teleological feedback Archives - Taming the TechnosphereTaming the Technosphere

Carbon dioxide emissions from increased energy use associated with air conditioning is one form of technosphere feedback to climate change. Image Credit: pxfuel

David P. Turner / July 12, 2021

The technosphere is often described by way of analogy to the biosphere. In both cases, energy throughput supports maintenance of order.

In the biosphere, the source of the energy is mostly the sun, and the fuel is often carbohydrates derived directly or indirectly from photosynthesis. The energy captured by photosynthesis is used for maintenance of metabolism in existing biomass (autotrophic respiration) and production of new biomass (of all types), which is ultimately broken down in heterotrophic respiration. These terms can be expressed in terms of energy flux or carbon flux.

In the technosphere, the energy source is also mostly the sun in that the fossil fuels that currently power the technosphere have their ultimate origin in ancient solar energy.

The technosphere equivalent of maintenance respiration is the energy throughput not associated with materials production, e.g., energy for heating, cooling, transportation, and communication. The technosphere equivalent of biomass production is manufacture of material artifacts like cars and buildings, much of which is turnover (replacement of worn-out or non-functioning objects) and some of which is new (expansion of the technosphere). The combination of energy spent on maintenance and manufacturing could loosely be considered technosphere respiration.

Respiration of both the biosphere and technosphere produces CO₂ that is released to the atmosphere. However, in the case of the biosphere, nearly the equivalent of the respired CO₂ is reabsorbed from the atmospheric pool in new photosynthesis. In contrast, much of the respired CO₂ from the technosphere is accumulating in the atmosphere. Hence the problem of global warming.

There are many feedbacks that operate as the global climate warms, most of them positive (amplifying) feedbacks. Two commonly cited positive feedbacks are the water vapor feedback and the snow/albedo feedback (Figure 1). In both cases, as the atmosphere warms, the physical environment changes in a way that accelerates the warming. In systems theory, positive feedbacks tend to be destabilizing.

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.

Here I would like to isolate two other positive feedbacks to climate warming that are not purely geophysical, rather they are mediated by the technosphere.

The first relates to energy use for cooling (air conditioning). As the low latitudes warm, people will increasingly prioritize air conditioning. At mid-latitudes, air conditioning will be used more frequently. At high latitudes, there will be some energy savings from reduced heating, but initial modeling suggests that the overall global effect of climate change on heating and cooling will be a large increase in energy demand (25-58% above a baseline by 2050).

To whatever degree that climate change induced technosphere energy consumption is supplied by fossil fuel combustion, i.e., business as usual, there will be more CO₂ emissions and more global warming. This positive feedback loop (Figure 2) will frustrate global efforts to rein in CO₂ emissions.

Box and arrow diagram of two technosphere respiration feedbacks. — Figure 2. The technosphere maintenance respiration (purple loop) and turnover (green loop) feedbacks. Climate warming induced by anthropogenic CO2 emissions drives changes in the technosphere that increase energy consumption. The associated increase in anthropogenic CO2 emissions pushes up the atmospheric CO2 concentration, and correspondingly the global mean temperature. Image Credit: David Turner and Monica Whipple.

Another source of increasing energy demand will be the more rapid turnover of technosphere artifacts because of a changing disturbance regime. More fires, extreme weather events, permafrost melting, and sea level rise will all be destructive and require new construction. Again, we will see more demand for energy and eventually more warming (Figure 2).

Besides these two forms of positive technosphere feedback to climate change, a recent study also analyzed the potential increase in energy spent on transportation as climate warms.

The 3 mechanisms of positive technosphere feedback noted here do not consider other factors that will be increasing technosphere energy demand in the near future, particularly the demands associated with a growing global population and continued economic development (rising per capita energy use).

A few sources of downward pressure on total energy consumption are in play, including increasing energy use efficiency, increasing building insulation, and longer artifact turnover time. They point to the importance of efficiency standards (e.g., for air conditioners), building standards (for insulation), and product standards (for extending product lifetime). To the degree that improvements in these fields are driven by an intent to limit climate change, they represent a negative technosphere feedback to climate change (effectively a teleological feedback).

The way to diminish the strength of the technosphere maintenance and turnover feedbacks is to ensure that maintenance and repair of the technosphere are based on renewable energy sources.

A shift of the global energy infrastructure away from fossil fuels would of course also limit the magnitude of the climate change that initiates these feedbacks in the first place. That worthy goal is technically feasible.

David P. Turner / March 30, 2021

Figures updated April 8, 2022

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.

Figure 1. The trend in global mean atmospheric methane concentration. Image Credit: NOAA.

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 2^oC 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.

Figure 2. The annual change in atmospheric methane concentration since 1984. After dipping from around 1992 – 2006 (for poorly understood reasons), the annual change in concentration has returned to substantial increases. Image Credit: NOAA.

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.

Figure 3. The global methane budget for 2008-2017. Image credit: Global Carbon Project.

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.

Figure 4. The atmospheric methane concentration over the last ~800,000 years showing glacial-interglacial oscillations (wetlands related) and a surge in the last 200 years. Different colors indicate different measurement techniques. Image Credit: EPA.

The upward trend in the growth rate of methane concentration over the last ten years is likewise caused by increasing anthropogenic emissions. Leakage from the fossil fuel infrastructure − some dispersed over regions of intense drilling and mining (Figure 5) and some in the form of massive leaks at particular sites − is one contributor.

Figure 5. Satellite mapped methane concentration. The color bar goes from purple (low concentration) to red (high concentration). Note the hot spot in the Four Corner’s area, possibly leakage from natural gas operations. Image Credit: NASA/JPL-CALTECH/UNIVERSITY OF MICHIGAN/AP

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.

2) The number of ruminant livestock could be reduced by a change in the demand for meat. Contributing factors would be changes in dietary preferences and further development of synthetic meat. Alternative types of cattle feed that reduce methane production are also under investigation.

3) Improved water management in rice fields can bring down methane emissions.

4) Landfills and municipal waste treatment facilities can be designed such that methane from decomposition of organic matter is captured and used for energy production.

Methane emissions in Europe are on the decline because of policy changes in some of these areas.

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.

Taming the Technosphere

An Earth System Science blog

Tag Archives: teleological feedback

The Technosphere Respiration Feedback

Peak Methane Emissions and Peak Methane Concentration

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