I haven’t spent as much time studying the global warming debate as I have studying the creation-evolution debate, but to the extent I have studied it, the evidence seems uniformly supportive of the view that human activity has caused significant warming.
I’ll note that most of the resistance to global warming that I’ve seen on LW is not on these points. (Bias note: I think my position is roughly central of global warming resistance I’ve seen on LW, but if I err in describing opinion on LW it will be by pushing the opinion too far towards myself.) The evidence seems very solid that human activity has altered the atmospheric concentrations of CO2, and that this results in higher temperatures.
The primary issues are:
Predictive climate models are in a class of computational problems known to computational modeling experts to be extremely vulnerable to fudging. That is to say, by judicious choice of parameters, you can get the models to say basically whatever you’d like them to say, and the models make several assumptions which are obviously wrong which could totally nullify their predictive ability.
Climate science has incentives that seem unusually pointed away from truth-discovery compared to other fields, and there seems to be evidence of climate scientists (rationally!) responding to those incentives.
The question of which temperature / global climate is optimal is rarely discussed, suggesting that the current climate is unlikely to be optimal.
Specific solutions to the problems of climate change are generally seen as moral and political goals, rather than seeing the problem as an engineering challenge. Geoengineering techniques in particular receive a surprisingly small amount of research, in part because it is perceived as ‘damaging the cause’ by making emission reduction seem less necessary. (If emission reduction is less necessary...)
The question of which temperature / global climate is optimal is rarely discussed, suggesting that the current climate is unlikely to be optimal.
Agree that this topic is not widely discussed in mainstream climate science as such, but not sure your conclusion follows.
The chances of the current global climate being optimal would be pretty remote, except for the facts that one very powerful (but slow) optimisation process has been busy adapting the existing biota (including humans) to the climate, followed by an even more powerful and much more rapid optimisation process adapting human capital and expertise to the existing climate.
It’s not that we can’t adapt to another set of climate and weather patterns, it’s that it’ll have a cost. There certainly is a reasonable amount of discussion in the mainstream climate literature about the likely costs of adaptation. Which, of course, one needs to weigh against the likely benefits.
Predicting the local weather impact of global climate change is fearsomely difficult and uncertain (far more so than global temperature), which makes adding up the cost/benefit analysis extremely difficult. (And makes planning long-term capital investments difficult.)
It seems to me pretty likely that the current global climate is at least a local optimum for humans.
It seems to me pretty likely that the current global climate is at least a local optimum for humans.
I think this depends on what you mean by “for humans.” We’re an equatorial species, and most of our global population is living in colder climates than most of our evolutionary adaptation was geared towards. However, humans are highly robust within a wide range of temperatures; many of the species we depend upon, less so.
except for the facts that one very powerful (but slow) optimisation process has been busy adapting the existing biota (including humans) to the climate, followed by an even more powerful and much more rapid optimisation process adapting human capital and expertise to the existing climate.
The first seems insignificant (given the second and the changing climate) and the second seems self-defeating (if we invented air conditioning to deal with the outside not being the correct temperature, it’s not at all obvious that local air-conditioning is the best way to manage the climate, especially given the known issues with using local heat dumps in, say, cities).
Which, of course, one needs to weigh against the likely benefits.
This is the point that I think is actually contentious in the wider world, but should not be.
It seems to me pretty likely that the current global climate is at least a local optimum for humans.
That seems unlikely. First, which one is optimal—the one right now when we already warmed up a bit, or, say, the climate of mid-XIX century? And second, the already posted link shows that within a particular range of temperature and CO2 concentration increasing them increased the world’s GDP. We are not at the end of that range so increasing the temperature and the CO2 further would get us closer to optimality—meaning we’re not there yet.
And second, the already posted link shows that within a particular range of temperature and CO2 concentration increasing them increased the world’s GDP. We are not at the end of that range so increasing the temperature and the CO2 further would get us closer to optimality
It takes some time for added CO₂ to exert its full effect on temperature. Because of that lag, I’d expect CO₂ levels to hit their optimum before temperature does, so it’s worth considering them separately.
