Update: apologies for formatting problems in a previous version
of this blog post.
Last week a study claimed that 97-98
percent of the most published climate scientists agree with the
scientific consensus that man-made climate change is happening.
Well, duh. Of course they would: it’s their livelihood. Anyway,
so do I. So do most `sceptics’: they just argue about how much and
through what means. You can believe in man-made carbon dioxide
causing man-made climate change but not in net positive feedbacks
so you think the change will be mild, slow, hard to discern among
natural changes and far less likely to cause harm than
carbon-rationing policies: that’s still within the range of
possibilities of the IPCC consensus.
Besides, what happened to previous declarations of certain
scientific consensus? In Reason magazineRon Bailey has gone back and looked up the
phrase in the mainstream media before 1985. He finds
that it was used about a whole bunch of assertions that later
proved false, exaggerated or misleading
First saccharin:
One of the first instances of the
uses of the phrase appears in the July 1, 1979 issue
of
TheWashington
Poston the safety of the artificial
sweetener saccharin. “The real issue raised by saccharin is not
whether it causes cancer (there is now a broad scientific consensus
that it does)”
Yet
Thirty years later, the National
Cancer Institute
reportsthat
“there is no clear evidence that saccharin causes cancer in
humans.
Second dietary cancer:
Similarly, the
Postreported later that same
year (October 6, 1979) a “profound shift” in the prevailing
scientific consensus about the causes of cancer. According to
thePost,
researchers in the 1960s believed that most cancers were caused by
viruses, but now diet was considered the far more important factor.
One of the more important findings was that increased dietary fiber
appeared to reduce significantly the incidence of colon
cancer.
Yet
Twenty years later,
a
major prospective
studyof nearly 90,000 women
reported, “No significant association between fiber intake and the
risk of colorectal adenoma was found.” In 2005, another big
study
confirmedthat “high dietary
fiber intake was not associated with a reduced risk of colorectal
cancer.”
Third, fusion:
The December 17, 1979 issue
of
Newsweekreported that the
Department of Energy was boosting research spending on fusion
energy reactors based on a scientific consensus that the break-even
point-that a fusion reactor would produce more energy than it
consumes-could be passed within five years.
Yet
That hasn’t happened yet and the
latest effort to spark a fusion energy revolution, the
International Thermonuclear Experimental Reactor, will not be ready
for
full-scale testing until
2026.
Fourth, acid rain:
The March 10, 1985
New York Timescited
environmental lawyer Richard Ottinger, who asserted that there is a
“broad scientific consensus” that acid rain is destroying lakes
and forests and ”is a threat to our health.”
Yet
The [official] assessment
concluded that acid rain was not damaging forests, did not hurt
crops, and caused no measurable health problems. The report also
concluded that acid rain helped acidify only a fraction of
Northeastern lakes and that the number of acid lakes had not
increased since 1980.
Had he been able to go back further in time, Bailey would have
found just as firm a scientific consensus behind eugenics.
Of course, some assessments are right. And of course, the
environmentalists most loudly proclaiming that we must obey the
scientific consensus on climate change take no such notice of the
consensus that genetically modified crops are safe.