The best way to do this is to recognize that mankind, in his present form, has been around on this world for a few hundred thousand years. Even to someone more than 80 years of age, like myself, that seems like one heck of a long time. It does, at least, until one considers that the world has existed and been undergoing change for an estimated four and a half billion years. That’s 56 million of my lifetimes.

Is it really any wonder then, that meteorologists charged with predicting the weather find that nature often fails to cooperate with their forecasts? This isn’t strange but is rather to be expected.

Geologic studies show that the Earth was materially different in the past from what it is today. Just several hundred million years ago, when the first mammals appeared, huge reptiles, ancestors of the dinosaurs, roamed the lands. Paleoclimatologists tell us that the average climate then was 70°F, with environments ranging from lush tropics to torrid deserts. Then, as the world cooled, some 65 million years ago, the dinosaurs became extinct when a huge asteroid struck the earth wiping out vegetation and the chain of critters that fed on it. The field was left open for mammals to prosper.

About five million years ago, a mere 62,000 of my lifetimes, average temperatures had dipped further to about 60°F. Human ancestors and chimpanzees split from their common predecessors. Fossil footprints show that the ancestor of modern apes and humans began to walk upright. The global cooling continued.

Some two and one half million years ago, a northern polar ice cap appeared. Average temperature was a chilly 55°F. The group of upright primates gave rise to several new species including one with an unusually large brain and the capacity to make tools - the beginning of human lineage. Concurrently, the tilt of the earth’s pole as the planet orbited the sun caused repeated cold cycles with a time span ranging from 50,000 to 20,000 years. with intervening periods of warmth lasting about 10,000 years. The probability exists that the world is close to the end of one of those spells as the long term temperature decline continues.

Then, 125,000 years ago, the average temperature warmed to 59°F, the last time Earth’s climate was as warm as it is today. The warm spell ended about 115,000 years ago and our climate suffered a drastic temperature decline with extensive glaciation. About this same time Homo Sapiens, an upright ancestor of modern man appeared in Africa and the Near East.

Then, 18,000 years ago, these humans went through the coldest climate in geologic history when temperatures dropped to 50°F. Cro-Magnon man survived in Europe through the skills of hunting and gathering and the ability to sew warm clothing from the animals they killed.

A turning point developed 11,000 years ago when the earth experienced a period of global warming. Average temperatures rose to 59°F, with the fertile conditions of the Middle East shifting northward and lush lands changing to an arid infertile area. When a 1,000 year cold spell developed, the people turned to farming the fertile areas of the valleys and gave up their nomadic ways.

The passage of time may be easier to grasp in relation to a 24 hour clock where the full 24 hour sweep of the hour hand represents the 4.5 billion year age of the earth. Then it become clear that what we are discussing here is only the last 1 hour and four minutes of the earth’s existence, and that 1 hour and 4 minutes ago, the average climate was 70°F. About 21 minutes ago the temperature had increased to 73°F. One minute and 18 seconds ago the temperature averaged 60°F. The 48 seconds ago, the temperature averaged 55°F. About 2½ seconds ago, the earth warmed to 59°F, but then 2.2 seconds ago the earth entered a period of glaciation, and temperatures dropped to 50°F about 0.35 seconds ago. Again the earth warmed to 59°F about 0.22 seconds ago, and then a cold spell 0.02 seconds long altered the way man survived.

Obviously, it is not feasible to make predictions that are valid for periods of several hundred years or less, but evidence strongly suggests that, for the long haul, it will get chillier. Today the world could be on the threshold of change. Warming for a brief period could occur but the long term trend of cooling is inevitable. Whichever does happen first, we may be certain that mankind will have to change to survive.