Professor James Lovelock Speech November 2006

A speech given by Professor James Lovelock at IChemE’s 5th John Collier Memorial Lecture, Savoy Place, London, 28th November 2006

I am much moved and greatly honoured to be chosen to receive the Collier Medal.

In my lifetime as a scientist chemical engineering has been an important part and this makes me more at home with many of you here than with the loftier practitioners of the pure sciences. I began work in 1938 as a lab assistant to a firm of consultants in London whose customers were the photographic industry, their business covered everything from gelatine manufacture to the synthesis of dyes for colour photography. It was hands on science and they gave responsibility, wisely I think, to school leavers that now would probably be denied graduates. Here I learnt the crucial importance of accurate measurement and had the chance to see chemistry in operation on an industrial scale. Later I graduated as a chemist from Manchester University and went directly to the National Institute for Medical Research (NIMR) in London to work on wartime problems involving medicine and physiology.

At my job interview, the director of the National Institute for Medical Research, Sir Henry Dale, who was also President of the Royal Society, told me with regret in his eyes, not to expect to do any proper science since work at the Institute was now just solving ad hoc wartime problems, preferably immediately. In fact, I found wartime science in the 1940s fascinating and an incredibly good apprenticeship for the kind of scientist I have become. It was a world that could not afford the niceties of scientific correctness and where biologists, chemists and physicists worked in close collaboration on urgent practical problems. Fire watching on the Institute roof gave me a unique opportunity for face to face encounters with distinguished older scientists. When bombs or missiles made a near miss they tended to reveal amazing truths about their lives and craft secrets.

Typical of the varied problems that confronted us was the prevention of cross infection in hospital wards and operating theatres that handled wartime casualties; and this in the days before antibiotics. My colleagues had invented an elegant device for measuring the bacterial content of the air. It drew air rapidly through a narrow slit poised above a circular plate of culture medium, about the size of a CD. The dish rotated slowly under the slit and after incubation, bacteria carrying particles collected on the plate grew to visible colonies and so we had a continuous measure of the bacteria in the air.

We were sent to a hospital that had an operating theatre with a poor record of cross infection; our sampler indicated an unhealthy contamination with pathogenic bacteria, which in those days were called haemolytic streptococci. We suspected that something was wrong with the ventilation and tried increasing the rate at which clean filtered air was blown in, but it made little difference to the bacterial count.

In those days the ventilation rate of a room was calculated from the measured flow rate of air though the input and output vents. The claimed rate was ten air changes per hour which should have been enough. But we checked it by releasing a small quantity of an easily measured gas, hydrogen, and then noting its decay in abundance. The decay was of course exponential and linear when plotted on log paper and the slope gave the ventilation rate in air changes per hour and it was if I remember correctly about two air changes per hour. We soon discovered that this was because the incoming air flowed across the top of the room and failed to mix with the air of the theatre itself. This was an exceedingly simple application of dynamics, where the operating room was viewed as a badly stirred reactor.

The concept must have stayed in my mind because many years later in the 1950s and still working for the MRC I made a number of detection devices for Martin and James newly invented gas chromatograph. A weakness of their first chromatograph was the lack of a sensitive vapour detector. I was able to provide them with two sensitive ionization detectors one of which could detect volume concentrations as dilute as parts per billion and the other less than parts per trillion. This helped to make gas chromatography a common but valued tool throughout science and industry. These detectors also provided an opportunity to use the concept of the stirred reactor. The detectors were small vessels of about one ml volume through which gas from the chromatograph column flowed. One of these ionization detectors, the ECD became quite famous as the starter of the environmental movement; it enabled gas chromatography to find the widespread distribution of chlorinated pesticides and gave support to Rachel Carson's hypothesis that these substances were destroying birds as well as insects and that their continued use in agriculture would lead to a silent spring. But how on earth do you calibrate an instrument capable of measuring vapours at parts per trillion? Standard mixture at the part per million are easy enough to make but at parts per billion the errors grow large. I doubt if anyone at that time the 1960s could make accurate ppt standards. I certainly could not and met this problem in the only way open to me namely to investigate the theory of operation of the ECD and see if it could serve as an absolute detector. He ECD is a small reactor containing a suspension of thermal energy electrons in pure nitrogen and when detectable substances separated by the GC column entered it there was an immediate reaction and molecules of many substances, including pesticides, such as DDT or dieldrin; reacted to form a negative ion at each collision with an electron in the chamber. It was easy to calculate from the number of electrons removed, what was the vapour concentration. In other words the detector had the potential to be absolute.