-- meaning we’re not there yet.
The results at that link and in its underlying source suggest we’re at (and maybe beyond) the optimum CO₂ level already. According to that paper, the temperature won’t reach the calculated optimum of 1.2°C to 1.3°C until 2025. But the CO₂ level is already high enough that we’re likely to overshoot that temperature unless we cut emissions aggressively.
Climate science has incentives that seem unusually pointed away from truth-discovery compared to other fields, and there seems to be evidence of climate scientists (rationally!) responding to those incentives.
This isn’t an issue I care much about, so I hope you won’t mind a quick treatment. The 5-second version is that more is on the line for the researchers personally with climate change research than other sorts of science, that scientific reports have consequences for politics which forces the scientists to be more involved in politics than other sorts of scientists, and that this corroding influence of politics adds friction to the processes that pump errors out of science. Here’s an incomplete list with more details:
The most visible one is media pressure, which rewards more shocking possibilities. (Did you ever hear about clathrate gun hypothesis? Did you hear that further research didn’t pan out?) In most other fields, the media rarely if ever comes calling, and so more of the incentives come from other researchers. (I remember a historian, who was called up because Sarah Palin had made a correct but non-obvious comment about Paul Revere, who pointed out that he had never been interviewed until Palin had mentioned Revere.)
Relatedly, the funding and visibility of climatology depends in large part on how much people care about climatology. This is true for many fields- NASA seems to find asteroids whose paths take them close to Earth whenever Congress debates NASA’s funding- but seems particularly true for climatology.
There is also a lot of money and influence going against climate change research. The decision to not fly DSCOVR, for example, was almost certainly political and did significant harm to our understanding of the climate and its dynamics. There are claims of data suppression during the Bush era which are harder to evaluate, but are suggestive of politicization of research.
The existence of climate deniers acting in bad faith poisons the well for normal scientific bug-checking. The Lenski affair happened in evolution, but the same sort of dynamic can show up between climatologists and skeptics. There is no social benefit in providing data to people acting in bad faith, and so it’s easier to just not give them your data, even though people acting in bad faith can identify scientific errors that you would need to correct. But this prevents normal criticism from taking place, and (as a general human tendency) scientists are more likely to see others as acting in bad faith if their work is being criticized. (This is pretty neatly captured by Climategate. Most critics stupidly focused on things that were benign- like the phrase “trick”- while the emails included evidence of data withholding and stonewalling, which are not benign.)
There is no social benefit in providing data to people acting in bad faith, and so it’s easier to just not give them your data
I am not sure I agree with that. I think I would phrase my position as “There is social benefit in providing data to absolutely everyone without any prequalifications”.
For example the Freedom of Information Act says government must provide certain kinds of information on request. It doesn’t get to peek into the requester’s mind and decide whether there was “bad faith” or “good faith”. I think it’s a very good thing that it doesn’t.
Similarly, I think science should provide supporting data to everyone who asks (subject to reasonable limits tied to the costs of providing data). In particular, scientists should stand ready to provide data to their worst critics regardless of what they think of their theories, competency, or fashion sense.
And yes, Climategate brought into the open a rather large fail in that respect on the part of pro-warming crowd (among other things).
Similarly, I think science should provide supporting data to everyone who asks (subject to reasonable limits tied to the costs of providing data). In particular, scientists should stand ready to provide data to their worst critics regardless of what they think of their theories, competency, or fashion sense.
Agreed that this is the most truth-seeking policy. I specified “social benefit” because I don’t think the two line up.
The “trick” has not benign, given it consisted of pretty blatant data cooking.
DISCLAIMER: literally the only thing I know about this is the code on the linked page.
I’m not sure thats true. The code you linked to seems to be implementing this correction pretty much directly from the literature:
Briffa, K.R., Schweingruber, F.H., Jones, P.D., Osborn, T.J., Shiyatov, S.G. and Vaganov, E.A., 1998
“Reduced sensitivity of recent tree growth to temperature at high northern latitudes.”
