fossil fuels (coal, oil, and natural gas).  The problem is that the resulting source of carbon to the atmosphere is orders of magnitude greater than the background source from volcanoes.  The background geologic sink for CO2 by way of mineral formation in the ocean depths is likewise small.

Some of the technosphere-generated CO2 is sequestered by land plants and in the ocean, but most of it is accumulating in the atmosphere and causing the planet to rapidly warm.  The technosphere has begun to disrupt the entire Earth system. 

The solution, as is well known, is conversion of the global energy infrastructure to renewable energy sources (solar, wind, hydro, geothermal, biomass, and renewable natural gas).  That conversion is a daunting task but technically it can be accomplished.  The challenge is as much to economists and politicians as it is to engineers.

Converting from fossil fuel-based energy sources to renewable energy sources.
Image credit for power plant and wind turbines.

The materials cycling factor in technosphere metabolism is problematic because the technosphere as currently configured is not effective at recycling its components.  Unlike the biosphere, in which nutrients are cycled, there is often a one-way flow of key chemical elements in the technosphere − from a mineral phase, to a manufactured product, to a landfill.

The problem is that sources of the technosphere components are not infinite.  Building the next mega-mine to extract aluminum degrades the biosphere, a key component of the global life support system. 

Again, this is a largely solvable problem using advanced industrial practices.  We now speak of the emerging circular economy and of dematerializing the technosphere.  More comprehensive recycling may require more energy than dumping something into a landfill, but the potential for renewable energy sources is large.

The information processing aspect of technosphere metabolism refers to its regulatory framework.  Regulation requires information flow, a receiver of that information, and a mechanism to act on it.   

Homeostasis at the level of an organism is a clear case of regulation.  Homeostasis of internal chemistry, such as the blood sugar level in mammals, depends on factors including signals based on chemical concentrations, DNA-based algorithms to formulate a response, and organs that implement a response.

Ecosystems also self-regulate in a sense.  Disturbances (e.g. a forest fire) are followed by vigorous regrowth.  As a result, nutrients that are released in the process of the disturbance are captured and prevented from loss by leaching.  Damaged ecosystems, say that lack species specialized for the early successional environment, may deteriorate after a disturbance.

At the global scale, Earth system scientists have long debated the issue of planetary homeostasis.  James Lovelock famously hypothesized that indeed the Earth system (Gaia) is homeostatic with respect to conditions that favor life.  His idea inspired much research, and many significant biophysical feedbacks to global change have been identified.  The biosphere clearly exerts a strong influence on global climate by way of its impacts on greenhouse gas concentrations, specifically through its role as an amplifier in the rock weathering thermostat.

A new research question concerns the degree to which the technosphere is homeostatic.  Continued exponential growth in many of the indices of technosphere metabolism is suggestive of inadequate regulation.  To begin with, the regulatory capability of the technosphere is obviously diffuse and underdeveloped. 

Monitoring is a necessary component of effective management systems but the self-monitoring capability of the technosphere barely existed until quite recently.  An anomalous growth in the atmospheric CO2 concentration was measured in the late 1950s by atmospheric chemist Charles David Keeling.  This observation was the first clear signal of technosphere impact on the Earth system.

The Landsat series of satellite-borne sensors that monitor land cover change, e.g. deforestation and urbanization, was initially launched in 1972.  These satellites have since tracked the explosive spatial expansion of the technosphere.  A fleet of other satellites now monitors many other features of the global environment.

From synthesis efforts by agencies such as the United Nations Food and Agriculture Organization, we have good observational data on the growth of key technosphere variables like global population size and energy use. 

As far as a decision-making organ for the technosphere, one barely exists at present.  You might say that market-based capitalism is the organizing principle of the current technosphere.  Everyone wants cheap, plentiful energy (the demand side) and the global fossil fuel industry has managed to keep ramping up the supply.  Under the current neoliberal economic regime, the environmental costs are externalized, and no global oversight is imposed.

