Ever since Dewey McLean (1978) proposed a dinosaur extinction theory that states that a climatic change killed the dinosaurs, it has become the single most accepted theory for the dinosaur extinctions within the scientific community. It is called the dinosaur- greenhouse extinction theory. It says that a climate change via the greenhouse effect killed off the dinosaurs. My paper takes this proposed theory and relates it to the world today.
Some of the things that happened back then are also happening now, and if the dinosaur- greenhouse extinction theory is indeed true, then we are also in danger of dying rom the greenhouse vertebrate killing mechanism, abrupt atmospheric changes, and the other effects caused by the increased greenhouse effect and people should know about the consequences of what we are doing to the earth. My paper examines the similarities occurring in the two time periods and the possible results that we may soon be facing in the very near future.
I am hoping that exposure to the inevitable danger that we are soon going to be facing, will spark action and concern within whomever reads my paper. It is a problem that we all have tended to shrug off and not worry about, but if we don’t start orrying about it soon, there will not be anyone around to worry about. The time for action is now. We may still be able to change the future. Humans Soon to Become Extinct? Can it be? Roughly sixty-five million years ago a tremendous extinction of global proportions hit the planet earth.
This global extinction was so severe that it has defined the boundary between two periods of geologic history called the Cretaceous and the Tertiary periods. All but a few mammals on land and water became extinct. (McLean,1978,p. 1) The best known of these extinct animals from this mass extinction are the huge and mighty dinosaurs. What killed them nobody really knows and probably will never know, but scientist haven’t hesitated to theorize about it.
There have been theories ranging from human involvement to disease to even aliens. However, of all the theories of the so called K-T extinctions, the single most accepted theory is called The Volcano Greenhouse Theory. This theory states that a chain of volcanoes in India, called “the Deccan Traps”, released vast quantities of the greenhouse gas carbon dioxide into earth’s atmosphere trapping heat from the sun, (McLean,1988,p. 2) and turning earth’s surface into “the hot, sterilizing, hell of a major greenhouse.
McLean 1981,p. 1) If the dinosaurs did in fact die from the Volcano-Greenhouse theory, then we are also in danger of becoming extinct from the Vertebrate Killing Mechanism, abrupt atmospheric changes, and other results from the greenhouse effect that they too died from. The earth is what is referred to as a “Greenhouse Planet”. This means that the earth is warmed by certain gases (fig a1) that without which our earth would be as cold and barren as the moon, and unsuitable for even the most basic life to exist.
These greenhouse gases, mostly carbon dioxide and water vapor, n the earth’s atmosphere trap heat from the sun causing the earth to be thirty degrees warmer than it would be without them. (fig a3) (McLean, 1978, p. 1) It is this extra warmth that allows earth to harbor life. Carbon dioxide was and still is released into the atmosphere continuously by natural sources such as volcanoes, hot springs, fumaroles, and geysers. The natural processes on the surface of the earth will absorb this normal effect. g a9) Over long periods of time, the process was accepted and became in balance with the earth. (McLean, 1985, p. 1)
Then a time of volcanic ctivity arrived as the Deccan Traps of the late Cretaceous Period erupted and the pieces had almost all fallen in place for a change. Volcanic dust and CO2 was strewn into the upper atmosphere for a period of around two hundred plus years. (McLean, 1985,p. 1) This caused a time of cooling on the earth due to the dust blocking out the sunlight. The dinosaurs began to adapt to the climatic cooling from the volcanic dust very well.
The large body size of the dinosaur was beneficial on the cooling earth, because it easily kept in their body heat allowing them to comfortably survive without harboring their ability to find food. McLean, 1995 p. 1) It seemed as if they were going to stay for a while. Then the ash cleared and, that was when the whole process was thrown out of balance. The carbon dioxide had been produced faster than the natural systems could absorb it. Also, instead of coming down with the ash to the surface, the carbon dioxide stayed in the upper atmosphere making it thicker and thicker.
