Climate Change - The Scientific Debate
Discussion
Variomatic said:
plunker said:
Your analogy seems to lack any physical mechanism connecting the two things. I would have said, scientifically, AGW is a bit like saying if you put a thicker jumper on your body will lose heat less rapidly. Notice how there's a physical mechanism linking the well understood enhanced insulating properties of thicker jumpers and the effect.
That's not as big a difference as you might think in terms of the point of the analogy.At the time of witch hunts, observed cause and effect was the truth, the whole truth etc as far as understanding went. It was primitive, in many cases barbaric, and we find it hard to believe that considered it science.
We have now added the concept of "mechanism" to the equation and that is the truth, the whole truth etc as far as our understanding goes.
AGW may or may not play out to have been a real threat in the future (the mounting evidence suggests not) but one thing that will undoubtedly happen in the future is that people will look back at our understanding (of many things) and see it as primitive, in many cases barbaric (especially in medicine), and will find it hard to believe we considered it science.
Believing anything else is displaying such incredible hubris that it really doesn't bear thinking about!
I think your point is perhaps more about politics than science ie the way we respond to the scientific evidence in hand.
plunker said:
jet_noise said:
deeen said:
dub16v said:
... (1) Out of interest, are you able to explain what causes 'climate change' as we now experience it? Is it the sun? Some cyclical system? CO2 from the oceans? An energy imbalance somewhere in the system?
(2) Or do you deny that the CO2 that we have emitted into the atmosphere since the industrial revolution is having no affect on our climate whatsoever? ...
1) The same things that caused climate change in the millions of years before humans existed, and the same things that will continue to cause it for millions of years after we have gone.(2) Or do you deny that the CO2 that we have emitted into the atmosphere since the industrial revolution is having no affect on our climate whatsoever? ...
2) I am sure that every bit of CO2 affects the climate, in the same way as if I pee off Brighton pier I affect the sea level.
Alarmists haven't quite got their head around the Null Hypothesis (1) or Beer's Law (2),
regards,
Jet
plunker said:
So when you said 'Scientifically, AGW is like...' you weren't actually referring to what AGW is scientifically like today but when viewed from the future when the theory is no longer valid. Or something like that. That does seem to pre-determine the course of future researches though doesn't it, but then you admit "AGW may or may not play out..." so now I'm totally confused about what AGW is scientifically like
I think your point is perhaps more about politics than science ie the way we respond to the scientific evidence in hand.
No, my point is very much about science. Part of which when it's removed from politics is acknowleging when you simply don't have enough, or good enough, data. That was the point of my quote, which I've put back in context for you:I think your point is perhaps more about politics than science ie the way we respond to the scientific evidence in hand.
Variomatic said:
Scientifically, AGW is akin to noticing that we had a good harvest the year after Molly Smith got burned to death in her hovel, remembering that Molly Smith was "a bit odd" and spending the next 200 years or so burning witches because that's what the evidence said we should do.
We have, at best, about 150 years of reliable data about one or two aspects of global climate (temperature and rainfall) as well as patchy data for sea level from port gauges.We also have "reconstructed" data for temperature, over an extremely limited area, which loses resolution very rapidly as we go back in time, until it's only capable (if at all) of resolving to decadal or even century averages.
Against that, we have a period where it wared quite rapidly (according to the data0 which lasted around 20 years. Since then it hasn't warmed - according to the same data, and before that it was cooling for a couple of decades.
In the context of a several billion year old chaotic system like the climate is, we have no more data available to know how it works than those villagers did with their one failed harvest.
If anyone pointed that out at the time (apart from having a toasty day) they would no doubt have been pointed to the Precautionary Principle as justification why they couldn't afford to risk not burning Mrs Jones tomorrow.
It isn't science.
deeen said:
plunker said:
jet_noise said:
deeen said:
dub16v said:
... (1) Out of interest, are you able to explain what causes 'climate change' as we now experience it? Is it the sun? Some cyclical system? CO2 from the oceans? An energy imbalance somewhere in the system?
(2) Or do you deny that the CO2 that we have emitted into the atmosphere since the industrial revolution is having no affect on our climate whatsoever? ...
1) The same things that caused climate change in the millions of years before humans existed, and the same things that will continue to cause it for millions of years after we have gone.(2) Or do you deny that the CO2 that we have emitted into the atmosphere since the industrial revolution is having no affect on our climate whatsoever? ...
2) I am sure that every bit of CO2 affects the climate, in the same way as if I pee off Brighton pier I affect the sea level.
Alarmists haven't quite got their head around the Null Hypothesis (1) or Beer's Law (2),
regards,
Jet
plunker said:
Greenhouse gas variation is associated with climate change before humans existed but so you're the one switching things off.
