Given the vast amount of order in the universe, can humans reasonably hope to add a new increment of order in the form of a sustainable, high-technology, global civilization?
On the plus side, the universe is said to be order-friendly. Complexity is a rough measure of order, and we can observe that from its Big Bang origin to the present, the universe displays a gradual build-up of complexity. Systems theorist Stuart Kaufmann says that we are “at home in the universe” and he emphasized the widespread occurrence of self-organization (Figure 1). From atoms to molecules, to living cells, to multicellular organisms, to societies, to nation states – why not onward to a sustainable planetary civilization?
Figure 1. The Belousov-Zhabotinsky Reaction. This mixture of chemicals generates geometric forms (order) that oscillate until chemical equilibrium is reached.
Whether the universe is order-friendly or not is of course not strictly a scientific question, but scientists do aspire to explain the origins and elaboration of order. Broadly speaking, they refer to the process of cosmic evolution with its components of physical evolution, biological evolution, and cultural evolution. Cosmic evolution is a unifying scientific narrative now studied by the discipline of Big History; it covers the temporal sequence from Big Bang to the present, emphasizing the role of energy transformations in the buildup of complexity.
Physical evolution of the universe consists of the emergence of a series of physical/chemical processes powered by gravity. Formation of the higher atomic weight elements by way of fusion reactions in successive generations of stars is a particularly important aspect of physical evolution because it sets the stage for the inorganic and organic chemistry necessary for a new form of order – life.
Biological evolution on Earth began with single-celled organisms, and by way of genetic variation and natural selection, led to the vast array of microbes and multi-cellular organisms now extant. Each creature is understood as a “dissipative structure”, which must consume energy of some kind to maintain itself and reproduce. Biological evolution produced increments of order – such as multicellularity – because each step allows for new capabilities and specializations that help the associated organisms prevail in competition for resources.
Scientists are just beginning to understand how biological evolution favors cooperation among different types of organisms at higher levels of organization. Ecosystems, which are characterized by energy flows and nutrient cycling, depend on feedback relationships among different types of organism (e.g. producers, consumers, decomposers). The biosphere (i.e. the sum of all organisms) is itself a dissipative structure fueled by solar energy. Biosphere metabolism participates in the regulation of Earth’s climate (e.g. by its influence of the concentration of greenhouse gases in the atmosphere), thus making the planet as a whole an elaborate system, now studied by the discipline of Earth System Science.
Cultural evolution introduces the possibility of order in the form of human societies and their associated artifacts. It depends on the capacity for language and social learning, and helps account for the tremendous success of Homo sapiens on this planet. As with variation and selection of genes in biological evolution, there must be variation and selection of memes in the course of cultural evolution. In the process of cultural evolution, we share information, participate in the creation of new information, and establish the reservoirs of information maintained by our societies.
The inventiveness of the human species has recently produced a new component of the Earth system – the technosphere. This summation of all human artifacts and associated processes rises to the level of a sphere in the Earth system because it has become the equivalent of a geologic force, e.g. powerful enough to drive global climate change.
Unfortunately, the technosphere is rather unconstrained, and in a sense its growth is consuming the biosphere upon which it depends (e.g. tropical rain forest destruction). Technosphere order (or capital) is increasing at the expense of biosphere order. The solution requires better integration within the technosphere, and between the technosphere and the other components of the Earth system – essentially a more ordered Earth system.
How might the technosphere mature into something more sustainable? One model for the addition of order to a system is termed a metasystem transition. I have discussed this concept elsewhere, but briefly, it refers to the aggregation of what were autonomous systems into a greater whole, e.g. the evolution of single-celled organisms into multicellular organisms, or the historical joining of multiple nations to form the European Union.
In the case of a global civilization, the needed metasystem transition would constitute cooperation among nation states and civil society organizations to reform or build new institutions of global governance, specifically in the areas of environment, trade, and geopolitics. Historically, the drivers of ever larger human associations have included 1) the advantages of large alliances in war, and 2) a sense of community associated with sharing a religious belief system. But perhaps in the future we might look towards planetary citizenship. Clear benefits to global cooperation would accrue in the form of a capacity to manage global scale threats like climate change.
Living in an order-friendly universe allows us to imagine the possibility of global sustainability. However, the next increment of order-building on this planet will require humans and humanity to take on a new level of responsibility.
Biological evolution gave us the capacity for consciousness and now we must use guided cultural evolution to devise and implement a pathway to global sustainability. Besides self-preservation, the motivation to do so has a moral dimension in terms of 1) minimizing the suffering of relatively poor people who have had little to do with causing global environmental change but are disproportionately vulnerable to it, 2) insuring future generations do not suffer catastrophically because of a deteriorating global environment caused by previous generations, and 3) an aesthetic appreciation or love (biophilia) for the beauty of nature and natural processes.
Our brains, with their capacity for abstract thought, are the product of biological evolution. They were “designed” to help a bipedal species of hunter-gatherers survive in a demanding biophysical and social environment. Hence, they don’t necessarily equip us to understand how and why the universe is order-friendly. But we can see the pattern of increasing complexity in the history of the universe, and aspire to move it forward one more step – to the level of a planetary civilization.
The technosphere is a component of the contemporary Earth system. Like the biosphere ̶ also an Earth system component ̶ the technosphere has a mass, requires a steady input of materials, and utilizes a throughput of energy.
Technosphere mass is composed of all human-made objects, including the mass of buildings, transportation networks, and communication infrastructure. That mass has built up over centuries, and is still accumulating at the rate of 3-5% per year.
The material inputs to the technosphere (besides fossil fuels) include food, water, wood, and minerals. These inputs are derived from the geosphere, hydrosphere, and biosphere ̶ often with destructive consequences. Upward trends in consumption of these inputs are associated with an upward trend in global Gross Domestic Product of about 3% per year.
The energy that drives technosphere metabolism comes mostly from fossil fuels (80%). Global fossil fuel consumption was increasing at a rate of about 5% per year (2009 – 2019) until the recent dip associated with the Covid-19 pandemic.
Earth system scientists have estimated both current technosphere mass (in use) and the current biosphere mass (i.e. including all microbes and multicellular organisms). Coincidentally, those numbers are of approximately the same magnitude (about 1018 g). However, technosphere mass is increasing substantially each year, while the multi-century trend in biosphere mass and diversity is towards a diminished and depauperate state. The technosphere is essentially now growing at the expense of the biosphere.
There are a few cases at the national scale where peak technosphere mass has been reached, albeit not specifically by design. In Japan, the number of automobiles is close to its peak and the length of pipelines and high-speed rail are not increasing. Ninety-two percent of the population is urban. Total energy use is declining. These trends can be traced to a high level of development and a declining population.