Nature 391, 678-682 (R)
(I found it by taking the name of the file briffa_sep98 and googling for a few minutes). I know nothing about tree-rings, but its a nature paper, so I assume the authors know about tree-rings. I can’t verify how correctly its implemented because I’m not going to trace the code leading into this routine to check the units for the tree ring thickness being adjusted..
The code in question seems to output a line on a graph labled “Northern Hemisphere MXD corrected for decline.”
So as far as I can tell there isn’t a lot of scientific misconduct going on- they took a data-correction from the literature (anyone know if its a standard correction?), coded it up, and labled the line on the graph as implementing the correction. The uncorrected line is also output by the code on to the same graph.
Or are we considering that the Briffa correction itself is cooking the data? If so shouldn’t the discussion center around the published paper and where it goes wrong?
The “trick” (“Mike’s Nature trick”) refers to a technique for plotting reconstructed temperatures (from tree rings) together with recent direct measurements, apparently simply by drawing them in different colours. The code you linked above is a separate technique (labelled “hiding the decline”), a correction for an anomalous decline in tree ring growth, which before 1960 had been closely correlated with temperature. It is speculated that the decline in tree ring growth is due to air pollution or other anthropogenic causes. See here for more detail.
Upvoted. This is much better than other reactions I’ve seen to discussion of global warming on LW, which often amount to knee-jerk downvoting paired with comments that amount to “global warming is politics and politics is the mindkiller!”
That said, regarding what climate is optimal, that’s not something that can be answered in isolation. Existing people and ecosystems are adapted to current conditions, so it isn’t surprising that rapid change away from those conditions would cause problems, at least on net (and note that the IPCC doesn’t claim effects of global warming will be universally negative, just negative on net). It’s like how a flood is a bigger problem than water that’s always been there. Same thing with sea levels rising—it means people need to move or build dikes or something, which is costly.
Climate change / global warming is real and man-made. It will come as a big surprise that climate change from 1900 to 2025 has mostly been a net benefit, rising to increase welfare about 1.5% of GDP per year. Why? Because global warming has mixed effects and for moderate warming, the benefits prevail. The increased level of CO₂ has boosted agriculture because it works as a fertilizer and makes up the biggest positive impact at 0.8% of GDP. Likewise, moderate warming avoids more cold deaths than it incurs extra heat deaths. It also reduces the demand for heating more than increases the costs of cooling, totaling about 0.4%. On the other hand, warming increases water stress at about 0.2% and negatively impact ecosystems like wetlands at about 0.1%. Storm impacts are very small, as the total storm damages (including naturally caused storms) are about 0.2%.
As temperatures rise, the costs will rise and the benefits decline, leading to a dramatic reduction in net benefits. After year 2070, global warming will become a net cost to the world, justifying cost-effective climate action.
The best reaction I’ve seen to discussion of global warming anywherewas on LW. Your post here is much better about specifically defining what the “expert consensus” says, but note that it’s a bar so low that all the well-informed “skeptics”/”deniers” I’ve read would agree with the majority of AGW experts on the second bullet point.
I saw that thread too, and was horrified—horrified that people were downvoting Stuart. And actually, on reflection, that that comment was upvoted is pretty horrifying too. The comment claims ambiguity in Stuart’s post when there is none: it brings up value judgments and policy and so on when Stuart was very specific that he was talking about denial of the very existence of AGW, rather than about disagreements on appropriate policy responses. That tells me the commenter—and everyone who voted it up—was emotionally uncomfortable with the idea that AGW delialists were just completely wrong, so they read ambiguity into Stuart’s statement that wasn’t there.
The problem with saying “I’m only talking about X, I’m not talking about Y” when Y is related to X but less extreme, is that in politics people who are Y are often caricatured as being X. It’s pretty hard to tell the difference between someone who really means to attack X and only X, and someone who is attacking Y by implicitly accusing them of being X and then attacking X.
