The Agatha Christie approach to global warming
- 14 Feb 2011, 09:51
- Christian
David Archer in his book 'the Long
Thaw' uses this analogy to explain the difficulties of arguing
that recent climate change is merely the result of natural cycles
in the Earth's climate:
"Think of it like a murder mystery. The
butler (CO2) was caught with a smoking gun in his hand in the room
with the dead guy. There is a lot of public interest in this case,
so your boss is driving you nuts writing reports and such like;
everything has to be pinned down on this one. Yes, the bullets came
from the gun. Yes, the gun was purchased by the butler. Everything
checks out."
"But now your partner Bob argues that it was really the chauffeur
did it. Actually, you find out that the chauffeur was at his
sister's wedding on the other side of town for the whole time and
lots of people saw him.. But Bob says, maybe there is some way he
did it but you're just not smart enough to figure it out. OK, you
retort, but if Bob is going to convict the chauffeur, he has to
think of a way to unconvict the butler. He would have to come up
with an innocent explanation for the butler's smoking gun, and the
bullets and all that."
Archer's point is this: If you want to argue that most recent
climate change has not been caused by humans putting greenhouse
gases into the atmosphere, but by something else, your theory has
to explain not only the warming planet, but also explain away all
of the evidence that suggests it's largely human-induced CO2 which
is to blame.
This has been on my mind, because Skeptical Science has
responded to a
challenge thrown out by climate-sceptic scientist Roy Spencer,
based at the University of Alabama. Spencer is described
by Skeptical Science as "one of very few climate scientists who
remain unconvinced that most of the recent global warming has been
caused by humans". (
Real Climate has also discussed his role in the climate
debate.)
Spencer recently
wrote on his blog:
"Show me one peer-reviewed paper that
has ruled out natural, internal climate cycles as the cause of most
of the recent warming in the thermometer record."
Skeptical Science argues
that:
"This challenge is problematic … the
fact that research has not ruled out a hypothesis does not mean the
hypothesis necessarily has any validity. For example, there
have been no peer-reviewed papers ruling out leprechauns as the
cause of most of the recent global warming, either. But
perhaps more importantly, our understanding that humans are causing
global warming is not based on just one scientific study, but
rather a very wide range of scientific evidence."
They go on:
"Skeptics like Spencer and [fellow
sceptic-scientist] Lindzen believe that the default assumption
should be one which requires that a very large body of scientific
evidence is wrong. The only alternative hypothesis they have
put forth cannot explain the many empirically-observed
"fingerprints" which are consistent with human-caused global
warming. Although Spencer's unspecified "natural internal
cycle" hypothesis has not been explicitly disproved, there is a
very low likelihood that it is correct. For this reason, we
should operate under the assumption that humans are causing
dangerous global warming - an assumption which is supported by a
very large body of evidence - until the skeptics can provide solid
reason to believe that this scientific theory is wrong."
In other words, it was the butler. (Or as the IPCC
would say, it's "very
likely" the butler dunnit.)
The Skeptical Science piece is here.