The reaction between electrons and molecules is second order and the dynamics of its differential equations in the flow system of a GC was well beyond my mathematical competence using traditional analytical methods of solution. But I happened to have Hewlett Packard as one of my customers and was able to buy from them one of their first simple desk top computers. It enabled me to write the programs for the numerical solution of the detector equations and this led to understand it and then prove that it was an absolute method of analysis and that calibration might not be needed. The rate constant for the reaction of room temperature gaseous electrons treated as a chemical is in the order of 3 time 10-7 cc per mol per second. About one thousand times faster than reactions between molecules. The ECD continued to be used to discover environmental hazards including PCBs and with it I first discovered the accumulation of CFCs in the atmosphere and of nitrous oxide and this played a major part in the research into the effect of CFCs on stratospheric ozone.

The invention of these sensitive detectors led in 1961 to an invitation from no less a person than the director of space flight operations of NASA to be an experimenter on their future lunar and planetary missions. It was this that gave me the courage to break the ties of loyalty that held me to that then near perfect employer the MRC, and become an independent scientist. NASA needed simple ultra sensitive devices to for analyzing the surface and atmosphere of Mars and the Moon and these I provided but soon, as a result of my years in medical research, I found myself involved with the biologists who were trying to invent ways to search for life on Mars. Their approach was to make small automated laboratories that mimicked a hospital path lab. They intended to scoop up soil samples on Mars and see if organisms could be grown in culture media and then detect growth either visually or by biochemical changes. They tested their prototype samplers in the nearby Mohave Desert and they worked well. I could not help asking them how you know that life on Mars is the same as here and will grow in your culture media. This was not a welcome question and they responded by asking me what I would do instead. I replied seek an entropy reduction of the whole planet, something that would indicate the existence of life whatever its form. Strangely this made them quite cross they seemed to think that I was mocking them but in fact I was serious having just read Schrödinger’s small but powerful book ‘What is Life?’

The next day I was summoned to the office of the lab director. A tough character named Bob Maghreblian. He wanted to know why I was upsetting his biologists and what did I mean by an entropy reduction detector? I replied that I would need time to think about it and he then said ‘you have until Friday’. It was then Tuesday and I realized that my next contract with JPL lay in the balance. On Thursday night it occurred to me that if I looked at a planetary atmosphere as a stirred reactor it would not be difficult to measure its entropy simply by analyzing the chemical composition of its atmosphere, then calculating how far it was departed from thermodynamic equilibrium. The idea behind this was that life on a planet is obliged to use a mobile medium like the atmosphere as a source of raw materials and a sink for waste products and such a use would make it characteristically different from the equilibrium atmosphere of a dead planet. When I told Maghreblian he was delighted by the idea and responded enthusiastically. He suggested that I write a letter on the concept to Nature, which I did, and it was published in 1965.

In September of that year I was in a small room at JPL together with a colleague Dian Hitchcock and the astronomer Carl Sagan, we were discussing planetary atmosphere when the door suddenly opened and another astronomer Lou Kaplan entered bringing data sheets of the latest infra red astronomical analyses of the Mars and Venus atmospheres. They showed both planets to have atmosphere made almost wholly of carbon dioxide with only a percent or less of the other gases. To me this meant they were close to chemical equilibrium and therefore lifeless.

