Eugine_Nier comments on Separating the roles of theory and direct empirical evidence in belief formation: the examples of minimum wage and anthropogenic global warming - Less Wrong

24 Post author: VipulNaik 25 June 2014 09:47PM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (65)

You are viewing a single comment's thread. Show more comments above.

Comment author: [deleted] 27 June 2014 04:59:50PM *  1 point [-]

http://xkcd.com/1321/ (SCNR).

More seriously, are you implying that any increase in the variance is irrelevant so long as the mean doesn't change much?

Also, on the occasions when global warming believers make independently verifiable predictions with definite dates they inevitably fail to occur as shown by the fact that Britain still has snow and Manhattan isn't under water.

Who predicted that Britain would no longer have snow or Manhattan would be under water by 2014?

Comment author: Eugine_Nier 28 June 2014 01:18:39AM 0 points [-]

More seriously, are you implying that any increase in the variance is irrelevant so long as the mean doesn't change much?

I never said anything about an increase in variance, temperature records haven't been around long enough for it to be hard to find record setting temperatures somewhere. Also, I notice you're shifting your hypothesis from "temperatures are rising" to "variance is rising".

As for the argument in the linked comic, when wine grapes can be grown in England and Newfoundland, as was the case during the medieval warm period I'll start taking arguments of that type seriously.

Who predicted that Britain would no longer have snow or Manhattan would be under water by 2014?

The Climatic Research Unit for the no more snow in Britain. The Manhattan underwater one (or at least the West Side Highway) is Jim Hansen.

Comment author: drnickbone 28 June 2014 11:18:24PM *  5 points [-]

Regarding the wine point, it is doubtful if wine grapes ever grew in Newfoundland, as the Norse term "Vinland" may well refer to a larger area. From the Wikipedia article:

the southernmost limit of the Norse exploration remains a subject of intense speculation. Samuel Eliot Morison (1971) suggested the southern part of Newfoundland; Erik Wahlgren (1986) Miramichi Bay in New Brunswick; and Icelandic climate specialist Pall Bergthorsson (1997) proposed New York City.[26] The insistence in all the main historical sources that grapes were found in Vinland suggests that the explorers ventured at least to the south side of the St. Lawrence River, as Jacques Cartier did 500 years later, finding both wild vines and nut trees.[27] Three butternuts were a further important find at L'Anse Aux Meadows: another species which grows only as far north as the St. Lawrence

Also, wine grapes certainly do grow in England these days (not just in the Medieval period). There appear to be around 400 vineyards in England currently.

Comment author: drnickbone 28 June 2014 10:30:00PM *  1 point [-]

Reading your referenced article (Independent 2000):

Heavy snow will return occasionally, says Dr Viner, but when it does we will be unprepared. "We're really going to get caught out. Snow will probably cause chaos in 20 years time," he said.

Clearly the Climatic Research Unit was not predicting no more snow in Britain by 2014.

Regarding the alleged "West Side Highway underwater" prediction, see Skeptical Science. It appears Hansen's original prediction timeframe was 40 years not 20 years, and conditional on a doubling of CO2 by then.

Comment author: gwern 28 June 2014 10:32:26PM *  6 points [-]

Clearly the Climatic Research Unit was not predicting no more snow in Britain by 2014.

Yes, but some googling suggests that average snowfall in England hasn't changed very much over the 2000s, which doesn't seem consistent with the linked article.

Comment author: drnickbone 28 June 2014 11:39:03PM *  1 point [-]

"Over the 2000s" is certainly too short a period to reach significant conclusions. However the longer term trends are pretty clear. See this Met Office Report from 2006.

Figure 8 shows a big drop in the length of cold spells since the 1960s. Figure 13 shows the drop in annual days of snow cover. The trend looks consistent across the country.

Comment author: gwern 29 June 2014 01:35:17AM 5 points [-]

"Over the 2000s" is certainly too short a period to reach significant conclusions.

I think the first question here is whether we have reached agreement on the forecasts being wrong, not what excuses should be made or conclusions drawn from said wrongness.