However, a new constraint has arisen.  The scientific community has built Earth system models to refine our understanding of Earth’s biophysical regulatory mechanisms and to simulate effects of various greenhouse gas concentration scenarios.  These simulations make clear that uncontrolled emissions of CO2 from fossil fuel combustion must cease or advanced technological civilization will be imperiled.  The 2015 Paris Agreement on Climate Change was a step towards reining in the technosphere, but the influence of that international agreement is not commensurate with the challenges of current global environmental change.

An essential feature of a needed paradigm shift regarding technosphere regulation is the development of a global environmental governance infrastructure.  The technosphere is having global scale impacts on the environment and must correspondingly be evaluated and regulated at the global scale.

A proposed World Environment Organization would not necessarily supersede the traditional nation-state-based architecture of global governance, but it could go a long way towards the required scale of integration needed to address global environmental change issues.

A revamped technosphere metabolism must be built over the course of the 21st Century in which the energy sources are renewable, the material flows are cyclic, and the regulatory framework is rooted in an understanding of limits.  Societies are more likely to change under extreme circumstances, and the economic shock of the 2020 coronavirus pandemic will certainly qualify as extreme.  As the global economy recovers, there will be significant opportunities to change technosphere metabolism.  Let’s hope they are not wasted.

The Icarus Scenario

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Jacob Peter Gowy’s The Flight of Icarus (1635–1637), courtesy of Prado Museum

David P. Turner / February 26, 2020

The future invades the present much more so in recent times than was the case in previous generations.  That’s because the global human enterprise (the technosphere) has initiated an era of global climate change – with potentially catastrophic impacts on future generations.  Thus, humans must now worry more about the future than might otherwise be the case.  While we still have time, humanity must alter course – we must redesign the technosphere.

Earth system scientists have a responsibility to discern coming changes to the Earth system as clearly as possible, and to evaluate potential mitigation strategies.  The time horizon of these scenarios for global change are commonly on the order of a century, or perhaps several centuries.  But examining scenarios that play out over hundreds to thousands of years is also necessary.

In the course of writing a book about global environmental change, I developed a rather dystopian long-timeframe Earth system scenario.  I call it the Icarus Scenario.  This story of Earth’s future is based on emerging Earth system science knowledge about past episodes of drastic global change over the course of geologic history.  On multiple occasions, tectonic movements have initiated periods of massive greenhouse gas emissions (sound familiar?) that led to strong global warming, followed by major alterations in ocean circulation and chemistry, as well as profound changes in the biosphere (including mass extinction events in some cases). 

Humanity might now be initiating the next iteration of that sequence, and the Icarus myth seems an appropriate referent.  Icarus was the figure from Greek mythology who, with his father, constructed wings of feathers and wax.  His father warned him not to fly too close to the sun for fear of melting the wax, but Icarus got carried away with the joy of flight.  He indeed flew too close to the sun, his wings disintegrated, and he crashed to his death on the ground.

A contemporary version of this myth might be manifest as the on-going build-out of the technosphere (with associated greenhouse gas emissions), warnings by scientists about the possibility of overheating the planet, continued fossil-fuel-based technosphere growth driven by an exuberant market economy, and global warming sufficient to push the Earth system through a series of tipping points that catastrophically warm the planet.  Recent geophysical observations suggest the risk of initiating that sequence is increasing.

We can’t of course know the future.  But there are several compelling reasons why we as a global collective should grapple with the Icarus Scenario.

It is likely that the wealthiest people in the world will be able to largely insulate themselves from impacts of climate change over the next generation or so.  Consequently, supporting societal investment in mitigation climate change (e.g. the Green New Deal) may not be a high priority.  However, if their legacy will amount to nothing in a somewhat longer perspective, they might pitch in more vigorously (thanks Jeff Bezos!).

The Icarus Scenario also strengthens the rationale for investing in climate change mitigation as soon as possible to reduce the possibility of passing a threshold and being unable to reverse the trajectory of the Earth system towards catastrophic warming.  The precautionary principle is more readily invoked as the magnitude of a threat increases, and the Icarus Scenario is the ultimate threat.