It’s the same reason as to why Jews might feel themselves to be a target when someone argues how bad it is to kill Christian babies to use their blood to bake matzohs, even if they have not personally killed any babies. Certainly if anyone posted such an argument I’d mod them down, even if I agreed that it’s bad to eat babies and that they have correctly stated why.
It’s the same reason as to why Jews might feel themselves to be a target when someone argues how bad it is to kill Christian babies to use their blood to bake matzohs, even if they have not personally killed any babies.
This is a really bad example in this context. It would only be similar if there were some people who were actually using blood to bake their matzohs. When X and Y both actually exist, the situation is different.
If that’s how you feel, replace it with “greedy Jewish bankers”. Real ones exist, but it’s unlikely that someone complaining about them is limiting his complaints to the ones that exist—he’s probably saying it because he thinks there are more greedy Jewish bankers than there really are.
The point is that it may make sense to object to an otherwise legitimate attack on a group that doesn’t include you if the attacker thinks that the group includes you.
I’m not sure that’s a good comparison either, although it is slightly better. In that context, there’d be a legitimate complaint possibly of “greedy bankers” but it is doubtful that “greedy bankers” is a subset of Jewish bankers. Not the case for the example in question.
I saw that thread too, and was horrified—horrified that people were downvoting Stuart. And actually, on reflection, that that comment was upvoted is pretty horrifying too. The comment claims ambiguity in Stuart’s post when there is none
Strong disagreement. Stuart_Armstrong uses interchangeably the phrases “global warming denial,” “someone who denies the existence of anthropogenic global warming (AGW),” and “global warming skeptic.” There is significant ambiguity there- many people identify as “global warming skeptics” in that they are skeptical of the moral and political claims of the global warming movement, not that they deny the existence of AGW. Similarly, many people identify as “global warming deniers” because they deny the moral, predictive, or prescriptive claims put forward by the global warming movement.
(Note that Thomas, who did express doubt in AGW, got downvoted to −3.)
when Stuart was very specific that he was talking about denial of the very existence of AGW, rather than about disagreements on appropriate policy responses.
I didn’t see any effort on Stuart_Armstrong’s part to disambiguate those or notice that he needed to. For example, in your post, it looked like you carefully limited the consensus to the actual scientific consensus on historical anthropogenic climate change, and if Stuart_Armstrong had mentioned that he was just talking about the historical record, there wouldn’t have been a need for steven0461′s comment.
There is significant ambiguity there- many people identify as “global warming skeptics” in that they are skeptical of the moral and political claims of the global warming movement, not that they deny the existence of AGW.
I’m not skeptical of CO2 as a greenhouse gas, or of the increase of atmospheric CO2, or that increasing CO2 levels will generally lead to higher temperatures, or that we have had higher temperatures in the last few decades.
But I am skeptical of the model projections into the future, and even more skeptical of the claims that the accuracy of those models have been established when they’ve proven inaccurate for the last decade. When you make predictions that fail, you should be decreasing your certainty in the model that gave those predictions.
if Stuart_Armstrong had mentioned that he was just talking about the historical record, there wouldn’t have been a need for steven0461′s comment
That demands seems a little strange. Should he have disclaimed any claim about future warming? But given past warming caused by human CO2 (and other) emissions, we should expect more warming if we continue that activity (actually, the IPCC thinks warming would continue even if CO2 were kept at current levels).
On the other hand, I’m not seeing any way to read Stuart’s statement as anything like, “if your estimate of future warming is only 50% of the estimate I prefer you’re irrational.”
I’ll note that most of the resistance to global warming that I’ve seen on LW is not on these points. (Bias note: I think my position is roughly central of global warming resistance I’ve seen on LW, but if I err in describing opinion on LW it will be by pushing the opinion too far towards myself.) The evidence seems very solid that human activity has altered the atmospheric concentrations of CO2, and that this results in higher temperatures.
The primary issues are:
Predictive climate models are in a class of computational problems known to computational modeling experts to be extremely vulnerable to fudging. That is to say, by judicious choice of parameters, you can get the models to say basically whatever you’d like them to say, and the models make several assumptions which are obviously wrong which could totally nullify their predictive ability.
