Global warming? Is it "man-made" or just nature’s cycle? Are we overdue for a warmer climate?

Source of climate material: "Ice Ages" from the Time-Life Books series "Planet Earth" (1983), pages 20-21.

You be the judge:

1. During Earth’s 4.6 billion years there have been seven "Ice Eras." Six have been within the last billion years -- long after the planet cooled from the extreme heat of it’s formation.

2. "Ice Eras" have had an average duration of approximately 50 million years. Therefore (in rough figures) during the last billion years of Earth’s history, 30% of the time (300 million years) has been during ice eras while 70% has been during periods of relative "global warmth." We are currently in an ice era whose duration has extended 65 million years -- or 15 million years longer than the average.

3. Each "ice era" contains a series of "ice epochs" -- in terms of global average temperature, relatively cold periods within the ice era. During our current 65 million year ice era there have been six ice epochs. We are currently in the last of those ice epochs, a period which began 2.4 million years ago. The current ice epoch has been one of the coldest climatic periods ever experienced by the planet. We are currently in an ice epoch within an ice era.

4. The particularly cold periods within an ice epoch are known as "ice ages." The average duration of these ice ages is 125,000 years. The most recent ice age began about 120,000 years ago and has had bitterly cold extremes about 50,000 years ago and again about 18,000 years ago. We are currently within an ice age, within an ice epoch, within an ice era.

5. Ice ages are marked by glacial periods when ice sheets are advancing and "interglacials" -- relatively mild periods within the ice age -- when ice sheets are in retreat. The current interglacial began about 10,000 years ago. We are currently within an interglacial (mild) period of an ice age within an ice epoch within an ice era.

6. The current interglacial has been marked by three sustained cold spells that sent the average global temperature below 59º F. The last of these, known as the Little Ice Age, began in the 15th Century and ended in the 19th Century. The 100-year warming trend that ended the last cold spell continued into the 1960’s when another drop in the global average temperature began.

7. Earth’s "normal" climate for living organisms (i.e., that climate which has dominanted Earth’s life-sustaining history) is markedly warmer than mankind has ever experienced -- a climate in which ice does not exist at sea level anywhere on the planet!

This material suggests that there are forces well beyond human control that have brought wide variability to the average global temperature during the life of our planet -- and we know little of what causes these changes.

Mankind has never experienced Earth’s normal climate -- our entire existence has been buried deep within the current ice era! In fact, for most of our planet’s 4.6-billion-years it has been "inhospitably hot or dry and utterly devoid of glacial ice." So why do some self-styled "environmentalists" wring their hands and shake at the prospects of retreating glaciers and rising ocean levels? Are they really so ignorant of the long term climate of the planet for which they would seek guardianship?

It is a fact that 70% of the past billion years the average global temperature has been markedly warmer than it has been during the current ice era which began 65 million years ago.

We also know that the current ice era is long overdue to end.

Further, we know that we are currently within an ice epoch -- a relatively colder period -- of this ice era.

In addition, we know that we are still within an ice age of this ice epoch -- although at present we are in an interglacial (relatively warmer) period.

Other studies have shown that less than 6% of the variability in the amount of "greenhouse gases" can be attributed to human activity.

It would appear from all of this that there is little likelihood that "global warming" can be either caused or averted by human action. It is worth pondering that, statistically, we are long overdue for an end to the current ice era.

Doesn’t it stand to reason that we should expect some considerable "global warming" to occur quite naturally?

Would it make sense to severely alter human activity in an attempt to alter the unalterable?

Is it ignorance, then, that drives some to assume a human cause for "global warming" as though it were some unnatural event that Earth had never experienced prior to human existence? Or is it just another "cause" for those who hope to profit from greater regulation of human activity?

By any reasonable standard it would seem that any real long term "global warming" could very well be the result of a long overdue naturally cyclic climatic event.

Before we support actions born of fear and ignorance, we should demand more integrity and honesty from scientists, politicians and "environmentalists" who claim humans are the significant source of global warming.