Climate Change, Gaia, and wise policy
Using systems thinking to portray the essence of James Lovelock’s Gaia Theory, Dennis Sherwood argues that, whilst reducing emissions is a good way to combat climate change, it is not the right way.
When I get hot, I sweat. I don’t think, “I’m getting rather hot, I need to do something about it” – sweating is a natural, and unconscious, response.
But underlying this very familiar experience are some rather less obvious concepts. Let’s dig deeper into what “I’m hot” actually means. Yes, one meaning is that my body temperature, as measured on a thermometer, might be around, say, 38°C. More important, though, is the fact that 38°C is greater than 36.9°C, the normal temperature of the human body - and it is the difference between my actual temperature and the normal temperature that triggers the appropriate physiological response: if this difference is positive, and my actual temperature is greater than the norm, I sweat; if this difference is negative, I shiver. The BIG QUESTION, though, is where does the ‘normal’ temperature of 36.9°C come from? Why is the value 36.9°C, rather, than, say 35°C or 40°C? And why does every human being have the same normal temperature, around the planet? Do we all possess some sort of ‘thermostat’, like the control box that keeps a domestic heating system at a comfortable 20°C?
No. I don’t have a ‘thermostat’ set to 36.9°C. Rather, this temperature is a consequence of the human body as a ‘self-organising system’ – a complex system, of many different mutually interacting parts, all of which work in harmony together, and which collectively display a number of ‘emergent properties’, properties which are features of the system-as-a-well-connected-whole, rather than of the individual ‘bits’ from which the system is comprised. That’s rather a mouthful, so let me give some very familiar examples.
Firstly, a hurricane. Hurricanes are immensely powerful; they are ‘born’ from particular weather patterns and ‘grow’ into structures of great power; they move; and – after a number of days – they peter out and ‘die’. Yet a hurricane is composed of nothing more than water and air. Under certain specific conditions, however, these simple components come together as a self-organising system which shows emergent properties such as structure and power. And the metaphor of ‘birth’, ‘growth’ and ‘death’ recognises how similar a hurricane appears to be to a living organism.
Secondly, a flock of birds. Here again, the flock as a whole comes together; maintains beautiful, dynamic, unity as the flock migrates; and ultimately disperses. Whilst the flock is together, each individual bird maintains its place in the crowd – not because the lead bird is sending each other bird a text message saying “in one-tenth of a second’s time, you must take your position at GPS co-ordinates [whatever]”, but because the flock as a whole is a self-organising system, with the emergent property of the flock’s shape and structure.
A third example is me, and you – as human beings, we are self-organising systems, showing emergent properties such as our normal body temperature.
A further emergent property of all self-organising systems is regulation. If my actual body temperature exceeds the normal temperature, I sweat. As a result, my actual body temperature drops, until it returns to normal, at which point I no longer sweat. This is an example of an in-built regulatory process which ensures that my body temperature stays at the norm, 36.9°C, so maintaining my life. Sometimes I get so hot that sweating no longer reduces my temperature enough, causing another mechanism to be invoked – the expansion of the blood vessels near my skin, allowing more blood to flow on my surface, so that more heat can be lost. Likewise, if my body temperature drops below normal, I shiver; if that is insufficient, then the blood vessels near my skin contract, with the dual benefit of reducing heat loss from my surface, and maintaining heat around my internal organs. These regulatory processes are vital to maintaining the integrity of the corresponding self-organising system, me. But they are not fail-safe: sooner or later, they break. If I become very hot, I will die of heat exhaustion; if I become very cold, I will die of hypothermia. I will no longer be a self-organising system, and I will no longer show emergent properties. I will be dead.
And so to a fourth example of a self-organising system; a self-organising system that shows emergent properties; a self-organising system that has in-built regulatory processes to maintain its integrity. Our planet. That’s what James Lovelock’s Gaia Theory is all about – our planet as a single self-organising system, with all its component parts doing ‘just the right thing’ to maintain itself over time – just as all the component parts within our bodies do ‘just the right thing’ to maintain our individual lives. Unfortunately, Lovelock’s Gaia has been hijacked by New-Age mystics, who have misrepresented, and misunderstood, Lovelock’s prodigious contribution to our knowledge: his book Gaia: The practical science of planetary medicine validates Lovelock as a truly great scientist.
If Gaia is indeed a self-organising system, then we would expect it to show emergent properties, and to exhibit regulatory processes. It does. One emergent property is its normal temperature, 14°C, and one regulatory process is what Lovelock calls the ‘living pump’, as shown in Figure 1.