When I looked at the composition of our own atmosphere as if I were an alien from some other world suddenly I realized that the conventional geochemical wisdom of the 1960s was probably wrong. It held that the atmosphere was a direct consequence of inorganic chemistry acting over the Earth’s long history. Viewed from outside the air which appears to be stable in composition over
long periods is in fact deep in chemical disequilibrium. The time constant for the photochemical reaction in the air between oxygen and methane, for example, is about twelve years. This requires a huge production rate for both of these gases and one that stays constant for long periods. . We knew that oxygen was made by green plants and Hutchinson had shown that other atmospheric gases including methane, and nitrous oxide were direct biological products and that the other principle gases oxygen nitrogen and carbon dioxide were massively cycled through the biota. Life at the surface seemed to me at least as influential as inorganic geochemistry.

As these thoughts passed through my mind in 1965 and it suddenly occurred to me that perhaps the air is kept dynamically stable by life at the surface and maybe the organisms were regulating the atmosphere in their own interest. I was encouraged further in this belief by the astronomer Carl Sagan, who shared the office with me, he said that astronomers were fairly sure that the sun has
increased its heat output by 30% since the Earth was formed. Carl wondered how the Earth seemed to have grown cooler not hotter in spite of it. We both knew that small changes in methane and carbon dioxide greatly affected climate and for me this was enough to postulate that life regulated the Earth’s atmosphere and climate so as always to keep it habitable.

When I returned to England I discussed the idea with a near neighbour the novelist William Golding and he suggested calling the hypothesis Gaia, after the Earth Goddess of the ancient Greeks; she was of course the same goddess that we acknowledge in the name of geology and geography and so on.

Shortly after I began collaboration with the eminent biologist Lynn Margulis; she enriched the hypothesis with her deep understanding of micro-organisms which were the whole of the biosphere until the end of the Proterozoic.

For the next few years Gaia was just another hypothesis neither welcomed nor rejected but in the late 1970s neo Darwinist biologists mounted a strong attack led by W. Ford Doolittle and soon followed by Richard Dawkins. Their main criticism was that the hypothesis invoked teleology, as Dawkins put it in his book The Extended Phenotype, there was no way for an organism to evolve to regulate anything beyond its phenotype. So powerful were these critics that by about 1980 the objections to Gaia were so strong it became almost impossible to publish a paper with Gaia in the title. I responded by expressing my ideas in books. The first ‘Gaia: a new look at life on Earth’ was published in 1979.

The criticism from biologists was painful but it was valuable because it forced me to think. In 1981 I realised that they were partially right and that there was no way for an organism or the biosphere to evolve by natural selection to regulate the whole planet.

From my background in industrial science I knew about feedback, control theory and how systems self regulate. It occurred to me that the Biologist’s objection could be answered if instead of life we considered the whole system of life and the material Earth taken together as a unit; this Earth system could be the entity that evolved planet scale self regulation. To test this idea I made a numerical model of two species of dark and light plants evolving on a simple world whose star increased it heat output as it aged as our Sun is doing. The climate of the model planet was determined by extent to which that dark and light coloured daisies reflected or absorbed sunlight; the model which regulated planetary temperature close to the optimum for plant growth over a wide range of solar output.

(Figure 1)

Daisyworld needs no careful choice of initial conditions, is never chaotic and is strongly resistant to perturbation. The temperature it predicts and holds constant is determined only by the normal preference of the daisies. There are no set points on daisyworld it evolves its temperature regulation. The model was welcomed by climatologists as a practical way of including the influence of natural ecosystems in their forecasts of future climates. Biologists were either unconvinced or irritated and made many attempts to falsify it but none of them succeeded. It is important to note that the mathematical models of both climate scientists and biologists at this time were of systems that an engineer would instantly recognize as open loop. Not surprisingly both climate and life scientists soon discovered deterministic chaos instead of the answers to their questions.

