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Universidade Fernando Pessoa

Porto, Portugal

Plate 75- At the earth's surface the heat equilibrium is controlled by the amount of received sun radiation. If two amounts of heat, L1 and L2 are received by a surface, its centesimal temperatures, T1 and T2, are related by the equation: (T1+273º)/(T2+273º)= (L1 /L2)1/4. Astronomic observations indicate that the distance to the Sun is roughly 3% smaller in December than in June. The difference in heat received on each hemisphere is around 6%, since the radiation's intensity decrease in function of the square of the distance. Using the amount of radiation received by a surface {(T1+273º)/(T2+273º)= (L1 /L2)1/4} one can say than in North hemisphere the summer average temperature is 4-5º lower, and during the winter the average temperature is 4-5º higher than in South hemisphere. Since the Proterozoic, geologists have recognized 5 or 6 ice ages with glaciations appearing and disappearing: (i) Proterozoic (roughly 2.7 Ga); (ii) Proterozoic (roughly 2.2 Ga); (iii) Precambrian (700-600 Ma); (iv) Ordovician (500-400 Ma); (v) Upper Carboniferous (290 Ma); (vi) Plio-Pleistocene (3-2 Ma). The first two took place between 2 and 3 Ga. Mounded rocks with glacial slickensides and deposits associated with glacial environments have been found, particularly in Eastern Canada. The Precambrian ice age took place during late Precambrian time, around 0.6-0.7 Ga. It seems to have affected mainly Australia, South Africa, China, Europe and North America. After a long mild period (± 200 My) without ice sheets, a new ice age onset at the end of the Ordovician. After this ice age a new mild period (± 150 My) took place before the Late Carboniferous ice age (290 Ma). The Late Carboniferous ice age was very short (± 20-30 My). It was partially induced by the agglutination of the Pangea supercontinent. Glaciations spread in Antarctica, South America, Africa, Arabia, India and Australia. After a period of almost 270 My of relatively mild climate the last ice age, the Cenozoic ice age, took place 2-3 Ma in the Plio-Pleistocene. To explain the ice ages and the sea level falls induced by glaciation, we need to find a mechanism able to reduce the amount of sun's energy received by the earth's surface. However, there is no logical reason to believe that the sun irradiated a constant amount of energy during the geological time. In addition, modern astronomic hypothesis assume that all stars, as the sun, increase their brightness with age. The calculation for the sun predicted an increase between 30 and 60 % during the last 5 Gy. A detailed study of sun's surface showed up the existence of important cyclic disturbances such as the sun's storms. They appear and disappear in average every 12 years and they seem to have a strong short term climate influence. The Proterozoic Ice Ages could be induced by the consumption of methane and ammonia in the atmosphere and the ending of the greenhouse effect, which seems to be predominant during the lower Proterozoic. In the same way, the amount of different gases, volcanic particles, steam, etc., in the atmosphere, which induce important cooling due to the fact that one part of the sun energy is lost and does not reach the Earth's surface, could have contributed to the development of these ice ages. Nevertheless, it is very difficult to relate the volcanism and the ice ages. In fact, several geologists advanced an opposite relation. The height of the continental ice sheets could induce volcanic activity. To make a long history short, one can say, that, so far, there is no hypothesis explaining why the volcanic activity and the ice ages should have the same rate. With the advent of plate tectonics, geologists associated the ice ages, to the periods of large amount of continental crust. They explained the Precambrian and the Late Paleozoic ice age, by the agglutination of the Proto-Pangea and Pangea. However, such an explanation cannot be invoked to explain the other ice ages. Stratigraphic studies suggest that large glacial periods seem to be, directly, or indirectly, associated with geological periods of continental shortening and uplift.

