General Climate Change Discussion.......

[Guest North Sea Snow Convection]

This a a climate CHANGE topic and as such climate may change to a warmer OR cooler setup. I think the point was being made is that every time someone tries to suggest that we are entering a cooler phase and we should consider the consequences of such a shift it always gets turned round as to why the poster doesn't agree with AGW. If the topic of Climate change is to be discussed properly then all possibilies should be up for grabs without forever returning to why you don't believe in AGW.

Some off us are open minded enough to believe that the signs are there to indicate that we maybe entering a significant cooling phase. We know that as yet there may not be enough scientific evidence to nail it but we are concerned enough to raise the poosibility because I can assure you the world will have significantly greater difficulty dealing with a cooling planet than a warming one.

Thank you - have a screen hug! lol can't find the real hug smilie!

Someone at last who has some idea of what I am trying to say.

You have also made the point about a cooling world posing potentially greater problems than a warming world (putting aside pretty fluffy snow flakes delights etc and personal likings for cold weather). That is expressly a centre piece of my own point too - and so on that basis why assume the only potential 'catastrophe' is associated with any interminable warming trend associated with AGW? Those assumptions continue to be pushed despite this point about other possible and different problems appearing instead that is being repeatedly made and largely failing to be accepted.

So the importance of not dismissing potential other feedbacks and causations is at least as valid than any banging on why someone disagrees with AGW and why this is so frowned upon.

AGW hypothesis btw does assume that CO2 et al overrides the natural processes. At least in terms of the positive feedbacks assumed to be at play to produce the alleged warming cycle. On the basis that these all exist and actually work as suggested by AGW'ers then the hypothesis does base its expectations that natural processes are all overriden.

Edited July 21, 2009 by North Sea Snow Convection

[Methuselah]

AGW hypothesis btw does assume that CO2 et al overrides the natural processes

No Tamara. It doesn't! It assumes no-such thing. It merely states that man-made CO₂ has exactly the same forcing effect as does its 'natural' counterpart...

[Guest North Sea Snow Convection]

No Tamara. It doesn't! It assumes no-such thing. It merely states that man-made CO₂ has exactly the same forcing effect as does its 'natural' counterpart...

there was more....

At least in terms of the positive feedbacks assumed to be at play to produce the alleged warming cycle. On the basis that these all exist and actually work as suggested by AGW'ers then the hypothesis does base its expectations that natural processes are all overriden

In other words CO2 is a vital catalyst in terms of the assumed relationship it has with temp in terms of producing cumulative heat in association with dominating and overriding positive feedbacks that exist exclusively within that relationship

Edited July 21, 2009 by North Sea Snow Convection

[weather eater]

This or something similar might have been posted before but it looks worth a post, I have yet to read all of it as we have guests round and I'm trying not to be anti social. Its a history of the study of CO2 in the atmosphere

[Methuselah]

there was more....

At least in terms of the positive feedbacks assumed to be at play to produce the alleged warming cycle. On the basis that these all exist and actually work as suggested by AGW'ers then the hypothesis does base its expectations that natural processes are all overriden

In other words CO2 is a vital catalyst in terms of the assumed relationship it has with temp in terms of producing cumulative heat in association with dominating and overriding positive feedbacks that exist exclusively within that relationship

Tamara, I sometimes wonder why I bothered studying Oceanography and Atmospheric Science. Because, the plethora of 'assumptions' you ascribe to me are quite new???

Anyway, maybe that's why I have never believed that AGW overrides all natural cycles. But, CO₂ is a GHG. That, I presume, is why 'as-yet undiscovered undersea volcanoes' were the sceptics' choice a few years back?

Every straw man has its counterpart, Tamara. Unfortunately, none of them achieves very much, IMO...

[jethro]

This or something similar might have been posted before but it looks worth a post, I have yet to read all of it as we have guests round and I'm trying not to be anti social. Its a history of the study of CO2 in the atmosphere

No link so could be assuming lots here....

