Climate Change - The Scientific Debate (Vol. II)
Discussion
Indeed, and bulls
t arguments (i.e. an argument made without apparently caring whether it is valid or not) like "And it's only two locations, quite far apart for splicing datasets.". Even the most cursory study of CO2 measurements is sufficient to tell you that argument is bogus. We have a network of monitoring sites around the world, and they all give essentially the same results, except for the seasonal cycle being larger in the Northern hemisphere (as it has a larger landmass and hence more terrestrial biota) and there being a small concentration gradient from the Northern Hemisphere to the Southern because most fossil fuel emissions are from the north). We even have satellite observations now, which confirm that (although they do also show there is shorter term variability of about 10ppm IIRC, that I mentioned earlier).
It is ironic that skeptics talk of the scientists being unconvincing, when the skeptics launch lame canards like that!
t arguments (i.e. an argument made without apparently caring whether it is valid or not) like "And it's only two locations, quite far apart for splicing datasets.". Even the most cursory study of CO2 measurements is sufficient to tell you that argument is bogus. We have a network of monitoring sites around the world, and they all give essentially the same results, except for the seasonal cycle being larger in the Northern hemisphere (as it has a larger landmass and hence more terrestrial biota) and there being a small concentration gradient from the Northern Hemisphere to the Southern because most fossil fuel emissions are from the north). We even have satellite observations now, which confirm that (although they do also show there is shorter term variability of about 10ppm IIRC, that I mentioned earlier).It is ironic that skeptics talk of the scientists being unconvincing, when the skeptics launch lame canards like that!
grumbledoak said:
ludo said:
I have to say, this is quite funny, objecting to the models being both too complex and too simple in the same sentence! LOL.
Fine, I'll clarify. It is tedious to write everything out longhand though. The omissions of known major factors like cloudst, clouds are modelled in GCMs. Not perfectly, of course, but they are there.ETA googling the obvious keywords reveals that argument was indeed bulls
t.Edited by ludo on Saturday 30th March 11:31
grumbledoak said:
... while ramping minor, possibly immeasurably small, effects such as CO2 ...
This is also a bullst argument. The direct effect of CO2 radiative forcing is uncontroversial and even accepted by climate skeptic scientists like Roy Spencer:RoySpencer said:
Now, you might be surprised to learn that the amount of warming directly caused by the extra CO2 is, by itself, relatively weak. It has been calculated theoretically that, if there are no other changes in the climate system, a doubling of the atmospheric CO2 concentration would cause less than 1 deg C of surface warming (about 1 deg. F). This is NOT a controversial statement…it is well understood by climate scientists. (As of 2008, we were about 40% to 45% of the way toward a doubling of atmospheric CO2.)
So it clearly isn't minor or "possibly immeasurably small".This is the joy of bulls
t, it is easy to produce in large amounts and waste the time and energy of your opponent in the debate who has to go and find the evidence to show that it is bullst. Of course if they know what they are talking about, it won't take long, but the asymmetry in effort required is the basic rhetorical device used throughout the public debate on climate. Sadly most people don't have the true skepticism required to check their own arguments or those of others, which is why these canards are still effective.ludo said:
Kawasicki said:
ludo said:
Kawasicki said:
Yeah, loads more.
Any consensus estimate on something as simple and incredibly important as predicting the start of the next ice age? Your assertion was that we understand our climate, the answer should be easy then.
Stay focused!
Except it isn't simple, is it? It depends on many things, one of which is the composition of the atmosphere, and we are constantly altering that. We can't predict fossil fuel emissions as they depend on political and economic considerations. Any consensus estimate on something as simple and incredibly important as predicting the start of the next ice age? Your assertion was that we understand our climate, the answer should be easy then.
Stay focused!
ETA: it also isn't that important either AFAICS. DO any of the estimates suggest an ice age is imminant (withing, say the next 1,000 years)?
Edited by ludo on Thursday 28th March 16:48
I note you do not address the substantive points that I made. Plus ca change...
Durbster, on the other hand seems to believe we understand the climate well enough that is behaved pretty much exactly as we expected it to. As he says “Clear proof that we do understand it.”
I disagree. I think our knowledge is at a fairly rudimentary level where we can’t even agree on the rough timing of massive natural climate changes.
