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Environmental News From the Communications Centre Contributed by Aristide Mbiock at AOSM and Robert H. Essenhigh at The Combustion Laboratory - Ohio State University IJmuiden, NL, 14th May 2001 - Ref.:0105art08
SPECIAL
CONTRIBUTION: Last week we received, at the Communication Centre, a Viewpoint article on the possible impact of CO2 in the atmosphere scheduled for publication in the upcoming (May) issue of Chemical Innovation, one of the journals of the American Chemical Society that I thought might be of interest to IFRF members. Robert's current conclusion is that it is not the CO2 that is driving up the temperature but the temperature that is driving up the CO2.
Robert H. Essenhigh is the E.G. Bailey Professor of Energy Conversion in the Department of Mechanical Engineering, Ohio State University, 206 West 18th Ave., Columbus, OH: 43210; 614-292-0403;
essenhigh.1@osu.edu. MNM readers, the editor of Chemical Innovation, Mike Block, will be interested in comment, either pro or con. He can be reached at: Michael Block; myb96@acs.org Excerpt from the article, which you may download (130 KB) here. <<< Viewpoint: Does CO2 really drive global warming? Robert Essenhigh: "I don’t believe that it does. To the contrary, in applying the IFF test – if-and-only-if or necessary-and-sufficient – the outcome would appear to be exactly the reverse. Rather than the rising levels of CO2 driving up the temperature, the logical conclusion is that it is the rising temperature that is driving up the CO2 level. Of course, this raises a raft of questions, but all are answerable nevertheless. What is particularly critical is distinguishing between the observed phenomenon, or the “what”, from the governing mechanism, or the “why”. Confusion between these two would appear to be the source of much of the noise in the Global Warming debate. In applying the IFF test we can start with the clear correlation between the global CO2 profile and the corresponding temperature signature. There is now in the literature a 400,000 year sequence clearly showing, as a phenomenon, that both go up – and down – together (1). The correlation is clear and accepted. But the causation, the mechanism, is something else: Which is driving which? Logically, there are four possible explanations, but only two need serious consideration unless they both fail.
Both appear at first to be possible, but both then generate crucial origin and supplementary questions. For Case 1, the origin question is: What, independently, is the source of the CO2, that is then rising and falling, and which then, somehow, is presumed to drive the temperature up and down. For Case (2) it is: What is the driver for the temperature changes; and if this then drives the CO2, then where does the CO2 come from? For Case 2, the questions are answerable; but for Case 1 they are not. Consider Case 2. This directly introduces the global warming behavior. Is global warming, a separate and independent phenomenon, in progress? The answer, as I heard it in geology class 50 years ago, was “yes”, and I have seen nothing since then to contradict that position. To the contrary, as further support, there is now documentation (that was only fragmentary 50 years ago) of an 850,000 year global-temperature sequence, showing that the temperature is oscillating with a period of 100,000 years, and with an amplitude that has risen, in that time, from about 5 deg-F at the start to about 10 deg-F “today” (meaning the latest 100,000 year period) (2). We are currently in a rise that started 25,000 years ago and, reasonably, can be expected to peak “very shortly”. On the shorter time scales of 1000 years and 100 years, further temperature oscillations are to be seen, but of much smaller amplitude, down to 1 deg-F and 0.5 deg-F in those two cases. Nevertheless, the overall trend is clearly up, even through the Little Ice Age following the Medieval Warm Period. So the global warming phenomenon is here, with a very long history, and we are in it. But what is the Driver? Arctic Ocean Model The postulated Driver, or mechanism, developed some 30 years ago to account for the “million-year” temperature oscillations, is best known as the “Arctic Ocean” model (2). According to this model, the temperature variations are driven by an oscillating ice cap on the northern polar regions; and the crucial element in conceptual formulation of this mechanism was the realization that such a massive ice cap could not have developed, and then continued to expand through that development, unless there was a major source of moisture close by, to supply, maintain, and extend the cap. The only possible moisture source was then identified as the Arctic Ocean which, therefore, had to be open – not frozen over – during the development of the ice ages. And it then closed again, stopping the moisture supply, by freezing over during the warming retreats. So the model we now have is that if the Arctic Ocean is frozen over, as is the case today, the existing ice cap is not being replenished and must shrink, as it is doing today. As it does so, the earth can then absorb more of the sun’s radiation and therefore will heat up – global warming – as it is doing today, so long as the Arctic Ocean is closed. When it is warm enough for the Ocean to open, which the oceanographic (and media) reports say is evidently happening right now, then the Ice Cap can start to reform. As it expands, the ice increasingly reflects the incoming (shorter-wave) radiation from the sun so that the atmosphere cools. But then, the expanding ice cap reduces the (longer-wave) radiative loss from the Earth, acting as an insulator, so that the earth below cools more slowly and can keep the ocean open although the ice cap is expanding. This generates “out-of-sync” oscillations between atmosphere and earth. The Arctic Ocean “trip” behavior at the temperature extremes, allowing essentially discontinuous change in direction of the temperature, is identified as a bifurcation system with potential for analysis as such. The suggested trip times for the change are interesting: They were originally estimated at about 500 years, then reduced to 50 years and, as