Plate 76- The temperature of the oceans and the amount of glacial ice on the continents has a strong influence on the amount of oxygen isotopes of seawater. Both, cooling temperatures and ice formation change the isotope values in the same sense. Even if the two effects cannot be untangled in detail, the timing of glacial fluctuations can be very well documented. Sudden changes occurred ±35 Ma, i.e., at the Eocene-Oligocene boundary. They have been interpreted as reflecting the onset and rapid growth of continental ice cap in the Antarctica. The hypotheses advanced to explain the different ice ages were very controversial. Before the advent of the Plate Tectonics, in order to explain the climate change suggested by stratigraphic studies, geologists proposed that, in the past, the location of the poles and the position of the continents have changed. Kreichgauer P. D. (Die Äquatorfrage in der Geologie. Steyl, 1902. 394 pp. 6 maps & 57 figs.), admitted that at the beginning of Cenozoic time the North Pole traveled, firstly, toward Alaska and, then, toward South Greenland. This could explain the large ice cape between North America and North Europe. The relatively mild climate nowadays was admitted to be due to the displacement of the North Pole from South Greenland to its present day position. Such an hypothetic migration of the poles is in contradiction to the present geological knowledge (rather the displacement of tectonic plates over a plastic substratum and not displacement of the poles). To explain the glaciation during the Appalachian Orogeny, in South America, South Africa, Australia and India, several geologists suggested that these areas were once agglutinated (Gondwana Continent). They located the south pole in Pacific ocean not far from Hawaii Islands. However, in the seventies, with the advent of the Plate Tectonics, some of the advanced ice age hypotheses were partially corroborated. The Ordovician glaciation (400-500 Ma), for instance, is nowadays well understood. In fact, according to the Plate Tectonics paradigm, after the break-up of the Precambrian supercontinent (Proto-Pangea), Baltica and Laurentia moved northward toward the equator and the Gondwana moved polewards. Baltica became warmer and the southern parts of Gondwana became much cooler. Few million years before the end Ordovician period, glaciers grew in around the south polar region of Gondwana. As the period came close, the glacial episode reached a climax and a coeval mass extinction in the marine realm took place. Nevertheless, the relationships between the fauna extinction and the glaciations are speculative and controversial. Presently, the majority of the geologists think that the sun’s radiation is the main parameter affecting the Earth's climate. A change in radiation has a large influence in temperature. G. Gamov ("Biography de la Terre" Dunod, Paris, 1956) proposed seven principal possible causes of glaciations: (i) Sun Storms; (ii) Amount of atmospheric gases; (iii) Volcanic activity; (iv) Amount of continental crust; (v) Supernova explosions; (vi) Galaxy revolutions; (vii) Milankovitch cycles.

Plate 77- These plots from the annual Glacier Commission surveys in Italy and Switzerland shows the percentage of advancing glaciers in the Alps. Mid-20th century saw strong retreating trends, but not as extreme as the present. Current retreats represent additional reductions of already smaller glaciers. Nevertheless, between 1975 and 1985 the majority of the alpine glaciers advanced. On this subject the site (http://pistehors.com/backcountry/wiki/Weather/Europe-S-Shrinking-Glaciers) says that C. Vincent (Laboratoire de Glaciologie in Grenoble) believes that "some of the alpine glacier retreat scenarios have been largely overestimated". By the same token, Robert Vivian even thought, controversially, that the "the in the second half of the 20th century was marked by a stabilization and even advance rather than retreat". Christian Vincent comments that glacier retreat is a poor indicator of global warming as it depends on a number of factors and large glaciers show considerable inertia between cause and effect. He prefers to work with total glacier mass and in work on French glaciers has identified four periods in the 20th century. Up to 1940 glaciers gained in size, this was followed by a sharp retreat in the years 1942-53 followed by advances then further retreat from 1982. The growth period from 1953-1982 covers the rapid expansion of the French ski industry. Currently at around 2900 m above sea level glaciers are in equilibrium, the rate of accumulation and ablation (or loss) is the same. Vincent says that the most of the losses from French glaciers can be accounted for by a 0.75° C rise in average temperatures over the century or a 20% decrease in precipitation. For each 0.6° C rise in average temperatures the glacier equilibrium line gains 100 m, assuming other factors such as precipitation remain constant. So is global warming and the greenhouse effect responsible? It seems hard to get a straight answer. “Skeptics” see it as a natural process. There are ice ages and warming, as during a local climate optimum around 1000 AD when Greenland was colonized by the Vikings and grapes were found on the east coast of America (Vineland). Luc Moreau (http://moreauluc.club.fr/index.htm) sees a paradox, global warming may result in more precipitation at altitude, this would fall as snow actually increasing the supply to glaciers that start high in the mountains that are currently suffering from a relatively dry period in the climate. This is already the case for glaciers as far afield as Norway and New Zealand.

