Ice age on the way (merged threads)

[The Eagle]

TBH id be chuffed with another below average CET. :unsure:

[Guest Viking141]

Okay, Im only just getting into this subject myself so It'll take time. But heres a few bits and bobs to be going on with. Im sure summer blizzard will be able to pitch in with plenty of stuff as he's much more up on this than me!

USGS info sheet

Solar variation

Maunder Minimum

It'll take some time to wade through the plethora of stuff thats out there on this subject! That said, if the theory holds good then we will see the effects with our own eyes in the not too distant future. After the solar maxima in 2011 to be precise. After that we should be heading towards much colder weather.

[parmenides3]

I'm not Viking, but I will say that the atmosphere is a chaotic system and that there are all kinds of things that could possibly sway the balance towards cooling. Humans still have a lot to learn about atmosphere and climate.

The evidence strongly points towards continued warming, but we can only predict the future, not foretell it. So the most we can say is that the warming is likely to continue.

Absolutely, TWS! I hope that one of the things we are doing on these posts is trying to work out what is likely, what is possible, and what is not credible; hence the challenge to Viking. I'll happily concede that a period of cooling coinciding with changes in solar irradiance is possible, when anybody provides me with the evidence, or, at the least, a reasonable hypothesis. Please consider all challenges and demands on this strand as searches for truth, not (ever) personal challenges about people's beliefs.

My claim would be that we can say with a good degree of certainty that the warming will continue, but concede that there may be unforeseen circumstances which might prevent this; the question is, which circumstances might, or might not, be even possible, let alone likely. This is my challenge.

:unsure: P

[Guest Viking141]

Heres another thought guys. Its all very well us looking at things like the Gleissberg Minima etc in isolation but has anyone consider the effects of two or more of these events happening together?

For example, what would be the likely effect of the Gleissberg Minima (due in 2030) AND a THC shutdown about the same time?

Usually anything from the smallest accident to the biggest cataclysm does not occur because of one event, they are usually as a result of several not necessarily connected events which, when combined, lead to a particular outcome. So as I said, would anyone care to hypothesise what could happen if we had a combination of the effects of the Gleissberg Minima and a THC shutdown happening in the same time scale (ie the next 20-odd years) both of which, IMO, are at least possible if not likely.

BTW P3 I take your challenges as they are intended Im just trying to make some sense of all this! I never take them as anything personal - more as a stimulant to a better understanding.

:unsure:

[Stratos Ferric]

However, he does, like it or not, have a point of sorts. Not an Ice Age but certainly the approach of, as summer blizzard, has pointed out, the Gleissberg Minima. And whats more we shall all find out in the next few years. Major cold ahead folks and in our lifetime.

Global Warming is not the only game in town, as much as some people would like it to be. There are some on here who are as much a "stuck record" about GW as Daniel is about his "Ice Age Cometh." It doesnt matter what part of the spectrum you come from a blinkered view is a blinkered view. I fully accept that GW is a fact and that humans are playing a role in that. What I do not accept is that there are not other things which could come along and undo all that - for example a 70-odd year spell of severe cold a la Maunder Minimum which could be just around the corner.

That's all quite fair, but all of the established cycles are just that, established. There is NOTHING of which I am aware that is just around the corner (in a sense of 'in my lifetime' rather than in the sense of geological epochs if you please) by way of cold forcing. The main difference on N-W between the stubbornly cold and the acceptingly warm is the weight of scientific evidence. Those of us, and I cound myself amongst them, who support the warming trend are not on the whole attached one way or the other, we are just going with the facts and the evidence. I am certainly willing to be swung by other thoeries, but whilst theory is all there is the global ice mass continues to diminish in the face of reality.

[crimsone]

I'm not Viking, but I will say that the atmosphere is a chaotic system and that there are all kinds of things that could possibly sway the balance towards cooling. Humans still have a lot to learn about atmosphere and climate.

I'm sorry TWS, but I couldn't resist, in spite of agreeing with the above quote, I just had to go and simplify it to a seemingly rediculous proposal...

