Presentation by Maria Kielmas to the UKELG Seminar, 22 March 2006 The title of this talk poses a question: is there really a scientifically proven link between carbon emissions and climate change? The answer is no. Philosophers and scientists have been debating the nature of scientific truth for thousands of years and have come to the conclusion that there is no such thing. All theories are necessarily tentative and temporary. Even experiments can be inconclusive. For most people everyday life provides us with proof of science: such as when we switch on a television, ride in a car or take an aeroplane. But we cannot bring the Earth and indeed entire Universe into a laboratory for experimentation. We can only observe and collect information. And this is where our problems begin. Weather and climate What is the temperature of the Earth? Instrumental measurements of Earth temperatures began only in the 1860s giving us nearly 150 years of information of varying quality. Most of this information is concentrated in the industrialised countries of the northern hemisphere, partly for obvious historical reasons of economic development, but mostly because some 80% of the southern hemisphere is ocean. Prior to the 1940s sea surface temperatures were taken from seawater collected by a bucket over the side of a ship. Satellite information about atmospheric temperatures didn’t enter the picture until the 1970s. Initially such temperature measurements were made to assist weather, not climate, forecasting. Weather is something we can recognise from day to day. The climate is a statistical analysis of weather data such as temperature, pressure, current speed and so on, over a relatively long period such as decades and centuries. The term “global mean temperature” was invented for this purpose. It is a weighted average of information from weather stations throughout the world. But as there are more of these in the industrialised north than in the southern continents the accuracy of measurements in the southern hemisphere is further compromised. Older data is provided by “proxy” sources such as the analysis of tree rings, where the density of the wood in each ring gives an indication of the prevailing temperature at a particular time. Other methods involve estimating the concentration of oxygen isotopes in ice sheets or older geological strata, and the identification of certain plant spores or invertebrates in the fossil record. The entire process is full of inaccuracies and assumptions on the part of the measurer. Outside of the instrumental records, the proxy data can really only be taken as an indication of climate trends. Even more care needs to be taken with historical accounts of the weather of the time. Ancient chronicles and personal diaries usually recorded extreme events such as windstorms and floods and, like today, the damage wreaked by these portents was the fault of the monarch.

Models The resulting data sets are used in computational modelling to make correlations between say, global temperature and carbon dioxide concentrations, or sunspot activity with pressure anomalies, and most recently, sea surface temperatures and hurricane strengths. The academic literature is full of health warnings about such correlations: they are not causality. The models try to simulate past climatic effects as well as to make projections about the future. This is a strange undertaking. You start out by wanting to model reality, so you already have your answer. The task is to work out the mechanics of how to move from your answer to your question, manipulating both your data and your model assumptions at the same time. It’s a trial and error process. Such simulations have been used with considerable success in the design of major engineering structures to withstand winds and earthquakes, and in the simulation of oil reservoir dynamics. But those are closed systems. The Earth is not. The vast number of variables – some models have up to five million variables – and the assumptions and subjectivity used in climate modelling makes it a complicated task and one whose results should be approached with caution. No one has managed to model the entire climate yet, not even a single monsoon. Public fear This is not the kind of explanation anyone would expect today when politicians from all sides vow to “combat climate change”; government officials inform us that climate change is a greater danger than international terrorism, designers exhort us to buy “climate neutral fashion” and supermarket magazines advocate “green parenting”. Broadcast, print and electronic media provide us with a continuous feed of information on how climate change caused by human activity is endangering our planet and life upon it. It has to be said at this point that climate extremes, such as hurricanes, are a normal part of climate processes just as earthquakes are a normal part of earth processes. They are not dangerous in themselves. They are dangerous because humans, for a host of historical, cultural and commercial reasons, choose to live in their path. The strength of Hurricane Katrina was equivalent to about 12 Hiroshima bombs. The strength of the earthquake which caused the Asian tsunami was equivalent to 700 million Hiroshima bombs. These are forces human beings cannot combat. Greenhouse The Earth’s average temperature is 15 degrees Celsius due in part the greenhouse effect. Certain gases, such as water vapour, carbon dioxide, methane, nitrous oxides, chlorofluorocarbons and ozone - trap a proportion of the Sun’s heat within the atmosphere. The relative proportion of trapped heat to that which is transported by air currents away from the Earth is the subject of dispute. Some scientists believe that the heat trapping agents are pulverised meteorites and other particles. But the popular