Being an inveterate optimist, I also formulated in my book a long-term Earth system scenario in which the technosphere builds a sustainable relationship with the rest of the Earth system.  My Noösphere Scenario (pronounced like noah-sphere) assumes cultural evolution towards a high technology global civilization that self-regulates to avoid overheating the planet and consuming the biosphere.  The root word nous refers to mind – Earth becomes a planet organized by collective thought.

Recommended Audio: Epilogue from Everest motion picture (Dario Marianelli)

Can Humanity be a “We”?

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David P. Turner / February 16, 2020

The peer-reviewed literature and the popular media today abound with concern about human-induced global environmental change.  Articles often argue that global scale problems require global scale solutions: humanity is causing the problem and “we” must rapidly implement solutions.  Environmental psychologists have found that people who sympathize with or identify with a group are energized to support its cause.  Can a majority of human beings identify with humanity in a way that motivates collective change towards global sustainability?      

Let’s consider several key constraining factors and unifying factors relevant to making humanity a “we” with respect to global environmental change.

Constraining Factors

Notable sociopolitical factors that impede global solidarity include the following.

1.  Climate Injustice among Nations 

In the process of their development, the most developed countries burned through a vast amount of fossil fuel and harvested a large proportion of their primary forests, hence causing most of the observed rise in atmospheric CO2 concentration.  But these countries are now asking the developing countries to share equally in the effort to curtail global fossil fuel emissions and deforestation to prevent further climate change.  At the same time, the impacts of climate change will tend to fall most heavily on the developing countries because of their lower capacity for adaptation.  The developing countries are pushing back on the basis of fairness, e.g. the outcome of the Kyoto protocol (albeit now obsolete) was that only the developed countries made commitments to reduce greenhouse gas emissions.

2. Rising Nationalism

Economists generally agree that economic globalization has spurred the global economy and helped lift hundreds of millions of people out of extreme poverty.  However, globalization of the labor market beginning around 1990 has also meant a large transfer of manufacturing from the developed to the developing world – and with it many jobs.

Likewise, immigration is helping millions of people a year find a better life by leaving behind political corruption, resource scarcity, and environmental disasters. 

Unfortunately, one effect of economic globalization and mass immigration has been political backlash within developed countries in the form of populism and nationalism.  Hypersensitivity to loss of national sovereignty is not conducive to international agreements to address global environmental change issues.

3.  Climate Science Skeptics

Although the global scientific community is broadly in consensus about the human causes of climate warming and other global environmental change problems, the rest of the world is more divided.  Most people in the U.S. accept that the global climate is changing, but only about half accept the scientific consensus that climate warming is caused by human actions.  Sources of skepticism about climate science include religious beliefs and vested interests. 

4.  Economic Inequality

Wealth inequality, both within nations and among them, is a pervasive feature of the global economy.  The rich end of the wealth distribution contributes to the vested interests problem as just noted.  At the poor end of the wealth distribution, the hierarchy of needs discourages concern for the environment; solidarity with the fight against climate change is a luxury when you are starving.

These four constraining factors are deeply rooted and are only the head of a list that would also include competition for limited natural resources and geopolitical conflict.  It is daunting to think about overcoming these obstacles to a “we” that includes all of humanity.  There are substantive ongoing research and applied efforts (not documented here) to overcome them, but in a general way let’s consider some equally significant factors that may help foster a global “we”.

Unifying Factors

The following rather disparate set of factors supply some hope for human unification under the banner of environmental concern.

1.  Our Genetic Heritage

Humans are social creatures.  Sociobiologists, such as Harvard Professor E.O. Wilson, have argued that many of our social impulses are genetically based.  We have an instinctual propensity to identify with a particular social group, and to draw a distinction between that group (us) and outsiders (them).  The average ingroup size during the hunter/gatherer phase of human evolution, which largely shaped our social instincts, is believed to have been about 30 people.  Remarkably, the size of the social group that humans identify with has vastly expanded over historical time − from the level of tribe, to the level of village, empire, and the modern nation-state.  Conceivably, that capacity could be extended to the global scale:  we might all eventually consider ourselves citizens of a planetary civilization.