If a butterfly flaps it's wings on one side of the world, it might start an iceage in Scotland :unsure:

[Thundery wintry showers]

I think that's known as "chaos theory"... :unsure:

[Guest Viking141]

That's all quite fair, but all of the established cycles are just that, established. There is NOTHING of which I am aware that is just around the corner (in a sense of 'in my lifetime' rather than in the sense of geological epochs if you please) by way of cold forcing. The main difference on N-W between the stubbornly cold and the acceptingly warm is the weight of scientific evidence. Those of us, and I cound myself amongst them, who support the warming trend are not on the whole attached one way or the other, we are just going with the facts and the evidence. I am certainly willing to be swung by other thoeries, but whilst theory is all there is the global ice mass continues to diminish in the face of reality.

Indeed. But that does not mean that something could not possibly come along and alter all that just because the current weight of evidence points us in another direction. Im also somewhat bemused by those (im not saying youre one of them BTW) who will only accept an idea as long as there is proof. What I mean by that is there seem to be a lot of people on this board who follow the idea that an idea can only be possible if it is scientifically proven beyond all reasonable doubt and that EVENT follows PROOF. Unfortunately our planet has a history of non-conformity to those rules and that quite often the opposite is the case PROOF follows EVENT. We only see the full scientific reality of something AFTER it has happened and we have had a chance to pick apart what led up to this event and are able to explain scientifically how this could have occured, and even then we are not particulary good at that sometimes! Climactic events which happened in the earths past still confound our best scientific brains today.

What I am saying is that as regards the climate of this planet we are not in a court of law where things can be proven beyond all reasonable doubt. Our climate is, as TWS has pointed out, chaotic and now matter how hard we try to rationalise it it will always spring unexpected surprises on us - if there is anything certain about our planets climate it is its uncertainty!

:unsure:

[Devonian]

Indeed. But that does not mean that something could not possibly come along and alter all that just because the current weight of evidence points us in another direction. Im also somewhat bemused by those (im not saying youre one of them BTW) who will only accept an idea as long as there is proof. What I mean by that is there seem to be a lot of people on this board who follow the idea that an idea can only be possible if it is scientifically proven beyond all reasonable doubt and that EVENT follows PROOF. Unfortunately our planet has a history of non-conformity to those rules and that quite often the opposite is the case PROOF follows EVENT. We only see the full scientific reality of something AFTER it has happened and we have had a chance to pick apart what led up to this event and are able to explain scientifically how this could have occured, and even then we are not particulary good at that sometimes! Climactic events which happened in the earths past still confound our best scientific brains today.

What I am saying is that as regards the climate of this planet we are not in a court of law where things can be proven beyond all reasonable doubt. Our climate is, as TWS has pointed out, chaotic and now matter how hard we try to rationalise it it will always spring unexpected surprises on us - if there is anything certain about our planets climate it is its uncertainty!

:o

Chaos, it's the bane of climatology forums :unsure: . I don't fully understand it, but I do know that to say our climate is chaotic and therefore anything can happen is wrong. Climate obeys the laws of physics. So do ghg's. Unless something comes along to 'force' the climate in another direction it will warm (by an ammount not fully known) because of anthro ghgs. That something wont arise becuase of chaos in the climate system. It will be either a huge volcanic eruption, a massive meteorite, or a cooling of the sun, or some a yet missed but nevertheless a vast climate forcing (err, how do you miss something vast?). None of those things are 'chaotic'.

Edited August 29, 2006 by Devonian

[Thundery wintry showers]

It's not necessarily that simple, for example when the climate is warmed, various positive and negative feedback mechanisms come into play, some of which are poorly understood and could accentuate the warming, or even result in a cooling.

If humans are contributing to the warming (which is highly likely), then the "rules" for how the climate shifts may be different to some extent than was the case with previous climate changes, e.g. changes of albedo due to land use, loss of Amazon rainforest, increased concentration of GHGs relative to what one would expect for the current climate state, etc. It's in this area that we have uncertainty.

