Ice doom of DOOM!

[james_davis_nicoll]

The previous ice age lasted some 110,000 years and ended about 11,000 years ago. In other words, some 4,000 generations of humans knew of nothing but harsh winds and eternal snows. The apparently "normal'' periods between ice ages, like the present one, have averaged between 8,000 and 12,000 years. In short, the next ice age is overdue. The key question is when it will come. Can space be colonised by a sufficiently large population so that, when the next ice age strikes, it will not threaten the survival of the race?

Comments

[movingfinger.livejournal.com]

The belief that the next ice age is overdue was being taught in the '60s and early '70s, before the full extent of anthropogenic climate change was generally apparent.

[mmcirvin.livejournal.com]

A lot of the discourse on this today is along the lines of "Scientists told us the Sun went around the Earth, now it's the Earth going around the Sun! MAKE UP YOUR MIND!!!! You can't trust anything they say!"

[calcinations.livejournal.com]

Nice analogy.

Why, it's almost as if scientists weren't supposed to change what they said according to the evidence.

Every subject suffers to some extent from people learning something about it at school or uni then never reading more about it, so when you make a statement about something that is based on the last 40 years of professional research into the topic, they immediately contradict you, as if nothing has changed in those 40 years. Some people even thing that the best SF ever was written by some bloke called Heinlein.

[keithmm.livejournal.com]

I had a geology prof (actually a paleontologist specializing in trace fossils) who was a living example of that: he still had some doubts about this new-fangled plate tectonics thing. This was in the 1990s.

He also had issues with impact geology. His office was, mind you, right down the hall from one of the world's leading experts on the subject and he was in the department hosting the Earth Impact Database.

[mmcirvin.livejournal.com]

It's actually kind of amazing how late plate tectonics became the consensus position in geology, given how foundational it seems now.

[pauldormer.livejournal.com]

They do say you never convince scientists with the contrary opinion, you just have to wait for them to die off. I recall reading that there were still scientists who didn't believe in atoms late into the nineteenth century.

Plate tectonics didn't really become a thing until the seventies. I did a geology O-level at school in 1969 and the idea wasn't even mentioned then. About three years later, the BBC did a Nigel Calder science special, Restless Earth, that popularised the idea. (I still have the tie-in book.) I imagine it would have taken at least 20 years for the old guard to die off.

[mmcirvin.livejournal.com]

Ernst Mach held out against atomism into the 20th century. There was a kind of extreme positivism that regarded anything not directly observable (for some value of "directly observable") as a hypothesis to be avoided. The standard histories usually say that Einstein's explanation of Brownian motion in 1905 was a major turning point.

[calcinations.livejournal.com]

I disagree- from what I was told at uni and have read subsequently, Plate tectonics was the solution to the problems that they had been worrying about since the early 20th century, so by the late 60's it was agreed upon, except for stupid people who held out longer. Also school textbooks are often decades behind actual up to date research. Don't confuse public understanding of the topic with the actual professional researchers understanding.

[mindstalk.livejournal.com]

My impression from being a geology major at Caltech in the 1990s, plus further reading, was that plate tectonics was adopted quite quickly. It's a good case of how a "paradigm shifted" *without* people dying off. People resisted the old evidence of continental drift, for lack of a mechanism, then seafloor spreading data came in, and they went and looked harder for a mechanism. (That's probably simplifying work that had been going on in parallel.)

The accelerating universe went from not even being a candidate idea to accepted pretty quickly, with two teams reporting the supporting observations.

I have the impression that quantum mechanics was adopted pretty fast as well, apart from Einstein, but then all the names you hear with it are young, so I dunno.

[calcinations.livejournal.com]

If you read old textbooks, such as those by Arthur Holmes, they knew the problem, and had an idea of the solution, but Wegener's mechanism was horribly wrong, verging on the stupid, and they had nothing to replace it with, so being scientists, they had to wait until someone came up with a decent mechanism.

[maruad.livejournal.com]

I had a prof who speculated that, bearing in mind this was at least 25 years ago, that melting the arctic and antarctic ice packs could lead to increased glaciation. In fairness to him, it was an intro course on environmental studies and he was throwing out a lot of ideas and thoughts to show how many unanswered questions were still out there to be explored and studied.