The historical expansion of social group size was driven in part by military considerations  − the need to have a larger army than your neighbor.  Obviously, this rationale breaks down at the global scale, but a distinct possibility for inspiring global solidarity is the looming threat of global environmental change. 

Note that being a citizen of the world does not require rejecting one’s local or national culture.  Multiple sources of identity could include being an autonomous individual, being a member of various ingroups, and being a member of humanity in its entirety.

2.  The Advance of Earth System Science

A conspicuous general trend favorable to achieving a collective sense of responsibility for managing human impacts on the Earth system is growth in our scientific understanding of the Earth system.  From studies of the geologic record, scientists know that Earth’s climate has varied widely, from cool “snowball” Earth phases to relatively warm “hothouse” Earth phases.  Greenhouse gas concentrations have consistently been an important driver of global climate change, which gives scientists confidence that as greenhouse gas concentrations rise, Earth’s climate will warm. 

The scientific community also has expansive monitoring networks that reveal the exponentially rising curves for metrics such as the atmospheric CO2 concentration.  Earth system models that simulate Earth’s future show the dangers of Business-as-Usual scenarios of resource use, as well as the benefits of specific mitigation measures.  At the request of the United Nations, the global scientific community periodically assembles the most recent research about climate change, the prospects for mitigation (i.e. reduction of greenhouse gas concentrations), and the possibilities for adaptation. 

If improved understanding of the human environmental predicament can filter down to the global billions, we might hope for a strengthening support for collective action.

3.  The Evolution of the Technosphere

The technosphere is a new global-scale part of the Earth system.  It joins the pre-existing geosphere, atmosphere, hydrosphere, and biosphere.  However, just as the evolution of the biosphere was a major disturbance to the early Earth system, the evolution of the technosphere is proving to be disruptive to the contemporary Earth system.  

Around 2.3 billion years ago, cyanobacteria evolved that could split water molecules (H2O) in the process of photosynthesis.  The resulting oxygen (O2) began to accumulate in the atmosphere, radically changing atmospheric chemistry.  Oxygen was toxic to many existing life forms, but eventually micro-organisms capable of using oxygen in the process of respiration evolved, which in time led to the evolution of multicellular organisms (and eventually to us). 

In the case of technosphere evolution, a process that emits excessive amounts of CO2 (combustion of fossil fuels) has arisen, which is altering the global climate and ocean chemistry in a way than may be toxic to many existing life forms.  One potential solution is that the technosphere can further evolve (by way of cultural evolution) to subsist on renewable energy rather than combustion of fossil fuels, thus moderating its influence on the atmosphere, hydrosphere, and biosphere.

A characteristic feature of technosphere evolution is ever more elaborate means of transportation and telecommunications.  These capabilities – especially the on-going buildout of the Internet – allow for increased integration across the technosphere and tighter coupling of the technosphere with the rest of the Earth system.  Sharing results of environmental monitoring in its many dimensions over the telecommunications network can help with creating and maintaining sustainable natural resource management schemes.   

Through the popular news and social media, nearly everyone in the world can learn about events such as regional droughts and catastrophic forest fires that are associated with climate change.  It is thus becoming easier to have a common frame of reference among all humans about the state of the planet.

There is not yet anything like a global consciousness that coordinates across the whole technosphere.  However, the Internet is facilitating the emergence of a global brain type entity.  One indication of what the nascent global brain is thinking about is the relative frequencies of different search terms on Google.  Interestingly, in the algorithms that determine the response to search engine queries, a high frequency of previous usage for a relevant web site makes that site more likely to reach the top of the response list.  That process is evocative of learning, i.e. reinforcement through repetition.  Similarly, the Amygdala Project monitors Twitter hashtags.  They are classified according to emotional tone, and a running visual summation gives a sense of the collective emotional state (of the Twitterers).  Advances in artificial intelligence and quantum computing may soon improve the module in the global brain that simulates the future of the Earth system.