The evidence we have at the moment suggests continued warming for the foreseeable future, but there may be more that we still have to know that could suggest otherwise, that's the main point- we don't know everything. Although when we do find new discoveries, there's every bit as much chance that our findings will point to even more warming as there is for reduced warming or a cooling- hence the best guess estimate being that the world will warm up at within the IPCC estimate range.

[Stratos Ferric]

Chaos, it's the bane of climatology forums :unsure: . I don't fully understand it, but I do know that to say our climate is chaotic and therefore anything can happen is wrong. Climate obays the laws of physics. So do ghg's. Unless something comes along to 'force' the climate in another direction it will warm (by an ammount not fully known) because of anthro ghgs. That something wont arise becuase of chaos in the climate system. It will be either a huge volcanic eruption, a massive meteorite, or a cooling of the sun, or some a yet missed but vast climate forcing (err, how do you miss something vast?). None of those things are 'chaotic'.

Dev,

I suspect, having read another post a few minutes ago that used the word, that different meanings are attaching here. I'm assuming that with your implied knoweldge of physics you're aware of, say, the chaos of drips falling from a tap, as opposed to the chaos of day to day variation in weather, the use of which owes more to Hardy than it does to Einstein.

I agree with your post; sudden change in our climate must come from forcing - which is absolutely not chaotic in the physical sense of the word (or at least we have far too little data to prove that it is). Reference Viking's post regarding theories, I think you're simply reitterating my point previously, albeit with slightly different emphasis perhaps. Theories are fine, but judgement has to based on more evidence than that. When I drive my car around a corner, experience tells me how quickly I can do so without coming off the road, and I can apply that experience to a whole host of different corners, driving faster or slower according to the data available. I'd need to be in a whole new machine on a whole new surface before I'd ever take my foot off the brake, and I wouldn't do so merely as an experiment. You can tell me about compund tyres and high grip surfaces, but I'd want to see them working first.

The global system has huge inertia in it, Devonian is quite right. There would need to be the equivalent of a hole in the road to stop me around that metaphorical corner, and something of the same order of scale and surprise would probably be needed to force the current trend in our climate.

It's not necessarily that simple, for example when the climate is warmed, various positive and negative feedback mechanisms come into play, some of which are poorly understood and could accentuate the warming, or even result in a cooling.

If humans are contributing to the warming (which is highly likely), then the "rules" for how the climate shifts may be different to some extent than was the case with previous climate changes, e.g. changes of albedo due to land use, loss of Amazon rainforest, increased concentration of GHGs relative to what one would expect for the current climate state, etc. It's in this area that we have uncertainty.

The evidence we have at the moment suggests continued warming for the foreseeable future, but there may be more that we still have to know that could suggest otherwise, that's the main point- we don't know everything. Although when we do find new discoveries, there's every bit as much chance that our findings will point to even more warming as there is for reduced warming or a cooling- hence the best guess estimate being that the world will warm up at within the IPCC estimate range.

The detail of impact may well vary, which is why the NAD cut-off theory, and the assumption that this leads to cooling in NW Europe, is highly localised and specific. The fact remains that if we accept that current warming in some measure results from a change in the basic thermal capacity of the planet then warming is the overall way forward until something dramatic happens to change the absorbed vs reradiated equation.

[Guest Viking141]

It's not necessarily that simple, for example when the climate is warmed, various positive and negative feedback mechanisms come into play, some of which are poorly understood and could accentuate the warming, or even result in a cooling.

If humans are contributing to the warming (which is highly likely), then the "rules" for how the climate shifts may be different to some extent than was the case with previous climate changes, e.g. changes of albedo due to land use, loss of Amazon rainforest, increased concentration of GHGs relative to what one would expect for the current climate state, etc. It's in this area that we have uncertainty.

The evidence we have at the moment suggests continued warming for the foreseeable future, but there may be more that we still have to know that could suggest otherwise, that's the main point- we don't know everything. Although when we do find new discoveries, there's every bit as much chance that our findings will point to even more warming as there is for reduced warming or a cooling- hence the best guess estimate being that the world will warm up at within the IPCC estimate range.