And your question about imminent ice age? Yes there are loads of peer reviewed papers from the 60’s and 70’s that show the cooling may have already begun.
Which kind of backs up my point that we have a very basic knowledge about our climate. Certainly not enough to support the normal catastrophic scare stories.
There are quite a few peer reviewed papers from the
grumbledoak said:
I didn't think anyone claimed to know the planet's average temperature to 1ºF. I stand corrected.
You don't need to know the absolute temperature of something to measure a change in its temperature, which is what Roy Spencer was talking about.Care to make a list of all the arguments you have made today that you are willing to admit were incorrect? Just so we know what we agree on.
Kawasicki said:
And your question about imminent ice age? Yes there are loads of peer reviewed papers from the 60’s and 70’s that show the cooling may have already begun.
Which kind of backs up my point that we have a very basic knowledge about our climate. Certainly not enough to support the normal catastrophic scare stories.
O.K. give me a few references to those peer reviewed papers.Which kind of backs up my point that we have a very basic knowledge about our climate. Certainly not enough to support the normal catastrophic scare stories.
IIRC the 60s and 70s were a time when scientists were not sure whether CO2 (which cause warming) or aerosols (which cause cooling) would win out. The thing that they didn't know at the time was that we did something about reducing aerosols, but increase CO2 emissions, which is largely why the planet warmed. Scientists of the 60s and 70s not being able to predict political action does not mean that we don't have a good basic knowledge of the climate now.
There is also the fact that science tends to work by bounding. So quite often papers show that something is possible, i.e. it isn't ruled out, rather than that it is probable. Peer review is only the most basic sanity check, so for any scientific question, you are almost certain to be able to find papers that support both sides, so being able to find a handful of papers that support your position is basically confirmation bias. What you need to do is to look at a review of the topic so you can see the balance of scientific opinion.
As it happens, the idea of scientists predicting cooling in the 70s is largely apparently a myth generated by media interest, rather than by the scientific community.
And please leave the "catastrophic scare stories" hyperbole for the political debate, this is for the scientific debate.
ludo said:
grumbledoak said:
... while ramping minor, possibly immeasurably small, effects such as CO2 ...
This is also a bullst argument. The direct effect of CO2 radiative forcing is uncontroversial and even accepted by climate skeptic scientists like Roy Spencer:RoySpencer said:
Now, you might be surprised to learn that the amount of warming directly caused by the extra CO2 is, by itself, relatively weak. It has been calculated theoretically that, if there are no other changes in the climate system, a doubling of the atmospheric CO2 concentration would cause less than 1 deg C of surface warming (about 1 deg. F). This is NOT a controversial statement…it is well understood by climate scientists. (As of 2008, we were about 40% to 45% of the way toward a doubling of atmospheric CO2.)
So it clearly isn't minor or "possibly immeasurably small".This is the joy of bulls
t, it is easy to produce in large amounts and waste the time and energy of your opponent in the debate who has to go and find the evidence to show that it is bullst. Of course if they know what they are talking about, it won't take long, but the asymmetry in effort required is the basic rhetorical device used throughout the public debate on climate. Sadly most people don't have the true skepticism required to check their own arguments or those of others, which is why these canards are still effective.
dickymint said:
ludo said:
grumbledoak said:
... while ramping minor, possibly immeasurably small, effects such as CO2 ...
This is also a bullst argument. The direct effect of CO2 radiative forcing is uncontroversial and even accepted by climate skeptic scientists like Roy Spencer:RoySpencer said:
Now, you might be surprised to learn that the amount of warming directly caused by the extra CO2 is, by itself, relatively weak. It has been calculated theoretically that, if there are no other changes in the climate system, a doubling of the atmospheric CO2 concentration would cause less than 1 deg C of surface warming (about 1 deg. F). This is NOT a controversial statement…it is well understood by climate scientists. (As of 2008, we were about 40% to 45% of the way toward a doubling of atmospheric CO2.)