How CO2 affects the atmosphere isn't an issue, it's accepted science, can't think of a sceptic on here who disputes it at all.

The contention focusses upon the feedbacks and how all the drivers act/interact with each other. Is the overall effect of increased CO2 one that super cedes natural negative feedback or will it merely hasten the onset of such cycles. The projections for the future all feature clouds and the hydrological cycle as a positive feedback, empirical observation is not supporting this assumption. It may sound trivial but clouds are incredibly important when trying to ascertain the radiative budget.

Pete....later.

[Guest North Sea Snow Convection]

Tamara, I sometimes wonder why I bothered studying Oceanography and Atmospheric Science. Because, the plethora of 'assumptions' you ascribe to me are quite new???

Anyway, maybe that's why I have never believed that AGW overrides all natural cycles. But, CO₂ is a GHG. That, I presume, is why 'as-yet undiscovered undersea volcanoes' were the sceptics' choice a few years back?

Every straw man has its counterpart, Tamara. Unfortunately, none of them achieves very much, IMO...

So AGW basing its hypothesis around the existence of positive feedbacks based on a relationship between CO2 and temp is something new?

If these positive feedbacks don't override natural processes then how exactly how else does it produce warming?

[weather eater]

No link so could be assuming lots here....

How CO2 affects the atmosphere isn't an issue, it's accepted science, can't think of a sceptic on here who disputes it at all.

The contention focusses upon the feedbacks and how all the drivers act/interact with each other. Is the overall effect of increased CO2 one that super cedes natural negative feedback or will it merely hasten the onset of such cycles. The projections for the future all feature clouds and the hydrological cycle as a positive feedback, empirical observation is not supporting this assumption. It may sound trivial but clouds are incredibly important when trying to ascertain the radiative budget.

Pete....later.

I'm a noob heres the link

http://www.aip.org/history/climate/co2.htm

[Thundery wintry showers]

This a a climate CHANGE topic and as such climate may change to a warmer OR cooler setup. I think the point was being made is that every time someone tries to suggest that we are entering a cooler phase and we should consider the consequences of such a shift it always gets turned round as to why the poster doesn't agree with AGW. If the topic of Climate change is to be discussed properly then all possibilies should be up for grabs without forever returning to why you don't believe in AGW.

Some off us are open minded enough to believe that the signs are there to indicate that we maybe entering a significant cooling phase. We know that as yet there may not be enough scientific evidence to nail it but we are concerned enough to raise the poosibility because I can assure you the world will have significantly greater difficulty dealing with a cooling planet than a warming one.

I see your point but unfortunately it also works the other way. My issue is that every time someone tries to suggest that we might be continuing within a warming phase with just a temporary blip, it always gets turned around as to why the poster agrees with AGW. Both sides of the argument are guilty of this.

A significantly cooling planet probably would indeed be more of a concern than a significantly warming one, although a cooling of 1 or 2C could probably be coped with, just as with a warming of 1-2C. However a substantial cooling over the course of the 21st century, though not impossible, appears much less likely than a substantial warming or a modest change in temperature either way.

So AGW basing its hypothesis around the existence of positive feedbacks based on a relationship between CO2 and temp is something new?

If these positive feedbacks don't override natural processes then how exactly how else does it produce warming?

In simplistic terms, the argument is that the increases in GHG concentrations cause the planet to adjust to a new equilibrium to keep the radiative balance in order, and that this new equilibrium is reached at a higher temperature. This is not a positive feedback mechanism in itself, although there may be positive feedbacks involved where more CO2 causes more warming which causes more CO2. However, past climates also suggest that there must be negative feedbacks in place to prevent this from becoming a runaway loop- as CO2 concentrations and temperatures have both been much higher in the past and we had no runaway feedback loop.

