Professor Ian Chubb, Australia's Chief Scientist and a director of the
CSIRO, is urging scientists to contribute to the climate change debate.
"The majority of scientists should be out there," he said recently,
"explaining to the public - why they do science, how they do science and
how they accumulate scientific evidence."
I became a scientist because I wanted to understand how things work. For
the only reliable way to gain this understanding is the scientific
method. Without it, we are left with prophecy, divination,
fortune-telling and group-think.
Science is primarily about evidence, and the rigorous testing of
According to the Anthropogenic Global Warming (AGW) hypothesis, an
observed increase in atmospheric carbon dioxide concentration was the
primary cause of the apparent global temperature increase of about 0.8
during the 20th century. Yet there is little observational evidence
supporting it, nor would a small temperature variation over one hundred
years be an unusual or "extreme" event.
The truth is AGW remains only an hypothesis; not a proven fact about the
Earth's climate. Support for it comes, we are told, from climate
modelling. But can a grab-bag of hypotheses expressed in numerical form
be described as genuine empirical evidence? And do the models stand up
well when rigorously tested against observation?
As a researcher with CSIRO with a PhD in Upper Atmosphere Physics, I was
involved in developing numerical fluid dynamical models similar to those
used by climate modellers today.
The CSIRO website statement - "Climate models, which are based on the
laws of physics and thoroughly tested, provide credible quantitative
estimates of future climate change" - is misleading. The "laws of
physics" actually play only a minor part in climate model design.
Furthermore, the models have no real predictive power. Their
"projections" rarely match observations. If they have been "thoroughly
tested", the public should be told of the outcomes - especially the
frequency of failure. As it is the modelers only show
graphs which support their hypothesis.
Why the Chief Scientist, whose research expertise is in neuroscience, is
so keen to defend them - and the AGW hypothesis they claim to "prove" -
is a mystery, at least to me.
Prof Chubb also expressed concern about the safety of climate change
scientists, some of whom apparently received anonymous death threats. If
true, I share his concern. Calls for them to be "thrown in jail" were,
he said, "reminiscent of a time long past." A little jail time, however,
would not be an unreasonable penalty for fraud - be it corporate,
criminal or scientific.
1. The "laws of physics" referred to relate to the conservation of mass
and energy and Newton's Second Law as encapsulated in the Navier-Stokes
equations. Numerical models based on these equations alone are generally
unstable. They have to be "tweaked" by assigning unrealistically large
values to internal frictional terms. Furthermore a large number of ad
rules-rules-of-thumb known as "parameterizations" need to be included to
account for wind stress, bottom friction, precipitation, cloud formation
and so on. Many such parameterizations are only loosely based on
experiment and can scarcely be described as "the laws of physics". Even
the massive transference of energy during tropical thunderstorms occurs
on a spatial
scale too small to be resolved by the models and must be parameterised.