I have expressed my views on climate change more forcibly than do most other climate scientists. And I did so from a top down view of the whole planet not from the specialist view more usual in science. I see it as a physiological system and something that actively responds to change and quite different from the dead planets Mars and Venus that respond passively. Far from decreasing my pessimism this Gaian view leads to climate models that suggest the Earth is now in what in medicine would be called failure; in other words, natural climate regulation is temporarily out of action. The models suggest a rapid change in temperature to a hot stable state that the Earth has experienced many times in its history. This is in contrast to conventional climate predictions that are almost all off them based on geophysical models that assume a planetary biota that responds passively not actively to change.

In 1994 the American geochemist Lee Kump and I made a simple model of the Earth that was intended to do no more than illustrate for teaching purposes how the Earth could self regulate its climate. As time has passed to our surprise this model has unusually well predicted the course of Global heating.

Our model was a descendant of daisyworld and was a simple planet that had land masses and oceans in similar proportion to the Earth. We had plants growing on the land and algae in the ocean. The model planet was illuminated by a star at the same distance and same luminosity as the sun. The surface temperature of the planet depended on the greenhouse effect of the carbon dioxide
in the atmosphere and the proportion of sunlight reflected by the surface and clouds. Carbon dioxide abundance was regulated by the growth of the planets vegetation. The most important part of the model was the variation with temperature of the area covered by algal and plants. In the laboratory the growth rate of plants and algae both increase as the temperature rises from 0oC to a peak near 30oC and then falls to zero at 50oC. In the real world geophysics intervenes. Algal growth and area cover increases with temperature from 0oC as in the lab but in the ocean growth ceases at about 10 to 12oC when the surface water forms a stable layer about 30 to 50 metres thick; when this happens nutrients in the cooler water below are no longer mixed in and the algae starve. On the land, plant growth similarly increases with temperature until the rate of water evaporation becomes greater than the rainfall and this is at a temperature of about 22oC, here also growth ceases except in the special case of tropical rainforests which have evolved a number of mechanisms to conserve water.

(Figure 2)

What is modelled here is an event similar to the geological accident 55 million years ago at the beginning of the Eocene period. In that event between one and two terratons of carbon dioxide were released into the air. We are fairly sure about this from measurements made by Professor Elderfield of Cambridge University and his colleagues. They measured the carbon and oxygen
isotopes of the sedimentary rocks of that time and confirmed the quantity of carbon put in the air and the extent the temperature changed. Putting this much CO2 in the air caused the temperature of the temperate and Arctic regions to rise 8oC and of the tropics 5oC and it took about 200,000 years for conditions to return to their previous state. In the 20th century we injected about half that amount of CO2 and if we continue as we are, we will have released in thirty years from now more than a million million tons of CO2. Moreover, the sun is now hotter than it was 55 Myears ago and we have disabled about 40% of Gaia’s regulatory capacity by using land to feed people. This is why climate scientists are so concerned that we have already set in motion damaging climate change.

The history of global heating 55 million years ago suggests that the injection of gaseous carbon compounds took place over a period of about 10,000 years, much slower than we are now doing. In his paper, Professor Elderfield’s suggests that because of the slow rate of introduction CO2 rose by no more than 70 and 160 ppm. Compared with our present pollution with CO2 this is a small
increase, we have already raised CO2 by 100 ppm with an injection of only 500 Gigatons. In thirty years, if we continue business as usual, we will have added 1000 Giga tons and raised CO2 by 200ppm, more than is thought to have been present in the early Eocene. The great rapidity of our pollution of the atmosphere with carbon gases is as damaging as is the quantity. The rapidity of our pollution gives the Earth system little time to adjust and this is particularly important for the ocean ecosystems; the rapid accumulation of CO2 in the surface water is making them too acid for shell forming organisms. This did not happen during the Eocene event because there was time for the more alkaline deep waters to mix in and neutralize the surface ocean.