Figure 1: How the Earth’s temperature is regulated
Figure 1 is an example of a ‘systems thinking causal loop diagram’ – a representation of ‘chains of causality’ which collectively describe how a complex system works. So, in this diagram, the ‘curly arrow’ linking solar energy to the actual Earth temperature captures the idea that the amount of solar energy (the ‘cause’) that falls onto the Earth’s surface over any given time period influences the actual Earth temperature (the ‘effect’), rather than the other way around. Furthermore, if the amount of solar energy falling onto the Earth’s surface were to increase, then we would expect the actual Earth temperature to increase too. This ‘direct’ relationship, in which an increase in a ‘cause’ drives an increase in an ‘effect’, is represented by a solid curly arrow. As we shall shortly see, an ‘inverse’ relationship, in which an increase in a ‘cause’ drives a decrease in an ‘effect’ is represented by a dotted curly arrow. (Some causal loop diagrams use a + sign or an S to designate a direct relationship, and a – sign or an O for an inverse relationship – in this article, to avoid clutter, I will use solid and dotted lines.)
As I have noted, as a self-organising system, the Earth has an emergent property, the normal Earth temperature, about 14°C. If, for whatever reason, the actual Earth temperature is rather higher, say, 15°C, then this opens a temperature gap, which we may define as the difference between the actual Earth temperature and the normal Earth temperature
Gap = Actual – Normal
which in this case, would give a temperature gap of 15°C – 14°C = 1°C. A moment’s thought will verify that, if the actual Earth temperature were to increase (say, to 16°C), then the temperature gap will increase to 2°C. These two variables therefore have a ‘direct’ relationship, and so the linkage between them is represented by a solid curly arrow. In contrast, if (for whatever reason) the normal Earth temperature were to increase (say, to 14.5°C), then the temperature gap decreases - this ‘inverse’ relationship being represented by a dotted curly arrow.
For humans, if our actual temperature exceeds our normal temperature, this triggers sweating, which brings our actual temperature back to normal. Gaia doesn’t sweat: rather, the Earth’s temperature is regulated by controlling atmospheric carbon dioxide.
Very briefly, atmospheric carbon dioxide acts as a ‘blanket’ – the greater the amount of atmospheric carbon dioxide, the ‘thicker’ the ‘blanket’, and so the higher the actual Earth temperature; conversely, the lesser the amount of atmospheric carbon dioxide, the ‘thinner’ the ‘blanket’, and so the lower the actual Earth temperature. Carbon dioxide is not the only gas to act as a ‘blanket’ in this way – so do all other ‘greenhouse gases’, such as methane.
As lucidly described in Gaia: The practical science of planetary medicine, when the actual Earth temperature rises above the normal Earth temperature, so opening a temperature gap, the higher temperature of the oceans causes an increase in the growth of marine algae. Amongst these are some that transform carbon dioxide, originating in the atmosphere, into calcium carbonate in their shells. When these organisms die, the shells fall to the bottom of the ocean, where, over long periods of time, they are compressed to form limestone and chalk – in fact, all the limestone and chalk on the planet was formed in this way, over many, many millions of years. The net effect of this process, which is mediated by marine algae, is to ‘pump’ carbon dioxide out of the atmosphere, and ‘bury’ it as rock. The rate at which this process operates depends on the magnitude of the temperature gap: when this is relatively large, the ‘living pump’ acts more quickly, so extracting relatively greater amounts of atmospheric carbon dioxide, thereby causing a greater cooling effect; when the temperature gap is relatively small, it acts more slowly. As a result, the actual Earth temperature is maintained at the normal Earth temperature, subject to small fluctuations, just as our actual body temperature is maintained at our normal body temperature.
The ‘living pump’ has been operating for billions of years, and has successfully maintained the actual Earth temperature to remain at about 14°C, allowing life to flourish. Over those billions of years, the nature of that life has changed as new species have evolved and others have become extinct. But life itself has continued.
All of these processes are captured in the diagram shown in Figure 1, the key feature of which is a continuous loop. This loop acts to close the temperature gap, so keeping the actual Earth temperature in line with the normal Earth temperature by invoking the ‘living pump’, as required, to extract more, or less, carbon dioxide from the atmosphere as needed to keep things ‘just right’. Since an increase in the activity of the ‘living pump’ drives a decrease in atmospheric carbon dioxide, then that link is an inverse link, whereas all the other links in the loop are direct links. This is important, for any loop which contains an odd number (one, three, five...) of inverse links, such as the loop shown in Figure 1 (which has a single inverse link), is known as a balancing loop, for it acts to keep the system in balance, bringing an actual into line with a target.
