GLOBAL WARMING OR RETURNING TO THE AGE OF AMPHIBIANS

GLOBAL WARMING OR RETURNING TO THE AGE OF AMPHIBIANS
The geological perspective.

In a few words what is happening to the earth's atmosphere as a result of global warming is that we are facilitating the return to a more primitive state:the Age of Amphibians some 400 million years ago. The earth began its history with an atmosphere rich in carbon dioxide...a result of “outgassing” a process in which volatiles formed by natural lithologic processes within the earth’s interior are naturally voided to the surface such as by volcanoes, fumaroles, and lava plain basalt flows. Over geologic time earthly and biological processes have altered the chemistry of the atmosphere and reduced the concentration of carbon dioxide gas, a heat absorbing gas, from the atmosphere by sequestering it underground in the form of coal, petroleum, natural gas and limestone. In the last few centuries man has reversed that process, by burning fossil fuels in the atmosphere and returning the formerly stored CO2 back to the atmosphere. To make matters worse, at the same time our industries and farmers are cutting down our forest and “ungreening” the planet at a rate of 16 million hectares each year (almost 40 million acres). It's that simple! The earth started out with an atmosphere rich in carbon dioxide and a humid, warm climate in which giant amphibians thrived and now man is undoing eons of earthly evolutionary processes in a few hundred years...returning it to a more primitive state, to a condition in which amphibians like frogs, toads, salamanders would best survive.

Carbon dioxide gas has a unique property. Its absorbs long wave earth radiation or heat waves. Gas molecules exposed to such radiation, as that generated by the sun-warmed earth surface, causes the gas to heat up and to warm the atmosphere as a whole. The more of this gas in the atmosphere, the warmer the atmosphere gets. Venus, an earth-like planet close to us in space, has an atmosphere composed mostly of CO2 (97%) which causes a “run away” greenhouse gas problem which traps the suns heat and generates a surface temperature of over 800 degrees F (or @ 470 deg C) or hot enough top melt lead. In comparison, the earth has only a very small percentage of CO2 in its atmosphere (@3/100 of one percent by volume) and a temperature of 57 deg F or 14 degrees C.

The early Earth atmosphere was primarily composed of methane, CO2 and water vapor, probably mostly derived from the earth’s interior. As the planet cooled, the water vapor condensed into water to eventually form the world oceans, but the carbon dioxide simply continued to accumulate. For these reasons during its the early history, the earth’s atmosphere was much warmer than it is at present due to the larger percentages of heat absorbing (greenhouse) gases. Throughout the last half-a- billion years of earth history, the planet has experienced a generalized downward trend in both temperature and carbon dioxide levels. The decrease in CO2, not possible on other planets in our solar system, was the result of the evolution of living things on its surface.

The accumulation of CO2 continued and with it the continued warming of the atmosphere, until nearly 400 million years ago (mya). At that time green plants evolved and began to spread over the earth surface. These plants use carbon dioxide in the process of photosynthesis to form carbohydrates (sugars, starches, cellulose). That process absorbs CO2, converts it into mostly insoluble plant matter and produces O2 oxygen as a waste product. The process of removal of carbon dioxide from the atmosphere and the cooling of the atmosphere began with the evolution of green plants and especially with their expansion and flourishing on the formerly barren continents.

The initial “greening” of the continents occurred more than 400 million years ago in the Devonian Period (420-360 million years ago). Before that time, there few or no green land-plants to sequester carbon dioxide. The period is characterized by barren continents, while sea level was high, as were atmospheric temperatures. During the Devonian period the carbon dioxide level has been inferred to have been nearly six times what it is today, or about 2200 ppm (parts per million). At that time the earth’s average surface temperature was about 20 degrees Celsius or about six degrees higher than it is today. Sea level was nearly 180 meters above its present levels or almost 600 feet higher than it is today.

But by the end of the Devonian and beginning time of the subsequent Carboniferous Period (360 to 300 mya) the CO2 level had dropped by half, to three times (3x) the present level and the earth's average surface temperature fell to about 14 degrees C or about (57 F) what it is at present late in the Industrial Age. In the Carboniferous Period (named for the vast coal seams found in the rock record of that time) the climate was warm and humid with vast forests of lush vegetation. Sea level was well above the present level with most of the present East Coast and Gulf Coast under a shallow sea similar to that of today's Florida Bay and Bahama Banks, while the remaining eastern half of North America was mostly low land covered with extensive swamps and marshes. This was the Age of Amphibians, and dense vegetative growth of green plants such as ferns, scale trees, cycads, and giant club moss trees covered the continents. The great quantity of lush green plant growth absorbed vast quantities of carbon dioxide from the atmosphere for photosynthesis. In the process forming enormous quantities of insoluble plant matter as leaves, tree trunks, bark, seeds, etc. In the swampy terrane typical of the time, the forest detritus, dead trees, spent leaves and fallen trees (all composed of carbon taken from the air)settled into the shallow acidic swamp waters where they underwent partial decay. Much of the carbon in these plants was preserved ( some as magnificent fossils) and eventually were entombed forming thick coal seams (giving the period its name). The carbon stored as coal, bitumen and other deposits remained buried underground and sequestered from the atmosphere for four hundred million years. The earth cooled slowly with a few fluctuations, eventually to arrive at conditions which approximate the present.

This ancient carbon, formerly in the atmosphere, remained safely isolated underground until the industrial revolution in geologically recent times, when man began to exploit coal, and eventually other forms of sequestered carbon such as oil and gas, for fuel. Today, we extract huge amounts of formerly stored carbon from the earth’s interior, burn it with atmospheric oxygen and them dump the resulting CO2 back into the atmosphere from which it had been removed over periods of hundreds of millions of years. What we are accomplishing as a world society is in effect reverting the earth to a more primitive “carbonized” atmosphere. We are in effect returning the earth to a time when the great primitive amphibians of the past thrived. But the high earth temperatures, humidity, swampy terrane, and inundated shores of that period which would limit our living space would not be conducive to us as advanced primates, or to the plants we rely on for our agriculture and our sustenance, or to our modern way of life.

Get the picture?

rjk