Posts Tagged ‘Ice Age’
A short history of nearly everything, by Bill Bryson (part 4)
Eco-system
Thomas Midgley, Junior was an engineer by training but developed an interest in the industrial applications of chemistry. With an instinct for the regrettable that was almost uncanny, Midgley invented chlorofluorocarbon CFC that is eating our ozone layer in the stratosphere and tetraethyl lead that spread devastation to human health by killing millions from lead contamination and increasing the lead content in our bones and blood 650 times the normal dose.
Tetraethyl lead was used to significantly reduce the juddering condition known as engine knock. GM, Du Pont and Standard Oil of New Jersey formed a joint enterprise called Ethyl Gasoline Corporation with a view to making as much tetraethyl lead as the world was willing to buy this new gasoline and introduced this product in 1923. Lead can be found in all manner of consumer products; food came in cans sealed with lead solder, water was stored in lead-lined tanks, and lead arsenate was sprayed onto fruit as a pesticide and even as part of the composition of toothpaste tubes. However, lead lasting danger came as an additive to motor fuel.
Clair Patterson turned his attention to the question of all the lead in the atmosphere and that about 90% of it appeared to come from car exhaust pipes. He set about to comparing lead levels in the atmosphere now with the levels that existed before 1923. His ingenious idea was to evaluate these levels from samples in the ice cores in places like Greenland; this notion became the foundation of ice cores studies, on which much modern climatological work is based. Patterson found no lead in the atmosphere before 1923. Ethyl Corporation counter attacked by cutting off all research grants that Patterson received. Although Patterson was the unquestionable America’s leading expert on atmospheric lead, the National Research Council panel excluded him in 1971. Eventually, his efforts led to the introduction of the Clean Air Act of 1970 and to the removal from sale of all leaded petrol in the USA in 1986. Lead levels in the blood of the Americans fell by 80% almost within a year; but since the atmosphere contains so much lead and cannot be eliminated and is for ever, we are to live with a new constitution of heavy lead concentration in our blood stream and our bones. Lead in paint was also banned in 1993, 44 years after Europe has banned it. Leaded gasoline is still being sold overseas. Ironically, all the research on lead effects on health were funded by the Ethyl Corporation; one doctor spent 5 years taking samples of urine and faces instead of blood and bones where lead accumulate.
Refrigerators in the 1920s used dangerous gases and leaks killed more than a hundred in 1929 in a Cleveland hospital. Thomas Midgley came to the rescue with a safe, stable, non-corrosive, and non-flammable gas called CFC. A single kilo of chlorofluorocarbon can capture and annihilate 70,000 kilos of atmospheric ozone which is no thicker than 2 millimeter around the stratosphere and whose benefit is to capture the dangerous cosmic rays. CFC is also a great heat sponge 10,000 times more efficient than carbon dioxide responsible for the greenhouse effect of increasing atmospheric temperature. CFC was banned in 1974 in the USA but 27 million kilos a year are still being introduced in the market in other forms of deodorant or hairspray for example. CFC will not be banned in the third world countries until 2010.
The natural level of carbon dioxide in the atmosphere should be 280 parts per million but it has increased to 360 and is roughly rising 0.025% a year and might be around 560 by the end of the century. The seas soak up tremendous volumes of carbon and safely locked it away. Since the Sun is burning 25% more brightly than when the solar system was young, what keeps our Earth stable and cool? It seems that there are trillions upon trillions of tiny marine organisms that capture carbon from the rain falls and use it to make tiny shells. These marine organisms lock the carbon and prevent it from re-evaporating into the atmosphere; otherwise, the greenhouse effect of warming the atmosphere would have done much damage long time ago. These tiny organisms fall to the bottom of the sea after they die, where they are compressed into limestone.
Volcanoes and the decay of plants return the carbon to the atmosphere at a rate of 200 billion tones a year and fall to the Earth in rain. The cycle takes 500,000 years for a typical carbon atom. Fortunately that most of the rain fall in oceans because 60% of the rain that fall on land is evaporated within a couple of days. Human has disturbed this cycle after the heavy industrialization era and is lofting about 7 billion tones each year. There is a critical threshold where the natural biosphere stops buffering us from the effects of our emissions and actually starts to amplify them.