A low birth rate and a low level of immigration account for the decreasing population. As a case study, Japan points to the role of population size in stabilization of technosphere mass. Per capita technosphere mass is relatively high, but is not rising because the country is already highly developed. Hence, technosphere mass at the national scale has likely peaked. By 2050, population is projected to decline about 25% from its peak, which may allow for a decrease in national technosphere mass.
China is an interesting case at the other extreme of technosphere mass dynamics, with vast on-going growth of its technosphere mass. Despite a low birth rate, China’s population is still growing (slowly). More importantly, per capita wealth is increasing. Consequently, the number of people owning modern housing and an automobile is rising rapidly. The government is also making huge investments in infrastructure – notably in power plants and high-speed rail.
Humans do sometimes place limits on technosphere mass expansion ̶ as in the urban growth boundaries around cites in the state of Oregon (USA), and in areas of land and ocean that are in a protected status (e.g. wilderness areas in the U.S.). Idealized prescriptions for future land use include 30 X 30 and 50 X 50. These values refer to 30 percent of Earth’s surface dedicated to biosphere conservation by 2030, and 50% by 2050. Seventeen percent of land and ten percent of ocean are in a protected status at present.
These conservation goals are consistent with the strong global trend towards urbanization. Over half of humanity now lives in an urban setting, a proportion that is projected to rise to 66% by 2050. The key benefits of urbanization with respect to technosphere mass are that 1) it potentially frees up rural land for inclusion in biosphere protection zones, 2) the per capita technosphere mass of urban dwellers is less than that of equally wealthy rural dwellers (e.g. living in multiple unit buildings as opposed to living in dispersed separate building, and using public transportation rather than everyone owning an automobile), and 3) birth rates decline as people urbanize, which speeds the global demographic transition.
Peak technosphere mass will occur sometime after peak global population. That assumes global per capita technosphere mass will also peak eventually, which brings up the fraught issue of wealth inequality. Individual wealth is equivalent in some ways to individual technosphere mass (e.g. owning a yacht vs. owing a row boat). Given that there are biophysical limits to human demands on the Earth system, the nearly 8 billion people on the planet cannot all live like billionaires. From a humanist perspective, a wealth distribution that brings standards of living for everyone up to a modest level is desirable. That worthy principle is the guiding light for significant philanthropic efforts and should figure into policies related to taxation of income and wealth. Whether to explicitly attempt to reduce the ecological footprint of the wealthy is a related, and highly contested, question.
Humans already appropriate around 25% of terrestrial net primary production, and divert 54% of available fresh water flows. Mining geosphere minerals for input to the technosphere covers approximately 57,000 km2 globally.
The concept of the Great Acceleration captures the problem of exponentially rising technosphere demands on the Earth system. It refers to the period since 1950 during which many metrics of human impact on the global environment have risen sharply (Figure 1). Obviously, those trends cannot continue. Humanity must bend those usage curves and redesign the technosphere to maintain itself sustainably.
Figure 1. The Great Acceleration refers to the period after 1950 when impacts of the technosphere on the global environment grew rapidly. Image Credit: Adapted from Welcome to the Anthropocene.
Some metrics, like wild fish consumption, have already peaked but that is because the resource itself has been degraded. Future increases in fish consumption will have to come from cultured sources.
Many rivers around the world are already fully utilized (and then some), e.g. the Colorado River Basin in Southwestern United States. Policies like tearing out lawns in Las Vegas to save water portend the future.
Global wood consumption increases several percent per year and is projected to continue doing so for decades. Much of current industrial roundwood production is from natural forests, sometimes in association with deforestation. Forest sector models suggest that high yield plantations in the tropical zone could supply most of the projected global demand for industrial wood, thus reducing pressure on natural forests.
Resource use efficiency can be increased by extending product lifetimes (e.g. automobiles), boosting rates of recycling (e.g. paper), and improvement in design (e.g. more efficient solar panels). Again, these changes must be made along with the stabilization of population if we are to end continuing growth of technosphere demand for natural resources.
In 2021, fossil fuel emissions roared back to about the level of 2019. Emissions in 2022 will likely be impacted significantly by the war in Ukraine, possibly reducing global emissions since moves to avoid purchasing Russian gas, oil, and coal are driving up prices for fossil fuels. Certainly, there is increased political support in the EU and elsewhere for rapid transition from fossil fuels to renewable energy sources. Technological constraints will slow the pace of that conversion, and emissions will continue to increase in many countries outside the EU (especially China and India). Thus, the actual peak year for global fossil fuel emissions is uncertain.
The faster that fossil fuel-based energy is replaced by renewable energy sources, the better chance of avoiding a climate change catastrophe. Multiple policy rationales, beside reducing carbon dioxide emissions, support the goal of a global renewable energy revolution.
Note that total energy consumption need not decline within the context of global sustainability if the energy sources are renewable. Projected peak global energy use – with accounting for increasing efficiency, population growth, and the curing cases of energy poverty – is on the order of current global energy use.
The sprawling mass of the technosphere, its demands on natural resources, and its flood of chemicals and solid waste into the global environment, have begun to diminish the biosphere and threaten human welfare on a massive scale. Humanity must begin to work as a collective to redesign technosphere metabolism such that it conforms to the biophysical limits of the Earth system.
The threat of global climate change points to the dire need for a renewable energy revolution in which energy from combustion of fossil fuels (coal, oil, natural gas) is rapidly displaced by energy from renewable sources (wind, solar, geothermal, hydro). Research by engineers and economists attests to the feasibility of building a global energy infrastructure that runs on renewable energy. However, forward looking policies must be designed and strong political will must be generated.
In a heavily politicized environment such as Washington D.C., policies are much more likely to get implemented when they are supported for more than one reason. The underlying mechanism is that with powerful forces aligned for and against any given policy proposal, several constituencies ̶ each supporting a desired policy for a different reason ̶ must coalesce to overcome opposition.
Clearly, the strongest rationale for a global renewable energy revolution is to reduce greenhouse gas emissions and mitigate climate change. But here are six additional rationales that should motivate leaders and legislators to support renewable energy policies.
1. Geopolitical strategy. The Russian invasion of Ukraine has thrown a spotlight on the vulnerability of nations to energy blackmail. Domestic production of renewable energy reduces dependency on imported fossil fuels and gives a nation greater flexibility in foreign policy. Many countries in the European Union are now ramping up renewable energy production in the face of threatened cut-off of fossil fuels from Russia.
2. The cost of renewable energy is decreasing. Renewable energy is already cheaper than fossil fuel energy in some cases, and technological advances in generation, storage, and distribution will continue to drive down costs. Each time a component of the global fossil fuel infrastructure ages to the point of needing replacement, a decision must be made to continue burning fossil fuel or switch to renewables. From a purely economic perspective, the better decision may be to go with renewable energy.