However the longer term trends are pretty clear.

Yes, I'm sure they were, and that those were the basis for the mistaken prediction. Your point?

Comment author: drnickbone 29 June 2014 07:54:48AM *  0 points [-]

I think we have agreement that:

A) The newspaper headline "Snowfalls are now just a thing of the past" was incorrect

B) The Climatic Research Unit never actually made such a prediction

C) The only quoted statement with a timeline was for a period of 20 years, and spoke of heavy snow becoming rarer (rather than vanishing)

D) This was an extrapolation of a longer term trend, which continued into the early 2000s (using Met Office data published in 2006, of course after the Independent story)

E) It is impossible to use short periods (~10 years since 2006) to decide whether such a climatic trend has stopped or reversed.

I can't see how that counts as a failed prediction by the CRU (rather than the Independent newspaper). If the CRU had said "there will be less snow in every subsequent year from now, for the next 20 years, in a declining monotonic trend" then that would indeed be a failed prediction. However, the CRU did not make such a prediction... no serious climate researcher would.

Comment author: gwern 29 June 2014 02:55:09PM 1 point [-]

C) The only quoted statement with a timeline was for a period of 20 years, and spoke of heavy snow becoming rarer (rather than vanishing)

From the article:

'"We're really going to get caught out. Snow will probably cause chaos in 20 years time," he said.'

Does heavy snow cause chaos in England now?

According to Dr David Viner, a senior research scientist at the climatic research unit (CRU) of the University of East Anglia,within a few years winter snowfall will become "a very rare and exciting event".

Is snow a 'very rare and exciting event' in England now?

"Children just aren't going to know what snow is," he said...Professor Jarich Oosten, an anthropologist at the University of Leiden in the Netherlands, says that even if we no longer see snow, it will remain culturally important. "We don't really have wolves in Europe any more, but they are still an important part of our culture and everyone knows what they look like," he said.

If we asked them, would they not know first-hand what snow is, anymore than they know first-hand what wolves are?

I can't see how that counts as a failed prediction by the CRU (rather than the Independent newspaper).

You can't?

Comment author: drnickbone 29 June 2014 05:02:47PM *  1 point [-]

What's the date?

By your reaction, and the selective down votes, I have apparently fallen asleep, it is the 2020s already, and a 20-year prediction is already falsified.

But in answer to your questions:

A) Heavy snow does indeed already cause chaos in England when it happens (just google the last few years)

B) My kids do indeed find snow a rare and exciting event (in fact there were zero days of snow here last winter, and only a few days the winter before)

C) While my kids do have a bit of firsthand knowledge of snow, it is vastly less than my own experience at their age, which in turn was much less than my parents' experience.

If you are a resident of England yourself, and have other experiences, then please let me know...

Comment author: gwern 29 June 2014 06:18:59PM 2 points [-]

What's the date?

Well, all the quotes I gave were drawn from http://www.independent.co.uk/environment/snowfalls-are-now-just-a-thing-of-the-past-724017.html which was 14 years ago. That sounds like it'd cover 'within a few years'. And as for the exact 20 year forecast of 2010, well, that's just 6 years away. Not a lot of time to catch up.

A) Heavy snow does indeed already cause chaos in England when it happens (just google the last few years)

Yes, looks like the usual chaos you could find in the '80s and '90s to which the predicted 'chaos' was being compared as being greater.

B) My kids do indeed find snow a rare and exciting event (in fact there were zero days of snow here last winter, and only a few days the winter before)

And has your region changed much? And is your anecdote very trustworthy compared to the nation-wide changes in snowfall since 2000 (not much) when these predictions were made?

Comment author: [deleted] 28 June 2014 10:45:30AM *  -1 points [-]

As for the argument in the linked comic, when wine grapes can be grown in England and Newfoundland, as was the case during the medieval warm period I'll start taking arguments of that type seriously.

I notice you're shifting your hypothesis from ‘it's not getting any warmer than in the 1990s’ to ‘it's still not as warm as it was in the 1000s’. ;-)