Ed Poor wrote:
Sheldon's formulation is fine, provided he can
locate a source for the
"overwhelming majority" part and gives a numerical definition for
"overwhelming majority".
As it stands now, the only survey mentioned at Wikipedia seems to show
much less than "overwhelming" support for the GW theory. Perhaps it
depends on how one interprets the survey results?
Yes, I guess it does depend on how one interprets the survey results.
If the results are "interpreted" by someone like Ed who doesn't know
the basic language of science, it is possible to misconstrue the
survey and imagine that it shows less than overwhelming support for
the GW theory. Ed is referring here to the Wikipedia article titled
"Scientific opinion on climate change" and a survey which it cites
that was conducted in 1996 by Bray and von Storch. As Gareth Owen has
pointed out, however, Ed has completely misunderstood the Bray and
von Storch survey. Evidently Ed doesn't understand some of the basic
scientific terminology in the questions to which the scientists were
responding.
The most relevant question in the Bray and von Storch survey was, "We
can say for certain that, without change in human behavior, global
warming will definitely occur in the future." The scientists were
asked to rate this statement on a scale of 1 to 7, with 1 meaning
they "strongly agree" and 7 meaning "strongly disagree." They gave it
a mean rating of 2.6, which is pretty high.
They were also asked to rate the statement, "There is enough
uncertainty about the phenomenon about global warming that there is
NO need for immediate policy decisions." The scientists strongly
_disagreed_ with this statement. Their responses were rated on the
same 1-to-7 scale. To quote the study itself, "Here there is
undisputed support for immediate policy to be implemented with the
overall mean response of 5.6 and no statistically significant
differences among groups."
So how did Ed read this survey and conclude that scientists are
"about equally split"? He misinterpreted _another_ question in the
survey which asked, "To what degree do you think the current state of
scientific knowledge is able to provide reasonable predictions of
inter annual variability?" In order to make this kind of error, Ed
would either have to be flagrantly dishonest (Gareth Owen's
interpretation) or simply incompetent (my interpretation). I think
the reality is that Ed doesn't know what the phrase "interannual
variability" means. Here's a definition: "Interannual variability"
means "climate variation from one year to the next." What the
scientists are saying is that they don't think the climate models are
precise enough to predict how the climate will change between 2003
and 2004. This is clearly not the same thing at all as the question
of whether they think "the global warming theory" holds up.
This is a really basic error on Ed's part. The term "interannual
variability" is widely used in climate research. If you do a Google
search for that phrase, you'll find more than 36,000 references,
almost all of which appear in scientific contexts. Of course, the
term is hardly used at all _outside_ of scientific contexts, which
undoubtedly explains why Ed doesn't know what it means. As I stated
previously, the fact that Ed doesn't grasp this kind of thing does
not mean that he is stupid or lacks integrity. Nevertheless, he ought
to be rather humbled by the fact that he keeps making this sort of
error. If he doesn't understand the everyday language of climate
science, he shouldn't be trying to impose his interpretations as
aggressively as he has been. This is rather akin to having someone
trying to rewrite articles on music theory who doesn't know the
meaning of phrases such as "chord progression."
Ed also wrote:
But really, on such a crucial issue as Global Warming
theory, with tens
or 100s of billions of dollars at stake (not to mention human lives,
assuming the theory is actually true!) -- I'd rather have more than an
average of answers from a survey question. Better to dig up exactly how
many answered "strongly agree", "somewhat agree", etc.
I agree completely. We shouldn't be relying on opinion polls to
assess the current state of scientific knowledge. Surveys like the
one conducted by Bray and von Storch can be helpful in getting a
general sense of the state of scientific opinion, but their utility
is limited. To begin with, surveys can only ask a limited number of
fixed questions, and responses to surveys can vary dramatically
depending on minor changes in wording of the questions. Moreover, the
value of the Bray and von Storch survey is limited by the fact that
they only sent it to 1,000 scientists and only got a 40 percent
response rate, and also by the fact that it was conducted seven years
ago.
Fortunately, we have a better indicator of what scientists think:
namely, the reports of the International Panel on Climate Change
(IPCC), which was established in 1988 by the World Meteorological
Organization (WMO) and the United Nations Environmental Program
(UNEP) to fulfill the critical role of providing objective
scientific, technical, and economic assessments of the current state
of knowledge about various aspects of climate change. Some 2,000
scientists, experts and government officials prepared and signed off
on the IPCC's 1995 report, which represented the broadest consensus
available on the issue at that time. The conclusions of the IPCC's
1995 report are consistent with the opinions expressed in the Bray
and von Storch survey, but the IPCC report is incomparably more
detailed and specific.
