Sustainable illusion

Sustainability is the magic word in the fight against climate change. However, the criterion of entropy sheds a different light on climate-neutral technologies and negative CO₂ emissions.

The content of the following article is based on a former popular scientific article published in „Naturwissenschaftliche Rundschau“ (May 2024), a translation of which can be found here: https://www.bernhard-wessling.com/wp-content/uploads/2024/05/entropy-sustainability-V7-translation-from-German.pdf. The following article is even more easy to understand by laymen.

Bernhard Wessling (Nov. 2024)*
*at the end of the paper: about the author

A worldwide discussion is still ongoing about how climate change can be stopped and which technologies can help. At the center of the discussion are special filter processes that cause “negative CO₂ emissions”. These are intended to either capture the unavoidable residual emissions at source or extract CO₂ from the atmosphere. This includes the lime and cement industry, waste incineration, agriculture, the raw materials and steel industry, which account for 25 to 30 percent of global CO₂ emissions and are considered unavoidable. In order to “neutralize” these emissions, CO₂ is to be either extracted from the atmosphere (Direct Air Capture, DAC) or captured at the source (e.g. in the cement factory) and then stored underground (Carbon Capture and Storage, CCS, or DACCS).

This technology is rejected by various groups for a number of reasons, although the arguments are often vague. It is often said, for example, that the technology must not be used to further delay the phase-out of fossil fuels.

Generally speaking, DAC and CCS as such are only viewed critically on the fringes. In addition to the political arguments mentioned above, there are also references to the possibility of leaking storage facilities or high costs. The energy requirements of the technology itself rarely provoke criticism, with some claiming that only renewable energy should be used or expecting that much better energy efficiency will certainly be achieved with further development. The electricity for the production of so-called green hydrogen is also to be obtained from renewable energy sources; this is to be used to chemically convert CO₂ into “sustainable” fuels, for example as a substitute for kerosene from fossil sources, or into chemical base materials such as methanol (“Carbon Capture and Use”, CCU).

Measure of sustainability: entropy

However, there is hardly any demand from politics, climate research institutes or the media as to whether DAC and CCS are sustainable at all. To answer this question, we would of course also have to ask ourselves what “sustainable” actually means: How can we measure “sustainability”, assess it objectively and verifiably, or compare which process or which product A is more sustainable than alternative B? And is renewable energy sustainable per se? What is the reasoning behind this?

In qualitative terms, sustainability for DAC and CCS as well as CCU would mean: In addition to the expected positive effects on the climate, they should not cause any serious collateral damage to other parts of the environment, especially in the various ecosystems, for example by contributing to the intensification of the already dramatic biodiversity crisis. If there is collateral damage, it would have to be significantly lower than the positive results expected for the climate. But what does “minor” mean, and what does “serious” mean?

“Sustainability” has become an empty buzzword. Everything is sustainable: vacation trips, air travel through the purchase of CO₂ offsets, shampoo delivered in a bottle made from recycled plastic, and Porsche seats made from recycled clothing. Everyone is allowed to use “sustainably” according to their own taste; there are no criteria for sustainability. Even the well-known and popular Brundtland definition from 1987, according to which the present generation must not limit the possibilities of future generations, eludes any verification. It is purely anthropocentric, i.e. focused on human needs, and even that cannot be verified objectively. Environment and nature do not play any role.

Since the first report of the Club of Rome (“The Limits to Growth”), I have been driven by the search for a criterion that can be used for all types of procedures, processes and products. Life cycle assessments are far too expensive, far too complicated and often not comparable with each other. In the following, I would like to propose “entropy” as such a generally applicable criterion for discussion and have applied it to DAC, CCS and CCU to examine whether these processes are sustainable. To understand this, you only need to have a rough but correct idea of entropy. Scientifically, entropy is absolutely well understood – in contrast to gravity, for which science does not know whether it is quantized or not. Nevertheless, it is not difficult for us to understand what gravity does in our lives. After all, we experience it daily throughout our lives, even at night, because otherwise we would not stay in bed.