But so but no but no but yeah but your mum is switching it off???"Greenhouse gas"? Well greenhouses are made of glass, which gas resembles glass?
"Associated with"... as in follows from, caused by?
This is supposed to be a scientific discussion... "but so you're the one switching things off", "clueless...", are these attacks because you don't have a logical argument? Or if you do have one, would you like to present it, now?
Variomatic said:
plunker said:
So when you said 'Scientifically, AGW is like...' you weren't actually referring to what AGW is scientifically like today but when viewed from the future when the theory is no longer valid. Or something like that. That does seem to pre-determine the course of future researches though doesn't it, but then you admit "AGW may or may not play out..." so now I'm totally confused about what AGW is scientifically like
I think your point is perhaps more about politics than science ie the way we respond to the scientific evidence in hand.
No, my point is very much about science. Part of which when it's removed from politics is acknowleging when you simply don't have enough, or good enough, data. That was the point of my quote, which I've put back in context for you:I think your point is perhaps more about politics than science ie the way we respond to the scientific evidence in hand.
Variomatic said:
Scientifically, AGW is akin to noticing that we had a good harvest the year after Molly Smith got burned to death in her hovel, remembering that Molly Smith was "a bit odd" and spending the next 200 years or so burning witches because that's what the evidence said we should do.
We have, at best, about 150 years of reliable data about one or two aspects of global climate (temperature and rainfall) as well as patchy data for sea level from port gauges.We also have "reconstructed" data for temperature, over an extremely limited area, which loses resolution very rapidly as we go back in time, until it's only capable (if at all) of resolving to decadal or even century averages.
Against that, we have a period where it wared quite rapidly (according to the data0 which lasted around 20 years. Since then it hasn't warmed - according to the same data, and before that it was cooling for a couple of decades.
In the context of a several billion year old chaotic system like the climate is, we have no more data available to know how it works than those villagers did with their one failed harvest.
If anyone pointed that out at the time (apart from having a toasty day) they would no doubt have been pointed to the Precautionary Principle as justification why they couldn't afford to risk not burning Mrs Jones tomorrow.
It isn't science.
deeen said:
plunker said:
Greenhouse gas variation is associated with climate change before humans existed but so you're the one switching things off.
But so but no but no but yeah but your mum is switching it off???"Greenhouse gas"? Well greenhouses are made of glass, which gas resembles glass?
"Associated with"... as in follows from, caused by?
This is supposed to be a scientific discussion... "but so you're the one switching things off", "clueless...", are these attacks because you don't have a logical argument? Or if you do have one, would you like to present it, now?
plunker said:
Still looks like your point is about policy responses to me, but never mind!
How? It's about unscientific use of available data (remember, computer model outputs are NOT data) The witch burners (in my example, not strictly in rl - I've used a little poetic licence to keep things simple for you) took very limited "evidence" and concluded that poor harvests and failing to burn witches were linked.
The AGW movement has taken equally limited evidence and concluded that CO2 and fangerous levels of warming are linked.
In both cases, those promoting the idea ignore large amounts of evidence that contradicts their position - they still had poor harvests in bumper witch-burning years / the total period of rapid warming (roughly 1978 - 1998) is now barely longer than the period of no warming (1998 - 2014) that's followed it, despite CO2 continuing to rise steadily.
Then, when the evidence builds to a point where ordinary people notice, change their claims just enough to keep it supportable - it's not crop failures after all, but animal deaths / it's not about the world warming it's about the climate changing / atmospheric temps adon't really matter, it's the oceans that count.....
NOT scientific in either case.
PRTVR said:
plunker said:
PRTVR said:
Please tell me the insulating properties of CO2
Really?It's transparent to visible light (or 'colourless' as you put it) but opaquae to infra-red. The sun's energy arrives mostly in the visible light range warming the surface and leaves in the infra-red range so therefore CO2 acts like insulation slowing the planet's ability to cool (aka the greenhouse effect).
PRTVR said:
And then we come to the concentration,. 04 that's an awful lot of molecules of other things in the atmosphere, even given that not all that small percentage is man made.
Why do you think it can have a major influence?
Because unlike those other molecules it slows the passage of infra-red to space.Why do you think it can have a major influence?
This is always a good illustration of what trace amounts can do optically:
http://www.youtube.com/watch?v=81FHVrXgzuA
Edited by plunker on Wednesday 12th November 23:47
Variomatic said:
plunker said:
Still looks like your point is about policy responses to me, but never mind!
How? It's about unscientific use of available data (remember, computer model outputs are NOT data) The witch burners (in my example, not strictly in rl - I've used a little poetic licence to keep things simple for you) took very limited "evidence" and concluded that poor harvests and failing to burn witches were linked.