thinking is that if humans do not curb such “greenhouse gas” emissions, Earth temperatures will rise uncontrollably, melt ice sheets and cause huge sea level rises, as well as increase the frequency and strength of extreme events such as hurricanes. IPCC Underpinning this view is a series of studies issued by the Intergovernmental Panel on Climate Change (IPCC). Created in 1988 under the auspices of the United Nations and the World Meteorological Organisation (WHO), this body has collated the work of several hundred scientists worldwide. The IPCC’s third report was issued in 2001 and a fourth report in due next year. These reports attempt to present the status of existing technical knowledge about climate processes, and have produced simulations of various climate parameters such as global temperatures under a number of different scenarios. The IPCC projections are that global temperatures will rise between 1.4 and 5.8 degrees Celsius in the next century, with a sensitivity range of 1.5 to 4.5 degrees C. The conclusion of these studies has been presented by the individuals involved as a “consensus” among scientists that human activity is responsible for warming the earth. “The Earth’s climate has demonstrably changed on both global and regional scales since the pre-industrial era and there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities,” said Dr. R.K. Pachauri, IPCC Chairman in December last year. Consensus “Consensus” is a political not a scientific term. With rolling 24-hour news coverage of natural disasters it would be unwise for a government to say, “Well, there’s nothing we can do, the science is uncertain”. Politicians have to be seen by their electorates addressing a disaster, even if their words and actions turn out to be meaningless or counter-productive. On the other hand scientists, rather than seeking consensus, are apt to fight like cats in a bag. Science progresses on the basis of accepting or rejecting a given hypothesis. A critical attitude to everything is imperative. It is called scepticism. This is derived from the Greek “skepticos” which means thoughtful. The term “climate scientist” is somewhat of a misnomer. Those who investigate the climate are mathematicians, physicists, meteorologists, oceanographers, astronomers, cosmologists, geologists, seismologists, biologists, zoologists, and botanists, even anthropologists. Specialists in one discipline may be aware of certain progress in another discipline but no one these days can claim to be an expert in all of them. The disagreement is vast. There is no agreement about the principal driving force for climate: whether it is the Sun, the Moon, plate tectonics, the carbon cycle, or indeed humanity. There is agreement on the following:

1. That global mean temperatures have risen abut 0.6 degrees Celsius over the past century.

2. That concentration of carbon dioxide in the atmosphere has increased by about

30% since the industrial revolution.

There is no agreement about the role of that increased carbon dioxide or its effect on the future climate.

Probably the two best-known proponents of opposing views about the future of the Earth’s climate are Americans who started the public argument in the first place. First, James Hansen, a physicist and astronomer who is head of NASA’s Goddard Institute of Space Studies. Hansen was among the first to propose in 1988 that fossil fuel burning by humans was warming up the atmosphere. Today, he says that the Earth’s climate is nearing a tipping point beyond which it will be impossible to avoid climate change with far-ranging undesirable consequences. He is opposed by Richard Lindzen, a physicist and atmospheric meteorologist who is Alfred Sloan Professor of Meteorology at the Massachusetts Institute of Technology (MIT). Lindzen claims that human induced climate change is a remote possibility and that the greenhouse effect is both overrated and due mainly to water vapour and clouds. He was lead author of the “Physical Processes and Feedbacks” chapter in the 2001 IPCC third report This argument takes place in the most respected research institutions and prestigious universities throughout the world. Some scientists make their opinions public; others think it wise to keep their mouths shut. Religion Both sides are accused of dogmatism. So it was apt in September last year that the National Association of Evangelicals, a US grouping of 52 member denominations, issued a statement identifying humans as the culprits behind global warming. An editorial in the science magazine, Nature, in early March welcomed this saying, “With a blessing from religious leaders, Americans no longer need to feel divided between their conservative beliefs and their concern for the planet.” Nature was way behind the times. Scientists brought religion into the climate debate a long time ago. Prof. Sir John Houghton, Chairman of the IPCC between 1988 and 2002 and regarded as Britain’s premier climatologist, is a leading Evangelical Christian and has spoken frequently on religious matters. He told a seminar in London three years ago “the world is facing environmental crises of unparalleled magnitude….looking after the Earth is a God-given responsibility. Not to look after the Earth is a sin. Christians need to re-emphasise that the doctrines of creation, incarnation and resurrection belong together. The spiritual is not to be seen as separate from the material. A thoroughgoing theology of the environment needs to be developed. “