Climate science has incentives that seem unusually pointed away from truth-discovery compared to other fields, and there seems to be evidence of climate scientists (rationally!) responding to those incentives.
The question of which temperature / global climate is optimal is rarely discussed, suggesting that the current climate is unlikely to be optimal.
Specific solutions to the problems of climate change are generally seen as moral and political goals, rather than seeing the problem as an engineering challenge. Geoengineering techniques in particular receive a surprisingly small amount of research, in part because it is perceived as ‘damaging the cause’ by making emission reduction seem less necessary. (If emission reduction is less necessary...)
Agree that this topic is not widely discussed in mainstream climate science as such, but not sure your conclusion follows.
The chances of the current global climate being optimal would be pretty remote, except for the facts that one very powerful (but slow) optimisation process has been busy adapting the existing biota (including humans) to the climate, followed by an even more powerful and much more rapid optimisation process adapting human capital and expertise to the existing climate.
It’s not that we can’t adapt to another set of climate and weather patterns, it’s that it’ll have a cost. There certainly is a reasonable amount of discussion in the mainstream climate literature about the likely costs of adaptation. Which, of course, one needs to weigh against the likely benefits.
Predicting the local weather impact of global climate change is fearsomely difficult and uncertain (far more so than global temperature), which makes adding up the cost/benefit analysis extremely difficult. (And makes planning long-term capital investments difficult.)
It seems to me pretty likely that the current global climate is at least a local optimum for humans.
I think this depends on what you mean by “for humans.” We’re an equatorial species, and most of our global population is living in colder climates than most of our evolutionary adaptation was geared towards. However, humans are highly robust within a wide range of temperatures; many of the species we depend upon, less so.
The first seems insignificant (given the second and the changing climate) and the second seems self-defeating (if we invented air conditioning to deal with the outside not being the correct temperature, it’s not at all obvious that local air-conditioning is the best way to manage the climate, especially given the known issues with using local heat dumps in, say, cities).
This is the point that I think is actually contentious in the wider world, but should not be.
That seems unlikely. First, which one is optimal—the one right now when we already warmed up a bit, or, say, the climate of mid-XIX century? And second, the already posted link shows that within a particular range of temperature and CO2 concentration increasing them increased the world’s GDP. We are not at the end of that range so increasing the temperature and the CO2 further would get us closer to optimality—meaning we’re not there yet.
It takes some time for added CO₂ to exert its full effect on temperature. Because of that lag, I’d expect CO₂ levels to hit their optimum before temperature does, so it’s worth considering them separately.
The results at that link and in its underlying source suggest we’re at (and maybe beyond) the optimum CO₂ level already. According to that paper, the temperature won’t reach the calculated optimum of 1.2°C to 1.3°C until 2025. But the CO₂ level is already high enough that we’re likely to overshoot that temperature unless we cut emissions aggressively.
Really? What kind of incentives?
This isn’t an issue I care much about, so I hope you won’t mind a quick treatment. The 5-second version is that more is on the line for the researchers personally with climate change research than other sorts of science, that scientific reports have consequences for politics which forces the scientists to be more involved in politics than other sorts of scientists, and that this corroding influence of politics adds friction to the processes that pump errors out of science. Here’s an incomplete list with more details:
The most visible one is media pressure, which rewards more shocking possibilities. (Did you ever hear about clathrate gun hypothesis? Did you hear that further research didn’t pan out?) In most other fields, the media rarely if ever comes calling, and so more of the incentives come from other researchers. (I remember a historian, who was called up because Sarah Palin had made a correct but non-obvious comment about Paul Revere, who pointed out that he had never been interviewed until Palin had mentioned Revere.)
Relatedly, the funding and visibility of climatology depends in large part on how much people care about climatology. This is true for many fields- NASA seems to find asteroids whose paths take them close to Earth whenever Congress debates NASA’s funding- but seems particularly true for climatology.
