David P. Turner / June 21, 2022

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.

The growing impact of the technosphere on the Earth system has been widely documented by the scientific community (IPCC, IPBES) and scenarios for a sustainable high technology global civilization require that technosphere mass, inputs, and use of fossil fuels peak as soon as possible.  If the peaks are left to occur spontaneously, the outcome may well be a collapse of civilization driven by the stress of global environmental change, rather than a soft landing at a state of global sustainability.

Peak Technosphere Mass

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.

An estimate of technosphere mass that includes landfills, and other cases of human-made objects not in use, is much larger that the 10¹⁸g estimate of technosphere mass in use.  Indeed, geoscientists looking for a depositional signal for the Anthropocene are considering discarded plastic as a marker.  It will take a concerted effort to decrease material flows into landfills before we will see a peak in unused technosphere mass.

Peak Technosphere Input of Material Resources

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.

Peak Technosphere Consumption of Fossil Fuels

An abrupt decline in carbon emissions from fossil fuel combustion in 2020 was induced by the COVID-19 pandemic, hinting at the possibility that 2019 was inadvertently the year of peak fossil fuel emissions. 

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.

Conclusion

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.