There are other differences between the earth 55 Myrs ago and now. It was about three degrees warmer at the start of the event and it took place on an Earth with a more uniform temperature than now. The polar ocean was a land locked fresh water lake. There were no ice caps and the sea was about 200 metres higher than now. On the other hand the sun was 0.5% cooler and there was no agriculture anywhere so that natural vegetation was free to regulate the climate. Another difference was that the world was not then experiencing global dimming – the 2 to 3 degrees of global cooling caused by the atmospheric aerosol of man made pollution. This haze that covers much of the Northern hemisphere offsets global heating by reflecting sunlight. The aerosol particles of the haze persist in the air for only a few weeks, whereas carbon dioxide persists for between 50 and 100 years. Any economic downturn or planned cut back in fossil fuel use, which lessened the aerosol density, could carry us beyond the threshold of irreversible change. This is why I say we live in a fool’s climate. We are damned if we continue to burn fuel and damned if we stop too suddenly.

Global heating is now a perceptible warming trend but as the 21st century unfolds the heat will intensify and together with drought, storms and floods make much of the world uninhabitable. Our remote ancestors lived through similar catastrophic climate changes as the Earth moved between glacial and interglacial periods but no record of their thoughts and fears has survived except perhaps the persistent legend of the flood. We can imagine an early civilization 13,000 years ago at the depth of the last ice age going about their daily business at a coastal site 120 metres below what is now sea level at some warm but temperate place at low latitudes. They did not know it then but soon their world would vanish as natural global heating melted vast accumulations of Arctic and Antarctic ice. Land, the area of the entire African continent disappeared beneath the sea and global temperatures rose to make the regions we now know as the tropics. The consequences of present day man made global heating will be at least as severe climatically but take place on our densely populated world hosting a set of fragile civilizations. The intolerably hot world soon to come can support only a remnant of today’s burgeoning humanity and the survivors will be driven to the cooler regions of the arctic and to a few continental oases and to islands. We have to understand that the catastrophe threatened by global heating is far worse than any war, famine, or plague in living memory; worse even than global nuclear war. Much of the lush and comfortable Earth we now enjoy is about to become a hot and barren desert.

These stark predictions may seem exaggerated but in fact they differ only in emphasis from the well respected Intergovernmental Panel on Climate Change (IPCC), which published its third assessment report in 2001. It was well and clearly written but reflected the natural caution of good scientists and did not often capture the attention of an intelligent lay person. For example it speaks of the probability of global temperatures rising as much as 3 degrees by the end of the century and the possibility of a rise as much as 5 degrees. To the average reader even 5 degrees seems a small and easily managed change but climate scientists know that a 5 degree shift in global temperature is a change of geological proportions. To me this serious and properly scientific report is the most scary and pessimistic document I have ever read, it is as frightening as it would be to receive personally the diagnosis of an untreatable malignancy. A climate scientist would find it difficult to escape the conclusion that by 2040 the intolerably hot European summer of 2003 when 20,000 died, will be the norm and by 2060, if anyone remains to observe it, that torrid summer would be thought cool. There will be painful human and natural consequences of repeated summers of such severity; agricultural and natural ecosystems will perish and no longer be able to support Europe’s dense population. Even the milder summer heat of 2006 has cut back European agricultural production by 40%. The Americas, Africa and Asia will endure similar adverse change and mass migration to cooler regions seems inevitable.

(Figure 3)

As a scientist I know that there are no certainties about the future only probabilities. The climate modellers are not unanimous in their predictions; the respected climatologists Tom Wigley and Meehl both think that temperatures will not rise much more than 2 degrees by the end of the century and rapid global heating may never happen. We might be rescued by a natural event, such as a series of large volcanoes each the size of Tamboura that erupted in sequence. This could put the Earth back on course towards the next glaciation. More probably, when the people of the United States become aware of the reality of global heating they will try to fix it with sunshades in space or by stratospheric particles that reflect sunlight away from the Earth. Technological fixes of this kind should not be unthinkingly condemned; they might buy us all some much needed time but more probably they would provide the excuse to continue business as usual. It would be as unwise to rely on them as a cure as for someone threatened with kidney failure to assume that dialysis would allow life to go on as before. But who would refuse dialysis if death was the alternative? Despite this reservation, I am fairly sure that our proper response to global heating lies in science and engineering and not by abandoning them. For many nations nuclear energy will a powerful aid for the sustenance of habitability and civilization.