[(Anonymous)]

Before orbital forcing was accepted as the principal natural driver of glacial cycles there was a theory that they were driven by an internal oscillation - warming of the oceans leads to greater snowfall at high latitudes leads to growth of icesheets leads to increased albedo leads to atmospheric cooling leads to cooling of the oceans leads to less snowfall leads to retreat of icesheets leads to decreased albedo leads to atmospheric warming leads to warming of the oceans, and round the cycle again.

I was taught this as a hypothesis in the early '70s.

As I recall, in the '90s there was concern about global warming kicking off a Scandinavian icesheet. But the climate has warmed too much for snow accumulation in Scandinavia.

[seth ellis (from livejournal.com)]

I was a little proud that my father, who taught Egyptology for thirty years, was still reading new research until the year he retired, sometimes things that were brought to him by students.

[elusis.livejournal.com]

I teach Human Development among other classes. All year, I'm squirreling away articles and blog posts that give new information on the many topics we cover, but then the semester comes and... WHAT, I have to UPDATE my SLIDES? UGH.

[mmcirvin.livejournal.com]

Recent descriptions of the science back then also often overstate how generally accepted global cooling and imminent ice ages were. Most of what you hear is ultimately references to an absurdly sensationalist 1975 Newsweek article.

Global warming from carbon dioxide emissions was definitely a widely discussed hypothesis; I recall a review pointing out that there were more 1970s papers on that than on anthropogenic global cooling, but what I know is that the notion of anthropogenic global warming was clearly in the air in popular culture, because the movie Soylent Green (1973) explicitly uses it as background.

What I remember being taught in school was that it was possible that human activity could either warm the earth (with greenhouse gases) or cool it (with smog), but that nobody knew for sure how climate was going to evolve. And later the science became stronger.

[james-nicoll.livejournal.com]

http://james-nicoll.livejournal.com/1445233.html

[mmcirvin.livejournal.com]

Several years ago I found an address Isaac Asimov gave to MIT students in the 1970s in which he seems to be endorsing the anthropogenic global cooling hypothesis. One of the points of evidence he gives is that global temperatures had been cooling slightly since the 1940s, and he attributes this to aerosols (smog). As far as I know, this is completely correct! Global warming did have a pause of about 30 years, with a very very slight declining trend, in the middle of the 20th century, and I think modern models attribute that to aerosols. But greenhouse gas emissions eventually powered right through (and some societies managed to reduce aerosol pollution).

[mmcirvin.livejournal.com]

...by the way, all subsequent "pauses" you may have heard of seem to be artifacts of some combination of noise, the El Nino cycle, and cherry-picking of data.

[neowolf2.livejournal.com]

Waiting for "global warming stopped in 2015" future memes.

[rwpikul.livejournal.com]

Not only do the modern models attribute the cooling for the 1940s-70s to aerosols, so did the work in the 1970s. One thing I have to repeatedly point out to the "they forecast an ice age in the 70s" crowd is that that minority[1] of forecasts were all based on high-aerosol emission scenarios.


[1] There was a period of a couple months where the cooling forecasts caught up to the number of warming forecasts. It ended when the third paper forecasting warming came out.

[scott-sanford.livejournal.com]

I assume somebody is now campaigning for increased aerosol production but I haven't encountered them.

[mindstalk.livejournal.com]

It's a common idea for geoengineering. Would apparently be pretty cheap and easy, within the reach of a dedicated billionaire.

[scott-sanford.livejournal.com]

We know what Elon Musk, Tony Stark, and Bruce Wayne are doing with their money. What about the rest of them?

[timgueguen.livejournal.com]

Robert Fripp used a clip of J.G. Bennett, one of his spiritual influences at the time, as part of the piece "Water Music II" on his 1979 solo album Exposure.(It appropriately leads into the album's version of Peter Gabriel's "Here Comes the Flood.") Bennett talks about a coming ice age being predicted by scientists, but also mentions the sea level rising as a result of that coming ice age, which would flood many costal areas. He also talks about this happening perhaps as early as 40 years in the future.

Fripp broke up King Crimson in 1974 when he became convinced the world was about to end, or at the very least the current system as we knew it was about to implode.