Plate 78- Yes, they are always the same. They want to save the Earth and they use all methods, even religion. But, in fact, they want to gain more governmental control over the economy and individual activity. Let's remind some illustrative examples: A) Before the 80's (quoted by C. Horner): (a) N. Calder (International Wildlife, June 1975) said: "The threat of a new ice age must now stand alongside nuclear war as a likely source of wholesale death and misery for mankind"; (b) R. Bryson (Global Ecology; readings towards a Rational Strategy for Man, 1971) said: "The continued rapid cooling of the earth since WWII is in accord with the increase in global air pollution associated with industrialization, mechanization, urbanization and exploding population"; (c) R. Bryson (Environmental Roulette, 1971) said: "The rapid cooling of the earth since World War II is also in accord with the increased air pollution associated with industrialization and an exploding population". After the 80's: (i) Environment Minister of Canada Christine Stewart said "No matter if the science is all phony, there are collateral environmental benefits....climate changes provides the greatest chance to bring about justice and equality in the world. It's a great way to redistribute wealth"; (ii) E. Brindal (coordinator of the Friends of the Earth Australia Climate Justice Campaign), said: "A climate change response must have at its heart a redistribution of wealth and resources"; (iii) S. Schneider (Professor of Environmental Biology and Global Change; Professor by Courtesy in the Department of Civil and Environmental Engineering at Stanford University), a Co-Director at the Center for Environment Science and Policy of the Freeman Spogli Institute for International Studies and a Senior Fellow in the Stanford Woods Institute for the Environment, serving as a consultant to Federal Agencies and/or White House staff in the Nixon, Carter, Reagan, George H. W. Bush, Clinton and George W. Bush administrations, said: "We have to offer up scary scenarios, make simplified, dramatic statements and make little mention of any doubts we may have. Each of us has to decide what the right balance is between effective and being honest"; (iv) M. Strong ( godfather of the environmental movement, who served from 1973-1975 as the founding director of the U.N. Environment Program, UNEP, in Nairobi) said: "We may get to the point where the only way of saving the world will be for industrial civilization to collapse".

Plate 79- Theses photographs show the Tschierva glacier as seen from Piz Corvatsch (http://photo.net/photodb/photo?photo_id= 5660737 &size=lg). The high peak dominating the center left of the image is Piz Bernina decorated with the Biancograt a distinct ice ridge. Piz Bernina is the only mountain exceeding 4000 m in Engadin (Switzerland). The peak on the right is Piz Roseg. The Tschierva hut is visible above the left glacier moraine. Admittedly, a global warming "Skeptic" will choose the photograph in left to illustrate the glacier, while an "Alarmist" prefers the photo on the right. Nevertheless, both were shot in the same year but in different months. The left one in December, while the right one was shot in June. The photo on the right was shot before the one on the left. However, the "alarmists" pretend the opposite. The procedure is always the same, they need to shock, so they show first the last photo and they say "It was like that", then they show the older picture and say: "Now, due to global warming, it is like that". Then, they add: "Helps us to combat global warming", showing the older photo and they continue "Help us to control global warming, controlling population, recycling, reduction consumption, etc............but for that we need a financing contribution". As everybody knows, alarmism matches big business. They promote mutually in order to disadvantage competitors or gain rents, generally income from governments.