Now embracing the greenhouse effect, the earth began to heat up like a hot oven, triggering ecological instability the world over. (McLean, 1985, p. 1) The Dinosaur’s large size made it impossible for them to even make an ttempt to recover from this sudden increase in heat. (McLean 1995) Whereas the thermal inertia contained in their bodies would have been a great benefit in the cooler climate, their small surface to volume ratios were huge disadvantages in the warming and caused the dinosaur’s bodies to essentially overheat. (p. 1) A smaller size, like that of the mammal, would have helped them to survive better. 2)
The abruptness of all these circumstances wreaked havoc in the internal systems of the dinosaurs causing the Greenhouse Vertebrate Physiological Killing Mechanism (fig a16) to begin occurring. (McLean,1995) The Greenhouse-Vertebrate Killing Mechanism states that climate triggers extinctions through it’s effects on a species’ females. Here’s what happens. In response to the growing environmental heat, a female’s body will give part of it’s blood supply away to the skin surface to help get rid of excess bodily heat. The result of this causes a reduction in the blood flow to the uterus of a pregnant female. (p.
Since the uterus is the place where the embryo gets all of it’s life providing oxygen, food, water, and nutrients, the reduction in blood will make these necessities less available and cause the embryo to die or become abnormal with warfing abnormalities or mutations. (p. 1) Large animals that couldn’t shed off their excess heat, such as the dinosaurs, were the animals most effected. (p. 1) The same thing that happened to the dinosaurs during the K-T extinctions is happening right now right in front of our own faces today as you read this, and most of us don’t even know it. Like the dinosaurs, we have also just had a cooling off period.
Broeker,1996,p. 3) Volcanic eruptions are thought to be responsible for the global cooling that has been observed. When large masses of gas reach the stratosphere, the uppermost layer of the atmosphere, they produce worldwide cooling effect. (Volcanoes and Climate,96) The amount and extent of this cooling action is dependent on the eruption size and it’s latitude. (Nasa, 1996) If it occurs in a place of great winds and air currents, then it will spread differently than one not in an air current would have on the world and have a different amount of a cooling or heating effect. (p.
The full extent of the current global warming probably hasn’t even come close to reaching us yet. That is because the effects of the Mt. Pinatubo eruption may just now be finally wearing off. (Nasa,1996) Due to the verlapping cooling effects of Mt. St. Helens, El Chichn, and the Cerro Hudson eruptions there was a continuing cool-off period that is just ending. (p. 1) One top meteorologist said (Broeker,1996) “If man made dust is unimportant as a cause of climate change, then a strong case could be made that the current cooling trend will give way to a pronounced warming induced by carbon dioxide. . 1)
One thing though that has already begun to happen to us again is the Greenhouse Vertebrate Killing Mechanism. Via this mechanism, summer heat kills mammalian embryos on a vast global scale. (McLean 1995,p. ) That is why there are more miscarriages in summer months than there are any other time of the year. How many miscarriages it has actually caused cannot be accurately measured due to the lack of a way to determine if they actually died from the mechanism. Now another coincidence, just as with the dinosaurs, the greenhouse gasses are once again increasing.
Fig a7, a8) Now though, instead of volcanoes causing the increase, humans are indirectly causing the increase. (unep/umo/94) Previously, the global climate was what changed the world, but now us humans are changing the world by changing the climate. p. 2) The principle change to date is within the makeup of the atmosphere. (p. 2) The greenhouse gasses carbon dioxide, methane, and nitrous oxide have always formed a blanket around the earth. The problem is that we are making the blanket much bigger by spitting out all these different gases into the atmosphere and throwing the proportional amounts off into a state of confusion.
2) According to the British Medical Journal, there are four main human causes of increased greenhouse gasses (1994). These are listed as follows: combustion of fossil fuels: 57% Agriculture: 19% deforestation: 17% ndustrial activities and waste: 8% The greenhouse effect today has been caused by multiple gasses in the upper atmosphere trapping long range radiation in the atmosphere and, therefore raising it’s temperature. (Fig a3) (Iucc,1993,p. 1) Carbon dioxide is one of these primary greenhouse gasses and it’s concentration has risen greatly since the industrial revolution began. 800 it was roughly two hundred and eighty parts per million as it had been for over a million plus years. Currently it is at three hundred and forty parts per million and still rising.
If it keeps rising at it’s current rate, by the year 100 the CO2 level will be as much as two thousand two hundred and forty parts per million or as little as four hundred and twenty parts per million. (British Medical Journal, 1994) As fig a4 and a6 show, there is a direct relationship of the amount of CO2 in the air and the temperature of the earth. “Carbon dioxide levels have climbed sharply in recent years.
By some estimates, global carbon dioxide emissions, mainly from burning of coal and oil, will have increased sixty percent within the next two decades. ” (Business week, 1996) The current rate is so fast that it is unprecedented in the entire eologic world history. Another danger to us humans is that the increased accumulation of carbon dioxide in the air translates into the marine life. (fig a11) Because of the added heat in the air, the ocean’s convection currents will change from taking warm water to the poles and bringing down cold water to a more stagnant ocean.