We also experience entropy every day throughout our lives, even at night – but to what extent? Roads and bridges deteriorate if they are not constantly renewed; the same applies to products made of wood; tires suffer abrasion, which spreads everywhere. Clothes and shoes can no longer be used after frequent use. Coal-fired power plants have an average global efficiency of 30 to 40 percent¹, the rest is entropy; of the energy content of premium gasoline, the engine only puts 20 percent on the road in the form of kinetic energy, a diesel engine at least 45 percent, the rest is entropy. All machines and means of transportation are subject to wear and tear; even with the best maintenance, they can no longer be used after a few years. And we ourselves have an efficiency of about 25 percent; we export 75 percent of the energy content of our food as entropy, in the form of heat, skin flakes, urine, feces etc.; we get sick, we age, waste products accumulate in our cells, and sooner or later we die.

Entropy costs

Unfortunately, entropy is often referred to in an extremely abbreviated and misleading way as a “measure of disorder”. In popular science articles, a glance at a child’s room is then recommended as an illustration. This is banal nonsense, just as wrong as the idea that entropy can only increase. It only increases to a maximum in closed systems (i.e. systems that exchange neither energy nor materials with their environment). The Earth, ecosystems, cities, animals, plants and even we ourselves are not closed systems, but open ones, even galaxies like our Milky Way. All of them exchange energy and materials with their respective environment. Only on the scale of the entire cosmos does entropy increase inexorably.

Modern thermodynamics shows under which circumstances entropy can decrease locally. It also shows much better what entropy is: inferior (in simple terms, no longer usable) energy; and because matter is also energy (Einstein: E=m*c²), entropy is also contained in inferior, no longer usable matter. This type of low-grade energy or matter can only be used if a considerable amount of energy is expended. This energy is used to reduce the amount of entropy contained in this low-grade energy/matter – although this has the effect of increasing the total amount of entropy where the energy required for this is provided. When energy is converted in a power plant, only about a third or a little more of usable heat or electricity is available – the rest, i.e. 60 to 70 percent of the primary energy used, becomes entropy. If we reduce entropy in a system, it will increase outside of this system (depending on the degree of efficiency) by a factor of two to three.

Let’s look at DAC, CCS and CCU in this context: CO₂ itself is a manifestation of entropy, because it is an inferior substance that is extremely difficult to use. As soon as CO₂ is released into the atmosphere and mixes with the other components of the air, so-called mixing entropy is created. Such mixing entropy arises when two or more substances spontaneously mix together, similar to how sugar dissolves in water on its own. When CO₂ is captured from the atmosphere or from waste gas, the mixing entropy is reduced. This means that DAC and CCS reduce the mixing entropy. With one ton of CO₂, the mixing entropy is reduced by 4.15 megajoules per Kelvin (MJ/K, i.e. energy unit per degree temperature).² To achieve this, we theoretically need 1.22 gigajoules (G J) of heat, plus considerable amounts of electricity. This generates a multiple of entropy compared to the amount of entropy extracted from the atmosphere, because we need at least three GJ of primary energy for the 1.22 GJ of heat. In practice, the total energy requirement for just a single ton of CO₂ is ten times higher than the theoretical requirement, at 16 GJ per ton of CO₂.

This means that the energy required to extract one ton from the atmosphere or from the exhaust air of a factory is about six times higher than the usable amount of energy that we have made available in the production of this ton of CO₂. This is justified and declared “sustainable” on the basis that the energy is provided by the sun and wind. However, this is neither realistic nor actually sustainable: in April 2024, the Leopoldina, Germany’s National Academy of Sciences, called for the permanent removal and storage (final disposal) or use of 60 to 130 million tons of CO₂ per year in addition to the reduction of CO₂ emissions. For 100 million tons, this would result in a primary energy requirement of 1,600 quadrillion joules. That would be 15 percent of Germany’s primary energy consumption in 2023 or a good 18 percent of the primary energy demand targeted for 2030 according to the German Environment Agency – which are not included in the calculation for 2030 and cannot be quickly provided within five years, let alone in the form of renewable energy.