Of course, the nature of science is that it continues to progress,
and the IPCC's 2001 report is an improvement over its 1995 report,
even though fewer scientists participated in drafting the 2001 report
(only 995, which is still more than double the 400 respondents to the
Bray and von Storch survey). The difference between the 2001 report
and the 1995 report is that the quality and quantity of scientific
research has improved in the meantime, while global warming has
accelerated, making it easier for scientists to measure and assess
the the impact of greenhouse gas emissions on global climate. (The
signal-to-noise ratio has improved, because the signal is stronger.)
Here are a few relevant excerpts from the IPCC's 2001 report:
Globally, it is very likely that the 1990s was the
warmest decade
and 1998 the warmest year in the instrumental record, since 1861.
The atmospheric concentration of carbon dioxide (CO2)
has increased
by 31% since 1750. The present CO2 concentration has not been
exceeded during the past 420,000 years and likely not during the
past 20 million years. The current rate of increase is unprecedented
during at least the past 20,000 years.
The warming over the past 100 years is very unlikely to
be due to
internal variability alone.
In the light of new evidence and taking into account
the remaining
uncertainties, most of the observed warming over the last 50 years
is likely to have been due to the increase in greenhouse gas
concentrations.
Emissions of CO2 due to fossil fuel burning are
virtually certain to
be the dominant influence on the trends in atmospheric CO2
concentration during the 21st century.
In reading these statements, it may help to understand that the IPCC
uses the term "likely" to mean a probability of 66% or higher. "Very
likely" means 90% or higher, and "virtually certain" means
probability of 99% or higher. Conversely, "unlikely" means
probability of less than 33%, and "very unlikely" means a probability
of less than 10%.
If we were dealing with someone who was less of an ideologue than Ed,
the IPCC's report would settle the matter. The problem is that Ed
doesn't want to accept the IPCC's standing as an indicator of what
climate scientists think. He prefers the opinion of S. Fred Singer
and the dozen or so people clustered around Singer at SEPP.
One way around this impasse might be to look at what other leading
scientific bodies have said about the matter, so here are a couple:
(1) The American Meteorological Society issued a detailed statement
this year, which strongly agrees with the IPCC:
http://www.ametsoc.org/policy/climatechangeresearch_2003.html
Here's an excerpt:
The nature of science is such that there is rarely
total agreement
among scientists. Individual scientific statements and papers-the
validity of some of which has yet to be assessed adequately-can be
exploited in the policy debate and can leave the impression that the
scientific community is sharply divided on issues where there is, in
reality, a strong scientific consensus.
[SNIP]
IPCC assessment reports are prepared at approximately
five-year
intervals by a large international group of experts who represent
the broad range of expertise and perspectives relevant to the
issues. The reports strive to reflect a consensus evaluation of the
results of the full body of peer-reviewed research. A large number
of U.S. scientists are on the international Working Groups of the
IPCC that prepare and review these reports. They provide an analysis
of what is known and not known, the degree of consensus, and some
indication of the degree of confidence that can be placed on the
various statements and conclusions. These reports have become the
prime scientific basis for international political decisions about
climate change.
(2) The U.S. National Academy of Sciences (the most prestigious
general scientific body in the world) has issued a number of reports
reaching similar conclusions. In a 2001 report, for example, it
stated that the IPCC "does an admirable job of reflecting research
activities in climate science." You can download the full report, or
simply read the accompanying press release, from the following URL:
http://www.nap.edu/catalog/10139.html?onpi_webextra6
Obviously I can't do full justice to the substance of these reports
in the space of a single email, and I see that this message has
already gotten quite long. I could continue citing similar reports
from other leading national and international scientific bodies, but
I think I'll stop here.
--
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| Sheldon Rampton
| Editor, PR Watch (
www.prwatch.org)
| Author of books including:
| Friends In Deed: The Story of US-Nicaragua Sister Cities
| Toxic Sludge Is Good For You
| Mad Cow USA
| Trust Us, We're Experts
| Weapons of Mass Deception
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