ON GLOBAL WARMING AND THE ROLE OF FOSSIL FUELS Dr. L.K.Walker BE, PhD (Cantab), MBA, FAusIMM

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1 ON GLOBAL WARMING AND THE ROLE OF FOSSIL FUELS Dr. L.K.Walker BE, PhD (Cantab), MBA, FAusIMM 1. Introduction The volume and technical diversity of material written on global warming, on the impact of human activity on greenhouse gas levels, and the consequences for the future of civilisation make it difficult for anyone to form a balanced view on the issue. In addition, the debate has become highly technical, politicized and increasingly acrimonious. On the one hand, there is the so-called consensus view favoured by the Intergovernmental Panel on Climate Change (IPCC), on the other, a sceptical or rationalist view offered by a range of well-qualified, independent scientists. These circumstances make it essential that professional non-climate scientists develop a sufficient understanding of the issue for them to offer guidance for the future planning of the world economy. One way to attempt this task is to focus on the logic of the key issue at hand which is what is the evidence that fossil fuel burning on earth is the cause of temperature rises this century and what, if any, are the implications for the future? In order to put the discussion into a consistent framework, reference will be made to data and commentary provided in the IPCC Report Climate Change 2001: The Scientific Basis (IPCC 2001), which represents a widely accepted version of the scientific community s position on global warming. 2. Global Warming in the Last Century The currently accepted record of world average temperature change as it relates to 20 th century global warming, after Jones et al. (2006), is represented by Figure 1 This graph is based on an averaging of several thousand worldwide weather station records, and shows that the last century was characterised by two periods of warming, between and , separated by an interval of cooling during FIGURE 1 Average Global Temperature Record (IPCC Fig. 2.1(a) updated)

2 It is worth noting that 2005 was not the hottest year in the last 100 years, as often reported in the media, one result of which is that mean temperature has not increased since In its Summary for Policymakers, IPCC (2001) concludes from the evidence it presents that The global average surface temperature has increased over the 20th century by about 0.6 C. This statement is true as far as it goes, but ignores the significance of the intermediate trend down from 1940 to 1975, and the post-1998 evidence of flattening. 3. Temperature and Carbon Use Correlations Establishing the evidence for a link between anthropogenic (man-made) fossil fuel burning and temperature changes has been made more difficult by the focus on CO 2 as an intermediate variable. IPCC (2001 Fig 3.3) presents a graph showing both fossil fuel usage and CO 2 level increases and concludes that Current anthropogenic emissions of CO 2 are primarily the result of the consumption of energy from fossil fuels. IPCC also concludes that Detection and attribution studies consistently find evidence for an anthropogenic signal in the climate record of the last 35 to 50 years. In other words, CO 2 levels have gone up with fossil fuel use over the last 50 years, and new modelling studies have been able to correlate these CO 2 level changes with temperature changes. It is evident that deterministic computer models can be massaged to reasonably reproduce the global temperature pattern of the last 100 years. However the IPCC report (Section ), properly (and despite the extent to which models are used predictively in policy presentations) summarises some of the problems of model construction as follows Different models may give quite different patterns of response for the same forcing, but an individual model may give a surprisingly similar response for different forcings. And again in Section 7.3,..considerable uncertainties still exist concerning the extent to which present climate models correctly describe the oceanic response to changes in the forcing. In addition, there does not appear to have been a significant attempt to calibrate the computer models to reflect past long-term glacial cycles, which would appear to be essential if they are to fairly represent the impact of natural factors. This modelling approach assumes that CO 2 levels drive temperature changes. However strong evidence exists to the contrary. De Freitas (2002) reports on a number of independent statistical analyses that conclude that the reverse is true, namely that temperature changes precede CO 2 level changes, calling into question the basis of the modelling procedure. The IPCC study does not attempt to directly correlate fossil fuel usage with temperature changes over a long period of history. It is therefore instructive to compare fossil fuel usage from published data directly with the global temperature changes shown on Figure 1. The following points (extracted from Figure 2 below) should be noted. Consider three equal time intervals and the two variables, temperature and fossil fuel use. o From 1910 to 1940, the global temperature rose 0.4 o C, and the average annual fossil fuel usage was about 2 billion metric tonnes of carbon

3 o o From 1940 to 1970, the global temperature declined by 0.2 o C, and the average annual fossil fuel usage increased to about 4 billion metric tonnes of carbon From 1970 to 2000, the global temperature again rose 0.4 o C as for , but this time the average annual fossil fuel usage was about 9 billion metric tonnes of carbon, nearly five times higher In a relevant statistical analysis, Klyashtorin and Lyubushin (2003) concluded that from the 1860 s to the present, world fuel consumption and temperature changes (Figure 2) underwent a year cycle of positive and negative correlations, that this cyclic trend was evident from ice core data going back 1500 years, and that a further cycle of cooling was imminent. Based on the available evidence, both of the key IPCC model assumptions, that global warming is driven by CO 2 and caused by fossil fuel usage, thus remain unsubstantiated. FIGURE 2 Fossil Fuel and Temperature Variations with Time 4. Past Climate History It is unrealistic to look at the last century s temperature changes without placing it in the context of historical evidence. Figure 3 (from IPPC 2001) presents ice core data over the past 400,000 years showing variations in temperature, CO 2, and CH 4, a period when fossil fuel usage by today s standards was effectively zero. Not only are the repetitions of the cooling/warming cycle striking, but a broad correlation in change of the three parameters appears evident. However the CO 2 levels ( ppmv) are very low compared to earlier geological times IPPC Figure 3.2 indicates that levels of 6000ppm existed 200 million years ago, due presumably to natural causes. Analysis of the ice core