Calculating with entropy

This alone should make it clear that these methods are anything but sustainable. The renewable energies such as solar or wind energy that are necessary for this are supplied to us without “entropy costs” (because their provision causes entropy in the sun). However, solar or wind power plants have to be built here for this energy (this requires the expenditure of raw materials and energy, and thus produces entropy); areas are needed that cannot be used for anything else, especially not for natural ecosystems; and each individual plant must be able to feed into the power grid, which means additional infrastructure – further “entropy costs”. All these plants will have to be completely replaced after 30 years at the latest. Finally, at least twice as much entropy, i.e. low-grade energy/matter, is created with sun and wind compared to the amount of usable electricity. Solar plants today have an efficiency of a good 20 percent³, wind power plants have an efficiency of a good 30 percent in practice⁴. The difference to 100 is therefore at least 70 percent, which is entropy. Since the recovery of CO₂ is already anything but sustainable (and not even enough renewable energy can be provided for it), the production of “green” hydrogen for CCU makes the problem worse: for this purpose, the renewable electricity would be used with a further high efficiency loss of 70 to 82 percent⁵, corresponding to massive entropy production; it is often forgotten that for the electrolytic hydrogen production, highly pure water must first be obtained with additional energy input and thus entropy; in Schleswig-Holstein and Mecklenburg, where the surpluses of wind energy occur. This electricity would be better used directly than to cause further high losses and thus environmental damage via the detour of “green hydrogen”.

The example of copper production can show what entropy specifically means: a high-voltage cable used to feed electricity from a wind farm into the grid has a very specific structure and function, and contains a very low amount of entropy compared to the copper ore from which the core of the cable was produced. So, during the production of the raw copper and then the pure copper, as well as later in the cable factory, entropy was first extracted from the copper ore and then from the cable being made. Where did it end up? We discover the entropy where the copper ore was mined and a landscape with functioning ecosystems has become a hostile environment.

The copper ore must first be chemically converted into crude copper, using a great deal of energy, before it can be electrolytically refined into pure copper. During the energy conversion, entropy is again created on a massive scale (in the form of waste heat and ash), and all kinds of unusable waste accumulate in the copper smelter and during the refining of the crude copper. These are “unusable” for us humans and just as useless for ecosystems, which no longer exist where the mountains of waste are located anyway. Of course, the copper wire still needs to be coated before the finished cable can be laid – all processes that in turn generate entropy, i.e. damage to the environment.

During the manufacture of all products and during the course of all kinds of processes and later when the products are used, entropy inevitably arises because entropy is reduced in the product or in the result of the process carried out. In the overall result, entropy has increased. It manifests itself in many forms: waste, waste heat, infertile soil, sinking groundwater levels, poisoned groundwater (and we can only get drinking water through energy-intensive water treatment, no longer simply from a nearby stream or a well in the garden), algal blooms on the coasts due to overfertilization, destroyed ecosystems, drained moors, dramatic decline in biodiversity. And last but not least, entropy manifests itself in the fact that it is becoming increasingly difficult to ensure the functioning of social coexistence, the financing of community tasks, pensions, health insurance; in short, we see entropy in the increase in national debt.

Collapse of complex systems

Entropy, i.e. inferior energy or matter, is also expressed in the loss of functions of complex systems. Let’s look at an ecosystem: When the streams were clean before, when there were diverse riparian zones, open and overgrown areas, and the streams supplied water to a landscape of mixed forest and wet meadows, ecosystems with a wide variety of plants could develop , which are inhabited by ruminant grazing animals (deer, roe deer), rodents, foxes, wolves, birds and insects, all of which find their food there – supplied with energy from the sun. With the development of the ecosystem and the growth of plants (from CO₂ and minerals), as well as the birth, hatching, growth and maturation of the numerous animals, entropy has fallen dramatically in all these organisms and in the ecosystem as a whole ; and this is at the expense of a multiple increase in entropy in the sun, while the entropy generated by the conversion of solar energy into complex ecosystems is radiated from the earth into space.

The complexity of life on Earth arises and is maintained by a great deal of energy input from the sun, very complex structures and networks form all by themselves (local entropy reduction), and the resulting entropy is radiated away from Earth. Entropy does not accumulate on Earth. Should this happen locally, due to natural disasters such as volcanic eruptions, periods of drought, floods or asteroid impacts, the sun, with its energy, takes over the task of rebuilding functioning complex ecosystems over thousands and millions of years. The entropy costs of the provision of solar energy are currently not borne by the Earth, but by the Sun itself – at some point the nuclear fuel there will be used up, and the Sun will no longer be able to sustain life on Earth.