the most recent, down to 5 years. So, if the Ocean is opening right now, we could possibly start to see the temperature reversal under way in about 10 years. What we have here is a Sufficient mechanistic explanation for the dominant temperature fluctuations and, particularly, for the current global warming rise – without the need for CO2 as a driver. Given that pattern, the observed CO2 variations then follow, as a driven outcome, mainly as the result of change in dynamic equilibrium between the CO2 concentration in the atmosphere and its solution in the sea. The numbers are instructive. The 1995 IPCC data on the carbon balance show ~ 90 Gigatons of carbon in annual quasi-equilibrium exchange between sea and atmosphere, and back again; and an additional 60 Gigatons exchange between vegetation and atmosphere giving a total of ~ 150 Gt (4). This interpretation of the sea as the major source is also in-line with the famous Mauna Loa CO2 profile for the last 40 years showing the consistent season-dependent variation of 5 or 6 ppm, up and down, through the year – when the average global rise is only 1 ppm per year. This oscillation is attributed in the literature to seasonal growing behavior on the “Mainland” (5), which is mostly China, > 2000 miles away; but no such profile with that amplitude is known to have been reported at any mainland location. Also, the amplitude would have to fall due to turbulent diffusive exchange during transport over the 2000 miles from the Mainland to Hawaii, but again there is lack of evidence for such behavior. The fluctuation can, however, be explained simply from study of solution equilibria of CO2 in water as due to emission of CO2 from and return to the sea round Hawaii governed by a +/-10 deg-F seasonal variation in the sea temperature. Man’s impact The next matter is the impact by man from fossil fuel combustion. Returning to the IPCC data and putting a rational variation as noise of about 5 Gt on those numbers, this float is then of the order of the further – almost trivial (< 5%) – annual contribution of 5-6 Gt from combustion of fossil fuels. This means that fossil fuel combustion can not be expected to have any significant influence on the system unless, to introduce the next point of focus, the radiative balance is at some extreme or bifurcation point that can be tripped by “small” concentration changes in the radiation absorbing-emitting gases in the atmosphere. Can that include CO2? This now starts to address the Necessity or “only-if” elements of the problem. The question focuses on whether CO2 in the atmosphere can be a dominant, or “only-if” radiative-balance gas; and the answer to that is rather clearly “no”. The full detailed support for that statement takes the argument into some largely esoteric areas of radiative behavior, including analytical solution of the Schuster-Schwartzchild Integral Equation of Transfer that governs radiative exchange (5-7); but the outcome is clear. The central point is that the major absorbing gas in the atmosphere is water, not CO2, and although CO2 is also the only other significant atmospheric absorbing gas, it is still only a minor contributor on account of its relatively low concentration. The radiative absorption “cross-sections” for water and CO2 are so similar that their relative influence depends primarily on their relative concentrations. Indeed, although water is actually stronger, for many engineering calculations, the concentrations of the two gases are added, and the mixture is treated as a single gas. In the atmosphere, the molar concentration of CO2 is in the range 350 to 400 ppm. Water, on the other hand, has a very large variation but, using the “60/60” [60% RH at 60 deg-F] value as an average, then from the standard American Society of Heating, Refrigerating, and Air-Conditioning Engineers Psychrometric Chart, the weight ratio of water to dry air is ~ 0.0065, or roughly 10,500 ppm on a molar basis. Compared with CO2, this puts water, on average, at 25-30 times the (molar) concentration of the CO2; but it can range from a 1:1 ratio to > 100:1. Even closer focus on this is given by solution of the Schuster-Schwartzchild Equation of Transfer applied to the U.S. Standard Atmosphere profiles for the variation of air temperature, pressure, and density with height (8). The results show that the average absorption coefficient obtained for the atmosphere closely corresponds to that for the 5.6 to 7.6 mm water radiation band, with the water concentration in the range 60 to 80% RH which is on-target for atmospheric conditions. The absorption coefficient is, correspondingly, one to two orders of magnitude higher than the coefficient values for the CO2 bands at a concentration of 400 ppm. This would seem to eliminate CO2 and thus provide a closure on that argument. This overall position can be summarized by saying that water accounts, on average, for >95% of the radiative absorption. And because of the variation in the absorption due to the variation in the water, then anything CO2 might do in the future by increase in its concentration, water will already have done. The common objection to that argument is that the wide fluctuations in the water make an averaging (for some reason) impermissible. Yet such averaging is applied without objection to global temperatures where the actual temperature variation across the Earth from poles to equator is roughly –100 deg-F to +100 deg-F; and a change in the average of ±1oF is considered major and significant. If this averaging procedure can be applied to the atmospheric temperature, it can be applied to the atmospheric water content, and if it is denied for water it must, likewise, be denied for the temperature – and then we don’t have an identified problem! What the evidence shows So what we have on the best current evidence is that:
The outcome is that the global warming advocate’s conclusion on the role of CO2 evidently has it back to front: It’s the temperature that is driving the CO2. If there are flaws in these propositions, I’m listening; but if there are objections, let’s have them with the numbers. References
1. Sigman, M. and Boyle, E.A.: Nature, 2000, 407, 859-869 >>>