Is our immune system still functioning properly?
In 1952, penicillin was fully effective against all strains of staphylococcus bacteria. The US surgeon-general, William Stewart declared: “The time has come to close the book on infectious diseases. We have basically wiped out infection in the USA”. Remarkably, 70% of the antibiotics used in the developed world are given to farm animals in stock feed to promote growth or as a precaution against infection. The bacteria mutated and evolved a resistance to antibiotics and 90% of the strains developed immunity to penicillin. Only one type of antibiotics called vanomyncin remained effective.
In 1997, vanomycin failed to check a new strain. The pharmaceutical industry hasn’t given the world an entirely new antibiotic since the1970s, preferring to produce a whole gamut of antidepressants that people take everyday for ever. There is a process of discovery that many ailments may be bacterial in origin such as ulcers, heart disease, asthma, arthritis, multiple sclerosis, several mental disorders, many cancers, and even obesity.
Fish is no longer that abundant in the surface seas. According to one estimate, there could be as many as 30 million species living in the sea, most are undiscovered. However, the world’s seas are not uniformly bounteous. For example, Australia has the longest coastline of 36,735 kilometers, yet it is not a fishing nation because it has no fish for lack of nutrients from the rivers that do not carry much there. In the 1970s, Australia and New Zealand discovered vast shoals of “orange roughy” at a depth of 800 meters. The fishing fleet was hauling 40,000 tons of roughy a year. In no time the roughy was disappearing because this type of fish was leading an unhurried lifestyle, spawning once in a lifetime, for the water was resource-poor.
Sharks are captured, the fin tail sliced off, and then dumped back to die: In the Far East, the kilo of fins is sold for $110 and a bowl of shark-fin soup retail for $100 in Tokyo. As of 195, some 37,000 industrial-sized fishing ships, plus about a million boats, were taking twice as many fish as they had 25 years earlier. A quarter of a fishing net contains “by-catch” that has to be dumped back, mostly dead, because they are too small or the wrong type. For every kilo of shrimp harvested, about 4 kilo of fish is destroyed. Cod and halibut are almost extinct off the northeast coast of America. A single lobster in the catch used to weight 9 kilos and they don’t weight one kilo presently: lobster can live up to 70 years but is not given time to mature. Fishermen are reduced to fishing the hideous hagfish; these days, “fish” is whatever is left. It seems that the crab-eater seals are the mammal species of large size that are the most numerous after humans and they live on the pack ice around Antarctica.
Earth Atmosphere
Without our atmosphere that extends 190 kilometers, Earth would be a ball of ice averaging minus 50 degrees Celsius. Altogether, the gaseous padding is equivalent to 4.5 meters of protective concrete. The immediate layer is the troposphere that represents 80% of the atmosphere mass and contains water vapor and oxygen; it is 16 kilometers’ thick at the equator and around 11 kilometers in the temperate climates.
The crowding of atoms in the troposphere and, although they travel at the speed of 8 millionths of a centimeter, their collisions provide enough warmth for our survival. Human can live to altitude around 4,500 meters by developing large chests and lungs and increasing the density of oxygen-bearing red blood cells by a third but we are not made for high altitudes. At an altitude of over 6,000 meters every step demands a colossal effort of will. The temperature drops about 1.6 degrees with every 1,000 meters you climb; around an altitude of 10,000 the temperature reaches minus 57 degrees. A rise of an inch in the barometer represents half a ton of air piled upon us; the reason we don’t feel crushed is that our body is almost of water that is not compressible. Only 0.035% of the Earth’s fresh water is floating around as cloud soaked water vapor.
The next layer is the stratosphere then the mesosphere and then the ionosphere or thermosphere where temperature reaches 1,500 degrees Celsius.