However given that CO2 concentrations and temperatures have both been much higher in the past than now, the talk of runaway warming in some quarters does seem rather OTT. What anthropogenic CO2 (and other GHG emissions) could do, though, is implement a rapid warming within the next few generations, which may be cancelled out by natural mechanisms on geological time scales, but prove dangerous for humans in the next century. Another possibility is that it could accelerate a move towards the next ice age.

[Methuselah]

So AGW basing its hypothesis around the existence of positive feedbacks based on a relationship between CO2 and temp is something new?

If these positive feedbacks don't override natural processes then how exactly how else does it produce warming?

Has CO₂ stopped being a GHG?

Of course there are feedbacks - both +ive and -ive; they are ubiquitous in nature and we don't yet fully understand them...But, no-one's claiming that together they override natural cycles. I think that augment is arguably a better word.

[weather eater]

I see your point but unfortunately it also works the other way. My issue is that every time someone tries to suggest that we might be continuing within a warming phase with just a temporary blip, it always gets turned around as to why the poster agrees with AGW. Both sides of the argument are guilty of this.

A significantly cooling planet probably would indeed be more of a concern than a significantly warming one, although a cooling of 1 or 2C could probably be coped with, just as with a warming of 1-2C. However a substantial cooling over the course of the 21st century, though not impossible, appears much less likely than a substantial warming or a modest change in temperature either way.

In simplistic terms, the argument is that the increases in GHG concentrations cause the planet to adjust to a new equilibrium to keep the radiative balance in order, and that this new equilibrium is reached at a higher temperature. This is not a positive feedback mechanism in itself, although there may be positive feedbacks involved where more CO2 causes more warming which causes more CO2. However, past climates also suggest that there must be negative feedbacks in place to prevent this from becoming a runaway loop- as CO2 concentrations and temperatures have both been much higher in the past and we had no runaway feedback loop.

However given that CO2 concentrations and temperatures have both been much higher in the past than now, the talk of runaway warming in some quarters does seem rather OTT. What anthropogenic CO2 (and other GHG emissions) could do, though, is implement a rapid warming within the next few generations, which may be cancelled out by natural mechanisms on geological time scales, but prove dangerous for humans in the next century. Another possibility is that it could accelerate a move towards the next ice age.

Either way a potential lose lose situation, I too would support the notion that its possible to tip the other way towards an ice age and Tamara’s right that does invite catastrophe for many of the earth inhabitants maybe more so than warming and especially for us.

[Admiral_Bobski]

I was looking up Arrhenius online and found some interesting stuff.

Arrhenius' high absorption values for CO2, however, met criticism by Knut Ångström in 1900, who published the first modern infrared spectrum of CO2 with two absorption bands.

Knut Ångström was a Swedish physicist who "especially devoted himself to investigations of the radiation of heat from the sun and its absorption by the earth's atmosphere."

I found this article from the Monthly Weather Review of June 1901:

http://docs.lib.noaa.gov/rescue/mwr/029/mwr-029-06-0268a.pdf

I shall leave you all with that for a while, and I shall follow this paper-trail further...!

CB

EDIT - The reason I'm following this up is because Angstrom's comments were in refutation of the principles underlying Arrhenius's greenhouse law (ΔF = α ln(C/C02) ), which is still in use today.

Edited July 21, 2009 by Captain_Bobski

[weather eater]

Has CO₂ stopped being a GHG?

Of course there are feedbacks - both +ive and -ive; they are ubiquitous in nature and we don't yet fully understand them...But, no-one's claiming that together they override natural cycles. I think that augment is arguably a better word.

Seems to me that the natural cycles would continue but might be altered in duration, intensity and so on. however given the time scales of some of these cycles coupled with a limited knowledge of know climate cycles and the possibility that others remain undiscovered we might never know the extent to which they have been altered.

