Arrhenius predicted that global warming would have positive humanitarian impacts, for reasons that are retrospectively wrong, and instead global warming appears to have negative humanitarian impacts.
This seems like an oversimplification. It would seem more accurate that Arrhenius thought on balance it would have a net positive humanitarian impact and current consensus is that it is net negative.
No idea. I have no idea if anyone has looked into this in that much detail. My guess would be that he was wrong, since agriculture would have been even more insensitive to change in many parts of the world (although less so in other areas since monocropping wasn’t as common).
He was writing soon after the end (in retrospect) of the Little Ice Age, which I think is generally agreed (then and now) to have had negative effects. So a predicted return to warmer temperatures would be a good thing—it’s not called the Medieval Climate Optimum for nothing!
The difference between the Optimum and the LIA was less than 1C, so saying warming up another 1C would be even better was extrapolation. But Arrhenius probably didn’t have historical climate data of that precision, and it may have been the reasonable prediction to make.
The LIA and the Optimum weren’t global—some places cooled down, others heated up. (As is true of most climate change). But again, Arrhenius wouldn’t have known that. The last 800 years of history up to his time, on either side of the North Atlantic, were of gradual cooling down with deleterious effects.
Yes, the Little Ice Age was part of what I was thinking of, although I was unsure it was really relevant—the Little Ice Age should’ve ended at least 50 years before Arrhenius seems to have done his relevant work.
One must be very careful here: Arrhenius is almost certainly using a different utility function for ‘positive’ than current consensus uses today. As I understand it, fewer people die yearly of heat than freezing and warming opens more land than it closes off, but in today’s environment more concern is given to things like “OMG GLOBAL WARMING” than actual data.
[edit]I was not referring to temperature or the temperature calculation model. I was referring to the net positive or negative effect on society. Sorry for the confusion.[/edit]
Are you trying to make sure we don’t inadvertently discard [hypothesis: unusual utility function]?
Well I’ll say the same thing about [hypothesis: Arrhenius simply had a bad model even though his utility function was not terribly different from ours]
From the wiki ( http://en.wikipedia.org/wiki/Svante_Arrhenius )
“In his calculation Arrhenius included the feedback from changes in water vapor as well as latitudinal effects, but he omitted clouds, convection of heat upward in the atmosphere, and other essential factors. His work is currently seen less as an accurate prediction of global warming than as the first demonstration that it should be taken as a serious possibility.”
-sounds like he used a simple, fast model, rather than a detailed one that only a cray-4something supercomputer could run in less than a year. All he has to do is neglect, say, storm damage for his model to feed the wrong results to his final utility function even if he manages to predict the correct temperature.
No, I’m not saying anything at all about temperature or the model; I was talking about the social effects, eg ‘positive effect on society’.
Positive and negative in this day and age is dominated by public opinion and is very different than what it was back then. His view back then could have been as simple as “fewer people will freeze to death and there will be more arable land and better crops”. Ours view today marginalizes those effects and seems almost entirely based on the idea that change of any sort is negative.
Oh, I’msure he gave different weights to different things in his utility function than say…well pretty much anyone other human…but there are plenty of models that show a disaster for any “typical” human utility function. The ones showing disaster: venus and disaster: new ice age…are not exactly rare, though I’m not exactly sure how seriously to take them myself. ”Positive and negative in this day and age is dominated by public opinion”
Relying on Public Opinion is a cheap and dirty variant of Auffman’s agreement theorem; it gives plenty of bad results, but it’s a million times easier to use, and is still slightly better-maybe-than pure random-decisions....er, maybe.
Either that or we just differ in terms of what we’re labeling utility function versus part of the model?
This seems like an oversimplification. It would seem more accurate that Arrhenius thought on balance it would have a net positive humanitarian impact and current consensus is that it is net negative.
Thanks, I fixed this.
Do we know whether Arrhenius was right at the time that it was a net positive? 1896 was quite a long time ago, as far as populations and economies go.
No idea. I have no idea if anyone has looked into this in that much detail. My guess would be that he was wrong, since agriculture would have been even more insensitive to change in many parts of the world (although less so in other areas since monocropping wasn’t as common).
He was writing soon after the end (in retrospect) of the Little Ice Age, which I think is generally agreed (then and now) to have had negative effects. So a predicted return to warmer temperatures would be a good thing—it’s not called the Medieval Climate Optimum for nothing!
The difference between the Optimum and the LIA was less than 1C, so saying warming up another 1C would be even better was extrapolation. But Arrhenius probably didn’t have historical climate data of that precision, and it may have been the reasonable prediction to make.
The LIA and the Optimum weren’t global—some places cooled down, others heated up. (As is true of most climate change). But again, Arrhenius wouldn’t have known that. The last 800 years of history up to his time, on either side of the North Atlantic, were of gradual cooling down with deleterious effects.
Yes, the Little Ice Age was part of what I was thinking of, although I was unsure it was really relevant—the Little Ice Age should’ve ended at least 50 years before Arrhenius seems to have done his relevant work.
One must be very careful here: Arrhenius is almost certainly using a different utility function for ‘positive’ than current consensus uses today. As I understand it, fewer people die yearly of heat than freezing and warming opens more land than it closes off, but in today’s environment more concern is given to things like “OMG GLOBAL WARMING” than actual data.
[edit]I was not referring to temperature or the temperature calculation model. I was referring to the net positive or negative effect on society. Sorry for the confusion.[/edit]
Are you trying to make sure we don’t inadvertently discard [hypothesis: unusual utility function]? Well I’ll say the same thing about [hypothesis: Arrhenius simply had a bad model even though his utility function was not terribly different from ours] From the wiki ( http://en.wikipedia.org/wiki/Svante_Arrhenius ) “In his calculation Arrhenius included the feedback from changes in water vapor as well as latitudinal effects, but he omitted clouds, convection of heat upward in the atmosphere, and other essential factors. His work is currently seen less as an accurate prediction of global warming than as the first demonstration that it should be taken as a serious possibility.”
-sounds like he used a simple, fast model, rather than a detailed one that only a cray-4something supercomputer could run in less than a year. All he has to do is neglect, say, storm damage for his model to feed the wrong results to his final utility function even if he manages to predict the correct temperature.
No, I’m not saying anything at all about temperature or the model; I was talking about the social effects, eg ‘positive effect on society’.
Positive and negative in this day and age is dominated by public opinion and is very different than what it was back then. His view back then could have been as simple as “fewer people will freeze to death and there will be more arable land and better crops”. Ours view today marginalizes those effects and seems almost entirely based on the idea that change of any sort is negative.
Oh, I’msure he gave different weights to different things in his utility function than say…well pretty much anyone other human…but there are plenty of models that show a disaster for any “typical” human utility function. The ones showing disaster: venus and disaster: new ice age…are not exactly rare, though I’m not exactly sure how seriously to take them myself.
”Positive and negative in this day and age is dominated by public opinion”
Relying on Public Opinion is a cheap and dirty variant of Auffman’s agreement theorem; it gives plenty of bad results, but it’s a million times easier to use, and is still slightly better-maybe-than pure random-decisions....er, maybe.
Either that or we just differ in terms of what we’re labeling utility function versus part of the model?