I'd say the real lesson of Hanson's article "Academic Overconfidence" is to do literature searches if you can and don't trust the media about science. If you had done a literature search in 1971, you would have found 6 modeling groups predicting warming, only 3 groups predicting cooling, and 1 predicting no change (pdf, see table 1 on page 1332 or figure 1 on page 1333).
In 1975, with mounting visibility of the issue, the National Academy of Sciences commissioned a report, which reached conclusions which we can interpret as an indicator of the consensus at the time:
Climatic change has been a subject of intellectual interest for many years. However, there are now more compelling reasons for its study: the growing awareness that our economic and social stability is profoundly influenced by climate and that man's activities themselves may be capable of influencing the climate in possibly undesirable ways. The climates of the earth have always been changing, and they will doubtless continue to do so in the future. How large these future changes will be, and where and how rapidly they will occur, we do not know.
And
the proposal of a major new program of research designed to increase our understanding of climatic change and to lay the foundation for its prediction.
So there was a consensus of uncertainty, need for research, and concern about large unknown effects. Meanwhile, the magazines Time and Newsweek released famous articles about global cooling in '74 and '75. Heck, just see the "Popular Literature of the Era" extended footnote from the previously cited pdf, pg. 1330, it's almost all about global cooling. There was even a bestseller in 1977 called "The Weather Conspiracy: The Coming of the New Ice Age."
By the way, Stephen Schneider, the very scientist held up by Hanson as overconfident in "Academic Overconfidence," reviewed "The Weather Conspiracy." Guess what he said:
it insists on maintaining the shock effect of the dramatic...rather than the reality of the discipline: we just don't know enough to choose definitely at this stage whether we are in for warming or cooling— or when.
So basically, the climate scientists were uncertain and the media were cherry picking and then sensationalizing what they cherry-picked. The moral is to not listen to the commercial media about science, and do a literature search.
-
Okay, so that concludes the main point, but there are still a few loose threads. Who wrote "The Weather Conspiracy," anyway? And why did famous scientist Cesare Emiliani give such great quotes saying that global cooling was imminent? What scientific conference concluded "the natural end of our warm epoch is undoubtedly near"?
I'll tell you: it was the villains of our story (okay not really, that's actually for-profit media)... the glaciologists! Yes! You see, Cesare Emiliani was famous because he helped discover that ice ages are cyclic phenomena, a huge advance in paleoclimatology, before that was even a thing. And it turns out, we're just about due for our next ice age! Thus why a glaciological conference would conclude in 1972 that "the natural end of our warm epoch is undoubtedly near." And thus why the author of "The Weather Conspiracy" was an ecologist who dabbled not in climate modeling, but... glaciology!
Now, glaciology is a science that runs on geological time. So when glaciologists say the end is nigh, they mean "Global cooling and related rapid changes of environment, substantially exceeding the fluctuations experienced by man in historical times, must be expected within the next few millennia or even centuries" (Science 1972). So I think the glaciologists may have been misunderstood, like King Kong - we were the real monsters.
Or, wait, maybe that was the people who approved and published a book literally called "The Cooling," by Lowell Ponte, in 1976, predicting billions of deaths from starvation by 2050 on no good evidence. And the author? You may find him at his home page: newsmax.com/blogs/LowellPonte/id-51. The end.
Another lesson of that article: When a professor at George Mason University says something that just happens to line up with the talking points of the US pro-business right, at least consider the possibility that it might not be perfectly correct in every particular. As Robin himself might put it (but probably wouldn't), "Overcoming Bias" is not about overcoming bias.
(Note: I don't think there's anything wrong with being pro-business. I do think there's something desperately wrong with the US political right at the moment. Regardless, all of the above would go through just the same for other institutions with different leanings -- though what I called the "US pro-business right" has a particularly strong track record of funding prestigious-looking institutions to promote viewpoints that it finds useful.)
I'll tell you: it was the villains of our story (okay not really, that's actually for-profit media)... the glaciologists! Yes! You see, Cesare Emiliani was famous because he helped discover that ice ages are cyclic phenomena, a huge advance in paleoclimatology, before that was even a thing. And it turns out, we're just about due for our next ice age!
Ice ages are not cyclical, but glaciations are. We are currently in an ice age, but in an interglacial period within that ice age. We may be "overdue" for the next glaciation, but it is also possible that the last glaciation of this ice age has already occurred, and we are heading back into a warm earth era typical of the overwhelming majority of the planet's history.