As long as there are people on Earth, we have the choice of living and acting more or less sustainably. The key criterion for sustainability is entropy. A society would only be truly sustainable if it only generated as much entropy as can be radiated from the earth together with the natural ecosystems – in other words, if no entropy is generated in the form of low-quality matter (waste and toxins that destroy functioning ecosystems). At least for the time being, this is an unattainable utopia because we would need an infinite amount of energy to achieve it. With today’s technologies, we can only live and work more sustainably, but not completely sustainably.

What would be more sustainable than DAC, CCS and CCU? The answer is obvious: climate change and the decline in biodiversity must be tackled together, using the same approaches. “Sustainability” requires that nature, the ecosystems we need to survive, must not be damaged either. So we need to take action that is suitable for both climate stabilization and the rescue and restoration of ecosystems. Peatlands, floodplains, seagrass meadows, and mangrove forests must be restored. Instead of virtually dead spruce monoculture forests, mixed forests with open clearings must be allowed to grow. Industrial agriculture must convert to organic farming of fields and pastures, without chemical fertilizers, without pesticides – this is demonstrably possible, but of course it also requires a change in diet and in consumer expectations regarding the prices and availability of food.

Natural ecosystems can store significantly more CO₂ in the soil than is generally assumed. It is not the fast-growing trees in monoculture forests, but the humus-rich soils, the extensively grazed grasslands, the moors and other wetlands that can absorb and store many times more of the CO₂ emitted by us humans through industry, transport and households than we can imagine – if we let them work as they have always been able to.

According to this study,⁶ 226 Gt CO₂ can be stored in the soils of natural forests, which is 20 times more than we currently emit through industry and transport; another study⁷ comes to “only” 45 Gt CO₂, which is “only” four times more than human emissions. According to the Thünen Institute⁸, 2.22 tons of carbon (corresponding to 8.15 tons of CO₂) can be stored annually on grazed grassland if the pastures are managed organically, and many times that amount if they are not.

The planet’s peatlands can store twice as much CO₂ as all the world’s forests combined. All the different wetlands (peatlands, mangroves, kelp forests, salt marshes and seagrass meadows) store 20% of the total global carbon, although they only cover 1% of the earth’s surface.⁹ However, we in Germany have drained 95% of all our peatlands – they have become CO₂ emitters. If they were rewetted, we would already be emitting measurably less CO₂. This is just a less quantitative indication.

At the same time, the renaturation of the most diverse ecosystems would also powerfully address the biodiversity crisis.

The World Economic Forum has estimated that half of the world’s economic output depends on functioning ecosystems¹⁰ (the other half on energy supply, whether from fossil or renewable sources). This alone should make it clear: processes such as DAC, CCS and CCU, which, as we can see from the entropy balance analysis, will cause far more damage to the environment and ecosystems than they contribute to climate stabilization, are not sustainable.

Bernhard Wessling is a chemist and entrepreneur. He has a doctorate in chemistry and has dedicated himself to research in sustainable chemical technology and modern thermodynamics. He has also been an active volunteer in environmental and species protection for decades, as well as being a part-time investor and co-managing director of a large organic agricultural business.

1

2Cf. the article by B. Weßling in “Naturwissenschaftliche Rundschau” May 2024

3https://www.energie-experten.org/erneuerbare-energien/photovoltaik/solarmodule/wirkungsgrad

4https://www.weltderphysik.de/gebiet/technik/energie/windenergie/physik-der-windenergie/

5https://www.faz.net/aktuell/wissen/physik-mehr/energiewende-synthetisches-methan-ist-eine-gruene-mogelpackung-19887343.html

6Lidong Mo et al., Integrated global assessment of the natural forest carbon potential, in: nature, Nov. 2023:

7p. Lewis, C. Wheeler, E. Mitchard and A. Koch, Comment: Restoring natural forests is the best way to remove atmospheric carbon, in: nature, April 2, 2019,

8 [10.04.2024]

9Temmink, Ralph, et al., “Recovering wetland biogeomorphic feedbacks to restore the world’s biotic carbon hotspots”, Science 2022, Vol 376 , Issue 6593, [] [10.04.2024]

10https://www.weforum.org/publications/nature-risk-rising-why-the-crisis-engulfing-nature-matters-for-business-and-the-economy/