Nobody has yet to explain to me why the scientific theory’s behind natural cycles is believed without question but when the same scientists put forward their theory’s about AGW they are dismissed as hopelessly flawed or exaggerated., its often implied that they have failed to take natural cycles into consideration this seems to me to be highly unlikely. I’ve asked this question several time before and nobody on the sceptics side of the argument seems to want to respond.

I was looking up Arrhenius online and found some interesting stuff.

Arrhenius' high absorption values for CO2, however, met criticism by Knut Ångström in 1900, who published the first modern infrared spectrum of CO2 with two absorption bands.

Knut Ångström was a Swedish physicist who "especially devoted himself to investigations of the radiation of heat from the sun and its absorption by the earth's atmosphere."

I found this article from the Monthly Weather Review of June 1901:

http://docs.lib.noaa.gov/rescue/mwr/029/mwr-029-06-0268a.pdf

I shall leave you all with that for a while, and I shall follow this paper-trail further...!

CB

See my link earlier there's some stuff on it there

[Admiral_Bobski]

See my link earlier there's some stuff on it there

I was actually looking at your link when I decided to check this out!

(I haven't read it for a while, but I know that page is one of Dev's favourites!)

CB

[Methuselah]

I was looking up Arrhenius online and found some interesting stuff.

Arrhenius' high absorption values for CO2, however, met criticism by Knut Ångström in 1900, who published the first modern infrared spectrum of CO2 with two absorption bands.

Knut Ångström was a Swedish physicist who "especially devoted himself to investigations of the radiation of heat from the sun and its absorption by the earth's atmosphere."

I found this article from the Monthly Weather Review of June 1901:

http://docs.lib.noaa.gov/rescue/mwr/029/mwr-029-06-0268a.pdf

I shall leave you all with that for a while, and I shall follow this paper-trail further...!

CB

Thank you, CB. My eyes are still watering!

Not wanting to pick nits, but is there anything a tad more contemporary???

[Admiral_Bobski]

Thank you, CB. My eyes are still watering!

Not wanting to pick nits, but is there anything a tad more contemporary???

I'm sure there's plenty of stuff that's more contemporary, but I suddenly had my interest piqued by the thought of starting right at the beginning of the story

Although the link that Weather Eater posted refutes Angstrom's conclusion, I thought I'd see if I could follow the argument through to the end with actual scientific studies.

It seems to me that an absolutely crucial point with regards to AGW is whether or not Arrhenius's law is actually valid. Angstrom said that it wasn't (and he was a physicist whose field of expertise was "investigations of the radiation of heat from the sun and its absorption by the earth's atmosphere"), so I thought I'd have a root around and see how his objections were refuted, and if those refutations were actually valid or not.

I'm sure there'll be plenty more to follow! If it gets really interesting then I might start a new thread for it (but I think it would be premature to start one right now!).

CB

[Methuselah]

Seems to me that the natural cycles would continue but might be altered in duration, intensity and so on. however given the time scales of some of these cycles coupled with a limited knowledge of know climate cycles and the possibility that others remain undiscovered we might never know the extent to which they have been altered.

Nobody has yet to explain to me why the scientific theorys behind natural cycles is believed without question but when the same scientists put forward their theorys about AGW they are dismissed as hopelessly flawed or exaggerated., its often implied that they have failed to take natural cycles into consideration this seems to me to be highly unlikely. Ive asked this question several time before and nobody on the sceptics side of the argument seems to want to respond.

I entriely agree with your first paragraph, WE.

On the subject of 'natural cycles' things are less clear, however: yes, the Earth's tilt changes cyclically, as does its proximity to the Sun; (see Milankovitch and Croll) the same can be said of ENSO, QBO etc. But, there's nothing cyclical about plate tectonics, they just happen.

As far as I understand AGW, it can either add to or subtract from whatever nature is doing: if we are in natural warming phase then AGW will accelerate it and, if in a cooling phase will decelerate it.

What I find a shame, is that extreme sceptics make the facile assumption that those of us that accept the AGW theory, of necessity, dismiss anything natural. Such an assumption is nonsense!