Robert H. Essenhigh is the E.G. Bailey Professor of Energy Conversion in the Department of Mechanical Engineering, Ohio State University, 206 West 18th Ave., Columbus, OH: 43210; 614-292-0403;
essenhigh.1@osu.edu MNM readers, the editor of Chemical Innovation, Mike Block, will be interested in comment, either pro or con. He can be reached at: Michael Block; myb96@acs.org German power industry close to completing CHP deal FRANKFURT - Germany's power industry was expected to conclude talks on cutting greenhouse gases emission by encouraging combined heat and power plants (CHP) late yesterday, the VKU association of municipalities said. Final details of the industry's proposal will then be presented to the economics ministry which is preparing a new CHP law for January 1, 2002, said VKU spokesman Wolfgang Prangenberg."We are confident that after some last-minute fine-tuning a draft paper with the final industry proposals will be signed later today," he told Reuters from VKU's base in Cologne. The paper would meet the government's two demands that CO2 emissions should be cut by 23 million tonnes via additional CHP usage by 2010 and that CHP-related state subsidies should not exceed eight billion marks, he added. Germany has to meet targets on CO2 emissions cuts as part of its obligations under international climate protocols. The CHP talks have been dragging on, because they needed to reconcile the interests of industry on the one hand and hundreds of small municipalities on the other. CHP-produced power, which is environmentally friendly but expensive to operate, accounts for 54 percent of the total generated by some 900 VKU members. Fearing CHP oversubsidisation, six large utilities organised in the VDEW electricity association's sub-section, VDV, offered voluntary CO2 emission cuts in order to avert a quota system for CHP output favoured by environmentalists. The final negotiations aim to combine both the voluntary cuts by the big utilities, but in connection with a scheme paying premiums to CHP power operators over and above the normal power price, Prangenberg said. The scheme envisages degressive extra payments to CHP operators of initially three pfennigs per kilowatt hour, which would be born by all consumers across the supply chain. Operators of old plants would qualify for the payments for eight years while those with new plants would receive payments for up to 12 years. Consumers would end up paying just under 0.5 pfennigs more for their electricity - current household prices range between 18 and 25 pfennigs per kWh. VDEW said it would issue a statement detailing the results jointly with VKU on Friday. Oil industry warns on latest green fuel push The oil industry warned on Friday that proposals to introduce sulphur-free petrol and diesel to all European Union member states by 2005 would lead to further cost increases for motorists. The warning came after the European Commission unveiled a two-stage plan to improve air quality by eliminating sulphur from motor fuels within a decade. The proposal - to be discussed by the European parliament and member states during the second half of the year - would require oil companies to introduce sulphur-free petrol and diesel across the EU from January 2005, and sell only zero sulphur fuels in petrol from 2011. Oil industry officials said this would represent a "sea change" to the refining industry, requiring large scale investment in new plant. "A complete switch to petrol and diesel with less than 10 parts per million of sulphur will require investment and increase operating energy use and costs. This would be reflected in higher fuel prices and CO2 emissions," said the UK Petroleum Industry Association. Ultra-low petrol, containing 50 parts per million of sulphur, is already available in some EU states. Brussels has already pushed through legislation banning lead and other pollutants from petrol, but in the process provisions to reduce sulphur content were watered down. The cost to the car and oil industries of implementing the first package of measures has been put at $40bn. A Commission spokeswoman said the proposal would reduce harmful emissions from vehicles, improving the environment in cities. The increase in carbon dioxide emissions during the refining process would be more than offset by lower emissions during combustion of the fuel. "Even though the price of petrol might go up, it should be compensated by more efficient engines," she added. Carmakers are expected to be broadly sympathetic to the new measure, because cleaner fuel will cause reduce engine corrosion. EU launches three-year probe to get cleaner air BRUSSELS - The European Commission said yesterday it had launched a three-year probe in how air quality can improve and reduce pollution-induced health problems. "We have come a long way in reducing air pollution, but we have not yet achieved our final objective, that is to make sure that everybody in Europe, even those who are particularly vulnerable to bad air, can breathe freely," EU Environment Commissioner Margot Wallstrom said in a statement. The "Clean Air For Europe" (CAFE) programme could culminate in new legislative proposals in 2004, the Commission, the European Union's executive arm, said. As EU anti-pollution laws had already made major progress in areas such as cutting acid rain, one of the focuses of the CAFE strategy would be the lesser known problem of particulate matter - tiny particles that can cause respiratory problems from lung irritation to cancer, a Commission official said. "What is not known is exactly how it causes these effects and what type of particulates cause these effects," the official said. A wide variety of emissions sources could be affected by any measures the Commission eventually decides to adopt against particulates. Any combustion process can generate particulates, including traffic, industry and domestic heating systems, the official said. CAFE will also look at the problems of ground-level ozone - a major cause of respiratory problems often related to traffic emissions, and on-going efforts to tackle acidification and the over-nutrification of water courses often caused by agricultural pollution.
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