[ExI] [wta-talk] Richard Lindzen on climate hysteria
max at maxmore.com
Sat Aug 1 04:12:14 UTC 2009
I'm preparing to leave for the weekend, so have only a little time to
devote to this comment.
James Hughes posted the results of one particular survey that
reported apparently strong agreement on something or other. James
especially highlights the figure of 97% agreement. That does indeed
sound very impressive. In contrast to Adrian (if I understand his
posts correctly), I do think that such a tight consensus among a
group of scientists would be something to give considerable epistemic
weight to -- at least in the absence of major objections, say from a
neighboring discipline. But let's look at little more closely at it.
>Two questions were key: Have mean global temperatures risen compared
>to pre-1800s levels, and has human activity been a significant
>factor in changing mean global temperatures?
>About 90 percent of the scientists agreed with the first question
>and 82 percent the second.
These numbers are lower than the most impressive one of 97%, but still high.
>The strongest consensus on the causes of global warming came from
>climatologists who are active in climate research, with 97 percent
>agreeing humans play a role.
Agreement was lower in certain groups:
>Petroleum geologists and meteorologists were among the biggest
>doubters, with only 47 percent and 64 percent, respectively,
>believing in human involvement.
Why would agreement be higher among the climatologists than among
other scientists, including meteorologists and physicists? One
plausible answer is that it's because the climatologists can make
better judgments. (Although evidence-based forecasting shows that
expert forecasts of future changes cannot be trusted with this kind
of problem.) Another plausible answer is that groupthink is at work,
as it is in so many areas of human activity. This is hardly an
arbitrary suggestion, given all the accusations of "denial" and
"planetary traitors" and the strong pressures being exerted against skeptics.
Of course there are other surveys, which produce different results.
Climatologists are only one group qualified to answer these
questions. But l'll set that aside here.
One question that comes to mind is; How were the people to be
questioned selected? What percentage of the total does the 3,100 or
so represent? From what I've seen, some 10,200 earth scientists were
contacted. Only 3,100 replied. Now, these *may* be representative, or
they may not be. Anyone with an academic background in the social
sciences, or statistics knows that samples can and often do
misrepresent the whole. Given the thousands of signed dissenting
opinions, I'm not terribly confident that the percentages of
respondents in this survey accurately represent the whole group. It
seems, for instance, that earth scientists working in private
industry were ignored. Given that government-funded scientists may
have an incentive (above and beyond the obviously heavy
peer-pressure) to agree, the results may not give an accurate picture
of all relevant scientists.
These questions come to mind especially because of the highly
politicized nature of this discussion. Also, specifically, because of
misrepresentations such as seen with the IPCC report, where a small
group of people claim to speak for a much larger group. (Compare the
summary of the IPCC report to the actual details of the report...)
Other surveys have yielded different percentages. You can see that
just from the Wikipedia article cited by James:
But, set aside these concerns.
Much more troubling are the questions and the conclusions so quickly
drawn from them. Consider the questions. What exactly were those
surveyed being asked?
1. "Have mean global temperatures risen compared to pre-1800s levels?"
1800 was around the tie that we began to recover more quickly from
the Little Ice Age. So what does this tell us? Not much about today
or about human activity. It does show that climate scientists agree
that the global temperature changes over time. Who is going to
disagree with *that*?
2. Has human activity been a significant factor in changing mean
So, 82% said yes to this. Is this anything to get excited about?
Should it impress those of us who are a bit skeptical about warming
catastrophe stories? Suppose you are entirely certain that carbon
dioxide released by humans is not the cause of global warming. You
would still easily grant that global mean temperatures has risen due
to the urban heat island effect.
In addition, the question is very vague, certainly if "significant"
is taken in the sense of statistical significance (as it presumably
is by these scientists). If those climate scientists believed that
only 2% or 5% of observed warming could be attributed to human
activity, they would still agree with that statement.
How many would still agree if the question was:
-- Do you agree that warming was almost certainly primarily due to
human activity? (Not just "significant".)
-- Is global warming principally or quantifiably due to human activity?
-- Are you certain or almost certain that human activity would cause
a degree of future warming that constituted a catastrophe?
-- Do you believe that large cuts in carbon dioxide would be
effective or cost-effective?
-- Do you believe that the Kyoto Protocol is a sensible solution?
Claiming consensus -- even if entirely justified -- on such vague
questions that few skeptics would disagree with is an easy victory
that gets us nowhere with any discussion that matters. Once again,
dumbing down the issue to a "consensus" of some vague kind isn't useful.
Aside from the foregoing points, I have to say that given the
inaccuracy of climate models (as shown comparing them to the past),
being impressed by a supposed (or even real) consensus of climate
scientists doesn't look too different from relying on a consensus of
astronomers. (I would have equally harsh things to say about
economists, when they model whole economies...) Granted, that's
overstating it. But not by a whole hell of a lot. Again, see my
previous post pointing to an audit of the forecasting methodology of
the IPCC report, which is considered the gold standard.
I just can't see climate modeling as having attained the status of a
hard science at this stage. Even if there was a rock solid consensus
on some point of interest (rather than on statements that I have no
problem with at all), I would not feel rationally compelled to assent
to it as I would, for instance, in the case of a consensus among
particle physicists who tell me not to worry about strangelets as
they start up the Large Hadron Collider.
P.S. Can a backer of the "consensus" view please point me to a good
explanation of the fact that human emissions of greenhouse gases has
continued unabated, and yet there has been zero global warming over
the last 10 to 11 years? I would appreciate it. (By a "good
explanation", I mean one that doesn't have to resort to something
like Ptolemeic epicycles.)
Max More, Ph.D.
Extropy Institute Founder
max at maxmore.com
More information about the extropy-chat