The AGW movement has taken equally limited evidence and concluded that CO2 and fangerous levels of warming are linked.
In both cases, those promoting the idea ignore large amounts of evidence that contradicts their position - they still had poor harvests in bumper witch-burning years / the total period of rapid warming (roughly 1978 - 1998) is now barely longer than the period of no warming (1998 - 2014) that's followed it, despite CO2 continuing to rise steadily.
Then, when the evidence builds to a point where ordinary people notice, change their claims just enough to keep it supportable - it's not crop failures after all, but animal deaths / it's not about the world warming it's about the climate changing / atmospheric temps adon't really matter, it's the oceans that count.....
NOT scientific in either case.
rovermorris999 said:
rovermorris999 said:
Plunker, you may know. If the current levels are bad, what's the best level of CO2 in the atmosphere and why?
Funny how this question never gets answered. plunker said:
This is always a good illustration of what trace amounts can do optically:
http://www.youtube.com/watch?v=81FHVrXgzuA
An almost completely pointless demonstration, but I do wonder what that demo would look like if you used red ink for CO2 for instance.http://www.youtube.com/watch?v=81FHVrXgzuA
... and black ink for water vapour?
plunker said:
PRTVR said:
plunker said:
PRTVR said:
Please tell me the insulating properties of CO2
Really?It's transparent to visible light (or 'colourless' as you put it) but opaquae to infra-red. The sun's energy arrives mostly in the visible light range warming the surface and leaves in the infra-red range so therefore CO2 acts like insulation slowing the planet's ability to cool (aka the greenhouse effect).
PRTVR said:
And then we come to the concentration,. 04 that's an awful lot of molecules of other things in the atmosphere, even given that not all that small percentage is man made.
Why do you think it can have a major influence?
Because unlike those other molecules it slows the passage of infra-red to space.Why do you think it can have a major influence?
This is always a good illustration of what trace amounts can do optically:
http://www.youtube.com/watch?v=81FHVrXgzuA
Edited by plunker on Wednesday 12th November 23:47
Let's see the same demonstration done in a fast flowing river, similar to the real world.
Does not the heated CO2 not give up its heat to surrounding molecules?
How does the heat get back down to the surface?
What happens at night, do we not just loose any small amounts of extra heat retained.
As an example look at the temperature in a greenhouse over night.
plunker said:
It's a difficult question and not well framed - best for what/whom? Overall, for our current civilisations, agriculture and world security etc the best level is probably one that doesn't change, or doesn't change so much that it causes rapid environmental changes.
The usual evasion. Not well framed? Give us all a break. It's you banging on about CO2 levels so presumably you have a view. How do you suppose to control the level of something that varies naturally and human contributions are minimal? Presumably you think 400ppm is too much? So is 300 better? 200? 500 but not varying?plunker said:
Equally limited evidence? I think your poetic license should be revoked
Have you seen some of the things the great poets got away with?Besides, in terms of the complexity of the problem, mathematically the evidence is just as limited in each case - if you have infinite complexity (for any given infinity) then any evidence is just scratching the surface
Silver Smudger said:
plunker said:
This is always a good illustration of what trace amounts can do optically:
http://www.youtube.com/watch?v=81FHVrXgzuA
An almost completely pointless demonstration, but I do wonder what that demo would look like if you used red ink for CO2 for instance.http://www.youtube.com/watch?v=81FHVrXgzuA
... and black ink for water vapour?
PRTVR said:
What is it with trying to demonstrate real world events in glass boxes?
And trace amounts can't have large effects is real world is it? PRTVR said:
Let's see the same demonstration done in a fast flowing river, similar to the real world.
The opacity to light would remain in moving water.PRTVR said:
Does not the heated CO2 not give up its heat to surrounding molecules?
Some I believe yes.PRTVR said:
How does the heat get back down to the surface?
It's probably better to think of it as delayed cooling. PRTVR said:
What happens at night, do we not just loose any small amounts of extra heat retained.
Same as day - slowed cooling.PRTVR said:
As an example look at the temperature in a greenhouse over night.
same as etcrovermorris999 said:
plunker said:
It's a difficult question and not well framed - best for what/whom? Overall, for our current civilisations, agriculture and world security etc the best level is probably one that doesn't change, or doesn't change so much that it causes rapid environmental changes.
The usual evasion. Not well framed? Give us all a break. It's you banging on about CO2 levels so presumably you have a view. How do you suppose to control the level of something that varies naturally and human contributions are minimal? Presumably you think 400ppm is too much? So is 300 better? 200? 500 but not varying?Part of the problem with answering your question is climate sensitivity which I don't regard as known with great precision.
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