Plate 80- When the president of IPCC, Sir J. Houghton said: "Unless we announce disasters, no one listens", it is clear that scientists working for IPCC, must adopt a substantiation attitude, i.e., they just take into account the data that corroborate their a prior hypotheses, completely forgetting the data refuting them. Such attitude is not scientific. Science progresses by trial and error, i.e., by critical approaches, in which the advanced hypotheses to solve a problem are aggressively tested by data and experiments, and when refuted, they are replaced by new conjectures and so on. B. Obama accused rival J.McCain of being "in the pocket of Big Oil", and the Democratic National Committee launched Exxon-McCain 2008, a website to promote the idea that the Republican candidate is in bed with the oil industry (http://gristmill.grist.org/story/2008/8/8/94449/57025). But, according to the same source (quoting the Center for Responsive Politics), Obama himself has received nearly $400,000 in donations from contributors in the oil and gas industries this election cycle. Americans willing to look at the manmade global warming debate with any degree of impartiality and honesty are well aware that those spreading the hysteria have made a lot of money doing so, and stand to gain much more if governments mandate CO2 emissions reductions (Noel Sheppard, October 3, 2007, http://newsbusters.org).

Plate 81- Gerhard et al. (Geological Perspectives of Global Climate Change edited by Gerhard, 2001, AAPG Studies in Geology #47, pp. 327) consider that climate drivers can be categorized by the dual attributes of range temperature change forced by the driver and length of time that the drivers cycles through. On the graph illustrated in next plate, the vertical axis is logarithmic and the horizontal axis is arithmetic, which permits comparison of climate drivers with their potential effects and separation of drivers of different magnitude. Human intervention, which may or may not exist, is in the same category as some other small natural drivers. Diamond shapes are interpreted and literature-documents ranges are values; dots indicate possible ranges of values: (A) First-order Climate Controls: Earth has a life-supporting climate because of its distance from the sun, solar luminosity and the evolution of a greenhouse atmosphere of water vapour, CH4, CO2 and other gases that trap solar energy and make it usable. This atmosphere evolved over the last 4.5 Ga and continues to evolve. It was suggested that CO2 content has decreased over the past 600 Ma from 18 times the current concentration. The greenhouse effect itself makes the earth warmer than it would otherwise be. (B) Second-order Climate Controls: Distribution of oceans and continents on the surface of the earth controls ocean currents, which distribute heat. This fundamental concept explains the 15°-20°C climate variations over hundreds of millions years. Such variations are exemplified by the two major earth cycles between glacial icehouse and warm greenhouse states. The Late Precambrian icehouse evolved into the Devonian greenhouse, then the Carboniferous icehouse, then the Cretaceous greenhouse, which evolved to the present icehouse state. Redistribution of heat around the earth is determined by the presence of equatorial currents that keep and thrust warm water masses away from the poles. Blockage of such currents, which permits the formation of gyres that move warm waters to the poles, creates the setting that allows continental-scale glaciation (see next)..

Plate 82- (C) Third-order Climate Controls: Solar insulation variability has emerged as a major climate driver, as are the orbital variations that change the distance between earth and sun. In addition, large-scale changes in ocean circulation through changes in current structure can be significant climate drivers. Large-scale ocean tidal cycles may drive climate, including the large-scale maximum and minimum associated with the Medieval Climate Optimum and the Little Ice Age, on an 1800-year cycle with 5000 year modulation. These drivers may cause temperature changes of 5°-15° C over hundreds to hundreds of thousands of years. (D) Fourth-order Climate Controls: There are many drivers that control small temperature changes (up to 5° C) over short periods of time (up to hundreds of years). Many are natural phenomena including smaller-scale oceanographic oscillations (La Niña and El Niño), volcanic activity (such as the eruptions of the Pinatubo and Krakatoa), solar storms and flares, small orbital changes, meteorite impacts, and human intervention (such as human-derived CO2 and CH4 alterations to atmospheric composition. Tectonic and topographic uplift have small temperature effects and are regional father than global, but may be of long duration. Eighteen-, 90- and 180-year cycles driven by ocean tides have been recognized and they drive climate by changing heat transfer rates between ocean and atmosphere.

Plate 83- In part II of these notes, all climate drivers reported by Gerhard et al. will be review in detail.