4.  The Expanding Domain of Human Moral Concern

In “The Slow Creation of Humanity”, psychologist Sam McFarland recounts the history of the human rights movement.  Writer H.G. Wells, humanitarian Eleanor Roosevelt, and others have helped develop the rationale and legal basis for including all human beings in our “circles of compassion” (Einstein’s term).  The concept of rights has now begun to be legally extended to Nature (in Ecuador) and specifically to Earth (in Bolivia).  Since protecting the rights of Earth (e.g. to be free of pollution) clearly requires that humans work collectively, we come to an incentive for global human solidarity.

Again, these four unifying factors are only the start of a list that might also include global improvements in education, as well as growth in the activities of global non-governmental environmental organizations. 

Conclusions

The field of Earth system science is producing an increasingly clear understanding of the human predicament with respect to global environmental change.  Scientist know what is happening to the global environment, what is likely to happen in the future under Business-as-Usual assumptions, and to some degree, what must change to avert an environmental catastrophe.

The process of changing the trajectory of the Earth system cannot be done unilaterally.  From the top down, an important step will be genesis or reform of the institutions of global governance – including institutions concerned with the political, economic, and environmental dimensions of governance.  This is a task for a generation of researchers, political leaders, and diplomats.  From the bottom up, individuals must be brought around as adults, and brought up as children, to adopt an identity that includes global citizenship and associated responsibilities for the global environment.  This is a task for a generation of educators, religious leaders, and business leaders.

If “we” human dwellers on Earth don’t gain a collective identity and begin to better manage the course of technosphere evolution, then we may no longer thrive on this planet.

Recommended Audio/Video, Mother Earth, Neil Young

Growth of the Technosphere

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David P. Turner / January 28, 2020

The growth of the technosphere is changing the Earth system, pushing it towards a state that may be inimical to future human civilization [1].  As technosphere capital − e.g. in the form of buildings, machines, and electronic devices – is increasing, biosphere capital −in the form of wild organisms and intact ecosystems − is decreasing [2].

Figure 1.  Decline in freshwater, marine and terrestrial populations of vertebrates.  Adapted from Ripple et al. 2015 [3].

The growth of the technosphere has tremendous momentum and we must ask if it can be shaped and regulated into something that is sustainable, i.e. able to co-exist with the rest of the Earth system over the long term.

Figure 2.  Earth system indicator trends 1750-2010.  Adapted from Steffen et al. 2015 [4].

Why is the technosphere growing so vigorously?  Let’s consider three quite different factors. 

1.  The most general driver of technosphere growth is what systems ecologist Howard Odum called the “maximum power principle”.  It states: “During self-organization, system designs develop and prevail that maximize power intake, energy transformation, and those uses that reinforce production and efficiency” [5].   Self-organization is a widely observed phenomenon, extending from the funnel of water formed in a draining bathtub, to inorganic chemical reactions that create arresting geometric designs, to giant termite mounds, and indeed, to cities [6].  Given Earth’s vast reservoirs of fossil fuel energy, and a selection regime that rewards growth, the technosphere will indeed tend to increase energy consumption, matter throughput, and complexity. 

2.  Underlying much of the momentum of technosphere growth is the global market economy.  Capitalism is essentially the operating system of the technosphere.  Corporations, the state, and workers are compelled to expand the economy and hence the technosphere [7]. 

The market economy rewards increasing efficiencies in production (to reduce costs) and often the route to greater efficiently and greater economies of scale is by investment in technology.  Technical progress is now the expected norm and investments in research and development are a part of corporate culture and national agendas.  Economists refer to the “treadmill of production” in which “competition, profitability, and the quest for market share has contributed to an acceleration of human impact on the environment” [8].  Economic globalization has geographically extended the market economy to the whole world.

3.  Historically, war has been one of the biggest drivers of technological expansion.  In the Parable of the Tribes, historian Andrew Schmookler describes the sustained pressure on societies to conquer or be conquered [9].  Technology advances certainly help in winning wars and national governments invest heavily in research and application of technologies for war.  The Internet began with U.S. Defense Department funding to build a communications infrastructure that was hardened against nuclear attack.