Edited July 21, 2009 by Pete Tattum

[weather eater]

I'm sure there's plenty of stuff that's more contemporary, but I suddenly had my interest piqued by the thought of starting right at the beginning of the story

Although the link that Weather Eater posted refutes Angstrom's conclusion, I thought I'd see if I could follow the argument through to the end with actual scientific studies.

It seems to me that an absolutely crucial point with regards to AGW is whether or not Arrhenius's law is actually valid. Angstrom said that it wasn't (and he was a physicist whose field of expertise was "investigations of the radiation of heat from the sun and its absorption by the earth's atmosphere"), so I thought I'd have a root around and see how his objections were refuted, and if those refutations were actually valid or not.

I'm sure there'll be plenty more to follow! :lol: If it gets really interesting then I might start a new thread for it (but I think it would be premature to start one right now!).

CB

If you find anything interesting slap it up, as I said my link was most likely old hat. Seems to me the trap that’s easy to fall into is to except the theory’s of which ever scientist or group of scientist’s that fit most with ones own natural inclinations, it works both ways. I can’t speak for others who think AGW theory is most likely sound, but I for one would love to be wrong, we don’t want warming we don’t want ice cap melt, sea rises etc. some decent winters would be a grand thing at nearly 50 these seem increasingly like memories of my child hood.

[Admiral_Bobski]

If you find anything interesting slap it up, as I said my link was most likely old hat. Seems to me the trap that’s easy to fall into is to except the theory’s of which ever scientist or group of scientist’s that fit most with ones own natural inclinations, it works both ways. I can’t speak for others who think AGW theory is most likely sound, but I for one would love to be wrong, we don’t want warming we don’t want ice cap melt, sea rises etc. some decent winters would be a grand thing at nearly 50 these seem increasingly like memories of my child hood.

I will certainly keep you posted.

CB

[Iceberg]

Just to say Hadley is finally out for last month and is the 3rd warmest June on record and compares well with the NCDC 2nd warmest and GISS 2nd warmest.

Pretty good consensus there for a very hot month globally. Maybe I should be posting this in the Global Cooling thread ; )

[osmposm]

I’m quite prepared to go along with the idea that AGW might not cause a catastrophe its by no means certain although I rather suspect that for the developed world, anything, as long as it does not effect us too much, would be seen as a non event, for it to be a true catastrophe, it must be so for the developed word and not just the third world. It seems to me that the dangers posed by not limiting the environmental impacts of our actions outweigh the impacts of making some efforts to do so, of course this is a double edged sword, do we have the right to hold back the developing world, in effect saying to them, we have lead the high life but you must sacrifice doing so for the benefits of us.

TWS has it right as far as I see it, we cannot wait in the road to be killed by a car to prove it could happen. History is I'm afraid littered with disasters caused by wait and see policies and inaction, we knew about theory’s that smoking caused lung cancer years before we did anything about it, black propaganda by the tobacco industry played a huge role in that and millions have died needlessly as a result, there are many people, who in the teeth of the evidence still don’t want to believe it......

The problem with the tobacco analogy is that - contrary to received wisdom - a large majority of smokers never get lung cancer. I've just calculated my risk as a 40 years smoker at age 58 - it's 4% of developing it in the next decade (dropping to 3% if I give up now). If I go with that 96% chance of not getting it, and survive till I'm 68, for the next decade it then rises to 8% if I carry on - i.e. a 92% chance that I won't. So I have overall an 88% chance of making it to age 78 without developing the disease - one year older than my father who never smoked and died particularly unpleasantly of leukemia at 77. His father, on the other hand, smoked a great deal, and did die of lung cancer.....but not till he was 81! We all have to die of something, and I'm not sure I wouldn't prefer a fastish, if unpleasant exit at 75, to my mother's ten-year bed-ridden, doubly-incontinent, increasingly-demented slide to a blessed release at 85.

