James Hansen is the leading global warming scaremonger after Al Gore. He recently wrote in the Ottawa Citizen that we should not develop Canada’s tar sands, lest we “initiate a continual unfolding of climate disasters over the course of this century”. According to him, atmospheric carbon dioxide must not go above 350 parts per million (ppm), whereas it has already risen to 385 ppm. By eliminating the burning of coal, and other hallucinations, we may just be able to get it back below 350 ppm.
When I read these dire warnings of the global warming alarmists , I am comforted by the fallowing facts, which have been a proven as anything in the geological record can be.
First, the world in the last million years has been fluctuating in and out of ice ages. A series of eight glacial/interglacial cycles, driven by changes in the earth’s orbit around the sun, has been our “recent” fate. The glacial periods last much longer than the interglacial. We are now living at the tail end of the latest and warmest interglacial period, which began with the most recent melting of the glaciers about ten thousand years ago.
Martha’s Vineyard, Long Island and Nantucket Island are the moraines, the rubble pushed forward by the continent-covering glaciers of the last ice age, which ended some twenty thousand years after humans left Africa.
All of human civilization has emerged in the latest global warming period.
Second, the earth’s warmth is largely determined by the amount of carbon dioxide (CO2) in the atmosphere. Without the greenhouse effect of carbon dioxide in the atmosphere, life could not continue: the oceans would freeze. The proportion of atmospheric carbon dioxide has been steadily shrinking over the past 50 million years. 500 million years ago the concentration of CO2 is estimated to have been 18 times higher than it is today. By comparison, the dinosaurs died out about 62 million years ago.
Why has the proportion of atmospheric CO2 diminished? Rock and oceans store dissolved carbon dioxide. Rain falling on bare rock causes dissolved CO2 to react and leach out of the atmosphere. The rise of the Himalaya Mountains, driven by the Indian tectonic plate colliding with the Asian plate, and the actions of monsoons raining on the resulting mountain range, have led to a gradual reduction of CO2 in the atmosphere. (A source of this information, among several others, is a standard introduction to geology available at the Smithsonian Museum).
Third, whatever the cause, atmospheric CO2 has been lowered over the past 50 million years until we have reached a point where, most of the time, the ice sheets cover North America down to the mid-Atlantic states. We are in an exceptionally warm period “at the moment” and our time in the heat is likely to come to an end within two to three thousand years, if previous inter-glacial periods are any guide.
These facts can be readily found out by readings in geology and climate history available from reputable publishers.
Whether the earth is getting colder or warmer is strictly a question of one’s time perspective. For this reason, most geologists, whose time perspective is in the millions of years, have a distinctly skeptical view of the global warming scare. Once you acknowledge the large facts revealed in the geological record, the minor blips up and down of temperature can be seen in the proper perspective. Man-caused global warming, to the extent it takes place, occurs against this backdrop.