4. Public health. Combustion of fossil fuels results in emissions of nitrogen compounds and hydrocarbons that participate in the formation of harmful ground-level ozone and particulates (Figure 1). A long history of research and monitoring by environmental agencies supports the conclusion that ground-level ozone is detrimental to human and crop health. The non-climate related economic benefits of reducing fossil fuel combustion (e.g. reduced sickness and death from air pollution) exceed the climate-related benefits in the early decades of greenhouse gas mitigation scenarios.
5. Nitrogen deposition. The nitrogen compounds associated with fossil fuel combustion eventually fall out of the atmosphere in precipitation or as dry deposition. This excess nitrogen is deposited to terrestrial, aquatic, and marine ecosystems and drives eutrophication and soil acidification.
6. Job creation. Building and maintaining an expansive renewable energy infrastructure will create on the order of seven times more jobs than will be lost from the fossil fuel and nuclear industries as they recede. The issue of job creation will become increasingly important in the coming decades as computer-driven artificial intelligence displaces human beings.
The multiple rationales noted here for policies that support a renewable energy expansion will hopefully, in aggregate, move the needle away from further investments in the fossil fuel infrastructure. Policies that stimulate renewable energy technology include subsidies on electric vehicles and residential solar power installation, whereas carbon taxes and regulation of drilling rights on public land can serve to limit fossil fuel development.
Of immediate concern is that a desire to reduce consumption of Russian fossil fuels will be used as a justification for increasing fossil fuel production in the U.S. and elsewhere. Considering the long turnover time of fossil fuel infrastructure (e.g. 50 years for a coal burning power plant) and the ample opportunities for expanding renewable energy, great caution should be taken with investments that prolong the era of fossil fuels.
There are many specific prescriptions about how humanity must change to restore a hopeful future (e.g. a global renewable energy revolution), and implementing these prescriptions will require new pro-environmental behaviors by individuals along with shifts in societal values. In this post, I briefly examine four aspects of a simple psychological framework that shapes the personal sphere of social transformation, and I consider how adoption of that framework could inspire pro-environmental behavior.
A common first approximation to explaining how humans behave is by reference to “nature and nurture”. I will add a third factor – the influence of self-determination, i.e. the products of self-directed thought. My fourth factor in this framework is one’s personal experience, which of course can crush us or enable us to blossom.
1. Nature refers to our genetic inheritance. Neurologists broadly understand the genetically-based architecture of the brain, and the role of neural circuity in brain function, but they are still working on how processes like memory and consciousness actually work biophysically.
Studies of brain function associated with specific activities show that certain areas or modules of the brain (genetically derived) perform particular functions, e.g. mathematical operations or making music. Psychologists and neurologists generally believe that humans are born with genetic predispositions in how we feel, think, and act (presumably related to the wiring of our brain). Some examples include our attraction to sweet foods, our fear of snakes, and how readily as children we learn a language.
Regarding our feelings and behaviors related to the environment, it is important to recognize that some genetically-influenced traits – while being the product of millions of years of biological evolution – may be obsolete in the context of our contemporary high technology civilization. We are much better at paying attention to rapidly changing threats (e.g. a charging rhinoceros) than to slow onset threats (e.g. climate change), yet now we must attend closely to threats in the long-term future.
On the other hand, some proposed genetically-based traits – such as biophilia (love of nature) – may be particularly helpful in the context of fostering pro-environmental behavior.
2) Nurture refers to the influences of our cultural environment on how we think, feel, and act. The success of Homosapiens is attributed in part to our capacity for social learning. Children mimic behaviors of their caregivers and tend to adopt their belief system. As adults, we continue to learn from a variety of cultural sources.
Learned behaviors (e.g. hunting in a hunter/gatherer society) are often adapted to the local environment, and learned cultural beliefs help bind us to our local social group. Here again, I think the term “programming” is appropriate if used in a metaphorical sense. We are culturally programmed in some respects.
Richard Dawkins referred to the units of cultural inheritance as memes. Note that memes do not have to be true to be useful. A mythical narrative of tribal origins may help create a sense of tribal identity, which could strengthen within group solidarity in the face of inter-tribal rivalry.
As with our genetic influences, some of our cultural influences may be obsolete or need modifying in the context of on-going environmental change, e.g. the current emphasis on consumerism in the developed countries.
To complicate things, we have significant biases (going back to our genetic programming) about what we learn. We are particularly likely to believe or imitate leaders (prestige bias) and tend to believe what is believed by a majority of our peers (conformity bias).
3) Self-determination (self-programming) is an overlay on genetic and cultural programming. Mature human beings can consciously consider alternative views and reflect on what to believe and how to act (albeit there is always a lot going on unconsciously). This capacity introduces a sense of agency and inspiration.
Self-determination is certainly impacted by emotions, thoughts, and information that originate from genetic and cultural programming. To some degree, however, impulses from these sources can be consciously recognized and over-ridden.
Education is in a sense cultural programming, but training in critical thinking and more broadly learning how to learn, can open the door to robust self-programming. The firehose of information now available through the various media (some true and some not) makes this kind of thinking especially relevant now.
4. Personal Experience. Many genes are expressed only under particular circumstances, and learned behaviors can only be acquired when there is exposure to a relevant example or information. Additionally, the degree to which learned information is internalized and begins to affect behavior depends on other psychological factors. Motivation to learn is stimulated by a) a positive connection between teacher and learner, b) a sense of autonomy or self-direction rather than being controlled, and c) a feeling of competence associated with accomplishing a well-designed gradation of tasks and getting approval from significant others.
Let’s consider two cases of pro-environmental behavior in which the three types of programming and experience interact.
Slowing Population Growth. Historically, most cultures encouraged high levels of reproduction, which is certainly predictable in the face of the kind of intergroup competition common in human history. More group members make for stronger groups.
Considering the importance of reproduction in biological evolution, it also makes sense that there is a strong genetic influence in favor of reproductive behavior (e.g. mate seeking and sexual pleasure in humans).
For a woman or couple to decide to have few or no children for pro-environmental reasons (potentially in the face of their own instincts and pro-natal cultural policies) would require significant self-programming. Growing up (experiencing) a society that values education and opportunities for self-actualization other than parenthood would make the choice easier.
Global andPlanetary Citizenship. Global scale problems, like anthropogenic climate change, require humanity to work collaboratively towards changing the current dangerous trajectory. However, we seem to be genetically primed to identify with a social group of some kind, which also implies a tendency to classify everyone outside the group as suspect.
Our local society inculcates a unique language and a belief system that differentiates us from outsiders and may induce xenophobia. Nationalism is on the ascendency these days, but it is not the limit of what a society can be.
Thus, becoming a global citizen requires some degree of self-programming. Individuals must learn about issues of global environmental change and deliberate on how to participate in ameliorating the problems.