So it clearly isn't minor or "possibly immeasurably small".This is the joy of bulls
t, it is easy to produce in large amounts and waste the time and energy of your opponent in the debate who has to go and find the evidence to show that it is bullst. Of course if they know what they are talking about, it won't take long, but the asymmetry in effort required is the basic rhetorical device used throughout the public debate on climate. Sadly most people don't have the true skepticism required to check their own arguments or those of others, which is why these canards are still effective.RoySpencer said:
BUT…everything this else in the climate system probably WON’T stay the same! For instance, clouds, water vapor, and precipitation systems can all be expected to respond to the warming tendency in some way, which could either amplify or reduce the manmade warming. These other changes are called “feedbacks,” and the sum of all the feedbacks in the climate system determines what is called ‘climate sensitivity’. Negative feedbacks (low climate sensitivity) would mean that manmade global warming might not even be measurable, lost in the noise of natural climate variability. But if feedbacks are sufficiently positive (high climate sensitivity), then manmade global warming could be catastrophic.
Indeed, things won't stay the same. For a start water vapour feedback is very certainly positive and will amplify any radiative forcing (natural or anthropogenic). The main uncertainty in the feedback is apparently cloud feedback. There is no evidence that the overall feedback is negative, and indeed if it were it would make it all but impossible to explain anything about paleoclimate, where large changes in temperature are seen from very modest variations in forcing. Current estimates of ECS are in the 1.5 to 4.5 C per doubling range, and as far as I am aware there are no credible arguments for ECS being less than one.ludo said:
dickymint said:
ludo said:
grumbledoak said:
... while ramping minor, possibly immeasurably small, effects such as CO2 ...
This is also a bullst argument. The direct effect of CO2 radiative forcing is uncontroversial and even accepted by climate skeptic scientists like Roy Spencer:RoySpencer said:
Now, you might be surprised to learn that the amount of warming directly caused by the extra CO2 is, by itself, relatively weak. It has been calculated theoretically that, if there are no other changes in the climate system, a doubling of the atmospheric CO2 concentration would cause less than 1 deg C of surface warming (about 1 deg. F). This is NOT a controversial statement…it is well understood by climate scientists. (As of 2008, we were about 40% to 45% of the way toward a doubling of atmospheric CO2.)
So it clearly isn't minor or "possibly immeasurably small".This is the joy of bulls
t, it is easy to produce in large amounts and waste the time and energy of your opponent in the debate who has to go and find the evidence to show that it is bullst. Of course if they know what they are talking about, it won't take long, but the asymmetry in effort required is the basic rhetorical device used throughout the public debate on climate. Sadly most people don't have the true skepticism required to check their own arguments or those of others, which is why these canards are still effective.RoySpencer said:
BUT…everything this else in the climate system probably WON’T stay the same! For instance, clouds, water vapor, and precipitation systems can all be expected to respond to the warming tendency in some way, which could either amplify or reduce the manmade warming. These other changes are called “feedbacks,” and the sum of all the feedbacks in the climate system determines what is called ‘climate sensitivity’. Negative feedbacks (low climate sensitivity) would mean that manmade global warming might not even be measurable, lost in the noise of natural climate variability. But if feedbacks are sufficiently positive (high climate sensitivity), then manmade global warming could be catastrophic.
Indeed, things won't stay the same. For a start water vapour feedback is very certainly positive and will amplify any radiative forcing (natural or anthropogenic). The main uncertainty in the feedback is apparently cloud feedback. There is no evidence that the overall feedback is negative, and indeed if it were it would make it all but impossible to explain anything about paleoclimate, where large changes in temperature are seen from very modest variations in forcing. Current estimates of ECS are in the 1.5 to 4.5 C per doubling range, and as far as I am aware there are no credible arguments for ECS being less than one.
In layman’s terms Tyndalls experiment works in a test tube ......without clouds and other stuff!
dickymint said:
In layman’s terms Tyndalls experiment works in a test tube ......without clouds and other stuff!
except that Tyndall's experiment only covers one component of the greenhouse effect (the absorption of IR radiation). It's a bit more complicated than that. Essentially the atmosphere is almost transparent to visible and UV light (which is where most of the solar energy is) so it gets absorbed by the surface, which then warms and hence radiates energy, but because it is much cooler than the sun it radiates in IR wavelengths. The atmosphere is not transparent to all wavelengths of IR, so some gets absorbed and re-radiated. Some gets radiated back down to the surface, which warms the surface, and some upwards. The important thing is altitude at which there isn't enough CO2 above to absorb the IR before it escapes into space. This layer is much cooler than the surface (because of the lapse rate), and being cooler, it radiates less IR than the surface. If CO2 levels stays the same, then eventually the surface warms to the point that it warms the atmosphere above it suffciently that the total outbound IR balances the incoming solar energy (compensating for albedo). However, if you increase CO2, the effective radiating layer rises and so is cooler, which means outbound IR no longer balances incoming solar radiation, so the planet gains energy and so warms until a new equilibrium is reached once more.