Quite so TWS. Devonian - perhaps the word "chaos" was a poor choice - unpredictable might have been better. Nevertheless what I am saying is true, no matter how hard we try to predict future climate based on current evidence it does not necessarily follow that because that evidence says "warm" at the moment that something either unexpected or unaccounted for in our calculations, could come along and push things in a direction we didnt expect. Our history as humans is absolutely littered with people who have followed a particular line of reasoning because thats what the evidence suggested to them at the time, only to have it all blow up in their faces (metaphorically speaking!) As you point out TWS - we dont know everything. We like to think we do but we dont.

:unsure:

[Devonian]

Quite so TWS. Devonian - perhaps the word "chaos" was a poor choice - unpredictable might have been better. Nevertheless what I am saying is true, no matter how hard we try to predict future climate based on current evidence it does not necessarily follow that because that evidence says "warm" at the moment that something either unexpected or unaccounted for in our calculations, could come along and push things in a direction we didnt expect. Our history as humans is absolutely littered with people who have followed a particular line of reasoning because thats what the evidence suggested to them at the time, only to have it all blow up in their faces (metaphorically speaking!) As you point out TWS - we dont know everything. We like to think we do but we dont.

We don't know everything 'tis true. Why does that mean that if something unexpected comes along it's not as likely to be something that enhances any anthro warming?

Dev,

I suspect, having read another post a few minutes ago that used the word, that different meanings are attaching here. I'm assuming that with your implied knoweldge of physics you're aware of, say, the chaos of drips falling from a tap, as opposed to the chaos of day to day variation in weather, the use of which owes more to Hardy than it does to Einstein.

Nope, not studied 'chaos' to any high level, I've just read a bit and I know what I agree with. Imo, climate isn't utterly chaotic. I think can quite accurately predict next year's CET - I predict it will be between 8 and 11C. I guess I've better than a, what, 90% chance of being right?

I agree with your post; sudden change in our climate must come from forcing - which is absolutely not chaotic in the physical sense of the word (or at least we have far too little data to prove that it is). Reference Viking's post regarding theories, I think you're simply reitterating my point previously, albeit with slightly different emphasis perhaps. Theories are fine, but judgement has to based on more evidence than that. When I drive my car around a corner, experience tells me how quickly I can do so without coming off the road, and I can apply that experience to a whole host of different corners, driving faster or slower according to the data available. I'd need to be in a whole new machine on a whole new surface before I'd ever take my foot off the brake, and I wouldn't do so merely as an experiment. You can tell me about compund tyres and high grip surfaces, but I'd want to see them working first.

The global system has huge inertia in it, Devonian is quite right. There would need to be the equivalent of a hole in the road to stop me around that metaphorical corner, and something of the same order of scale and surprise would probably be needed to force the current trend in our climate.

The detail of impact may well vary, which is why the NAD cut-off theory, and the assumption that this leads to cooling in NW Europe, is highly localised and specific. The fact remains that if we accept that current warming in some measure results from a change in the basic thermal capacity of the planet then warming is the overall way forward until something dramatic happens to change the absorbed vs reradiated equation.

Yup, I agree

Edited August 29, 2006 by Devonian

[parmenides3]

Some of you may be interested in 'Chaos and Climate', by Annan & Connolley

http://www.realclimate.org/index.php/archi...os-and-climate/

In the article, James Annan explains the difference between weather forecasting and climate modelling with respect to chaos theory. Basically; forecasting weather, because of perturbation, is difficult. Forecating climate, however, is not. This is why some of you are correct in saying that a forcing or feedback - probably, in the case we are considering, a forcing, would have to be totally unexpected/unknown as yet. That such unknowns might exist is a possibility, but what they might be, and how they might work, is the essence of our problem, here.

Please note also: I am not asking for proof, as such, only a well-founded hypothesis. Any suggestions?

P

[Thundery wintry showers]

We don't know everything 'tis true. Why does that mean that if something unexpected comes along it's not as likely to be something that enhances any anthro warming?

I actually mentioned that in my post- I did say that if we find new evidence, it's every bit as likely to suggest enhanced warming as reduced warming or a cooling.

