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 I DEVOTED six years to carbon accounting,
building models for the Australian Greenhouse Office. I am the rocket
scientist who wrote the carbon accounting model (FullCAM) that measures
Australia's compliance with the Kyoto Protocol, in the land use change
and forestry sector.
FullCAM models carbon flows in
plants, mulch, debris, soils and agricultural products, using inputs
such as climate data, plant physiology and satellite data. I've been
following the global warming debate closely for years.
When I started that job in 1999 the evidence that carbon emissions
caused global warming seemed pretty good: CO2 is a greenhouse gas, the
old ice core data, no other suspects.
The evidence was not conclusive, but why wait until we were certain
when it appeared we needed to act quickly? Soon government and the
scientific community were working together and lots of science research
jobs were created. We scientists had political support, the ear of
government, big budgets, and we felt fairly important and useful (well,
I did anyway). It was great. We were working to save the planet.
But since 1999 new evidence has seriously weakened the case that
carbon emissions are the main cause of global warming, and by 2007 the
evidence was pretty conclusive that carbon played only a minor role and
was not the main cause of the recent global warming. As Lord Keynes
famously said, "When the facts change, I change my mind. What do you
do, sir?"
There has not been a public debate about the causes of global
warming and most of the public and our decision makers are not aware of
the most basic salient facts:
1. The greenhouse signature is missing. We have been looking and measuring for years, and cannot find it.
Each possible cause of global warming has a different pattern of
where in the planet the warming occurs first and the most. The
signature of an increased greenhouse effect is a hot spot about 10km up
in the atmosphere over the tropics. We have been measuring the
atmosphere for decades using radiosondes: weather balloons with
thermometers that radio back the temperature as the balloon ascends
through the atmosphere. They show no hot spot. Whatsoever.
If there is no hot spot then an increased greenhouse effect is not
the cause of global warming. So we know for sure that carbon emissions
are not a significant cause of the global warming. If we had found the
greenhouse signature then I would be an alarmist again.
When the signature was found to be missing in 2007 (after the latest
IPCC report), alarmists objected that maybe the readings of the
radiosonde thermometers might not be accurate and maybe the hot spot
was there but had gone undetected. Yet hundreds of radiosondes have
given the same answer, so statistically it is not possible that they
missed the hot spot.
Recently the alarmists have suggested we ignore the radiosonde
thermometers, but instead take the radiosonde wind measurements, apply
a theory about wind shear, and run the results through their computers
to estimate the temperatures. They then say that the results show that
we cannot rule out the presence of a hot spot. If you believe that
you'd believe anything.
2. There is no evidence to support the idea that carbon emissions
cause significant global warming. None. There is plenty of evidence
that global warming has occurred, and theory suggests that carbon
emissions should raise temperatures (though by how much is hotly
disputed) but there are no observations by anyone that implicate carbon
emissions as a significant cause of the recent global warming.
3. The satellites that measure the world's temperature all say that
the warming trend ended in 2001, and that the temperature has dropped
about 0.6C in the past year (to the temperature of 1980). Land-based
temperature readings are corrupted by the "urban heat island" effect:
urban areas encroaching on thermometer stations warm the micro-climate
around the thermometer, due to vegetation changes, concrete, cars,
houses. Satellite data is the only temperature data we can trust, but
it only goes back to 1979. NASA reports only land-based data, and
reports a modest warming trend and recent cooling. The other three
global temperature records use a mix of satellite and land
measurements, or satellite only, and they all show no warming since
2001 and a recent cooling.
4. The new ice cores show that in the past six global warmings over
the past half a million years, the temperature rises occurred on
average 800 years before the accompanying rise in atmospheric carbon.
Which says something important about which was cause and which was
effect.
None of these points are controversial. The alarmist scientists agree with them, though they would dispute their relevance.
The last point was known and past dispute by 2003, yet Al Gore made
his movie in 2005 and presented the ice cores as the sole reason for
believing that carbon emissions cause global warming. In any other
political context our cynical and experienced press corps would surely
have called this dishonest and widely questioned the politician's
assertion.
Until now the global warming debate has merely been an academic
matter of little interest. Now that it matters, we should debate the
causes of global warming.
So far that debate has just consisted of a simple sleight of hand:
show evidence of global warming, and while the audience is stunned at
the implications, simply assert that it is due to carbon emissions.
In the minds of the audience, the evidence that global warming has
occurred becomes conflated with the alleged cause, and the audience
hasn't noticed that the cause was merely asserted, not proved.
If there really was any evidence that carbon emissions caused global
warming, don't you think we would have heard all about it ad nauseam by
now?
The world has spent $50 billion on global warming since 1990, and we
have not found any actual evidence that carbon emissions cause global
warming. Evidence consists of observations made by someone at some time
that supports the idea that carbon emissions cause global warming.
Computer models and theoretical calculations are not evidence, they are
just theory.
What is going to happen over the next decade as global temperatures
continue not to rise? The Labor Government is about to deliberately
wreck the economy in order to reduce carbon emissions. If the reasons
later turn out to be bogus, the electorate is not going to re-elect a
Labor government for a long time. When it comes to light that the
carbon scare was known to be bogus in 2008, the ALP is going to be
regarded as criminally negligent or ideologically stupid for not having
seen through it. And if the Liberals support the general thrust of
their actions, they will be seen likewise.
The onus should be on those who want to change things to provide
evidence for why the changes are necessary. The Australian public is
eventually going to have to be told the evidence anyway, so it might as
well be told before wrecking the economy. Source
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