That a regulatory process of this nature works at the level of our planet may be something of a surprise; but if you substitute ‘my temperature’ for Earth temperature in the diagram, and replace the combination of ‘living pump’ and atmospheric carbon dioxide by ‘sweating’, the resulting diagram represents how all human beings regulate their temperature when they get hot. That is not a surprise – it is familiar to us all. The planetary process is analagous, but on a larger scale.
In terms of the time horizons we have been considering – billions of years – it is in the very latest blink-of-an-eye that the human species has emerged. Although all living things impact their local environment to a degree, man’s impact is disproportionately large – and in particular, over the last century, the human activity of burning carbon-based fossil fuels has resulted in steadily increasing emissions of carbon dioxide, which has to go somewhere – and that ‘somewhere’ is into the atmosphere:
Figure 2: The effect of carbon-based emissions
Figure 2 illustrates that as there is progressively more human activity, then (amongst very many other things not shown) one result is an increase in carbon-based emissions, so adding to the amount of atmospheric carbon dioxide. This in turn causes an increase in the actual Earth temperature, opening a temperature gap, thereby activating the ‘living pump’. This then reduces the amount of atmospheric carbon dioxide, so bringing the actual Earth temperature down, and closing the temperature gap. At this point, the actual Earth temperature is equal to the normal Earth temperature, and the regulatory mechanism has served its purpose in keeping the actual Earth temperature stable. Overall, the additional carbon dioxide introduced into the Earth’s atmosphere by human activity is removed by the additional activity of the ‘living pump’, so maintaining stability.
For many thousands of years of man’s existence, this is exactly what has happened. But as the human population, and (driven by technological development) the corresponding human activity, have continued to increase, the quantity of carbon-based emissions has increased very substantially – causing the ‘living pump’ to ‘work’ harder and harder to keep the actual Earth temperature stable. But just as, sooner or later, sweating fails to regulate our body temperature, sooner or later, the ‘living pump’ reaches a maximum capacity. And if the rate of introduction of atmospheric carbon dioxide from human activity exceeds the rate of extraction of atmospheric carbon dioxide attributable to the ‘living pump’, then the quantity of atmospheric carbon dioxide must get greater minute by minute, month by month, year on year. And, as Figure 2 makes very clear, the actual Earth temperature must inexorably increase. It’s rather like a bath, with a tap and a drain. The amount of water in the bath is the net result of how fast water comes in through the tap, and how fast it runs away through the drain. If the flow through the tap is relatively modest, then as much water flows into the bath as flows out through the drain, and the level of water in the bath stays constant. But as the tap is opened, and more and more water flows in, a point is reached at which the inflow through the tap exceeds the outflow through the drain, and the level of the water in the bath must rise.
That is what is happening right now – and has been happening for at least twenty or thirty years – as regards global warming. The ‘outflow’ of atmospheric carbon dioxide attributable to the ‘living pump’ has reached its maximum capacity, whilst the ‘inflow’ attributable to human activity has continued to rise. The consequence is inevitable. The quantity of atmospheric carbon dioxide steadily increases, and the actual Earth temperature must rise too.
But, just as our bodies have more than one method to control our body temperature, our self-organising planet does not rely solely on the ‘living pump’. If the ‘living pump’ can’t pump fast enough to remove a continuing build-up of atmospheric carbon dioxide, another mechanism is invoked, as shown in Figure 3:
Figure 3: A second planetary regulatory mechanism - storms
Storms. Hurricanes and cyclones, for example, dissipate prodigious quantities of energy, and that energy loss reduces the actual Earth temperature, so cooling the planet down. Technically, this is represented by a second ‘balancing loop’, which, like the first one through the ‘living pump’, acts to regulate the Earth’s temperature, and keep it constant.
Storms, however, have an additional effect, as shown in Figure 4:
Figure 4: Man under threat
Storms, and the associated high winds and flooding, cause devastation – devastation made even more severe by direct results of a rise in the actual Earth temperature, such as causing previous fertile land to become desert, and the flooding of low-lying land attributable to rising sea levels (caused by the heat-induced expansion of the water in the oceans, as well as the melting of Antarctic ice). Furthermore, attempts to protect against these disasters could well be counter-productive. If, for example, flood protection is to be provided by building sea walls, and if these are made from concrete, then the emissions created in the manufacture of the concrete and in building the walls could themselves add to the atmospheric carbon dioxide, so causing Gaia’s feedback loops to act even more vigorously: trying to protect against storms could make the storms even more violent.