I don't think I can think of a hypothesis- I haven't seen anything myself that suggests that the Earth is likely to cool down shortly, except as a temporary blip. But if a possibility A cannot be proven true or untrue, that doesn't make it untrue. I tend to think that the evidence is already strong enough that it's worth taking action anyway.

[Guest Viking141]

We don't know everything 'tis true. Why does that mean that if something unexpected comes along it's not as likely to be something that enhances any anthro warming?

Nope, not studied 'chaos' to any high level, I've just read a bit and I know what I agree with. Imo, climate isn't utterly chaotic. I think can quite accurately predict next year's CET - I predict it will be between 8 and 11C. I guess I've better than a, what, 90% chance of being right?

Yup, I agree

I agree, it could be that something comes along that enhances the warming rather than cooling, I fully accept that. I just happen to believe that cooling is on the cards.

That said, the point Im trying to make is that there appear to be some on this board who, because the current trend is for warming, believe that that is what will happen, it is pre-ordained and ever more shalt be-oh. I dont accept that for one moment.

Stratos - agreed it would need to be a helluva big hole in the road but just because that is so does not mean it is unlikely to happen. Things like that have happened in the past and there is no reason to suggest they wont happen again. Doesnt have to be that enormous either, if the Gleissberg Minima lives up to expectations it could put an enormous dent in the current warming trend.

[crimsone]

Well, I think the "chaos" definition mixup was my fault, and I'm about to do it again.

If a butterfly flapping it's wings causes an iceage in Scotland, it might cause a Saharan drought in Portugal.

With Chaos theory, (though I'm no authority on it) as far as I understand the implication is that even though the basic laws of physics have to be followed, a minor event (such as a butterfly flapping its wings) can set off a chain reaction. The effects of that chain reaction could skew the results of a given known process one way or the other to varying degrees and in various ways depending on the orientation of the initial event to the reaction and end result.

For a nonsensical but explanatory example, if that butterfly was in Scotland, flapping east/west could send a self propagating domino effect around the planet which could resonate like a bell on the otherside and bring back something quite severe to Scotland on it's return in the form of severe weather.On the other hand, the same flap might potentially cancel out any severe weather that scotland should have, bringing unusually mild conditions instead. If it was oriented about the polar axis, it migh skew a delecate mild system into either extreme hot, or extreme cold. In effect, it all depends on what systems are being effected, and the way the effects (in accordance with the natural laws of physics) propogate, not to mention the way in which things are affcted in accordance with the prevailing conditions of that moment.

In short, crazy things can happen, but they don't happen very often on any extreme scale. What we do know though is that when a crazy and unexpected scenario does unfold, we wouldn't be able to pin it down to that butterfly, and so it might at least seem like the laws of physics have been broken through our lack of understanding.

Just in case anybody wondered what that lot was about, it was pretty much a demonstration that we don't know everything, and even though human kind sometimes thinks it does, we can and will be caught unawares by something beyond our meagre awareness. There is no certainty - only probability (a bit like quantum physics that! lol).

Even though I'm the only one to use "chaos" as a reference to the completely differently intended "chaos theory", it still kinda brings it's own little point. Don't ask me to discuss this post in any depth though, because I'll admit even now that I'm really not capable of doing so.

Edited August 29, 2006 by crimsone

[Devonian]

I actually mentioned that in my post- I did say that if we find new evidence, it's every bit as likely to suggest enhanced warming as reduced warming or a cooling.

I don't think I can think of a hypothesis- I haven't seen anything myself that suggests that the Earth is likely to cool down shortly, except as a temporary blip. I tend to think that the evidence is already strong enough that it's worth taking action anyway.

Sorry, I'm guilty of not reading everything

Some of you may be interested in 'Chaos and Climate', by Annan & Connolley

http://www.realclimate.org/index.php/archi...os-and-climate/

In the article, James Annan explains the difference between weather forecasting and climate modelling with respect to chaos theory. Basically; forecasting weather, because of perturbation, is difficult. Forecating climate, however, is not. This is why some of you are correct in saying that a forcing or feedback - probably, in the case we are considering, a forcing, would have to be totally unexpected/unknown as yet. That such unknowns might exist is a possibility, but what they might be, and how they might work, is the essence of our problem, here.

