Do humans contribute to climate change substantially?
Poll: Do humans contribute to climate change substantially?
Total Members Polled: 599
Discussion
In the article Bellamy said:
For the last 16 years, temperatures have been going down and the carbon dioxide has been going up and the crops have got greener and grow quicker. We’ve done plenty to smash up the planet, but there’s been no global warming caused by man.’
Pretty clear to me Bedazzled. Spin it however you wish, this is what he actually said. Bedazzled said:
The 16 year trend is a classic example of cherry picking, the start point rides the crest of an El Nino wave and it destroys the credibility of anything else you say. Ironically if skeptics flagged a 10 year plateau at least it would be an honest observation worthy of discussion, but they can't resist spinning it.
I tend to agree.However, the MMGW fiasco has been created by gross exaggeration of the impact of CO2 on the climate by interested parties - which if you like is 'spin'. Spin by proponents of the hypothesis and by politicians with vested interests.
I think we can now dismiss many of the more extreme and hysterical predictions such as:
'tipping point' to thermageddon
'inundation of landmasses' by rising sea levels
'no more snow'
'mediterranean climate' in UK
etc. etc.
If the IPCC and politicians had simply said 'we expect a little more warming which we will be unable to distinguish from natural variations in a noisy system, and are unable to predict future temperatures to any precision due to the chaotic nature of the climate' then this would all have been a damp squib.
Quite simply, in isolation, it would seem that there should be some increase in global temps due to an inrease in CO2 - but there is a large caveat to this! The amount of warming due to increasing levels of CO2 is not fully determined and is subject to computer modelling. Also, there are many other mechanisms at play which are either poorly understood and/or not factored into consideration and may offset warming from CO2.
In short, the modelling is, at this stage, very crude and not fit for purpose and the 'science' of the planet is not yet fully understood (an undersatement).
One good thing coming out of this, is that 'climate science' was once a backwater for no-marks (Physicist would want to earn their spurs at Cern). Now that there is funding in this area, maybe there will be higher quality candidates willing to take this subject on. But suspect this will only happen once the 'old guard' are out of the way picking up their pensions, but in the meantime will be vetting any candidates with a view to not being shown up in the future. This, unfortunately, is life!
All just my opinion, of course!
Is the supposed complaint about 15 or 16 years rather than 10 years and if so is it cognisant or ignorant of error bars and statistical significance levels?
As to start and end points, for a plateau ending at present it extends back as far as it does.
Irrelevant point, but there has been plenty of El Nino abuse on the warmist side. More abuse there.
As to start and end points, for a plateau ending at present it extends back as far as it does.
Irrelevant point, but there has been plenty of El Nino abuse on the warmist side. More abuse there.
Ali G said:
Bedazzled said:
The 16 year trend is a classic example of cherry picking, the start point rides the crest of an El Nino wave and it destroys the credibility of anything else you say. Ironically if skeptics flagged a 10 year plateau at least it would be an honest observation worthy of discussion, but they can't resist spinning it.
I tend to agree.However, the MMGW fiasco has been created by gross exaggeration of the impact of CO2 on the climate by interested parties - which if you like is 'spin'. Spin by proponents of the hypothesis and by politicians with vested interests.
I think we can now dismiss many of the more extreme and hysterical predictions such as:
'tipping point' to thermageddon
'inundation of landmasses' by rising sea levels
'no more snow'
'mediterranean climate' in UK
etc. etc.
If the IPCC and politicians had simply said 'we expect a little more warming which we will be unable to distinguish from natural variations in a noisy system, and are unable to predict future temperatures to any precision due to the chaotic nature of the climate' then this would all have been a damp squib.
Quite simply, in isolation, it would seem that there should be some increase in global temps due to an inrease in CO2 - but there is a large caveat to this! The amount of warming due to increasing levels of CO2 is not fully determined and is subject to computer modelling. Also, there are many other mechanisms at play which are either poorly understood and/or not factored into consideration and may offset warming from CO2.
In short, the modelling is, at this stage, very crude and not fit for purpose and the 'science' of the planet is not yet fully understood (an undersatement).
One good thing coming out of this, is that 'climate science' was once a backwater for no-marks (Physicist would want to earn their spurs at Cern). Now that there is funding in this area, maybe there will be higher quality candidates willing to take this subject on. But suspect this will only happen once the 'old guard' are out of the way picking up their pensions, but in the meantime will be vetting any candidates with a view to not being shown up in the future. This, unfortunately, is life!