Adherents of New Age quasi-religions have been drawn to the climate debate through Gaia hypothesis. First proposed by NASA scientist James Lovelock in the 1970s and named after the Greek earth goddess Ge or Gaia, this states that the Earth is a closed system and that life creates the conditions on Earth for its survival. Advocating a pre-industrial era, pastoralist existence, the Gaia hypothesis states that humans should live in “symbiosis” with the Earth. You might get the impression that both conventional religion and the New Age are placing humanity again at the centre of the Universe, as well as searching for certainty. The Universe The last time this view was prevalent was in the 1500s when Nicholas Copernicus began circulating his concept that the Earth revolved around the Sun. He was to publish his treatise “On the Revolutions of Heavenly Spheres” in 1543. Copernicus did not set out to overturn the dogma of the day. He merely wanted to simplify the accepted Ptolemaic system whereby the Earth was at the centre of the Universe with the Sun, Moon and six planets revolving around it in a variety of complicated cycles. But the neatest configuration turned out to be heliocentric. The first mathematicians to propose the Earth circulating around the Sun were Indians: Yajnavalkya in the 9th century BC and then Aryabahta in the 5th century BC. Aryabahta also determined that the orbits of the planets were ellipses, devised the first differential equations which described these motions and even calculated the value of π as 3.1416. His work was translated into Arabic in the 8th century. In the third century BC Greek philosopher Aristarchus of Samos proposed that the Earth rotated around the Sun but his critics called him “impious”. Astronomers and philosophers in the Islamic world, most notably Ibn Al Shatir of 14th century Damascus, questioned the Ptolemaic system of representing the Universe. In the 17th century the German mathematician Johannes Kepler was the true developer of the Copernican thesis and was the first European to calculate planetary orbits around the sun as ellipses. For Kepler, mathematics was a matter of religious piety and heavenly harmony. Gallileo, who corresponded with Kepler and pioneered the use of experiments to validate theories, was also deeply religious as was Isaac Newton in England who in the 17th century formulated the laws of motion and thermodynamics. Uncertainty Over the next two centuries scientists developed thermodynamics, the wave theory of light, discovered the nature of electricity, electromagnetism and nuclear physics. But from the 19th century they began to questioning the nature of science and human observations of it. Karl Friedrich Gauss in Göttingen studied errors in observations, while in Berlin Max Planck concluded that energy is made up of finite parts, giving rise to quantum physics. But Planck, like Copernicus, was no revolutionary. He was

seeking a unified theory to science, as indeed was Planck’s spiritual heir, Albert Einstein. Einstein’s theory of relativity states that space and time do not have absolute values but depend on each other. Later in the 1920s Werner Heisenberg underlined this in the Uncertainty Principle. This states, essentially, that all knowledge is limited and imperfect. So it has taken nearly 500 years for European science to conclude that we know very little and what we do know is imperfect. This also applies to the Earth and its climate. Lyell and Darwin We have to begin with Charles Lyell whose “Principles of Geology” published in 1830, was the starting point for today’s earth sciences. Lyell stated that the present, meaning those natural processes, which we can observe today, is the key to the past. We can recognize coastal features, river channels, past glaciations and even meteorite impact in the geological record and which indicate that the age of the Earth is about 4.5 billion years. Lyell was a great influence on Charles Darwin whose concept of natural selection is the basis for the theory of evolution. Lyell and Darwin were crucial in the removal of religious concepts from the study of the Earth and life on it. Time But this has left many people bemused about the nature of time. The Creationist view that the Earth is just several thousand years old at least provided a time scale with which people felt reasonably comfortable. Today, geological time and climate time seem to contradict each other: you have the immediacy of news about a coming climate disaster that could have been caused by a million-year geological process. Evidence of “catastrophic climate change “ in the media is often prefaced by an interview with a member of an indigenous hunting or fishing tribe in the Polar or Equatorial regions. Such an individual may be quoted as saying that things have changed greatly since his childhood and that it is no longer possible to fish or to hunt in a certain area. But the oral history tradition of such societies is based on what a person’s grandfather’s grandfather would say about his times. Today, we can barely appreciate the lives of our own grandparents, and most of us in the industrialised world tend to have little or no knowledge or our great-grandparents. How then will we be able to appreciate that certain Earth forces take hundreds, thousands, millions, billions of years? At the opposite extreme, we are persuaded to worry that the 0.6 degree Celsius rise in global mean temperature will be catastrophic. But the geological record shows that temperature rises of over 10 degrees Celsius have also occurred over less than a decade.