Thanks for pointing out this terminological issue. I'm going to keep calling glaciations "ice ages," just because that's how they were labeled to the public in the 1970s, viz. the title of Emiliani's 1978 paper The cause of the ice ages, or, of course "The Weather Conspiracy: The Coming of the New Ice Age." :)
The paper
provides evidence that periods of glaciation begin when northern hemisphere insolation (which varies due to changes in the precession, obliquity and eccentricity of Earth's orbit) falls below a "trigger" level that depends on the amount of CO2 in the atmosphere. Archer & Ganopolski suggest that we're currently approaching a solar minimum, but we've already released enough CO2 into the atmosphere to avoid a glaciation in the next few thousand years. (If we burn all available fossil fuels, "The model predicts the end of the glacial cycles, with stability of the interglacial for at least the next half million years".)
I made an EPUB file from all these posts to read at my e-reader. If someone else is interested, you can download it here: Overcoming bias selected.epub
I'd say the real lesson of Hanson's article "Academic Overconfidence" is to do literature searches if you can and don't trust the media about science. If you had done a literature search in 1971, you would have found 6 modeling groups predicting warming, only 3 groups predicting cooling, and 1 predicting no change (pdf, see table 1 on page 1332 or figure 1 on page 1333).
In 1975, with mounting visibility of the issue, the National Academy of Sciences commissioned a report, which reached conclusions which we can interpret as an indicator of the consensus at the time:
Climatic change has been a subject of intellectual interest for many years. However, there are now more compelling reasons for its study: the growing awareness that our economic and social stability is profoundly influenced by climate and that man's activities themselves may be capable of influencing the climate in possibly undesirable ways. The climates of the earth have always been changing, and they will doubtless continue to do so in the future. How large these future changes will be, and where and how rapidly they will occur, we do not know.
And
the proposal of a major new program of research designed to increase our understanding of climatic change and to lay the foundation for its prediction.
So there was a consensus of uncertainty, need for research, and concern about large unknown effects. Meanwhile, the magazines Time and Newsweek released famous articles about global cooling in '74 and '75. Heck, just see the "Popular Literature of the Era" extended footnote from the previously cited pdf, pg. 1330, it's almost all about global cooling. There was even a bestseller in 1977 called "The Weather Conspiracy: The Coming of the New Ice Age."
By the way, Stephen Schneider, the very scientist held up by Hanson as overconfident in "Academic Overconfidence," reviewed "The Weather Conspiracy." Guess what he said:
it insists on maintaining the shock effect of the dramatic...rather than the reality of the discipline: we just don't know enough to choose definitely at this stage whether we are in for warming or cooling— or when.
So basically, the climate scientists were uncertain and the media were cherry picking and then sensationalizing what they cherry-picked. The moral is to not listen to the commercial media about science, and do a literature search.
-
Okay, so that concludes the main point, but there are still a few loose threads. Who wrote "The Weather Conspiracy," anyway? And why did famous scientist Cesare Emiliani give such great quotes saying that global cooling was imminent? What scientific conference concluded "the natural end of our warm epoch is undoubtedly near"?
I'll tell you: it was the villains of our story (okay not really, that's actually for-profit media)... the glaciologists! Yes! You see, Cesare Emiliani was famous because he helped discover that ice ages are cyclic phenomena, a huge advance in paleoclimatology, before that was even a thing. And it turns out, we're just about due for our next ice age! Thus why a glaciological conference would conclude in 1972 that "the natural end of our warm epoch is undoubtedly near." And thus why the author of "The Weather Conspiracy" was an ecologist who dabbled not in climate modeling, but... glaciology!
Now, glaciology is a science that runs on geological time. So when glaciologists say the end is nigh, they mean "Global cooling and related rapid changes of environment, substantially exceeding the fluctuations experienced by man in historical times, must be expected within the next few millennia or even centuries" (Science 1972). So I think the glaciologists may have been misunderstood, like King Kong - we were the real monsters.
Or, wait, maybe that was the people who approved and published a book literally called "The Cooling," by Lowell Ponte, in 1976, predicting billions of deaths from starvation by 2050 on no good evidence. And the author? You may find him at his home page: newsmax.com/blogs/LowellPonte/id-51. The end.
I'll tell you: it was the villains of our story (okay not really, that's actually for-profit media)... the glaciologists! Yes! You see, Cesare Emiliani was famous because he helped discover that ice ages are cyclic phenomena, a huge advance in paleoclimatology, before that was even a thing. And it turns out, we're just about due for our next ice age!
Ice ages are not cyclical, but glaciations are. We are currently in an ice age, but in an interglacial period within that ice age. We may be "overdue" for the next glaciation, but it is also possi...
Those aching for good rationality writing can get their fix from Great rationality posts by LWers not posted to LW, and also from the Overcoming Bias archives. Some highlights are below, up through June 28, 2007.