The next several essays will focus on the general topic of pollution (various types) and their effect on the environment that we usually interpret as climate change. As the reader will soon discover (I hope), my plan is to state facts as accurately as possible whenever factual data is available and let you, the reader, interpret the data and draw your own conclusions. In a later essay I will share my conclusions. Because of the volatility of the subject I will try to cite references whenever possible. I will use newspaper articles, books, videos, etc. as reference points. I plan to cover air and water pollution and their effects on the climate which then has a domino effect on the flora (plants) and fauna (animals) including humans and the effect of human activity in the reverse direction… Together we will try to discover the root causes of some of today’s problems. I will often refer you back to earlier essays.
First, let me distinguish between weather and climate. Generally speaking weather refers to the here and now day to day changes in temperature, barometric pressure, humidity, wind speed and direction, etc. Climate is weather patterns over a long period of time
If weather patterns (temperature and precipitation) over a long time determines climate, what determines weather, that is, what are the root causes? First and foremost, the “machine” that drives everything are the thermonuclear reactions of our sun (nuclear fusion) and the earth’s proximity to it. Too close and we would bake (more like vaporize) and too far we would freeze. But our mean distance of 93,000,000 miles is just right. Another factor is the inclination of the earth’s axis of 23.5 ͦ. Because the earth revolves around the sun in a tilted fashion during its yearly journey, various points on its surface receive varying amounts of sunlight which, along with its rotation around its axis affects wind speed and direction, rainfall amounts, and changes in air pressure. For those of us living in the Northern Hemisphere, even though the earth is farther away from the sun in June we are experiencing warmer temperatures simply because the sun’s rays of light and heat are more direct. The reverse is true in December when the earth is closer but the sun’s rays are more slanted. And the reverse is true in the Southern Hemisphere because of the earth’s tilt. Yes, the earth’s orbit is an ellipse (egg shaped) which puts it 152,500,000 km (94,759,108 miles) at aphelion (July 3) and 147,500,000 km (91,652,252 miles) at perihelion which is around January 3. These factors create highs and lows which also causes wind. Do you get the idea that the forces of nature are intricately and intrinsically interwoven?
The earth has repeatedly gone through periods of climate change brought about by various cataclysmic events. It has often collided with asteroids, meteorites, etc. Some of those collisions have undoubtedly blackened or darkened the sun for long periods of time resulting in ice ages. Ice core samples taken in Greenland and the Antarctic indicate ice ages occurred about:
· 65 mya (end of Mesozoic era) causing extinction of dinosaurs?
· 1.5 mya (Pleistocene era) (Curtis & Barnes.Biology.1989)
The following geologic time scale taken from Clarkscience 8 weebly.com/geologic-scale.html will perhaps put things in proper prospective.
A detailed annotated account of the history of ice ages and alternate global warming along with their causes is beyond the scope of these essays. Suffice it to say, that the earth has gone through repeated warm and cold periods. However, (and this is verified) since the Industrial Revolution there has been an upward if not steady trend in average global temperatures. Air pollution, greenhouse gases, and their cause and effect will be the subject of the next essay
Certainly there have been many alternating periods of global warming and cooling with average temperature swings of perhaps 10 to 15 degrees C (50-59 degrees F) but that was perhaps 100 million years ago when the continents were in different places than they are now with different ocean currents. Evidence of such temperature swings linked to greenhouse gases results from air bubbles trapped in the Antarctic ice sheets according to Schneider. Fast forward to modern times (the past 200 years); there has been a 25 percent increase in CO2 above the interglacial level of millions and billions of year ago and twice as much methane. More recently the 1980’s apparently was the warmest decade on record up through the 1980’s with 1988 the warmest year.
References
Schneider, S. (1996) Laboratory Earth Weidenfeld & Nicolson London
