18 Aug, 2005 by Fintan
Earth's climate is your responsibility too, so buy
a gas-guzzling SUV, burn plenty of fossil fuels; and keep asking yourself
are you doing enough to keep global cooling at bay?
incessant hype over 'global warming' may turn out to be a dreadful
mistake, if some scientists' more long term assessments of climate
change proves right.
They say that without the presence of greenhouse gasses over the last
8,000 years we might already be well on the way to another mini-ice
A sudy by William
Ruddiman, Professor Emeritus of Environmental Sciences and his
team at the University of Virginia Charlottesville, Virginia has shown
that if ancient agriculturists had not systematically cleared forests,
planted crops and raised domesticated herds, global temperatures today
would be an average of two degrees centigrade lower.
And you thought that greenhouse gasses were at issue only in the recent
industrial era? You've been misled. The relentless focus on modern
fossil fuels ignores the dramatic climatic effect of the forest clearances
and other effects since the dawn of mass agriculture around 8,000
CENTRAL HEATING FOR EARTH
Modern climatology has assumed that the relatively recent increases
in greenhouse gasses were driving up temperatures which were otherwise
But the latest research confirms that without ancient greenhouse gasses,
a decreasing level of solar radiation driven by Earth-orbital changes
would have caused global temperatures to plunge.
Professor Ruddiman's study, published
in the journal Quaternary Science Reviews reports
a test of this hypothesis using the GENESIS global climate computer
When the scientists reduced atmospheric carbon-dioxide and methane
to their estimated ‘natural’ levels --without the greenhouse contribution
by early agriculturists-- the model showed a current global climate:
"almost 2C cooler than today and roughly one third of the way
toward full glacial temperatures."
Since the dawn of civilization, we have been burning wood to cook
food and keep warm. That adds up to a lot of campfires and a lot of
CO2. Much more of the warming gas came from forest burning in Eurasia
8,000 years ago. Factor in the introduction of livestock and rice
irrigation by 5,000 years ago and we have mass sources of methane,
another greenhouse gas.
The combination seeded the atmosphere with about 40 parts per million
of carbon dioxide and 250 parts per billion of methane. That was enough
to produce nearly 0.8 °C of warming before 1700, when industrialization
began. Since then, our modern greenhouse contribution is reckoned
to have added an equivalent warming effect.
EVIDENCE IN THE ICE NEEDS EXPLAINING
of focussing on the last 350 years, research should take a less myopic
scope and encompass Earth's solar rotation cycles over the last 350,000
Ice cores show that decreases in summer sunshine caused by these great
cyclical changes in Earth's orbit have caused levels of carbon dioxide
and methane in the air to fall in tandem. But the pattern changes
8000 years ago. "Both gases followed the expected trend for a while
but then went up instead of down," says Ruddiman.
Without that trend-breaking change, glaciers would have already been
forming over north-eastern Canada about 4000 years ago, the latest
climate modeling shows. And there are some interesting CO2 variations
in more recent times.
The conventional assumption is that a centuries-long mini-ice age
beginning around 1300 caused the significant disease outbreaks and
population drops historians know took place around that time.
Ruddiman turns that idea on its head. He proposes the bubonic plague
pandemics in Eurasia did not follow the fall in temperature, rather
they caused it. Disease had so depleted the population that resurgent
wild vegetation soon began to draw CO2 from the atmosphere and lock
it up in biomass. Temperatures soon fell. They only recovered when
agriculture flourished once again.
TOO COLD IS WORSE THAN TOO WARM
Reaction to the overdue glaciation hypothesis has been varied.
Geochemist Jeff Severinghaus at the Scripps Institution of Oceanography
in San Diego, California, called the idea "very speculative."
"I doubt that ancient humans could have done that," he says.
Yet the ice cores show that regardless of cause, something was clearly
going on. "It's absolutely worth following up," said Pennsylvania
State University glaciologist Richard Alley.
Benny Peiser of John Moores University, Liverpool is a strong
proponent of the new thinking. "Instead of driving us to the brink
of disaster," he says, "human intervention will be seen
as vital activities that have unintentionally delayed the onset of
a catastrophic ice age."
Amid modern fears that so-called "global warming" could
potentially destroy our civilization, Dr Peiser has studied factors
that have contributed to the collapse of urban civilizations. The
fall of the Akkadian era, and the demise of the Hittites, Mycenaeans,
Mayans and even the Roman Empire were triggered by climate change
--but not the kind you might think.
Peiser told the 2003 annual conference of the Royal Geographical
Society that "none of the known cases of civilization collapse has
ever been linked to episodes of global warming, but many are thought
to have happened during climatic downturns."
"Warmer temperatures... have never contributed to the decline
or disintegration of any society, but have been mostly advantageous,"
said Dr Peiser.
MEANWHILE IN THE FAITH-BASED
Here's an example from the UK Independent of typical alarmist reporting
with a very misleading headline:
warming is 'twice as bad as previously thought'
You might get the impression that this means 'global warming is right
now twice as bad as expected. Wrong. It's all hype:
"Global warming might
be twice as catastrophic as previously thought, the world's biggest
study of climate change shows. Researchers from some of Britain's
leading universities used computer modelling to predict that
under the "worst-case" scenario, London would be under water
and winters banished to history as average temperatures in the UK
soar up to 20C higher than at present."
So, it's a worst-case
prediction, not a current anlysis. Retitle that headline, please:
"Global warming MIGHT IN FUTURE be 'twice as bad as previously
thought' IF THINGS REALLY GO BAD."
The 'global warming' skeptics base their questions on actual ice core
analysis. Ice cores which unquestionably show solar radiation versus
greenhouse gas anomalies. By comparison, the global warming alarmists
use models to make dire predictions.
Those models rely on current warming estimates are likely skewed by
overreliance on ground based temperature recordings --often compromized
by the proximity of nearby relatively warm cities. Furthermore, not
all layers of the athmosphere are showing this claimed current heating.
"Global Warming," has many of the hallmarks of an elite-inspired
"global crisis" needing the kind of sweeping "global
action" that politicians love. They can, and do, relentlessly
hijack such issues to remind us all of their "global" importance.
But that is a story for another day.
Meanwhile, let's get on with the science. Without the hype.