A common model for societal change begins with an early adopter minority that inspires broader uptake of new values, leading (with some help from prestige and conformity biases) to a majority view (e.g. the broad adoption of anti-littering in the U.S. in the 1960s). The early adopter minority may come from people who recognize the possibility that the majority view is wrong, and then begin to envision and act on alternatives. It is encouraging to see a bubbling up of pro-environmental minorities nearly everywhere on the planet now that could grow in an organic manner to become a pro-environment majority.
In the case of hunter/gatherers, the human contribution to production of harvested food was limited. But as technology became more important in provision of ecosystem services, the human element (including machines and knowledge) began to dominate.
A problem has arisen because humans have tended to consume not only ecosystem services (flows) from natural capital, but also the nature-built capital (stocks) itself. A striking example is the cod fishery in the North Atlantic Ocean: overfishing led to a collapse of the cod population and an abrupt decline in productivity.
For centuries, humans have gotten away with depleting or destroying natural capital by simply moving on to the next unexploited natural resource. Commodity frontiers often have a geographic dimension, e.g. the wave of primary forest exploitation in temperate North America that extended from the New England hardwoods, through the pines of the Great Lakes states, and on to the Pacific Northwest conifers.
A massive erosion of nature-built capital over the last two centuries is evident in the spatial patterns of land use change, distortions in animal and plant population structure, and outright extinction of species. As natural capital is depleted, human interventions (often subsidized by energy from fossil fuels) must be ramped up to maintain the same level of ecosystem services.
From an Earth system science perspective, we can describe the interaction of the human enterprise and natural capital in terms of interaction of the technosphere with its natural resources base.
Biosphere capital is the sum of all organisms and the associated information in the form of genetic material. It is a subset of global natural capital.
Biosphere mass is estimated at 550 Pg (carbon) and the estimates for the number of species range from 5.3 million and 1 trillion. Inputs to the biosphere include solar energy and material flows from the geosphere (minerals) and hydrosphere. Besides sustaining itself, the biosphere outputs vast flows of food and fiber (including wood) to the technosphere.
From the global perspective, technosphere manufactured capital is clearly increasing and biosphere capital is clearly decreasing. Examples include:
Meanwhile, technosphere manufactured capital is growing at a rate of 1-8% per year, depending on the level of development in a given country. It will likely peak at a much higher level than at present because of the still growing global population and increases in per capita manufactured capital in the developing world.
In principle, biosphere inputs to the technosphere can be derived in a sustainable manner. A landscape of tree plantations can be continuously harvested and replanted to produce a sustained yield of wood. Plantation forests supplied about one third of industrial roundwood in 2000. Likewise, there is such a thing as a sustainable marine fishery if the harvest is properly managed.
However, much of the current material transfer from biosphere to technosphere is drawing down biosphere capital. Differentiating between sustainable and depleting production of food and fiber, and increasing attention to sourcing, will play an important role in the transition to a soci-economic metabolism that is sustainable. Accounting practices that treat all forms of capital – including natural capital and technosphere capital in its various forms (manufactured, financial, human, social) – is necessary.
Since different natural resources must be managed at different scales, a hierarchy of socio-ecological systems is needed. This arrangement points to the importance of zonation on the Earth surface in terms of the strength of the coupling between technosphere and biosphere. We can have large areas of relatively undisturbed intact ecosystems (e.g. marine reserves and terrestrial wilderness areas), significant areas of heavy technosphere dominance (as in urban and industrial zones), significant areas of intensive food and fiber production (e.g. forest plantations), and a scattering of areas with a moderate intensity of biosphere/technosphere interaction. This view supports the development of spatially-explicit simulation models – implemented at a range of spatial scales – that can be used within a socio-ecological system to organize the co-production of ecosystem services. Potentially, with a well-designed combination of monitoring, modeling, and environmental governance, the technosphere will drive increases rather than decreases in biosphere capital (e.g. the recovery of whale populations).
Earth System Science has come to a remarkably good understanding of the global carbon cycle in recent decades. The various pools (stocks) of carbon have been quantified (e.g. vegetation, soil, and atmosphere), along with the annual fluxes from one pool to another. A key revelation has been that the quantity of carbon dioxide (CO2) in the atmosphere is increasing and that the increase is driven by anthropogenic factors (fossil fuel combustion and deforestation).
Since the rising CO2 concentration is associated with a trajectory towards dangerous climate change, humanity has slowly moved towards commitments to reduce CO2 emissions. Some types of emissions are more glaring than others, and this blog highlights four of the most egregious examples (signs of madness).
Likewise, there are many technical and policy options for reducing CO2 emissions or speeding CO2 uptake, and this blog highlights four of the most promising (signs of hope).
Signs of Madness
1. Oil from Tar Sands. Given the goal of reducing anthropogenic CO2 emissions as quickly as possible, an obvious candidate for termination is extraction of oil from tar sands (Figure 1). The whole process of extracting hydrocarbons from the Earth and refining them has an energy cost, with related CO2 emission. Unlike conventional oil, which comes out of the ground ready for the refinery, tar sands hydrocarbons must be mechanically extracted in a bulk form that includes many contaminants. This material is then heated to isolate the oil component, a treatment requiring substantial energy – usually provided by combustion of natural gas. The net effect is a 15% higher overall emissions of CO2 per gallon of gasoline coming from tar sands compared to conventional oil.
3. Supersonic Passenger Jets. United Air Lines has announced plans to operationalize a fleet of supersonic passenger jets around 2029. Their virtue would be cutting flight times across oceans by about half (they generally aren’t used over land because of sonic booms). Their downside is a factor of 2.5 to 7 increase in carbon emissions per passenger mile. In theory, their engines could burn sustainable aviation fuel but there are many issues with scaling up production of this fuel if demand increased substantially.
1. Natural Climate Solutions (NCS). The land surface is currently a net sink for carbon dioxide, even after accounting for effects of deforestation. Most of that carbon accumulation is showing up in live wood (Figure 3), thus it is tracked by global forest inventories. However, a significant amount may also be accumulating in global soils (in part because of CO2 fertilization of plant growth). The aim of the NCS strategy is to maintain all existing land carbon sinks and foster new carbon sequestration by way of altered land management. Besides stopping deforestation, and reforesting large tracts of previously deforested land, NCS (more broadly Nature-based Solutions) will operate in the agricultural sector, wetlands, and grasslands. Scientists estimate that NCS could provide up to 30% of the reduction in CO2 emission needed to hit net zero emissions at the global scale by 2050.
