Posted on 01/02/2002 7:36:53 AM PST by blam
Sudden Ice Age or World Drought Possible, Study Says
Robert C. Cowen
The Christian Science Monitor
January 2, 2002
If you're concerned about forecasts of long-term global warming, you might be worried about the wrong thing.
The United States National Academy of Sciences warns that sudden, unexpected climate change—on a scale that could cause widespread drought or plunge Earth into a deep freeze—poses a more immediate danger.
The evidence? Embedded in ancient tree rings and ice cores are signs that quick, drastic change is a fundamental characteristic of Earth's climate. These data show that the climate can switch abruptly from one mode—such as an ice age—to another, such as a milder interglacial period, climatologists say.
Humans have no remembered experience of such sudden, far-reaching shifts. If one were to occur in the near future, human civilization could be vastly ill-equipped to adjust.
The Academy's National Research Council (NRC) organized a study to assess this knowledge, which has come to a head over the past five years. The NRC report was distributed at a meeting of the American Geophysical Union held in early December in San Francisco.
Flipping the Climate Switch
In a sense, the report notes, humanity has been living in the meteorological equivalent of a fool's paradise. Agriculture and other aspects of civilization have developed during a period of relatively benign climate.
The workings of this climate system can be likened to a light fixture that is controlled by both a dimmer and an on-off switch, says Richard Alley of Pennsylvania State University in University Park, chair of the NRC study. You can continuously change the light level by turning the dimmer dial. But nothing may happen until you push hard enough to throw the switch. Then the lights abruptly go out.
"It's clear that climate has both dimmer dials and switches," says Alley.
In the case of global warming, for example, is the heat-trapping effect of greenhouse gases such as carbon dioxide twiddling a dimmer dial—and is it also pushing on a switch that might suddenly flip the climate?
The NRC committee emphasizes that it isn't trying to alarm people. But it does want to inject a sense of urgency into discussions of climate change to encourage research. Currently, scientists do not understand what drives drastic changes, which in turn means they cannot simulate or forecast them.
Path of No Regrets
Yet researchers are already aware that some degree of change seems to be under way. For example, the Arctic is warming. Air circulation around the North Pole region has changed. It is bringing warmer, wetter winters to northern Europe, Siberia, and parts of North America. Also, a changed wind pattern is moving young Arctic ice out of the ocean faster. That means it doesn't linger as long and build up its former thickness.
Dorothy Peteet from the NASA Goddard Institute for Space Science in New York—and NRC committee member—notes the Arctic is a good region to explore climate questions. There could well be a climate switch, which might be as simple as permafrost melting. Among other things, that could release methane, a powerful greenhouse gas.
The NRC committee members realize they are sounding a warning that is cloaked in uncertainty. Therefore, they urge what they call a "no regrets" policy: Take no action based on vague fear. Do take actions that will be beneficial, whatever happens. These include measures to curb global warming.
Continue to work to ensure adequate resources of clean air and water. Build resiliency into economic systems. And support the extensive research needed to understand how the climate system works.
Alley says scientists need to face up to a certain amount of inevitable uncertainty, since natural processes may throw climate switches in random ways that are impossible to forecast. To help people learn to anticipate surprises, he says, "We need to build uncertainty into our models of climate change."
Copyright 2001 The Christian Science Monitor
And it's possible that I will float out of this chair I'm sitting in and magically rise up to the ceiling. Possible, but not likely.
And the gun owners, somehow, are sure to be blamed.
HUH?
More seriously, these "no regrets" approaches studiously avoid accounting for how many poor people starve because of a pseudoscience-based fetish about oil consumption in the developed nations.
Seriously thought this article is full of crap. And of course gunowners and Christians are to blame.
But that's impossible because it's the Greenhouse effect of the last 100 years or so that is warming our earth.....ARRGH! Don't switch theories on me now! (And nobody tell Al Gore.)
Quite right. But this article (about climate fluxuations in the past) is one of the main reasons global warming is junk science. If, regardless of what humans do, the climate can change in unexpected ways, and in levels far greater than the global warming models, then what should we do? One thing we should not do is follow every economic change recommended by the warmer alarmers.
"The bottom line of all these studies thus seems to be that we really do not know if there are any long-term positive or negative mass balance changes occurring on either the Greenland or Antarctic ice sheets. Hence, it is important that we continue to collect data in these two polar regions, so that someday we will be able to unambiguously discern whatever trends or non-trends are representative of reality.
In the mean time, don't buy into anything about these ice sheets that sounds either too good or too bad to be true. It likely isn't."
But what if we're headed for a sudden cooling? Now I'm really confused....
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