From the American Thinker
The Coming Ice Age
By David Deming
Those who ignore the geologic perspective do so at great risk. In fall of 1985, geologists warned that a Columbian volcano, Nevado del Ruiz, was getting ready to erupt. But the volcano had been dormant for 150 years. So government officials and inhabitants of nearby towns did not take the warnings seriously. On the evening of November 13, Nevado del Ruiz erupted, triggering catastrophic mudslides. In the town of Armero, 23,000 people were buried alive in a matter of seconds.
For ninety percent of the last million years, the normal state of the Earth’s climate has been an ice age. Ice ages last about 100,000 years, and are punctuated by short periods of warm climate, or interglacials. The last ice age started about 114,000 years ago. It began instantaneously. For a hundred-thousand years, temperatures fell and sheets of ice a mile thick grew to envelop much of North America, Europe and Asia. The ice age ended nearly as abruptly as it began. Between about 12,000 and 10,000 years ago, the temperature in Greenland rose more than 50 °F.
We don’t know what causes ice ages to begin or end. In 1875, a janitor turned geologist, James Croll, proposed that small variations in Earth’s orbit around the Sun were responsible for climate change. This idea enjoyed its greatest heyday during the 1970s, when ocean sediment cores appeared to confirm the theory. But in 1992, Ike Winograd and his colleagues at the US Geological Survey falsified the theory by demonstrating that its predictions were inconsistent with new, high-quality data.
The climate of the ice ages is documented in the ice layers of Greenland and Antarctica. We have cored these layers, extracted them, and studied them in the laboratory. Not only were ice ages colder than today, but the climates were considerably more variable. Compared to the norm of the last million years, our climate is remarkably warm, stable and benign. During the last ice age in Greenland abrupt climatic swings of 30 °F were common. Since the ice age ended, variations of 3 °F are uncommon.
For thousands of years, people have learned from experience that cold temperatures are detrimental for human welfare and warm temperatures are beneficial. From about 1300 to 1800 AD, the climate cooled slightly during a period known as the Little Ice Age. In Greenland, the temperature fell by about 4 °F. Although trivial, compared to an ice age cooling of 50 °F, this was nevertheless sufficient to wipe out the Viking colony there.
In northern Europe, the Little Ice Age kicked off with the Great Famine of 1315. Crops failed due to cold temperatures and incessant rain. Desperate and starving, parents ate their children, and people dug up corpses from graves for food. In jails, inmates instantly set upon new prisoners and ate them alive.
The Great Famine was followed by the Black Death, the greatest disaster ever to hit the human race. One-third of the human race died; terror and anarchy prevailed. Human civilization as we know it is only possible in a warm interglacial climate. Short of a catastrophic asteroid impact, the greatest threat to the human race is the onset of another ice age.
The oscillation between ice ages and interglacial periods is the dominant feature of Earth’s climate for the last million years. But the computer models that predict significant global warming from carbon dioxide cannot reproduce these temperature changes. This failure to reproduce the most significant aspect of terrestrial climate reveals an incomplete understanding of the climate system, if not a nearly complete ignorance.
Global warming predictions by meteorologists are based on speculative, untested, and poorly constrained computer models. But our knowledge of ice ages is based on a wide variety of reliable data, including cores from the Greenland and Antarctic ice sheets. In this case, it would be perspicacious to listen to the geologists, not the meteorologists. By reducing our production of carbon dioxide, we risk hastening the advent of the next ice age. Even more foolhardy and dangerous is the Obama administration’s announcement that they may try to cool the planet through geoengineering. Such a move in the middle of a cooling trend could provoke the irreversible onset of an ice age. It is not hyperbole to state that such a climatic change would mean the end of human civilization as we know it.