Causes of climate So what causes the climate? It is the result of multiple interactions between the oceans, the atmosphere, land and ice masses and the biosphere as the Earth spins on its own axis, is orbited by the Moon, and itself orbits the Sun. That description provides for many millions of permutations. The entire system is non-linear. That means that the reaction to a given input is not proportional and continuous but chaotic and random. That is why a number of scientists believe that the climate one day will flip into a catastrophic state. Others say that even if carbon dioxide concentrations were to triple, there would be little effect. Sun Let’s start with the Sun. In Space the Earth is surrounded by the magnetosphere, which deflects high energy particles emitted by the Sun known as the solar wind, and which otherwise would burn the planet. About half of the solar energy, which impacts on the Earth, is converted into heat on the Earth’s surface. Thirty percent of all total solar radiation is reflected back into space, 20% is reflected by clouds, 6% by the atmosphere and 4% by the Earth’s surface, manipulated by effects such as vegetation, snow and ice. Sunspot activity, an upwelling of visible dark spots on the surface of the Sun, has some influence on climate. Willie Soon, a physicist at the Harvard-Smithsonian Center for Astrophysics, has postulated that the Little Ice Age, a cold period between approximately 1550 and 1880 which destroyed agriculture in places as far apart as Scotland and China, as well as famously freezing over the Thames, could have been related to the Maunder Minimum, a period when sunspot activity decreased sharply. Changes in the Earth’s orbit around the Sun, as well as the Earth’s wobble on its own axis, are known as Milankovitch cycles, after a Serbian astronomer tried to link these changes to the Ice Ages. Scientists also study the Moon to see changes in the Earth’s albedo, or the fraction of sunlight that is reflected back into space. This reflectance deceased in the 1980s and 1990s but has reversed over the past few years. You can’t draw any sweeping conclusions about climate from this but it is another part of the whole jigsaw. Clouds Clouds play and enormous part in the climate but are not well understood. They reflect the Sun’s radiation but there is also a coupling between surface temperatures and clouds. When the temperature changes the clouds change and that in turn may amplify or diminish the temperature. This is known as “cloud feedback”. None of the climate models have managed to simulate this effect.

Source: Simon Lamb & David Sington, “Earth Story”, 1998

Plate tectonics Back on Earth we have recognized that the land mass and ocean floors appear to conform to the idea of plate tectonics, one of the most successful theories in the history of natural science largely because, like heliocentrism and quantum theory, it turned out to be a neat fit. The boundaries of these plates are delineated by frequent and severe earthquakes and volcanoes. We do not understand what really drives these plates: is it due to convention currents in the earth’s interior? Do the plates organize themselves? Has the Moon any influence? Volcanoes are well known to affect climate patterns, albeit for short period. The eruption of Tambora in Indonesia in 1815 chilled the European and North America climates for the next two years. The eruption of Mount Pinatubo in 1992 was responsible for anomalously cold winters in the Middle East over the following three years. Over geological time the relative extents and positions of the oceans and land mass has varied significantly, and so has the nature of the circulation within the oceans and its own interaction with the atmosphere. There were catastrophic events such as the extinction of 95% of life on earth 300 million years ago during the Permian cold period. Carbon dioxide concentrations in the Earth’s atmosphere at this time were about 20 times greater than today’s. It appears from the figure above that the Earth began to cool about 100 million years ago. Large ice sheets began to form about 35 million years ago. The last time this occurred was during that Permian cold period. Teleconnections Teleconnections - interactions between the atmosphere and the oceans such as the El Nino Southern Oscillation (ENSO) - bring climate forces down to a human time scale. ENSO appears to come about every two to seven years when prevailing easterly trade winds in the equatorial Pacific weaken. This allows for the “migration” of anomalously warm water masses, sometimes with a surface area comparable in size to Canada. Sea temperatures may rise by up to 8 degrees Celsius. ENSO causes droughts in Asia, Australia and Africa, and both floods and droughts in Latin America. It is one of the most important influences on climate over a human time scale but has never been modelled. A similar process is the still poorly understood Pacific Decadal Oscillation (PDO) over the North Pacific Ocean. The time scale of this phenomenon varies between 20 and 50 years. The North Atlantic Oscillation has a timescale of about 11 years and is essentially an atmospheric pressure field between Iceland and the Azores. This has a strong influence on temperature and precipitation in Western Europe and eastern North America. A change in the cycle of the NAO could be one explanation for this year’s long and cold winter in Europe. There are similar pressure phenomena around the Arctic and Antarctic, the Artic Oscillation and Antarctic Oscillation. These have