The 1F (I gather other sources suggest it is more like 1C), I think, relates to that process, but ignoring water vapour, clouds, lapse rate feedbacks etc. as you suggest.
It's worth noting that Roy Spencer also said
RoySpencer said:
But if feedbacks are sufficiently positive (high climate sensitivity), then manmade global warming could be catastrophic.
My guess would be somewhere between 2 and 3 C per doubling. I don't really like using words like "catastrophic" because people have very different ideas about what constitutes a catastrophe (especially if it doesn't directly affect them) - it has a large ethical/economic/political dimension, rather than being a scientific issue. However, there is nothing in what Roy Spencer says that rules out very substantial temperature changes if we continue to exploit fossil fuels at the current rate.Edited by ludo on Saturday 30th March 13:13
ludo said:
Kawasicki said:
And your question about imminent ice age? Yes there are loads of peer reviewed papers from the 60’s and 70’s that show the cooling may have already begun.
Which kind of backs up my point that we have a very basic knowledge about our climate. Certainly not enough to support the normal catastrophic scare stories.
O.K. give me a few references to those peer reviewed papers.Which kind of backs up my point that we have a very basic knowledge about our climate. Certainly not enough to support the normal catastrophic scare stories.
IIRC the 60s and 70s were a time when scientists were not sure whether CO2 (which cause warming) or aerosols (which cause cooling) would win out. The thing that they didn't know at the time was that we did something about reducing aerosols, but increase CO2 emissions, which is largely why the planet warmed. Scientists of the 60s and 70s not being able to predict political action does not mean that we don't have a good basic knowledge of the climate now.
There is also the fact that science tends to work by bounding. So quite often papers show that something is possible, i.e. it isn't ruled out, rather than that it is probable. Peer review is only the most basic sanity check, so for any scientific question, you are almost certain to be able to find papers that support both sides, so being able to find a handful of papers that support your position is basically confirmation bias. What you need to do is to look at a review of the topic so you can see the balance of scientific opinion.
As it happens, the idea of scientists predicting cooling in the 70s is largely apparently a myth generated by media interest, rather than by the scientific community.
And please leave the "catastrophic scare stories" hyperbole for the political debate, this is for the scientific debate.
ludo said:
Kawasicki said:
And your question about imminent ice age? Yes there are loads of peer reviewed papers from the 60’s and 70’s that show the cooling may have already begun.
Which kind of backs up my point that we have a very basic knowledge about our climate. Certainly not enough to support the normal catastrophic scare stories.
O.K. give me a few references to those peer reviewed papers.Which kind of backs up my point that we have a very basic knowledge about our climate. Certainly not enough to support the normal catastrophic scare stories.
IIRC the 60s and 70s were a time when scientists were not sure whether CO2 (which cause warming) or aerosols (which cause cooling) would win out. The thing that they didn't know at the time was that we did something about reducing aerosols, but increase CO2 emissions, which is largely why the planet warmed. Scientists of the 60s and 70s not being able to predict political action does not mean that we don't have a good basic knowledge of the climate now.
There is also the fact that science tends to work by bounding. So quite often papers show that something is possible, i.e. it isn't ruled out, rather than that it is probable. Peer review is only the most basic sanity check, so for any scientific question, you are almost certain to be able to find papers that support both sides, so being able to find a handful of papers that support your position is basically confirmation bias. What you need to do is to look at a review of the topic so you can see the balance of scientific opinion.
As it happens, the idea of scientists predicting cooling in the 70s is largely apparently a myth generated by media interest, rather than by the scientific community.
And please leave the "catastrophic scare stories" hyperbole for the political debate, this is for the scientific debate.
Kawasicki said:
No Tricks Zone!? Good grief. 