There is also a lot of money and influence going against climate change research. The decision to not fly DSCOVR, for example, was almost certainly political and did significant harm to our understanding of the climate and its dynamics. There are claims of data suppression during the Bush era which are harder to evaluate, but are suggestive of politicization of research.
The existence of climate deniers acting in bad faith poisons the well for normal scientific bug-checking. The Lenski affair happened in evolution, but the same sort of dynamic can show up between climatologists and skeptics. There is no social benefit in providing data to people acting in bad faith, and so it’s easier to just not give them your data, even though people acting in bad faith can identify scientific errors that you would need to correct. But this prevents normal criticism from taking place, and (as a general human tendency) scientists are more likely to see others as acting in bad faith if their work is being criticized. (This is pretty neatly captured by Climategate. Most critics stupidly focused on things that were benign- like the phrase “trick”- while the emails included evidence of data withholding and stonewalling, which are not benign.)
I am not sure I agree with that. I think I would phrase my position as “There is social benefit in providing data to absolutely everyone without any prequalifications”.
For example the Freedom of Information Act says government must provide certain kinds of information on request. It doesn’t get to peek into the requester’s mind and decide whether there was “bad faith” or “good faith”. I think it’s a very good thing that it doesn’t.
Similarly, I think science should provide supporting data to everyone who asks (subject to reasonable limits tied to the costs of providing data). In particular, scientists should stand ready to provide data to their worst critics regardless of what they think of their theories, competency, or fashion sense.
And yes, Climategate brought into the open a rather large fail in that respect on the part of pro-warming crowd (among other things).
Agreed that this is the most truth-seeking policy. I specified “social benefit” because I don’t think the two line up.
The “trick” has not benign, given it consisted of pretty blatant data cooking.
DISCLAIMER: literally the only thing I know about this is the code on the linked page.
I’m not sure thats true. The code you linked to seems to be implementing this correction pretty much directly from the literature:
Briffa, K.R., Schweingruber, F.H., Jones, P.D., Osborn, T.J., Shiyatov, S.G. and Vaganov, E.A., 1998 “Reduced sensitivity of recent tree growth to temperature at high northern latitudes.” Nature 391, 678-682 (R)
(I found it by taking the name of the file briffa_sep98 and googling for a few minutes). I know nothing about tree-rings, but its a nature paper, so I assume the authors know about tree-rings. I can’t verify how correctly its implemented because I’m not going to trace the code leading into this routine to check the units for the tree ring thickness being adjusted..
The code in question seems to output a line on a graph labled “Northern Hemisphere MXD corrected for decline.”
So as far as I can tell there isn’t a lot of scientific misconduct going on- they took a data-correction from the literature (anyone know if its a standard correction?), coded it up, and labled the line on the graph as implementing the correction. The uncorrected line is also output by the code on to the same graph.
Or are we considering that the Briffa correction itself is cooking the data? If so shouldn’t the discussion center around the published paper and where it goes wrong?
The “trick” (“Mike’s Nature trick”) refers to a technique for plotting reconstructed temperatures (from tree rings) together with recent direct measurements, apparently simply by drawing them in different colours. The code you linked above is a separate technique (labelled “hiding the decline”), a correction for an anomalous decline in tree ring growth, which before 1960 had been closely correlated with temperature. It is speculated that the decline in tree ring growth is due to air pollution or other anthropogenic causes. See here for more detail.
I hope nobody just starts listing incentives here, but also explains what’s unusual about them.
Yeah, that “compared to other fields” part confuses me too.
Upvoted. This is much better than other reactions I’ve seen to discussion of global warming on LW, which often amount to knee-jerk downvoting paired with comments that amount to “global warming is politics and politics is the mindkiller!”
That said, regarding what climate is optimal, that’s not something that can be answered in isolation. Existing people and ecosystems are adapted to current conditions, so it isn’t surprising that rapid change away from those conditions would cause problems, at least on net (and note that the IPCC doesn’t claim effects of global warming will be universally negative, just negative on net). It’s like how a flood is a bigger problem than water that’s always been there. Same thing with sea levels rising—it means people need to move or build dikes or something, which is costly.
