By Prof Stephan Lewandowsky, Australian Professorial Fellow, Cognitive Science Laboratories at University of Western Australia
Reposted from The Conversation (May 16 2011)
Quick, consider the following: all polar bears are animals. Some animals are white.
Therefore, some polar bears are white. Is this conclusion logically implied or not?
There is a 75% chance you might endorse this conclusion despite it being logically false.
This instantly becomes apparent if you replace “white” in the foregoing with “brown”.
You just witnessed a fundamental aspect of human cognition. Our logical reasoning is often compromised by irrelevant features such as the familiarity of white (but not brown) polar bears.
This frailty is routinely exploited by those who are trying to confuse the public about the well-established scientific fact that the Earth is warming due to human CO₂ emissions.
There is an upside to this frailty, however: whether due to mere ignorance or ideologically-driven mendacity, denier illogic can be revealed for the nonsense it is by translating it into an everyday equivalent.
Consider the famous denialist two-step, often uttered in the same breath: “it’s not warming… but it’s natural variation.”
This is logically equivalent to the claim: “decaying teeth don’t exist… but they fall out naturally.”
No one would place much faith in that dental opinion and no one should place any trust into equivalent illogic when it comes to climate.
In other instances, compromised reasoning can be more subtle, especially when couched in calm and civil terms, as in a recent article in these pages.
At first glance, Emeritus Professor Paltridge makes very reasonable points, for example by noting that some skeptics just like being a nuisance and that some of their scientific arguments are “hairy”.
Alas, the pernicious illogic lurking beneath this veneer can be revealed in its stark menace by translating the argument made about climate change into the context of HIV/AIDS.
In translation, the principal premises of the article are as follows:
(1) The medical community is polarised about whether or not HIV causes AIDS.
(2) On the one hand there is the establishment that endorses this link, on the other hand there are some sceptical but reputable scientists, and the scientists in the middle say little.
(3) Some vocal medical researchers insist true science can only be found in peer-reviewed medical journals.
(4) A situation has developed reminiscent of religion in the Middle Ages, in which only establishment theologians can do medical science.
(5) The establishment should be expected to bridge the divide between the two sides, because it must be remembered:
(6) most new ideas in research come from the outside.
(7) The first step is for establishment medical scientists to acknowledge the material emerging on reputable homeopathic blogs, which after all,
(8) have access to a store of enthusiastic labour.
(9) Medical researchers need to be positive and helpful when identifying errors in some of the more extreme homeopathic ideas.
This chillingly surreal narrative is far from hypothetical.
Precisely this form of AIDS denial — for denial is what it is — was embraced by the former government of President Thabo Mbeki in South Africa.
Although the U.S. National Academy of Sciences expressed the consensus in 1988, saying “the evidence that HIV causes AIDS is scientifically conclusive,” Mbeki’s government rejected that consensus, called Western medicine “racist”, and instead treated AIDS with garlic and beetroot, not anti-retroviral drugs.
A recent peer-reviewed Harvard study estimated this denialism caused more than 330,000 deaths from AIDS.
For that, Mbeki and his ilk are now held in richly deserved contempt around the world.
Let us return to climate change.
In 2010, the U.S. National Academy of Sciences expressed the scientific consensus on climate change by calling it a “settled fact”.
It is not surprising, therefore, that 97% of domain experts accept that fact, which is supported by an almost unimaginably overwhelming body of evidence in the peer-reviewed literature.
In light of those facts, Professor Paltridge’s view of a “polarization” in the scientific community, in which there are scientists in the “middle” who “say little” and skeptics outside the “establishment” who are “reputable” appears misguided.
Worse — it is tantamount to celebrating the few seemingly-credentialed individuals in the medical community who abused their academic privileges by feeding AIDS denial through bizarre publications or by side-stepping peer review altogether as heroes.
No, the handful of AIDS denialists within the medical community are not heroes.
On the contrary, they have blood on their hands. In light of current WHO estimates of 150,000 annual deaths from climate change, any appeal to those chimerical “reputable” skeptics runs a similarly grave moral risk.
Posterity is likely to judge that stance at least as harshly as AIDS denial.
Finally, what about those “reputable” skeptic blogs, such as WattsUpWithThat, recommended by Professor Paltridge? What about their enthusiastic followers?
The plethora of content provided by WattsUpWithThat defies summary in a few words, although it is nicely illustrated by the considerable effort this blog expended on a photograph of Professor Ray Bradleytaken in a hallway at the University of Massachusetts.
The backdrop to this picture happened to be a large graph of ice-core data affixed to the building’s wall.
The “reputable” blog thereupon spent several frantic days on the alleged shortcoming of this incidental backdrop to a photo.
In the end, enthusiastic followers sought to strip Professor Bradley of all scientific credibility based on the presumed graphical impropriety of… a wall in a university building.
It is difficult to see any merit in such verbiage other than to reveal the obsessions of the originator.
And this may explain why pre-emeritus scientists do not see fit to devote part of their 80-hour work weeks to patiently defending their university’s hallways against assault by a crowd that almost defies parody.
Sometimes, building bridges in times of conflict is a valiant and commendable endeavour.
But there are other times, readily evoked by the name Neville Chamberlain, where the attempt to seek reconciliation is inadvisable because it misjudges the situation.
Peer-review and blog frenzy over irrelevant photographic backdrops cannot be bridged or reconciled.
This realization must now be dawning on the proprietor of WattsUpWithThat, who has just published in a reputable peer-reviewed journal in collaboration with various academics.
It will come as no surprise that this paper has largely reaffirmed the work of NASA, NOAA, and countless scientists by concluding there is a robust warming trend in the U.S. temperature record.
This conclusion is the precise opposite of the many years of incessant caterwauling by WattsUpWithThat, which built its enthusiastic audience — but no scientific reputation — on claims that warming is merely an artifact of bad thermometers.
So where do we go from here?
The answer is simple.
In South Africa, a new President was elected in 2008.
On her first day in office, the new Health Minister, Barbara Hogan, expressed shame at her predecessor’s denial of science and declared, “The era of denialism is over completely.”
On that day, health officials in South Africa jettisoned the garlic and beetroot and the denialist blogs.
On that day, South Africans embraced the Western medical “establishment” and its life-saving antiretroviral drugs developed by research subjected to peer review rather than to the noise of the blogosphere.
All we have to do now is catch up with South Africa.