You probably heard about the recent discovery of a fossil that is an important missing link between fish and land animals. The creature was a fish with a crocodile-like head and fins that had begun evolving into limbs, enabling it to lift itself out of shallow water. The fins show arm joints and the beginnings of a wrist.
The find was made on Ellesmere Island, at the uppermost reaches of the North American continent, hundreds of miles north of the Arctic Circle and only 887 miles from the North Pole. Due to the extreme weather at that remote location, fossil excavations were limited to the month of July.
Now, this creature, like all fish and reptiles, was cold-blooded. So it could not have survived were it lived unless the earth was VERY much warmer at that time. Which shows that the earth has been subject to VERY large temperature variations over a long time without human activities. In fact, perfectly natural climate changes in the past dwarf the one degree temperature rise of the past century that the public has been panicked into believing is a cause for alarm.
The effect of human activities on climate is trivial compared to the scale of changes wrought by nature all by itself. In the last 10 million years there have been 17 ice ages, which alternately formed and melted ice sheets hundreds of feet thick and covering much of the continents. Most centuries have had climate changes of a degree or more, either warmer or colder. And there have been centuries when atmospheric carbon dioxide increased at least three times faster the current rate. At the time of the dinosaurs, the carbon dioxide content of the atmosphere was 3 to 5 times what it is today. 500 million years ago, it was twenty times what it is today.
The long range threat to life on earth is not from too much carbon dioxide but from too little. The earth’s atmosphere has been gradually losing its carbon dioxide as the carbon has become tied up in fossil fuels. If this continues, eventually plants will be unable to reproduce and the earth will become as barren as mars. We should be glad if we can recycle some carbon from fossil fuels back into the atmosphere!
For more on global warming, see my 3,000 word booklet “What Global Warming”? available from American Liberty Publishers (www.amlibpub.com).
Tuesday, April 11, 2006
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1 comment:
an interesting view point. Thanks
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