So what should we do? First we have to change the way we think about the Earth. We have been led unintentionally astray both by our traditional religious beliefs and by the lack of a unified Earth and Life science. Our morality requires a belief in the transcendence of human welfare and we act as if the Earth was given to us and we are in charge of it. These precepts ignore the fact that we share the planet with a host of other life forms and we depend on them to sustain a habitable environment.

We also need to change our thinking about environmentalism. Environmentalism is an urban belief that encompasses a wide spread longing for a more natural way of life but has little understanding of the natural world and which has an irrational fear of almost anything scientific. At present Environmentalists pay lip service to threats to wild life and to ecosystems like coral reefs and the Amazon forest but in practice they are obsessed with hazards to personal health such as: pesticide residues in foodstuff, nuclear radiation, and genetically modified food. They have near completely ignored regulatory functions of natural ecosystems and failed to see that they can not be replaced by farmland. Indeed we are only just beginning to suspect that human changes in the Earth’s surface ecosystems by primitive farmers may have affected climate for perhaps as much as 100,000 years. The early settlers in Australia were almost as good at destroying ecosystems as a modern agribusiness farmer, and organic farmers are unlikely to be better.

Green ideology is an understandable response to adverse change but it is wrong to make science and technology the scapegoats for its anger. Not surprisingly any alternative energy scheme that seems natural and not based on science or technology is embraced by environmentalists. Some of these alternatives, such as biofuels are positively dangerous and if exploited on a large scale would hasten disaster. Others such as wind energy are inefficient and expensive. In the now rapidly changing world the green concepts of sustainable development and renewable energy that inspired the Kyoto meeting are far too late to have any value. What we need now is a well planned and sustainable retreat from the polluted and degraded world of today. The only way, I think, to do this is to welcome science and technology and make maximum use of environmentally friendly nuclear fission energy. We are an urban civilization and to survive the severe climate change soon due we need secure supplies of food water and electricity. We cannot expect to go on burning fossil fuel nor establish a non polluting way to do it in time. Therefore, except where electricity is powered by abundant water flow or geophysical heat, there is no safe alternative to nuclear energy.

I think that all of us here who are well informed about the benefits of nuclear energy have a duty to humanity to speak strongly in its favour. We cannot stand aside from the persistent fiction that nuclear energy is uniquely unsafe. We have started a new century still disregarding the true nature of the Earth and the consequences of this neglect are beginning to be felt; as the century proceeds they could be devastating. As the Earth changes to its new hot state there will be vast geographic and demographic changes. There is almost certain to be major unrest as whole communities are displaced by flood or drought. Modern civilization is energy intensive and we cannot turn it off without crashing, we need the security of a powered descent. We have to start now the expensive task of preparing our defences against change. Island nations like Japan and the UK, because of their oceanic position, will be less affected but become an ever more attractive destination for the world’s climate refugees. We must prepare as global heating intensifies to make maximum use of our own indigenous sources of food and fuel. Supplies from abroad are likely to become expensive and eventually unobtainable. Chemical engineers may have to consider synthesizing food.

In no way do I mean that there is no hope for us or that there is nothing that we can do. I see our predicament as like that of a nation about to be invaded by a powerful enemy; now we are at war with the Earth and faced with much more than a blitzkrieg. All our efforts and energies should go towards adapting to the ineluctable changes we may soon experience. Perhaps the saddest thing is that if we fail Gaia will lose as much or more than we do. Not only will whole ecosystems and most of their wildlife go extinct but in human civilization the planet has a precious resource. We are not merely a disease; we are through our intelligence and communication the nervous system of the Earth. We should be its heart and mind, not its malady. I have tried to show that Gaia theory provides an intellectual habitat where understanding of the Earth can evolve and grow. Perhaps its greatest value lies in its metaphor of a living Earth, which reminds us that we are part of it and most of all that there are no human rights only human obligations.