So smoking & lung cancer was a very different kettle of fish. The consequences of doing nothing about it were really not that catastrophic - people who did so (or do so) die perhaps 10% younger on average than they might otherwise have done, that's all. The financial cost to the country - again contrary to popular wisdom - was/is negligible or negative, since not only did smokers pay 25% of the NHS's entire 1998 budget in excise duty (more like 10% now with fewer smokers and a vastly more expensive health service), but they save the country a staggering amount in senile dementia care (they die before they get it) and pension payments (a shorter life).

If - IF - our current actions are heading us towards climate catastrophe, the consequences would be rather more profound for rather more people - both directly on the ability of many in the undeveloped world to live their lives at all, and indirectly in the costs to the economies of many of even the word's richest countries.

But I'm afaid that's really an "in praise of smoking" post masquerading as one on Climate Change!? Mods, if ever I deserved to be deleted it is now.....

[weather eater]

I entriely agree with your first paragraph, WE.

On the subject of 'natural cycles' things are less clear, however: yes, the Earth's tilt changes cyclically, as does its proximity to the Sun; (see Milankovitch and Croll) the same can be said of ENSO, QBO etc. But, there's nothing cyclical about plate tectonics, they just happen.

As far as I understand AGW, it can either add to or subtract from what nature is doing: if we are in natural warming phase then AGW will accelerate it and, if in a cooling phase will decelerate it.

What I find a shame, is that extreme sceptics make the facile assumption that those of us that accept the AGW theory, of necessity, dismiss anything natural. Such an assumption is nonsense!

Hi Pete yes I know of those cycles, I have some good books on the subject, the problem remains either the scientists have a clue about what they are talking about or the science is likely to be flaky to one degree or another in regards both AGW and natural cycles. What I do find a worry is that in all of the books that I have read in regards natural cycles, is that they all seem to indicate that climate changes can be dynamic and sudden, add to this the possibility that we are having a significant effect on climate we could see very swift changes in a very short space of time.

[Thundery wintry showers]

Nobody has yet to explain to me why the scientific theory’s behind natural cycles is believed without question but when the same scientists put forward their theory’s about AGW they are dismissed as hopelessly flawed or exaggerated., its often implied that they have failed to take natural cycles into consideration this seems to me to be highly unlikely. I’ve asked this question several time before and nobody on the sceptics side of the argument seems to want to respond.

My understanding is that the scientists do take natural cycles into consideration, but that many of them are poorly understood and poorly represented in climate models (which form the main basis for making projections into the 21st century).

The IPCC's temperature rise graphs do not appear to take natural cycles into consideration but I think that's for purposes of simplification so that the graphs are easy to digest and the main point gets across. Natural variability will, of course, be superimposed on any warming trend, be it due to AGW or something else, but that is difficult to represent on a graph. However perhaps the IPCC should be more vocal in saying "natural variability will occur either side of the mean" to cover their backsides against people assuming that they've presented AGW as over-riding everything else.

[weather eater]

The problem with the tobacco analogy is that - contrary to received wisdom - a large majority of smokers never get lung cancer. I've just calculated my risk as a 40 years smoker at age 58 - it's 4% of developing it in the next decade (dropping to 3% if I give up now). If I go with that 96% chance of not getting it, and survive till I'm 68, for the next decade it then rises to 8% if I carry on - i.e. a 92% chance that I won't. So I have overall an 88% chance of making it to age 78 without developing the disease - one year older than my father who never smoked and died particularly unpleasantly of leukemia at 77. His father, on the other hand, smoked a great deal, and did die of lung cancer.....but not till he was 81! We all have to die of something, and I'm not sure I wouldn't prefer a fastish, if unpleasant exit at 75, to my mother's ten-year bed-ridden, doubly-incontinent, increasingly-demented slide to a blessed release at 85.