been linked by scientists to a thinning of the stratospheric ozone layer, as well as polar ice caps. Carbon cycle As we move into the biosphere the situation is complicated by the blurring between what has happened as a result of human activity and what may be the result of a natural climate cycle. It is clear that deforestation and subsequent soil erosion has limited the absorption of carbon dioxide. There is an overall recognised effect known as the carbon cycle by which carbon flows between the atmosphere, soil and vegetation, and to a lesser extent the oceans, then the Earth’s crust, to be later extruded in volcanism or weathering back into the atmosphere. It’s worth noting that 500 years ago most of northern Europe was a swamp. Wetlands are well known for emitting methane into the atmosphere. The draining and reclaiming of land, and straightening of rivers, has taken away much of the methane output, while urban expansion and industrialisation has increased the carbon dioxide output, as well as increasing localised temperatures, a phenomenon known as the urban heat island effect. Curiously, the past few hundred years of attempting to control nature, whether the rivers or the sea, has made inhabitants of the northern hemisphere even more vulnerable to climatic changes. Politics Those were just a selection of the factors that drive the climate. The level of uncertainty makes it amazing that the topic has become so politicised. Briefly, climate study became part of military planning in the 1940s, during the Second World War and later at the outset of the Cold War. It became important to work out the trajectory of fallout from a nuclear attack. Developments in long range weather forecasting as well as the launch of space programmes in the US and the Soviet Union provided further impetus to climate science, and indeed its huge funding. The fear of sudden climate change began as a scare about global cooling during the 1960s moving to global warming in the 1980s. Former British Prime Minister Margaret Thatcher was the first head of government to warn about the dangers of global warming in the 1980s and established of the Hadley Climate Research Centre in Britain. Al Gore, as both a US Senator and later as Vice President, pushed the climate change agenda at home and internationally. Many research institutes today depend on the need to “combat global warming” in order to survive. Climate science used to be a minor specialisation. But since the 1992 Earth Summit in Rio de Janeiro and the ratification of the Kyoto Treaty, its study underpins every discipline. “Climate change” is a necessary ingredient to a research grant proposal. Public concern with climate change has given governments a blank cheque to raise taxes, in order to save the planet, even though these funds will most likely be subsumed in bureaucracy. There is also the looming danger of future population control. Government scientists wander into the policy arena and suggest publicly that populations need to fall if humanity is to survive. The engagement of scientists with politics and policy has created a vicious circle which has generated even more fear.

For business climate change is a huge opportunity for profits in say, emissions trading, and burnishing of public relations. But the whole enterprise is driven by governments and now looks like the biggest pork barrel in the world. Danger I see serious dangers ahead. Instead of concentrating funds and efforts to improve the environment in those places where man has been too keen to subsume nature – river basins being a case in question – let alone find ways in which teeming megacities in the developing world may have access to affordable energy supplies – the money is being poured into computer modelling on the research front and an international emissions trading process open to huge corruption.. The climate models generated may compare with each other but do not compare with the climate reality. They are a tool for the understanding of climate mechanisms. But they are no proof. They are just projections of a hot future, based on an uncertain science that has turned into dogma and ideology. The eminent mathematician and polymath Jacob Bronowski, who advocated that governments should keep out of science, said in his famous television series “The Ascent of Man” that: “There is no absolute knowledge. And those who claim it, whether they are scientists or dogmatists, open the door to tragedy. All information is imperfect. We have to treat it with humility.” Ladies and Gentlemen, we should also treat Earth and planetary forces with humility. Thank you for your attention.