The rejuvenating processes on Earth
Huge amount of heat, energy and electricity are created and transferred around the globe every second. A single thunderstorm contains an energy equivalent to 4 days use of electricity for the whole USA. At any moment an average of 1,800 thunderstorms are in progress around the world. Day and night about 100 lightning bolts hit the ground every second. A typical weather front may consist of 750 million tons of cold air pinned beneath a billion tons of warmer air; the strength of wind grows exponentially so that a wind blowing at 300 kilometers an hour is 100 times stronger than 30 kilometers per hour wind. Thus, a tropical hurricane can release in 24 hours as much energy as France uses in a year.
Air always flows from areas of high pressure coming from the equator to areas of low pressure to keep pressure in balance. Moist and warm air from the equator rises until it hits the barrier of the troposphere and spreads out. As it travels away and cools, it sinks. When it hits bottom, some of the sinking air looks for an area of low pressure to fill and then heads back for the equator, completing the circuit through convection. This convection process is explained by the Coriolis effect that results from the fact that Earth spins at 1,675 kilometers an hour at the equator but the spin reduces its velocity as it is closer to the poles to become almost negligible; a straight line seems to curve to the right at the north hemisphere and to the left at the southern hemisphere. The Coriolis effects sends hurricanes spinning off like tops.
The other current that is the main agent of heat transfer is known as thermohaline circulation. For example, England and Ireland are very lucky that the Atlantic is more saline than the Pacific; the denser saline water sink at the bottom, and aided by the Coriolis effect, huge amount of warm water are charred by the Gulf Stream to warm the weather and keep many part of Western Europe from becoming icy like Canada and Russia.
As the water of the Atlantic gets to the vicinity of Europe, it grows denser and sinks to great depths and begins a slow trip back to the southern hemisphere. When they reach Antarctica, they are caught up in the Antarctic Circumpolar Current and driven onward into the Pacific. This process takes 1,500 years for water to travel from the North Atlantic to the mid-Pacific, but the volume of heat and water they move are very considerable and the influence on the climate is enormous. Unfortunately, with the increase of the greenhouse effect the higher melting rate of the Greenland ice is diluting the Atlantic Ocean and could disrupt the cycle disastrously.
Earth experienced many periods of Ice Age; we are in one Ice Age but within a period of a warmer one. Just figure an ice sheet 800 meter thick and many kilometers long and wide progressing at 150 meters a year; no obstacles can resist the progress of this monster ice sheet; boulders are carried away and placed at mountain tops and many islands were thus attached to mainland such as Cape Code, Long island, and Nantucket in the east of the USA.
The Swiss Natural History professor Louis Agassie borrowed that idea from his colleague Jean de Charpentier and then toured the world lecturing his theory and traveling and climbing the craggiest Alpine peaks. The USA was the homes that embraced his idea and offered him a chair in Harvard and build him a first-rate Museum of Comparative Zoology.
The cause of ice age starts in cool summers that prevent snow to melt in the poles and incoming sunlight bouncing off by the reflective surface and thus, exacerbating the cooling effect and encouraging more snow to fall and stick. It is not necessarily the amount of snow that causes ice sheets but the fact that snow is lasting. The process is self-enlarging and unstoppable.
The last chapter of “A short history of nearly everything” by Bill Bryson described how Man came to exist 100,000 years ago; modern human is so recent on Earth that the genetic differences among 55 chimpanzees are much larger than the whole human species.
Yet, modern human has managed to damage extensively Earth, its environment, and thousands of species in such a short period. Apparently, human activities are causing more than one thousand species to go extinct per week. The nineteenth century, especially in the USA and Britain, experienced a deliberate wiping out of any animal species that was not considered a pet such as animals living in farms.
The States in America paid out bounties for eastern mountain lions and other pests. The dodo flightless bird was wiped out from the island of Mauritius in 1693 simply because the ship crews needed to have something to do. In the USA thirty genera of very large animals disappeared; ten million mammoth carcasses are thought to be frozen in the Siberian tundra. A walrus-like creature called Steller’s sea cow, 9 meters in length and weighting 10 tones got extinct in the mid 18th century. The golden head and emerald green Carolina parakeet was wiped out because it was considered a pest by farmers. The dog-like Tasmanian tiger was wiped out in Australia by 1936.
I generated two articles from that manuscript: “A version of the genesis of Earth and Man” and “What animal instincts do they fear in me?”
Adonis Diaries 