This will then inhibit the ocean’s ability to absorb or deposit out carbon dioxide. (Wunch,1988) Accumulation of carbon dioxide in marine environments is known to have grim effects on many marine animals (McLean,1996) because, the elevated carbon ioxide levels disrupt the Ph balance of the internal fluids of the marine life causing a medical condition called “narcotizing acidosis”. Basically their body’s Ph becomes too acidic and kills them by taking away the hemoglobin’s ability to carry oxygen essentially drowning them. (p. 3) High carbon dioxide levels also may cause metabolic arrest and reduction. 3)
This means that they wouldn’t be able to change food into energy or create the essential hormones or chemicals their bodies need. Since the entire food chain of the world depends upon marine life, this would be a catastropic event for all the world. Bleaching of coral in Tahiti and reduced ocean circulation are a few of the symptoms we have already begun experiencing. (Earthaction, 1996) We aren’t just affecting ourselves anymore. Because of us, a change in the world is evident, but when it will change is anyone’s guess.
Although nobody really knows exactly how things will change, scientists can use data form what happened during the K-T extinctions of dinosaur days to predict what will happen. One of the many changes predicted by scientists that has already begun to happen, (fig a2) is an atmospheric temperature rise between 1. 5 degrees C and 4. 5 degrees C. That is a very small increase but as fig a12 shows, there is only a few degrees difference between today’s temperature and the temperature of the last ice age. An increase of that magnitude will cause the sea to rise (fig a13,a14) between 1. d 2. 2 feet higher from melting snow and ice. (British Medical Journal, 1994)
Although the sea level rise may seem small, the effects may be very drastic. (fig a15) Large areas of agricultural land may become flooded, many islands will disappear, death rates from heart disease and stroke will rise. (British Medical Journal, 1994) Malaria, Rocky Mountain Spotted Fever (Fig a19) nd other temperature dependent diseases that travel by insect will be able to become virulent at higher altitudes, latitudes, and in more places due to the ability of the insects to survive in a greater area.
Fig a20) (Iucc,1993) According to one researcher five of the numerous mosquito borne viruses now common in hot countries, will become threatening in the U. S. if the world temperature rises one half a degree. (p. 1) Also, the earth’s entire biosphere, (the thin film of life covering the earth) would be affected. The biosphere depends on the rate of something called the Solar-earth- Space-Energy-Flow (SES). fig a18) (Mclean,1988) This is the method in which earth sheds it’s heat into outer space. Greenhouse gases inhibit the SES from occurring correctly.
(p. The rate of release of carbon dioxide within the earth by “mantle degassing” increases or decreases the earth’s ability to carry out the process of SES. (Earthaction, 1996) The more carbon dioxide there is, the harder that it will be for SES to occur, but a lack of it will make SES occur too fast making the earth cool too quickly. (McLean,1995,p. 2) Right now it is happening too slowly causing the earth to heat up. Over long periods of time ystems adjust, but how much time do we really have? No matter what all of this global warming stuff isn’t good for us humans.
Most people don’t recognize the threat but a few do. Dewey McLean gave a speech to the Senate where he stated, “A major carbon cycle perturbation is the most dangerous global scale phenomenon that life on earth can experience. Today, our civilization is facing a possible modern greenhouse. Via the greenhouse-physiological killing mechanism, the direct effects of the greenhouse warming upon the female mammals and embryos can go in one direction only. That is toward increased embryo death, reduction f mammalian populations, and collapse of mammalian populations in the vulnerable middle latitudes.
McLean,1988,p. 4) Earth’s surficial systems are never truly stable, and must continually adjust to the fluctuations in the atmosphere. Although modest fluctuations may be absorbed, major ones that go above a critical threshold force systems to find a new configuration. Those systems that do not find a new configuration cease to exist and die off. (McLean, 1988) I really hope that humanity isn’t a part of one of those systems that cannot find a new configuration. Since we may be going extinct, we must do something now. Not next year or ten years away. Now!
The world government needs to propose and enforce strict regulations. The scientific community needs to find methods to slow or reverse the trend. Auto makers have a responsibility to create alternative fuels and methods of travel such as electric cars and to cut emissions from their vehicles. It is the end of the world as we know it and we all must do our own part to save it. The time for action has come. It’s now or never. If something is not done, there will be no future and no more life. Only the death of the human race and the other beings on the earth.