3. Carbon taxes. Economists have long argued that the fastest and more practical strategy for driving down anthropogenic carbon emissions is to establish taxes on fossil fuel carbon emissions. That approach of course tends to arouse political opposition, but several case studies prove carbon taxation is possible and effective. The province of British Columbia in Canada imposed a moderate tax on fossil fuel emission in 2008, which has reduced fuel emissions on the order of 5-15%. Sweden has one of the oldest and highest taxes on fossil fuel emissions. Again, follow-up studies suggest emissions have declined, while maintaining solid GPD growth. Various strategies have been employed to insulate the most vulnerable energy consumers from price increases.
4. Satellite-based Monitoring of Methane Leakage. Methane is a strong greenhouse gas in its own right and is eventually oxidized in the atmosphere to CO2. Unfortunately, methane emissions are on the rise in recent years, with leakage from expanding coal and natural gas mining and infrastructure a significant factor. Because methane has a relatively short atmospheric lifetime (about 8 years) compared to carbon dioxide, a decrease in methane emissions would have an especially large influence on global warming in the next few decades. Earth system scientists use satellite borne sensors to track atmospheric methane concentrations and infer regional patterns in methane emissions. But a new generation of sensors, including one run by the Environmental Defense Fund, is transforming the attribution of leakage sources by increasing the spatial and temporal resolution of the coverage. These sensors will contribute to monitoring the effectiveness of the Global Methane Pledge recently signed at COP26.
The world is at, or fast approaching, the year of peak carbon dioxide emissions. The signs of madness identified here serve to push that year farther into the future. The signs of hope will hasten its arrival and help sustain a multidecadal trajectory towards net zero emissions.
The threat of anthropogenically-induced global environmental change imposes a challenge on humanity to reconceptualize its relationship to the other components of the Earth system. Historically, Nature was the background for the human enterprise. It provided unlimited sources of ecosystem services, such as ocean fish, clean air, and clean water. However, as the human enterprise expanded – especially after the “Great Acceleration” of technological development beginning about 1945 – real limits have become obvious.
Because the sum of human impacts on the environment is now global, humanity as a collective must act to self-regulate. Unfortunately, humanity is not at present a collective, and we are only beginning to construct a worldview that is consistent with living within the biophysical limits of the planet. This post examines three concepts that may help move us towards those goals.
The term technosphere has been used for decades in the field of Science and Technology Studies and is loosely construed as the sum of all technological artifacts on Earth. Often it is credited with having a degree of autonomy in the sense of its growth having a direction and momentum outside of human control. The current difficulty in reducing fossil fuel related emissions of greenhouse gases is indicative of that autonomy.
the set of large-scale networked technologies that underlie and make possible rapid extraction from the Earth of large quantities of free energy and subsequent power generation, long distance, nearly instantaneous communication, rapid long-distance energy and mass transport, the existence and operation of modern governmental and other bureaucracies, high-intensity industrial and manufacturing operations including regional, continental and global distribution of food and other goods, and a myriad additional ‘artificial’ or ‘non-natural’ processes without which modern civilization and its present 7 × 109 human constituents could not exist.
Earth system scientists now make quantitative estimates of the properties of the technosphere such as total mass and annual energy throughput. The juxtaposition of technosphere metrics like global fertilizer use, with biosphere metrics like global nitrogen fixation, reveals the growing dominance of the technosphere in the global biogeochemical cycles and points to the limits to technosphere growth.
The technosphere is in some ways analogous to the biosphere. Both are globe girdling aggregations of quasi-independent subsystems. In energetic terms, both the biosphere and the technosphere are dissipative structures, meaning they capture and use energy to maintain order. The biosphere changes by way of biological evolution; the technosphere changes by way of cultural evolution.
Humans and their institutions are parts of the technosphere, and human thinking is required to organize the technosphere. But the question about technosphere autonomy, and its possible danger to humanity, remains. Notably, the capitalist economic system that underlies the technosphere thrives on growth. Relentless technosphere growth is in effect consuming Earth system capital, such as biodiversity and fossil fuel, that has accumulated over millions of years. Astrobiologists, who ponder evolution of intelligent life on other planets, suggest that an environmentally self-destructive technosphere may significantly limit (filter) how often sustainable high technology planetary civilizations arise in the universe.
A critical problem with Earth’s current technosphere is that due to its rapid and recent evolution, it does not have the kind of feedback loops (as found in the biosphere) needed for self-regulation. Humans are programmed (biologically) to exploit all available resources, but we haven’t evolved culturally to understand limits. Haff emphasizes that the lack of recycling within the technosphere (with the accumulation of CO2 in the atmosphere from fossil fuel combustion as an iconic example). Life cycle analyses of all manufactured products, and better monitoring of input/recycling/output budgets (e.g., for aluminum) at the global scale is required for a sustainable technosphere.
Russian biogeochemist Vladimir Vernadsky (1863 – 1945) was one of the first scientists to explicitly study Earth as a whole. He understood that the biosphere (the sum of all living matter) added an unusual feature to the planet. The biosphere uses the energy in solar radiation to maintain a new form of order (life) on the surface of the planet. That layer of living matter is a major driver of the global biogeochemical cycling of elements such as carbon, nitrogen, and phosphorus. Vernadsky emphasized that the biosphere was a new kind of thing in the universe, i.e. a step forward in cosmic evolution.
He also recognized that humanity, as a result of the industrial revolution, had become of geological significance. Like the biosphere, humanity and its technology are a product of cosmic evolution – in this case relying upon an organism-based nervous system capable of consciousness and symbolic thinking. By extension from the existing concepts of lithosphere, hydrosphere, atmosphere and biosphere, Vernadsky adopted the term noosphere for this new layer of thinking matter that could alter the global biogeochemical cycles.
The noosphere as conceived by Vernadsky was just getting powered up in his lifetime. He defined it more as a potential transformation of the biosphere – “a reconstruction of the biosphere in the interests of freely thinking humanity as a single entity”.
Vernadsky’s noosphere concept lay mostly dormant for much of the 20th century (although see Sampson and Pitt 1999). Around the turn of the century, Nobel Prize winning atmospheric chemist Paul Crutzen evoked Vernadsky’s idea of transforming the biosphere into a noosphere. But in this 21st century usage, the issue of dangerous human meddling with the Earth system had risen to prominence and the inevitability of a stabilized noosphere was less certain. Similarly, Turner proposed that an updated meaning for noosphere would refer to a planetary system as a whole in which an intelligent life form had developed advanced technology but had learned to self-regulate so as to not degrade the planetary life support system.
In a slightly different take, noosphere is proposed as a paradigm for an era to follow the Great Acceleration. In this case, the noosphere is still imagined as emerging from the biosphere, but here in response to the threats of anthropogenic global environmental change. The maturation of the noosphere would mean the arrival of a global society that collaboratively self-regulates its impact on the Earth system.