Humanity has of course benefited broadly as the technosphere expanded.  Billions of people now have standards of living rivaling those of royalty a few hundred years ago.  The proportion of the global population living in poverty continues to decline.

But even before the use of the term technosphere, scientists and philosophers had begun to question whether technology was always a benevolent force.  The concept of “autonomous technology” suggests that the growth and elaboration of technology can escape human control [10, 11].  The possibilities for a nuclear holocaust or a greenhouse gas driven climate change catastrophe are indicative of technology-mediated global threats. 

What can be done?

The maximum power principle does promote energy throughput, but there is plenty of scope for insuring that technosphere energy prioritizes renewable energy.  Carbon taxes may be the simplest approach to rapidly driving down fossil fuel combustion.  Comprehensive recycling, based on a circular economy, will help constrain the mass throughput of the technosphere.  Finishing the global demographic transition [12] will reduce future demand for natural resources.

Capitalism will not go away but could undergo a Reformation.  That means more corporate responsibility, better governmental oversight of corporate behavior, and increased attention by consumer to the environmental footprint of their consumption.

The global incidence of physical war is decreasing, which will help slow the growth of the technosphere.  Wars are often based on the threat of an enemy, but humanity may become more unified based on the common threat of global environmental change.  The Paris Accord is suggestive of the possibilities.

Implications

The trajectory of the technosphere is towards limitless growth.  However, we live on a planet – there are indeed limits to the natural resources upon which the technosphere depends.  Humans are only a part of the technosphere, thus cannot truly control it (13).  But they can certainly shape it .  Likewise, the technosphere is only part of the Earth system, thus cannot fully control the Earth system: quite possibly, the Earth system will respond to the environmental impacts of the technosphere with changes that suppress the technosphere and associated human welfare.  Improved understanding of technosphere growth in the context of the rest of the Earth system is clearly warranted.

1.  Steffen, W., et al., Trajectories of the Earth System in the Anthropocene. Proceedings of the National Academy of Sciences of the United States of America, 2018. 115(33): p. 8252-8259.

2.  Diaz, S., et al., Pervasive human-driven decline of life on Earth points to the need for transformative change. Science, 2019. 366(6471): p. 1327-+.

3.  Ripple, W.J., et al., World Scientists’ Warning to Humanity: A Second Notice. Bioscience, 2017. 67(12): p. 1026-1028.

4.  Steffen, W., et al., The trajectory of the Anthropocene: The Great Acceleration. The Anthropocene Review, 2015. 2: p. 81-98.

5.  Odum, H.T., Self-Organization and Maximum Empower, in Maximum Power: The Ideas and Applications of H.T. Odum. 1995, Colorado University Press: Boulder CO.  See Hall review.

6.  Prigogine, I. and I. Stengers, Order out of Chaos. 1984: Bantam.

7.  Curran, D., The Treadmill of Production and the Positional Economy of Consumption. Canadian Review of Sociology-Revue Canadienne De Sociologie, 2017. 54(1): p. 28-47.

8.  Hooks, G. and C.L. Smith, Treadmills of production and destruction – Threats to the environment posed by militarism. Organization & Environment, 2005. 18(1): p. 19-37.

9.  Schmookler, A.B., The Parable of the Tribes: The Problem of Power in Social Evolution, Second Edition 1994: Suny Press. 426.

10.  Winner, L., Autonomous Technology: Technics-out-of-Control as a Theme of Political Thought. 1978: The M.I.T. Press. 402.

11.  Kelly, K., Out of Control: The New Biology of Machines, Social Systems, & the Economic World. 1995: Basic Books.

12.  Bongaarts, J., Human population growth and the demographic transition. Philosophical Transactions of the Royal Society B-Biological Sciences, 2009. 364(1532): p. 2985-2990.

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

The Teleological Feedback

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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

Joni Mitchell, They Paved Paradise

Discovery of the Technosphere

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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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