Just to try to "level" the field wherein all the argument takes place over
AGW.
Richard Lindzen is probably the most respected of the atmospheric scientists
who are sceptical about catastrophic climate change. He has been the AGW
sceptical scientist-of-choice on many TV programmes and writes leading
articles for newspapers such as the Wall St journal.
From the Wall St Journal that Terry Blanton linked to
http://www.opinionjournal.com/extra/?id=110008220 Lindzen said a variation
of the position he has held for many years (early 90's). BTW, this is not
cherry picked - it represents his frequently expressed opinion.
"To understand the misconceptions perpetuated about climate science and the
climate of intimidation, one needs to grasp some of the complex underlying
scientific issues. First, let's start where there is agreement. The public,
press and policy makers have been repeatedly told that three claims have
widespread scientific support: Global temperature has risen about a degree
since the late 19th century; levels of CO2 in the atmosphere have increased
by about 30% over the same period; and CO2 should contribute to future
warming. These claims are true. However, what the public fails to grasp is
that the claims neither constitute support for alarm nor establish man's
responsibility for the small amount of warming that has occurred." I hope
that Vorts are sufficiently literate to understand exactly what he is saying
here...
The most serious sceptic is admitting that 1) there has been warming 2) that
CO2 has increased in parallel with that warming 3) that CO2 should
contribute to future warming. Virtually all of the "AGW denier" propaganda
and deliberately deceptive claims can therefore be thrown in the bin - their
main sceptical scientist does not back them up. Throw in the bin the urban
heat islands, the increased solar irradiance, the so called debunked hockey
stick (the debunking has since been debunked), the "warming" on other
planets and all of the other, often mutually contradictory, theories and
logical falsehoods that the denier industry propagates ad nauseam, despite
them having been answered time and time again - they just keep on endlessly
resurrecting them, like the killer in a Freddy/Jason slasher movie, as long
as there are new gullible people to swallow it.
Lindzen's argument is that he does not agree with the IPCC projections
because he comes up with a different, lower, figure for the "sensitivity" of
the climate to greenhouse gas "forcing" and feedbacks. He tacitly admits
that there has been warming, that there will be further warming and that we
are responsible for some of it. Where he differs from the majority is that
his lower "sensitivity" figure leads to predictions of lower temperature
rise and much lower probability of excess positive feedbacks adding to the
problem. He states that there will be further warming and we will be
responsible for it but it won't be a problem. He is effectively claiming
that, according to his research, assumptions, projections and logic that in
a similar situation, Dirty Harry usually has shot 6 bullets, or the last
bullet always misfires, so challenging him won't be dangerous. The IPCC
models say that their "sensitivity" figure, projections, assumptions and
logic etc show that Dirty Harry will almost certainly have bullets left and
that it will be at least risky to definitely dangerous to challenge him.
A fundamental problem is that the actual "sensitivity" figure to various
inputs CANNOT be known with certainty without a lot of experimental climate
science, which I have pointed out, over the years, would need a time
machine, as we only have one "test tube" to do the experiment in.
It comes down to this - both the sceptical scientists and the far greater
number of pro AGW scientists are advising us that they're assessments and
assumptions about reality are better and more accurate than the
opposition's. Neither has got sufficient experimental climate science behind
them to fully validate their positions. Who do we trust? Answer - neither.
What we should do is use the techniques of risk assessment to decide what to
do.