Limitations of the Noosphere Concept
As noted, Vernadsky was writing before the scientific discovery that humanity was altering the atmosphere, e.g., by increasing the concentrations of greenhouse gases. Thus, he did not foresee humanity’s possible self-destructive tendencies. His noosphere concept was more about Promethean management of the Earth system than about humanity learning how to self-regulate, which is what we need now.
In most versions of the noosphere concept, the biosphere is “transformed” into a noosphere, hence in its fruition it would physically include the biosphere. However, the biosphere (much of it microbial) will always be capable of functioning independent of human attempts to manage the Earth system. The biosphere could be said to have agency relative to human impacts, which might be a more realistic basis on which to attempt to manage it.
Vernadsky’s noosphere was purely physical, but other users of the term have interpreted it more metaphysically, especially Teilhard de Chardin who referred to a purely spiritual endpoint of noosphere evolution. This spirituality and teleology have made the noosphere concept aversive to many scientists (see Medawar in Sampson and Pitt 1999).
The Global Brain
About the same time (1920s) that the noosphere meme was fostered by Vernadsky, Teilhard de Chardin, and Le Roy, the concept (or metaphor) of the global brain also emerged. Novelist and futurist H.G. Wells (1866 – 1946) proposed that all knowledge be catalogued in a single place and be made available to anyone on the planet. His hope was that this common knowledge base might lead to peace and rapid human progress. Given that World War II was soon to erupt at the time of his “World Brain” proposal, Wells was clearly ahead of his time.
Like the noosphere concept, the World Brain concept was not much referred to in the decades following its origin in Well’s imagination. However, the late 20th century Information Technology revolution has reinvigorated discussion about it. With rapid build out of the global telecommunications infrastructure, the global brain has begun to be envisioned as something wired together by the Internet.
Systems theorist Francis Heylighen and his collaborators at the Global Brain Institute have devoted considerable attention to building the analogy between the human brain and a proposed global brain, especially in relation to the process of thinking.
Heylighen sees the global brain as a necessary part of an emerging social superorganism – a densely networked global society. His global society will coalesce because information technology now offers a growing proportion of the global population access to a wealth of information and an efficient way to organize production and consumption of goods and services. Rather than totalitarianism, the high level of connectivity in Heylighen’s model of the social superorganism stimulates individuals to develop themselves (while still acknowledging membership in a global collective). This model leads to more distributed, less hierarchical, power centers.
Collaborative development of the Community Earth System Model is an example of collective thinking on a limited scale. Specialist scientists work to improve the many subsystems of the model, and periodically the computer code is updated based on a consensus decision.
One other intriguing analogy relates to a characteristic feature of the human brain in which it makes frequent (conscious or unconscious) predictions. If they are not fulfilled, a motivation to act may be instigated. With Earth system model scenarios now produced in the context of climate change assessment, the global brain might also be said to be constructing scenarios/predictions for itself. Comparisons of scenarios, or detection of discrepancies between favorable scenarios and how reality is playing out, could inspire corrective action by the global collective.
Limitations of the Global Brain Concept
The analogy of global brain to individual brain is certainly a stimulant to conceptualizing new global scale structures and processes. However, since we barely understand our own consciousness and decision-making processes, it is an analogy that still needs a lot of work, especially with respect to the executive function. In the near-term, humanity needs research and models on how to integrate governance among 8-10 billion people (i.e. what form of institutions?) and how to convince billions of planetary citizens to cooperate in the effort that humanity must make to self-regulate. The global brain concept does not facilitate the coupling of the human enterprise to the rest of the Earth system.
The technosphere, noosphere, and global brain concepts share a common concern with understanding the relationship of the burgeoning human enterprise, including its technology, to the entirety of the Earth system. Anthropogenic global environmental change poses an existential threat to humanity and there is a clear need for a Great Transition involving massive changes in values as well as technology. These three concepts serve as beacons pointing towards global sustainability.
The utility of the technosphere concept is that it refers to measurable entities, and formally meshes with the existing Earth system science paradigm. Given that humans are only part of the technosphere, and a part does not control the whole, awareness of the technosphere argues against hubris. However, the technosphere concept doesn’t engage the host of psychological and sociological issues that must be addressed to rapidly alter the Earth system trajectory. It helps reveal the danger humanity faces but doesn’t foster a worldview that will ameliorate the danger.
The utility of the global brain concept is that it confirms we have the technical means to actualize global collective intelligence, which will be required to deal with the overwhelming complexity of the Earth system. A weakness is a limited model of global governance and a lack of attention to the rapid erosion of the human life support system (the biosphere) that must function well for the emerging global brain to flourish. The capacity of individuals to know themselves, i.e. to reflect on their own behavior and its consequences, can potentially be scaled up to the global human collective. This process will depend on the communication possibilities opened up by the Internet.
The technosphere, noosphere, and global brain concepts will contribute to synthesizing a new model of the planetary future that includes a functioning global society and a technological support system that maintains a sustainable relationship to the rest of the Earth system.
Think of the entire global human enterprise as a system − what Earth system scientists are beginning to call the technosphere. It consists of all the material artifacts and energy flows associated with our global high technology civilization, as well as all the social bonds and institutions that tie us together. A high degree of connectivity is evident in the technosphere (Figure 1), and it is worth asking if more connectivity (e.g., a stronger United Nations) or less connectivity (e.g., effects of anti-globalization) would help in the struggle for global sustainability.
Systems are often specified in terms of parts and wholes, and in terms of interactions between the parts that help maintain the whole. The quantity and nature of these within-system connections have long been of interest to systems theorists because of their influence on system stability. The connectivity concept offers a lens through which to view technosphere structure and function.
In the ecological literature, (eco)system connectivity has two aspects. One is geographic (2-dimensional) – as in corridors across a landscape that allow movement of animals or dispersal of seeds. High connectivity is important because, for instance, after a disturbance such as fire, early successional species must find their way to the disturbed patch.
The second aspect of ecosystem connectivity relates to the way processes are coupled. In a highly connected forest ecosystem, the processes of decomposition (which releases nutrients) and net primary production (which requires nutrient uptake) are coupled by way of a network of fine roots or mycorrhizae. In a weakly connected tree plantation, where a significant proportion of nutrients are provided by fertilizer, that coupling is missing. High connectivity of processes usually means more effective system regulation.
In the technosphere, geographic connectivity is maintained by the transportation and telecommunications infrastructure. Process-based connectivity relies on coupling between sources and sinks of energy, materials, information, and money.