All just my opinion, of course!
Without models all we have is paleo-climate and that suggests a sensitive planet.
Dismiss the models and 'thermogeddon' remains firmly on the table.
Guam said:
never added up
This doesn't add up. We've passed several tipping points, it's worse than previously thought, yet the first complete ice core record of the last interglacial period shows the climate of Greenland to be significantly warmer than today! But recent warming is unprecedented!! The President is invoking divine intervention and godly justification for his bulls
t!!! We're doomed!!!!
New research from the NEEM ice core drilling project in Greenland led by the Niels Bohr Institute shows that the period was warmer than previously thought.
How can that be? There musht be shome mishtake Shirley?
Clearly big oil rotters have paid off those Niels Bohr chappies.
kerplunk said:
I find you self-contradictory AG. If the models are junk what basis do you have for dismissing... well, anything?
Without models all we have is paleo-climate and that suggests a sensitive planet.
Dismiss the models and 'thermogeddon' remains firmly on the table.
And I think we can safely say that the models are pretty much junk at the moment - for the reason that have been discussed many times before. The Met Office seems to agree that so far the models have been wrong - hence why they have had to carry out a 're-forecast'.Without models all we have is paleo-climate and that suggests a sensitive planet.
Dismiss the models and 'thermogeddon' remains firmly on the table.
So, if all you have to go in is 'computer sez' then you are in a heap of trouble.
I tend to think that a 'thermogeddon' would have occured in the past on this planet if it were a realistic proposition. To date, there have been a few global catastrophic events (meteor impact/super volvanoes etc.) - but nothing obvious from CO2. Even when CO2 levels have been a lot higher, there has been no run-away meltdown. Looks to me that a CO2 generated thermogeddon is either an impossibility, or the conditions to cause such an event are very, very unlikely.
Ali G said:
kerplunk said:
I find you self-contradictory AG. If the models are junk what basis do you have for dismissing... well, anything?
Without models all we have is paleo-climate and that suggests a sensitive planet.
Dismiss the models and 'thermogeddon' remains firmly on the table.
And I think we can safely say that the models are pretty much junk at the moment - for the reason that have been discussed many times before. The Met Office seems to agree that so far the models have been wrong - hence why they have had to carry out a 're-forecast'.Without models all we have is paleo-climate and that suggests a sensitive planet.
Dismiss the models and 'thermogeddon' remains firmly on the table.
So, if all you have to go in is 'computer sez' then you are in a heap of trouble.
Ali G said:
I tend to think that a 'thermogeddon' would have occured in the past on this planet if it were a realistic proposition. To date, there have been a few global catastrophic events (meteor impact/super volvanoes etc.) - but nothing obvious from CO2. Even when CO2 levels have been a lot higher, there has been no run-away meltdown. Looks to me that a CO2 generated thermogeddon is either an impossibility, or the conditions to cause such an event are very, very unlikely.
Paleocene–Eocene Thermal Maximum?http://en.wikipedia.org/wiki/Paleocene%E2%80%93Eoc...
kerplunk said:
Ali G said:
kerplunk said:
I find you self-contradictory AG. If the models are junk what basis do you have for dismissing... well, anything?
Without models all we have is paleo-climate and that suggests a sensitive planet.
Dismiss the models and 'thermogeddon' remains firmly on the table.
And I think we can safely say that the models are pretty much junk at the moment - for the reason that have been discussed many times before. The Met Office seems to agree that so far the models have been wrong - hence why they have had to carry out a 're-forecast'.Without models all we have is paleo-climate and that suggests a sensitive planet.
Dismiss the models and 'thermogeddon' remains firmly on the table.
So, if all you have to go in is 'computer sez' then you are in a heap of trouble.
Ali G said:
I tend to think that a 'thermogeddon' would have occured in the past on this planet if it were a realistic proposition. To date, there have been a few global catastrophic events (meteor impact/super volvanoes etc.) - but nothing obvious from CO2. Even when CO2 levels have been a lot higher, there has been no run-away meltdown. Looks to me that a CO2 generated thermogeddon is either an impossibility, or the conditions to cause such an event are very, very unlikely.
Paleocene–Eocene Thermal Maximum?http://en.wikipedia.org/wiki/Paleocene%E2%80%93Eoc...