Collectively, storms, floods, and rising sea levels reduce the land available for agriculture, so causing starvation; living space will also become restricted, causing mass migration, which in turn could cause conflict and war. The inevitable consequence is to reduce the number of humans on the planet, which will reduce human activity, and so emissions will fall - a feedback process which ‘solves the global warming problem’ by eliminating the ‘root cause’, human beings.
That sounds dramatic, but it is worth thinking about. Suppose, for example, that you are on holiday, and some mosquitos start attacking you. What do you do? You swat the mosquitos, of course, killing them. They are a nuisance, and what does it matter if a few mosquitos are killed? Now scale that concept up. Human activity is annoying Gaia. So what might Gaia do? And let’s remember that life has existed on Earth for billions of years, and that man is a new arrival. If man is proving a nuisance, and needs to be ‘swatted’, then so be it. Man needs Gaia more than Gaia needs man. So a rise in the actual Earth temperature does not necessarily imply the end of life (although if the rise is large enough, Earth will become as dead as Mars); rather, it highlights that life could well be sustained - but that man might not.
Gloomy stuff indeed. That’s why I’m writing this article. My purpose is not to rant; rather, it is to provoke thought and discussion. For Figure 4 presents my ‘mental model’ of how I believe the global ‘system’ works, and of where we are right now. The amount of atmospheric carbon dioxide is steadily increasing, year-on-year, primarily due to emissions attributable to human activity. The ‘living pump’ is working at maximum capacity, but can no longer hold the actual Earth temperature stable, as it has done for countless millions of years. And the global weather systems are becoming progressively more erratic, and storms more frequent and violent, as the planet’s self-organising regulatory processes strive to maintain control.
Of course, the ‘system’ is much, much, more complicated than as depicted in Figure 4, and there are a huge number of events, and effects, that I haven’t captured. But one of the powerful features of systems thinking is the licence it gives to allow the ‘wood’ to be distinguished from the ‘trees’. To my mind, fundamentally, the global system can be represented as shown by Figure 4. Certainly, other features – the albedo effect (the reflection of heat from white surfaces, such as snow, in contrast to the absorption of heat by darker surfaces, such as the sea); the existence of other sources of atmospheric carbon dioxide (such as respiration, and volcanic activity); Stefan’s Law of Radiation (which is about how quickly the Earth loses heat into space); the influence of the education of women on the birth rate (which impacts the Earth’s population, and hence the total human activity), to name just a few - can be incorporated (giving a much bigger picture), but the key inferences will, I think, remain unchanged.
If Figure 4 is a valid representation of the global system – and I welcome debate on that – then this raises the very important question “what policies can we adopt to intervene in this system wisely, so that the actual Earth temperature does not rise to a level that is a significant danger to human life?”.
Figure 4 helps us answer that question, for it identifies a host of opportunities as to where to intervene in the system. So, for example, if there were ways to reduce the amount of solar energy falling onto the Earth’s surface, then less heat would need to escape to maintain the actual Earth temperature in line with the normal Earth temperature – which in turn implies that higher levels of atmospheric carbon dioxide could safely be tolerated. In principle, this could be achieved, for example, by making the sun-facing surfaces of clouds whiter - which is not an easy thing to do, and could have other ‘unintended consequences’, but it is a possibility.
Figure 5 shows three other policy options:
Figure 5: Which is the wisest policy mix?
Policies relating to adaptation address the question “given that bad things are likely to happen, what can we do influence human activity to minimise the likely damage?”. This is an important, and very sensible, question, and leads to, for example, enquiring as to how to design housing which is tolerant of flooding, how to develop ways of providing food which are much less dependent on dry land, and how best to deal with the possible migration of populations from low-lying areas, such as many islands, Bengal, and much of Northern Europe.
Policies relating to emissions reduction are sensible too, and have featured strongly at international conferences over the past few decades. But as those international conferences bear witness, getting international agreement is very difficult, if not impossible: quite legitimately, many developing countries see fossil-fuel energy as the key to their economic development, and regard the imposition of emission reduction targets as a not-so-disguised tool of economic imperialism, which the more developed countries are using as a pretext to hold them back.
Certainly reducing emissions is a good thing to do, for not only does it have the benefit of slowing down the rate at which carbon dioxide is introduced into the atmosphere, but it also has a number of other benefits too, such as reducing waste. But a moment’s thought shows that reducing emissions does not solve the fundamental problem that there is too much carbon dioxide in the atmosphere now. This is best appreciated by reference to the analogy of the bath, with a tap and a drain.