No Tricks Zone's lists are not what they say they are. It's a propaganda site.
If you want to know where the global cooling thing comes from, here's a summary for laymen:
https://skeptoid.com/episodes/4487[/footnote]
Edited by durbster on Sunday 31st March 08:18
durbster said:
Kawasicki said:
No Tricks Zone!? Good grief. No Tricks Zone's lists are not what they say they are. It's a propaganda site.
If you want to know where the global cooling thing comes from, here's a summary for laymen:
https://skeptoid.com/episodes/4487[/footnote]
Edited by durbster on Sunday 31st March 08:18
skeptoid's lists are not what they say they are. It's a propaganda site.
If you want to know where the global cooling thing comes from, here's a summary for laymen:
http://notrickszone.com/285-papers-70s-cooling-1/
Kawasicki said:
durbster said:
No Tricks Zone!? Good grief.
No Tricks Zone's lists are not what they say they are. It's a propaganda site.
If you want to know where the global cooling thing comes from, here's a summary for laymen:
https://skeptoid.com/episodes/4487[/footnote]
skeptoid.com!? Good grief. No Tricks Zone's lists are not what they say they are. It's a propaganda site.
If you want to know where the global cooling thing comes from, here's a summary for laymen:
https://skeptoid.com/episodes/4487[/footnote]
Edited by durbster on Sunday 31st March 08:18
skeptoid's lists are not what they say they are. It's a propaganda site.
If you want to know where the global cooling thing comes from, here's a summary for laymen:
http://notrickszone.com/285-papers-70s-cooling-1/
But you don't have to do that, just go and read some of the abstracts and you can usually see they are misrepresenting them. It's a simple thing that would take a minute and avoid embarrassment. The abstracts are usually available to read online for free even if the full paper isn't.
I therefore have good reason to say why NTZ is not to be trusted so what's your reason for discounting the Skeptoid article? It's obviously not a climate change propaganda site as it discusses all sorts of topics, and the article I posted has full citations and references at the bottom that you can check.
Kawasicki said:
Right, now expand the search criterion similarly the other way and include the papers that supported global warming.Lets look at paper #2
NoTricks said:
2. Ellsaesser , 1974 Has man, through increasing emissions of particulates, changed the climate? It is estimated that man now contributes 13.6% of the 3.5 x 109 tons of primary and secondary particulates presently emitted to the atmosphere annually. … [W]hile an anthropogenic upward trend in airborne particulates existed in the past, it was halted and may even have been reversed over the past few decades. … [pq
[F]or 50 or so years the world has been warmer than at any time in the last 300 years; in the 1940’s warmer than at any time during the last 1000 years. Since 1945 there has been a cooling trend and we are now nearly back down to the averages of the early 19th century. None of the calculations of which I am aware found that the man augmented CO2 could have contributed more than a small fraction of the warming up to 1940. Whatever the cause of the warming the post 1940 cooling appears to be primarily a return to normal. … Of the climatic problems raised the CO2 one is best understood. There is essentially universal agreement that atmospheric CO2 is increasing, increasing as a result of the consumption of fossil fuels and that this should enhance the “greenhouse” effect leading to a warming of the planetary surface. The strongest support for the upward trend in airborne particulates derives from the failure of observational data to support our understanding of the CO2 effect. Yet no one ever hears the argument that man might consider a deliberate increase in particulates to counter the CO2 effect or alternatively that the CO2 effect is just what is needed to prevent or delay the onset of the next glacial advance which is now imminent according to students of this problem. The failure of these latter arguments to receive equal time indicates a decided bias in our systems for informational exchange and it is the possibility that such a decided bias can exist that I consider to be the greatest threat to our future.