Ecologist C.S. Hollings has argued that late successional ecosystems become overconnected. In his panarchy model for ecosystem development, a four-stage cycle (Figure 2) begins with a catastrophic disturbance (Release phase). The disturbance stimulates decomposition of dead organic matter and frees up resources for colonizing species that seed in and rapidly accumulate biomass (Reorganization Phase). As the ecosystem fills in (Exploitation or Growth Phase), the connectivity increases (note the x-axis). In contrast to earlier theories of ecosystem dynamics, Hollings suggested that ever increasing ecosystem connectivity may ultimately be destabilizing because nutrients get locked up in biomass, and a high density of organisms means strong competition that stresses the organisms and makes them vulnerable to disturbance (Conservation Phase). Eventually, the stressed condition of the biota allows another major disturbance, such as an insect outbreak (Release Phase), that sweeps across the ecosystem and restarts the panarchy cycle. The Reorganization phase is a period of low connectivity, leaving the ecosystem susceptible to degradation.
The technosphere system is like an ecosystem in having a throughput of energy (mostly fossil fuel) and a turnover of its components. It has certainly gone through a growth phase (often referred to as the Great Acceleration) and is now accumulating connections rapidly as it matures. Let’s place it somewhere between the Exploration and Conservation phases in Figure 2. It might be underconnected in the sense of weak links between different geographic areas (e.g., in the face of global scale problems like climate change) and limited coupling of critical processes (e.g., mobile phone manufacturing and mobile phone recycling). The opposite concern is that it may at some point become overconnected and vulnerable to a major disturbance.
Let’s examine ways in which the technosphere could be considered underconnected.
1. An underconnected technosphere is one in which global scale coordination is unable to meet the challenges of Earth system maintenance. Lack of connections allows global scale problems to escape technosphere control. The situation with global climate change evokes this sort of underconnection. In broad terms, we have inadequate institutions for global environmental governance (not to mention global economic governance). The shambolic global response to COVID-19 is also indicative of underconnection; a better coordinated global vaccination program would have been in the best interest of everyone.
2. The technosphere is causing massive disruption of the biosphere and Earth’s climate. These impacts on the Earth system are associated with failure to fully recycle technosphere “waste products”, e.g., the production of carbon dioxide by fossil fuel combustion is not connected to the removal of carbon dioxide from the atmosphere by some other industrial process.
3. A renewable energy revolution is clearly needed to mitigate climate change, but the sources of renewable energy (e.g., wind and solar) may not be co-located with the demand for energy (urban areas). Hence, a more robust grid (nationally and internationally) for distribution of electricity is required (along with other energy infrastructure upgrades).
4. We think of the global Internet as foundational for global connectivity. And, in fact, the Internet facilitates the kind of global coordination that is needed to address global environmental change issues that threaten the technosphere. However, nations such as China and Russia have built national Internet firewalls that prevent their citizens from freely accessing the Internet. That kind of fence raising promotes nationalism, but not the planetary citizenship we need to create a sustainable future.
The case for an overconnected technosphere is less compelling. The rapid spread of the 2007-2008 financial crisis around the planet is suggestive of fragility in the global economy. And the crush of 7.8 billion people striving for a high quality of life is contributing to widespread stress in the biosphere (upon which the technosphere depends). Ironically, solving these problems may require greater international connectivity.
We are still in the early stages of technosphere evolution, and my sense is that greater global connectivity is desirable. With regard to the global environment, we are in dire need of 1) a well-connected circular economy that recycles all manufactured products, and 2) new international institutions for global environmental governance that coordinate monitoring, assessments, adaptation, and mitigation of global environmental change problems. The anti-globalization movement calls for less connectivity but the proliferation of global scale problems points to the need for more connectivity.
Recommended Reading: Connectography: Mapping the Future of Global Civilization. Parag Khanna. 2016. Random House. My review.
A Great Transition is hopefully underway − from humanity’s current chaotic rush towards environmental disaster, to a more ordered Earth system in which the global human enterprise (the technosphere) becomes sustainable. However, achieving the necessary planetary scale organization of the human enterprise will be a challenge.
The discipline of systems theory offers insights into how new forms of order emerge, and here I will introduce two of its concepts − holarchy and metasystem transition − as they relate to the process of creating a sustainable planetary civilization.
The technosphere is commonly presented as a whole. I like to draw the analogy between the technosphere and the biosphere: both use a steady flow of energy to maintain and build order. Just as the biosphere evolved by way of biological evolution from microbes to a verdant layer of high biodiversity ecosystems cloaking the planet, the technosphere is evolving by way of cultural evolution into a ubiquitous layer of machines, artifacts, cities, and communication networks that likewise straddles the planet.
This formulation of the technosphere as a global scale entity is a glossy overview that allows one to make the point that the growth of the technosphere has altered the Earth system in ways that are toxic to some components of the biosphere, and indeed to the technosphere itself. Technosphere emissions of greenhouse gases leading to rapid climate change is the iconic example.
The view of the Earth system as composed of interacting spheres (geosphere, atmosphere, hydrosphere, biosphere, cryosphere, technosphere) is also useful for imagining and modeling the feedbacks that regulate Earth system dynamics, e.g., the positive feedback of the cryosphere to climate warming in the atmosphere, or the negative feedback to climate warming by way of the geosphere-based rock weathering thermostat.
But systems theory offers another lens through which to examine the technosphere and its relationship to the contemporary Earth system. This view relies on further disaggregation.
Systems theory is a discipline that studies the origin and maintenance of order. The objects of study are systems − functional entities that can be analyzed in terms of parts and wholes.
Complex systems are often structured as holarchies , i.e., having multiple levels of organization. Complexity in general refers to linkages among entities at a range of spatial and temporal scales, e.g., a city is more complex than a household.
Like the more familiar hierarchy (e.g., a military organization), there are levels in a holarchy; lower levels are functional parts of the levels above. The entities (holons) at each level are “wholes” relative to the level below but “parts” relative to the level above. The difference between holarchy and hierarchy lies in representation of both upward and downward causation in a holarchy compared to primary concern with downward-oriented control in a hierarchy.
Let’s consider the environmental management aspect of the Earth system as a holarchy (Table 1).
Table 1. Levels in a planetary natural resources management holarchy. The Integrating Factors refer to how the components within a holon interact.
The emphasis in this management-oriented holarchy is on holons that consist of coupled biophysical and sociotechnical components. Environmental sociologists term a holon of this type a socio-ecological system (SES) (Figure 1). In an SES, stakeholders coordinate amongst themselves in management of natural resources.
Figure 1. A socio-ecological system holon. Integration of the Biophysical Subsystem and the Sociotechnical Subsystem is achieved by management of natural resources and delivery of ecosystem services. Adapted from Virapongse et al. 2016. Image Credit: David Turner and Monica Whipple.
At the base of the Earth system SES holarchy (Figure 2) are managed properties, such as a farm or wildlife refuge, where humans and machines manipulate the biophysical environment to produce ecosystem services such as food production and biodiversity conservation.