The amount of atmospheric carbon dioxide corresponds the amount of water in a bath; the combination of the ‘living pump’ and storms corresponds to the flow of water out of the bath through the drain; and the human-induced emissions correspond to the flow of water into the bath through the tap. Until relatively recently – say, a few decades ago – the inflow of emissions through the ‘tap’ was less than the maximum flow through the ‘drain’ of the ‘living pump’. Furthermore, the planet’s self-organising regulatory system, as depicted in Figure 2, controlled the outflow through the ‘drain’ so that the amount of atmospheric carbon dioxide in the ‘bath’ remained at just the right level to keep the actual Earth temperature at just the right value.
Recently, however, more and more emissions have come through the ‘tap’, and the ‘drain’ of the ‘living pump’ can’t ‘expand’ any more. The additional ‘drain’ of storms has also come into play, but even these two ‘drains’ together can’t take carbon dioxide out of the atmosphere as fast as it is coming in. As a result, the amount of carbon dioxide in the atmosphere is steadily increasing. And here is the key point: if the water in a bath is rising because the tap is allowing more water to flow in than the drain is allowing water to flow out, then turning the tap down just makes the level rise more slowly than it did before – but the level continues to rise nonetheless. And even if the tap is turned off altogether, it will still take some time for the water to return to the ‘right’ level, at which point the tap can be turned on again, but at a setting such that the inflow must never be greater than the maximum possible outflow.
Reducing emissions is indeed sensible, for it slows down the rate at which the climate change problem is getting worse. But, as the water-in-the-bath analogy vividly demonstrates, reducing emissions does not solve the problem of an increase in the Earth’s temperature. Reducing emissions is therefore a good policy. But it isn’t the right policy.
Figure 4, however, helps us identify what the right policy is. To develop a technology, which works at scale, to extract carbon dioxide directly from the atmosphere – this being a technology that operates alongside the natural process of the ‘living pump’, helping the pump to pump harder, just like incorporating another ‘drain’ into the ‘bath’. Let me note that this is not (directly) the same as carbon-capture-and-storage. Currently, carbon-capture-and-storage is used in association with manufacturing plants that produce high levels of emissions to trap the emissions so they do not enter the atmosphere; direct extraction is a technology which operates in the atmosphere in general, ‘sucking’ air in, and separating out the carbon dioxide.
This idea is not new. It is one of a class of ideas under the general heading “geoengineering”, and it featured in the 2009 report from the Royal Society, Geoengineering the Climate – Science, governance and uncertainty, in which, on page 49, we read the words “...by reducing CO2 concentrations, CDR methods [namely, those methods that directly extract carbon dioxide from the atmosphere] deal with the root cause of climate change and its consequences.” Furthermore, some research to develop this technology is being done in the US, but very little in the UK and Europe. And, very importantly, this approach is absent from the political map – all the political discussions are about emissions reduction rather than direct extraction. Which is a paradox, for direct extraction solves an otherwise insoluble political problem. As already mentioned, gaining international agreement to reduce emissions is politically very difficult for the good reason that developing countries (correctly) perceive this to be a restriction of their economic development. But if there were an effective, large scale, deployment of direct extraction, then it doesn’t matter what the emissions are: as long as the carbon dioxide is extracted from the atmosphere as fast as it is put in, then the actual amounts going in and out are irrelevant – if the ‘drain’ is big enough, it doesn’t matter how fast the ‘taps’ are running, for the water in the ‘bath’ can always be maintained at the ‘right’ level. So, in principle, developing countries can burn as much fossil fuel as they like, growing their economies as fast as they like, with just the single proviso that they also use the required quantity of direct extraction technology.
The BIG PROBLEM, of course, is that the technology doesn’t exist. Once-upon-a-time, though, steam engines and aeroplanes didn’t exist either. But whereas steam engines and aeroplanes were invented and developed, piece-meal, over long periods of time, there is an urgency in inventing, developing and scaling-up direct extraction NOW. Which is more likely to be a question of commitment, funding and organisation than one of scientific and engineering difficulty – after all, those carbon dioxide molecules are in the air all around us, not chemically bound to other molecules, and so the fundamental issue is one of separation and extraction, rather than complex chemistry and physics. And if Marie Curie was able to separate minute quantities of polonium and radium from pitchblende over one hundred years ago, it must be possible to discover how to separate (albeit at large scale) carbon dioxide from the atmosphere today.
Commitment, funding, organisation. Why doesn’t the government, and the EU, build commitment to fund a UK (European?)-wide research programme, bringing together, and organising, an inter-disciplinary team of scientists, engineers, economists, and other experts, to solve the problem? It can be done. It just requires commitment, funding and organisation.