4 data has also shown that CO 2 level changes precede temperature changes (De Freitas 2002). FIGURE 3 Variations of temperature, methane, and atmospheric carbon dioxide concentrations derived from air trapped within ice cores from Antarctica (IPCC Fig. 2.22) The IPCC Report puts aside the significance of natural geological climatic changes in temperature and CO 2 as being too slow to be of relevance. However in Section it addresses the question How Rapidly did Climate Change during the Glacial Period?, this covering the period after the last peak of glacial conditions which occurred between about 25 to 18ky BP. In particular, the Report states that very rapid warming at the start of the Bölling-Alleröd period (14.5 to 13ky BP), or at the end of the Younger Dryas (12.7 to 11.5ky BP) may have occurred at rates as large as 10 C/50 years for a significant part of the Northern Hemisphere. Again in an earlier paragraph, it states The warming phase, that took place about 11,500 years ago, at the end of the Younger Dryas was also very abrupt and central Greenland temperatures increased by 7 C or more in a few decades. And so wide and very rapid changes in temperature, as well as wide changes in CO 2, have been part of the past natural order. The 7 0 C rise in northern hemisphere temperatures, in a few decades 11,500 years ago, dwarfs the rise of C in average global temperature in the last century, but showed a comparable rise in CO 2 levels of

5 around 150ppm. Factors other than CO 2 level must clearly have driven these rapid temperature changes. 5. Summary The bulk of publications on global warming focus on: o Interpretation of current and past (proxy) temperature data to determine the extent of global warming occurring over the past century and past millennium o Debate on the impacts of current and future increases in global temperature, projected using deterministic computer modelling eg. sea levels, weather patterns and their volatility, flora and fauna etc o Further development of the computer models to try and better reflect current understanding of global weather processes. Within all of this information, it is surprisingly difficult to find a coherent presentation of the argument that asserts that global temperature increases are linked to fossil fuel use, which is the cornerstone of logic behind the Kyoto agreement. This link is made more complex because of the insertion of CO 2 levels as an intermediate step between these two variables. The historical data involving these variables can be summarised as follows. o During the past century, when annual fossil fuel consumption has grown from near zero to nearly 12 billion tonnes of carbon, global temperatures have increased overall by a modest C, and in a number of phases that do not correlate with the growth in fossil fuel use. o In geological times past, with effectively no impact from man-made carbon emissions, global temperatures changed rapidly by many degrees in a few decades, and changes in temperature preceded, rather than responded to, parallel changes in atmospheric CO2. It can only be concluded that there is no demonstrated evidence that links fossil fuel use to global temperature increase, and that the dominant effects of natural factors are still in play. 6. Conclusion From the above brief review, it must be stressed that no consistent logical basis exists for the current consensus view that fossil fuel usage is largely the cause of global warming. Rather, the modest temperature increases of the past century may well result from natural causes alone. A concerted attempt to address this logic, and to understand the natural climate drivers in past glacial cycles, is essential before economic decisions of international significance are taken based on a fear of uncontrolled future global warming.

6 This fear might be expressed by the following quotes: There are ominous signs that the earth s weather patterns have begun to change dramatically The evidence in support of these predictions has now begun to accumulate so massively that meteorologists are hard-pressed to keep up with it. Climatologists are pessimistic that political leaders will take any positive action to compensate for the climate change, or even allay its effects These quotes, extracted from an article in Newsweek, April 28, 1975 titled The Cooling World, might have been written recently in connection with global warming fears. That the so-called consensus scientific view could have completely reversed in only 25 years is of itself a grave warning to community leaders to consider the facts carefully before committing to decisions with immense long-term consequences. References de Freitas (2002) Are Observed Changes in the Concentration of Carbon Dioxide in the Atmosphere Really Dangerous. Bulletin of Canadian Petroleum Geology, Vol 50, No. 2, pp IPCC (2001) Climate Change 2001:The Scientific Basis Houghton, J.T., Ding, Y., Griggs, D.J., Noguer, M., ven der Linden, P.J. and Xiaosu, D. (eds.). Cambridge University Press Jones, P., and Palutikof, J.(2006) Global Temperature Record Climate Research Unit, University of East Anglia, Klyashtorin, L.B., and Lyubushin, A.A. (2003) On the Coherence between Dynamics of the World Fuel Consumption and Global Temperature Anomaly. Energy and Environment, Vol 14, No. 6, pp