Hat tip to Robin Hanson:
Sounds plausible.
The best reaction I’ve seen to discussion of global warming anywhere was on LW. Your post here is much better about specifically defining what the “expert consensus” says, but note that it’s a bar so low that all the well-informed “skeptics”/”deniers” I’ve read would agree with the majority of AGW experts on the second bullet point.
I saw that thread too, and was horrified—horrified that people were downvoting Stuart. And actually, on reflection, that that comment was upvoted is pretty horrifying too. The comment claims ambiguity in Stuart’s post when there is none: it brings up value judgments and policy and so on when Stuart was very specific that he was talking about denial of the very existence of AGW, rather than about disagreements on appropriate policy responses. That tells me the commenter—and everyone who voted it up—was emotionally uncomfortable with the idea that AGW delialists were just completely wrong, so they read ambiguity into Stuart’s statement that wasn’t there.
The problem with saying “I’m only talking about X, I’m not talking about Y” when Y is related to X but less extreme, is that in politics people who are Y are often caricatured as being X. It’s pretty hard to tell the difference between someone who really means to attack X and only X, and someone who is attacking Y by implicitly accusing them of being X and then attacking X.
It’s the same reason as to why Jews might feel themselves to be a target when someone argues how bad it is to kill Christian babies to use their blood to bake matzohs, even if they have not personally killed any babies. Certainly if anyone posted such an argument I’d mod them down, even if I agreed that it’s bad to eat babies and that they have correctly stated why.
This is a really bad example in this context. It would only be similar if there were some people who were actually using blood to bake their matzohs. When X and Y both actually exist, the situation is different.
If that’s how you feel, replace it with “greedy Jewish bankers”. Real ones exist, but it’s unlikely that someone complaining about them is limiting his complaints to the ones that exist—he’s probably saying it because he thinks there are more greedy Jewish bankers than there really are.
The point is that it may make sense to object to an otherwise legitimate attack on a group that doesn’t include you if the attacker thinks that the group includes you.
I’m not sure that’s a good comparison either, although it is slightly better. In that context, there’d be a legitimate complaint possibly of “greedy bankers” but it is doubtful that “greedy bankers” is a subset of Jewish bankers. Not the case for the example in question.
Strong disagreement. Stuart_Armstrong uses interchangeably the phrases “global warming denial,” “someone who denies the existence of anthropogenic global warming (AGW),” and “global warming skeptic.” There is significant ambiguity there- many people identify as “global warming skeptics” in that they are skeptical of the moral and political claims of the global warming movement, not that they deny the existence of AGW. Similarly, many people identify as “global warming deniers” because they deny the moral, predictive, or prescriptive claims put forward by the global warming movement.
(Note that Thomas, who did express doubt in AGW, got downvoted to −3.)
I didn’t see any effort on Stuart_Armstrong’s part to disambiguate those or notice that he needed to. For example, in your post, it looked like you carefully limited the consensus to the actual scientific consensus on historical anthropogenic climate change, and if Stuart_Armstrong had mentioned that he was just talking about the historical record, there wouldn’t have been a need for steven0461′s comment.
Note this subthread in particular.
I’m not skeptical of CO2 as a greenhouse gas, or of the increase of atmospheric CO2, or that increasing CO2 levels will generally lead to higher temperatures, or that we have had higher temperatures in the last few decades.
But I am skeptical of the model projections into the future, and even more skeptical of the claims that the accuracy of those models have been established when they’ve proven inaccurate for the last decade. When you make predictions that fail, you should be decreasing your certainty in the model that gave those predictions.
I put “predictive or prescriptive claims” into my second bit, but I probably should have included it there as well.
That demands seems a little strange. Should he have disclaimed any claim about future warming? But given past warming caused by human CO2 (and other) emissions, we should expect more warming if we continue that activity (actually, the IPCC thinks warming would continue even if CO2 were kept at current levels).
On the other hand, I’m not seeing any way to read Stuart’s statement as anything like, “if your estimate of future warming is only 50% of the estimate I prefer you’re irrational.”