This paper does not support the contention that scientists were predicting an imminent ice age (except with considerable cognitive bias):[F]or 50 or so years the world has been warmer than at any time in the last 300 years; in the 1940’s warmer than at any time during the last 1000 years. Since 1945 there has been a cooling trend and we are now nearly back down to the averages of the early 19th century. None of the calculations of which I am aware found that the man augmented CO2 could have contributed more than a small fraction of the warming up to 1940. Whatever the cause of the warming the post 1940 cooling appears to be primarily a return to normal. … Of the climatic problems raised the CO2 one is best understood. There is essentially universal agreement that atmospheric CO2 is increasing, increasing as a result of the consumption of fossil fuels and that this should enhance the “greenhouse” effect leading to a warming of the planetary surface. The strongest support for the upward trend in airborne particulates derives from the failure of observational data to support our understanding of the CO2 effect. Yet no one ever hears the argument that man might consider a deliberate increase in particulates to counter the CO2 effect or alternatively that the CO2 effect is just what is needed to prevent or delay the onset of the next glacial advance which is now imminent according to students of this problem. The failure of these latter arguments to receive equal time indicates a decided bias in our systems for informational exchange and it is the possibility that such a decided bias can exist that I consider to be the greatest threat to our future.
Ellsaesser said:
Has man, through increasing emissions of particulates, changed the climate? It is estimated that man now contributes 13.6% of the 3.5 x 109 tons of primary and secondary particulates presently emitted to the atmosphere annually. … [W]hile an anthropogenic upward trend in airborne particulates existed in the past, it was halted and may even have been reversed over the past few decades.
Standard stuff.Ellsaesser said:
The 1968 AAAS Symposium on Global Effects of Environmental Pollution initiated a flood of papers supporting monotonically if not exponentially increasing pollution. The particulate increases were usually cited as at least contributing to the post 1940 cooling and possibly capable of bringing on another ice age.
This is not indicating that the author agrees with them. Indeed the first paragraphs of the paper are critical of "doomsday syndrome". Given that he was writing in the early 1970s when global temperatures had been basically flat for 30 years, I doubt he meant global warming doomsday. Indeed if you read the paper, you will find that it prevodes evidence against an upward trend in aerosols that might plausibly override the effects of increasing GHGs.Ellsaesser said:
[F]or 50 or so years the world has been warmer than at any time in the last 300 years; in the 1940’s warmer than at any time during the last 1000 years. Since 1945 there has been a cooling trend and we are now nearly back down to the averages of the early 19th century. None of the calculations of which I am aware found that the man augmented CO2 could have contributed more than a small fraction of the warming up to 1940. Whatever the cause of the warming the post 1940 cooling appears to be primarily a return to normal. …
This is pretty standard stuff for the early 1970s before we had much proxy data on paleoclimate. Indeed the IPCC suggest that only about half of the warming in the first half of the 20th century is anthropogenic.Now the above paragraph is from the penultimate paragraph of the paper [page 49]. One might ask whether the quotes have been silently rearranged to imply that the next paragraph was a response to the previous one. It clearly isn't. So much for "No Tricks"!
This paragraph is from the introduction [page 42].
Ellsaesser said:
Of the climatic problems raised the CO2 one is best understood. There is essentially universal agreement that atmospheric CO2 is increasing, increasing as a result of the consumption of fossil fuels and that this should enhance the “greenhouse” effect leading to a warming of the planetary surface. The strongest support for the upward trend in airborne particulates derives from the failure of observational data to support our understanding of the CO2 effect.
Note that the author is explicitly endorsing the warming effect of CO2 and downplaying the claims about a new ice age which was predicated on increasing aerosol levels, the only evidence for which is the lack of observed warming. That is arguing against an new ice age.Ellsaesser said:
Yet no one ever hears the argument that man might consider a deliberate increase in particulates to counter the CO2 effect or alternatively that the CO2 effect is just what is needed to prevent or delay the onset of the next glacial advance which is now imminent according to students of this problem.
This is ironic as Svante Arrhenius apparently made just that suggestion back in 1906. More recently people have also argued for increasing aerosols to offset global warming.Ellsaesser said:
The failure of these latter arguments to receive equal time indicates a decided bias in our systems for informational exchange and it is the possibility that such a decided bias can exist that I consider to be the greatest threat to our future.
Yup. Dispassionate analysis of the science is what is called for, which is why I have to keep asking people to avoid hyperbole about "catastrophe" for the politics thread. Oddly enough, it mostly is introduced as a climate skeptic straw man (IIRC you wond find the word used very often in the IPCC WG1 report).So, the second paper I found is, if anything, arguing AGAINST a possible future ice age. This sort of thing says it all about climate skepticism.
Edited by ludo on Monday 1st April 09:57
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