Earth’s climate is controlled by the Sun. In comparison, every other factor is trivial. The coldest part of the Little Ice Age during the latter half of the seventeenth century was marked by the nearly complete absence of sunspots. And the Sun now appears to be entering a new period of quiescence. August of 2008 was the first month since the year 1913 that no sunspots were observed. As I write, the sun remains quiet. We are in a cooling trend. The areal extent of global sea ice is above the twenty-year mean.
We have heard much of the dangers of global warming due to carbon dioxide. But the potential danger of any potential anthropogenic warming is trivial compared to the risk of entering a new ice age. Public policy decisions should be based on a realistic appraisal that takes both climate scenarios into consideration.
(h/t to Ron de Haan)
David Deming is a geophysicist and associate professor of Arts and Sciences at the University of Oklahoma.
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Smokey (15:56:49) :
This excellent article is by the same Dr. David Deming:
Is there any reason why the “major person” cannot be named?
I hope this helps on a few points raised in this discussion.
“Heaven and Earth” will be published on different dates in different countries.
It initially appeared in Australia. I have read it is available in NZ.
The last information I saw, claimed US publication was scheduled for May 28,2009.
Brian Fagen’s “The Great Warming” claimed extensive cannibalism during the little ice age. Families swapped children so they would not have to eat their own.
Fishermen in modern times report nets snagged on trees on the sea floor at Grand Banks and Georges Banks; trees confirmed by divers.
Francis (21:40:32) :
Ron de Haan (13:30:25) re: CURRENT COOLING ?
Local weather is pretty simple here: heating season and air conditioning season, separated by nice weather. I only pay attention to outside temperatures mid-month, when last month’s global average becomes available.
From the Summary of the April, 2008; Fawcett & Jones paper: Waiting for Global Cooling. (This is Aussie–I like the accent.)
There is very little justification for asserting that global warming has gone away over the past ten years, not least because the linear trend in globally-averaged annual mean temperatures (the standard yardstick) over the period 1998-2007 remains upward. While 1998 was the world’s warmest year in the surface-based instrumental record up to that point in time, 2005 was equally warm and in some data sets surpassed 1998. A substantial contribution to the record warmth of 1998 came from the very strong El Nino of 1997/1998 and, when the annual data are adjusted for this short-term effect (to take out El Nino’s warming influence) the warming trend is even more obvious.
Because of the year- to-year variations in globally-averaged mean temperatures, about ten years are required for an underlying trend to emerge from the “noise” of those year-to-year fluctuations. Hence, the fact that 2006 and 2007 were cooler than 2005, is nowhere near enough data to clearly establish a cooling trend.
And of course this most recent La Nina continued, thru 2008, until it ended last month.
I would hope for some standard weather for a while…so we can keep score without the down and up adjustments”.
Francis,
The point is that there is no reason at all for any of the warming alarmism.
Everything that happens today, has happened hundreds of times in the past.
We have had much higher temperatures and much higher CO2 and never experienced scary things like dangerous run away warming and all the other fear mongering the AGW scare mongers are dishing up only to serve a political agenda.
To reduce our CO2 emissions by 80% based on 1990 levels by 2050 as demanded by the UN is a joke and it will never happen.
It’s a matter of time before the shoe will drop and heads will role.
Ron de Haan (15:32:02)
“Everything that happens today has happened hundreds of times in the past. We have had much higher temperatures and much higher CO2…”
I’m just winging it now…I’ve gotta go do the laundry and buy the groceries, etc….so I can’t double check anything…But, a list of the above would be a potent argument against AGW.
The hockey stick graphs (that don’t list Michael Mann among the authors…to avoid that discussion) don’t show any such events…in the past 1000 years.
There is a medieval warm period in those graphs…but it doesn’t match current warming.
The global warming portion of the hockey stick graph would be that after about 1975…note how steep the slope is.
Geological time on this would probably start when South America butted up against North America…in order to get similar continental layouts…whenever that was. And periods of mass extinctions would be inappropriate.
No doubt my skepticism (in the general sense) shows thru this exposition. But I have encountered a number of such historical/glacial/geological arguments…are there any that are any good?