Game set and match I think
Goody and Yung said:
Line-by-line calculations are often adopted as a standard against which to test certain approximations. Their value in a relative context is indisputable, but that should not be taken to mean that line-by-line calculations are necessarily of high absolute accuracy. This comment is relevant to an implicit assumption in much of the current literature: that more and more detailed physics encoded onto larger and larger computers will eventually yield accurate weather and climate predictions. This is more an article of faith than a demonstrable proposition. It is also possible to argue that numerical complexity hides or introduces its own sources of error, in addition to making it impossible to penetrate the algorithms of another investigator.
William Kininmonth said:
High powered computers allow us to carry out more complex modelling but the veracity of models relies on the specification of the individual interactions between the variables.
Weather forecasting models rely on initial specification of mass and momentum fields and, largely, the ability to conserve momentum (conservation of mass, although not of critical importance, is generally a basic specification). Within a few days of simulation the mass and momentum fields have diverged irreconcilably from the true evolution of the atmosphere as errors and computational uncertainty expand and propagate.
Climate forecasting is quite different from weather forecasting. It relies on an ability to conserve energy and to accurately reflect the transformation of energy within the climate system (solar radiation, sensible heat, latent energy, potential energy, terrestrial radiation, etc). Climate forecasting is a much more difficult task because of the exchange of energy and momentum between mediums, especially the gaseous and liquid fluids of the atmosphere and oceans.
Although computing power might allow us to do modelling in powerful new ways the integrity of the models is only as good as the specifications of the interactions between the components. Climate models are severely limited in this respect, despite the access to powerful computers.
Weather forecasting models rely on initial specification of mass and momentum fields and, largely, the ability to conserve momentum (conservation of mass, although not of critical importance, is generally a basic specification). Within a few days of simulation the mass and momentum fields have diverged irreconcilably from the true evolution of the atmosphere as errors and computational uncertainty expand and propagate.
Climate forecasting is quite different from weather forecasting. It relies on an ability to conserve energy and to accurately reflect the transformation of energy within the climate system (solar radiation, sensible heat, latent energy, potential energy, terrestrial radiation, etc). Climate forecasting is a much more difficult task because of the exchange of energy and momentum between mediums, especially the gaseous and liquid fluids of the atmosphere and oceans.
Although computing power might allow us to do modelling in powerful new ways the integrity of the models is only as good as the specifications of the interactions between the components. Climate models are severely limited in this respect, despite the access to powerful computers.
Grant Petty said:
Even now (2004), however, a fully comprehensive treatment of radiation and other physical processes remains too complex a problem for the most powerful computers to tackle for the entire atmosphere at once. General circulation models therefore continue to rely on grossly simplified representations of these processes, with the attendant risk of error in the model's predictions. Finding ways to improve the accuracy and other physical parameterizations within the limits of available computing power is a major focus of current research in atmospheric science.
kerplunk said:
Even then there was no 'runaway' warming though, and it was hardly catastrophic.Ice age was worse for the planet.
Chicxulub is arguably the greatest catastrophe (certainly for the dinosuars!)
Ali G said:
kerplunk said:
Even then there was no 'runaway' warming though, and it was hardly catastrophic.Ice age was worse for the planet.
Chicxulub is arguably the greatest catastrophe (certainly for the dinosuars!)
). We're digressing from my point which was how exactly have you ruled out certain outcomes? Inundation by the sea was one of them so I wasn't really thinking as big as venus syndrome and you didn't say 'runaway' before but 'tipping points'. They are different things to my mind. A Venus runaway clearly hasn't happened before (as we're here) but climate tipping-points are everywhere (eg the sharp warming at the end of glacial periods in the ice-cores) which brings us back to my original 'a sensitive planet' comment.
kerplunk said:
A Venus runaway clearly hasn't happened before (as we're here) but climate tipping-points are everywhere
No, the reason Venus is where it is (temperature wise) is due to atmospheric composition, which is very very dry.Climate 'Tipping Point' is another phrase of ignorance - sorry.
Bedazzled said:
Slight tangent, I've been reading about extreme climate events in history and found an interesting account of severe cooling in 536AD thought to be caused by a volcanic dust cloud - see here. It was followed only a couple of years later by the Plague of Justinian (first black death pandemic)... not a nice time to be around.
Apparently the Vikings sacrificed all their gold to the Gods in a desperate plea for a better climate; nothing changes!
Have a read about the 1938 storm that hit New York.Apparently the Vikings sacrificed all their gold to the Gods in a desperate plea for a better climate; nothing changes!
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