So smoking & lung cancer was a very different kettle of fish. The consequences of doing nothing about it were really not that catastrophic - people who did so (or do so) die perhaps 10% younger on average than they might otherwise have done, that's all. The financial cost to the country - again contrary to popular wisdom - was/is negligible or negative, since not only did smokers pay 25% of the NHS's entire 1998 budget in excise duty (more like 10% now with fewer smokers and a vastly more expensive health service), but they save the country a staggering amount in senile dementia care (they die before they get it) and pension payments (a shorter life).

If - IF - our current actions are heading us towards climate catastrophe, the consequences would be rather more profound for rather more people - both directly on the ability of many in the undeveloped world to live their lives at all, and indirectly in the costs to the economies of many of even the word's richest countries.

But I'm afaid that's really an "in praise of smoking" post masquerading as one on Climate Change!? Mods, if ever I deserved to be deleted it is now.....

Very good, you smoke to your hearts content, I don’t and never have, can’t stand the taste or smell and although I don’t want to smoke your fags by proxy what you do on the street or in your home car etc is your business, the point I was trying to make was that there is a link between smoking and cancer, heart disease, etc and for years we where told the evidence is inconclusive, I was not comparing it to AGW as a potential world wide killer.

[Methuselah]

Hi Pete yes I know of those cycles, I have some good books on the subject, the problem remains either the scientists have a clue about what they are talking about or the science is likely to be flaky to one degree or another in regards both AGW and natural cycles. What I do find a worry is that in all of the books that I have read in regards natural cycles, is that they all seem to indicate that climate changes can be dynamic and sudden, add to this the possibility that we are having a significant effect on climate we could see very swift changes in a very short space of time.

I don't pretend to be an expert on paeleoclimatic things, WE. But, since Pangea and Gondwanaland broke up, things changed gradually over many millennia, such that, now, Antarctica is isolated by the Circumpolar Current and the Arctic Ocean is (almost) landlocked.

Now, assuming (?) that Milankovitch cycles carry on regardless - the Earthly cycles, that in the geological past were 'warm' and 'less warm' periods - are now Glacials and Interglacials???

I don't know, mate. A lot is guesswork!

Hi Pete yes I know of those cycles, I have some good books on the subject, the problem remains either the scientists have a clue about what they are talking about or the science is likely to be flaky to one degree or another in regards both AGW and natural cycles. What I do find a worry is that in all of the books that I have read in regards natural cycles, is that they all seem to indicate that climate changes can be dynamic and sudden, add to this the possibility that we are having a significant effect on climate we could see very swift changes in a very short space of time.

I don't pretend to be an expert on paeleoclimatic things, WE. But, since Pangea and Gondwanaland broke up, things changed gradually over many millennia, such that, now, Antarctica is isolated by the Circumpolar Current and the Arctic Ocean is (almost) landlocked.

Now, assuming (?) that Milankovitch cycles carry on regardless - what, in the geological past, were 'warm' and 'less warm' periods, are now Ice-Ages and Interglacials???

I don't know, mate. A lot is guesswork! :lol:

Hi Pete yes I know of those cycles, I have some good books on the subject, the problem remains either the scientists have a clue about what they are talking about or the science is likely to be flaky to one degree or another in regards both AGW and natural cycles. What I do find a worry is that in all of the books that I have read in regards natural cycles, is that they all seem to indicate that climate changes can be dynamic and sudden, add to this the possibility that we are having a significant effect on climate we could see very swift changes in a very short space of time.

I don't pretend to be an expert on paeleoclimatic things, WE. But, since Pangea and Gondwanaland broke up, things changed gradually over many millennia, such that, now, Antarctica is isolated by the Circumpolar Current and the Arctic Ocean is (almost) landlocked.

Now, assuming (?) that Milankovitch cycles carry on regardless - what, in the geological past, were 'warm' and 'less warm' periods, are now Ice-Ages and Interglacials???

I don't know, mate. A lot is guesswork!