Figure 2. The planetary socio-ecological system holarchy. Arrows are indicators of interactions, with larger arrows suggestive of slower more powerful influences. Adapted from Koestler 1967. Image Credit: David Turner and Monica Whipple.
A step up, at the landscape level, are mosaics of rural and urban lands. A town with parks and an extensive greenbelt, or a national forest in the U.S., which is managed for wood production as well as water quality and other ecosystem services, are sample landscapes. Disturbances within a landscape, such as wildfire on the Biophysical side or a change in ownership on the Sociotechnical side, can be absorbed and repaired by resources elsewhere in the landscape (e.g., reseeding a forest stand after a fire).
At the ecoregion level, there is a characteristic climate, topography, biota, and culture. My own ecoregion, the Pacific Northwest in western North America, is oriented around the Cascades Mountains, coniferous forests, high winter precipitation, and an economy that includes forestry, fishing, and tourism. These features help define optimal natural resources management practices. A significant challenge at the ecoregion level is integration of management at the property and landscape scales with management of the ecoregion. Ecoregions interact in the sense of providing goods and services to each other, as well as collaborating on management of larger scale resources such as river basin hydrology.
The national level is somewhat arbitrary as a biophysical unit, but the sociotechnical realm is significantly partitioned along national borders, so the nation is in effect a clear level in our SES holarchy. Nations have, in principle, well organized regulatory and management authorities that aim for a sustainable biophysical environment as well as a stable and prosperous socioeconomic environment.
At the planetary level, the sociotechnical aim is to manage the global biophysical commons − the atmosphere and oceans − and coordinate across nations on transborder issues like conservation of biodiversity. That would mean agreements on policies to limit greenhouse gas emissions, reduce air and water pollution, and manage open ocean fisheries.
A strong global environmental governance infrastructure is needed at the planetary level to ensure a sustainable relationship of the technosphere to the rest of the Earth system.
But what we have now at the global scale is a weakly developed array of intergovernmental organizations (e.g., the United Nations Environmental Program), transnational corporations that heavily impact the global environment, and international nongovernmental organizations like Greenpeace. We do not have a fully realized planetary level of environmental governance.
The systems theory term for emergence of a new level in a holarchy is “metasystem transition”. This process involves an increasing degree of interaction and interdependency among the constituent holons (nations in this case). Eventually, positive and negative feedback relationships are established that promote coexistence and cooperation. The origin of the European Union is a relevant case study of a metasystem transition in the geopolitical realm.
Resistance to planetary scale management is understandable – notably because nations fear losing sovereignty. Less developed nations worry about external imposition of constraints on their economic development that may be unjust considering the global history of natural resource use. Working through these political issues is fraught with complications, thus the process would benefit from focused institutions. Global environmental governance researchers have proposed creation of a United Nations-based World Environment Organization, which would coordinate building environmental management agreements with follow through monitoring and enforcement.
A key driver for the success of planetary-level SES integration is that each nation is faced with environmental problems, like climate change, that it cannot address on its own. Survival will require a new level of integration with its cohort of national-level holons. Possibly, progress in collaboratively addressing global environmental threats like climate change could even lead to further progress in collaboratively addressing global geopolitical threats like the proliferation of nuclear weapons.
The technosphere is gearing up for a full mobilization against rising greenhouse gas concentrations and associated climate change. The struggle to bring down methane emissions is a key feature of that effort; thus, initiatives by individuals, NGOs, industry, and governments deserve our attention and support. The dangerous trajectory of the atmospheric methane concentration (Figure 1) speaks to the urgency of acting now.
The increasing concentration of methane (CH4) in the atmosphere contributes about 23% to anthropogenic strengthening of the greenhouse effect on Earth. As with carbon dioxide (CO2), the rising concentration of methane in the atmosphere must peak as soon as possible if humanity is to avoid a global environmental change crisis. A significant difference between these two greenhouse gases is that methane has a relatively short atmospheric lifetime (~ 8 years) and hence its concentration will respond rapidly to reductions in emissions.
Scenarios for limiting Earth’s warming to 2oC or less assume that methane emissions will peak soon, followed by a peak and fall off in the methane concentration. However, rather than shrinking, emissions are actually increasing and the rate of annual increase in the methane concentration is growing (Figure 2). The increases in 2020 and 2021 were the highest on record.
The concentration of methane in the atmosphere is the net effect (Figure 3) of sources (emissions) and sinks (consumption). Human driven sources amount to about 60% of total sources. The primary sink of methane is the hydroxyl radical (OH), which is produced in the atmosphere photochemically. The OH molecule has a very short lifetime (~ 1 second) and is difficult to measure. From modeling of atmospheric chemistry and limited OH observations, the oxidation capacity of the atmosphere is considered stable, but there is concern that the increasing methane emissions are extending the atmospheric lifetime of methane and therefore increasing its global warming potential per molecule emitted.
The tripling of methane concentration since around 1800 (Figure 4) is largely attributable to human factors, including expansion of rice agriculture, increase in the number of ruminant livestock, build out of the fossil fuel infrastructure, a rising number of landfills and municipal waste facilities, and more biomass burning associated with agriculture and deforestation.
Another major factor is the number of ruminant livestock on the planet, which continues to increase in association with growth in the human population and its level of affluence. Deforestation and related biomass burning are also on the rise (2010s > 2000s), notably in Brazil.
Although recent increases in methane emissions are related directly to human factors, Earth system scientists are also concerned about possible increases in emissions from natural methane sources. These include 1) high latitude wetlands and shallow seas where warming temperatures increase rates of decomposition and melting of frozen methane hydrates, and 2) extensive tropical latitude wetlands, where warming temperatures similarly increase rates of decomposition. The potential for pumped up high and low latitude natural sources in response to climate warming is worrisome because it would indicate that a positive (amplifying) feedback to global warming had been engaged. There will be little that humanity can do to disengage that feedback once it gets started.
A lot could be done to reduce current methane emissions of anthropogenic origin, what I refer to as a teleological feedback to climate change.
1) Much of the leakage from the fossil fuel infrastructure could be eliminated if the industry took greater precautions (probably requiring stronger regulations). The Biden clean energy plan includes provisions for reducing methane emissions from the oil and gas sectors of the economy in the United States. An especially exciting development is that the Environmental Defense Fund is working to build an operational satellite-based methane monitoring system, which will report areas of leakage in near real time.
The prospects for a rapid peak in global methane emissions, followed by a peak in concentration, are linked to success in bringing down CO2 emissions. The potential problem is that if CO2 driven climate change continues in a business-as-usual fashion, it is possible that natural wetland emissions will increase, which would tend to cancel out successes in reducing anthropogenic methane emissions.
Despite quite a bit of uncertainty about past and future trends in the methane budget, Earth system scientists agree that human-driven methane emissions can and should be reduced.