Please note also: I am not asking for proof, as such, only a well-founded hypothesis. Any suggestions?

P

I remember that.

I also remember thinking that chaos seems to be a problem with not knowing the initial conditions when running models - so small errors build up.

But, the Earths climate isn't a model? It 'knows' what it's intial conditons are? How could it's initial conditons change so that chaos would come into effect? It's like one model run, and it goes along, new inputs changing it? It's models of it that go 'wrong/chaotic' not the actual climate?

Right? Wrong? Way off?

Well, I think the "chaos" definition mixup was my fault, and I'm about to do it again.

If a butterfly flapping it's wings causes an iceage in Scotland, it might cause a Saharan drought in Portugal.

With Chaos theory, (though I'm no authority on it) as far as I understand the implication is that even though the basic laws of physics have to be followed, a minor event (such as a butterfly flapping its wings) can set off a chain reaction. The effects of that chain reaction could skew the results of a given known process one way or the other to varying degrees and in various ways depending on the orientation of the initial event to the reaction and end result.

For a nonsensical but explanatory example, if that butterfly was in Scotland, flapping east/west could send a self propagating domino effect around the planet which could resonate like a bell on the otherside and bring back something quite severe to Scotland on it's return in the form of severe weather.On the other hand, the same flap might potentially cancel out any severe weather that scotland should have, bringing unusually mild conditions instead. If it was oriented about the polar axis, it migh skew a delecate mild system into either extreme hot, or extreme cold. In effect, it all depends on what systems are being effected, and the way the effects (in accordance with the natural laws of physics) propogate, not to mention the way in which things are affcted in accordance with the prevailing conditions of that moment.

In short, crazy things can happen, but they don't happen very often on any extreme scale. What we do know though is that when a crazy and unexpected scenario does unfold, we wouldn't be able to pin it down to that butterfly, and so it might at least seem like the laws of physics have been broken through our lack of understanding.

Just in case anybody wondered what that lot was about, it was pretty much a demonstration that we don't know everything, and even though human kind sometimes thinks it does, we can and will be caught unawares by something beyond our meagre awareness. There is no certainty - only probability (a bit like quantum physics that! lol).

Even though I'm the only one to use "chaos" as a reference to the completely differently intended "chaos theory", it still kinda brings it's own little point. Don't ask me to discuss this post in any depth though, because I'll admit even now that I'm really not capable of doing so.

I think the arguement (see the RC post?) is whether the peterbation builds or fades away. Tbh I think the effect of butterfly wings fades away. After all, look at all the cars whizzing around, much bigger efect than a butterfly, have they cause a change to depression tracks? It's not in any way obvious they have...

[parmenides3]

Returning to your earlier point about multiple events, Viking, here ar some thoughts.

Assuming the background of current GW:

reduced solar irradiance from the 11 -year cycle or, conceivably the 'Gliessberg minimum', might have a cooling effect of c. 1-1.2 C.

complex, little understood ocean circulation flux might, conceivably, reduce the speed/salinity/heat transport of the Gulf Stream to Northern Europe by 1-2C

The Arctic Oscillation may shift phase, from negative to positive, resulting in a cooling of higher latitutes, therefore us, by 1-2C

a large volcanic eruption might, in the short term (2-3 years), cause a cooling of 0.3C

alterations in cloud formation/reflectivity/albedo might have a cooling effect of 0.5-1C

All of this happening over a period of, say, thirty years.

Meanwhile, the increase of heat stored in the oceans and the atmosphere continues to rise, because of CO2, forcing a warming, in the same period, globally, of 1-2C

Consequence?

Plausible?

P

[crimsone]

I think the arguement (see the RC post?) is whether the peterbation builds or fades away. Tbh I think the effect of butterfly wings fades away. After all, look at all the cars whizzing around, much bigger efect than a butterfly, have they cause a change to depression tracks? It's not in any way obvious they have...

That's the thing though - it's probability. In most cases you are probably right, but in other cases, I would suggest not so. If a butterfly flapping it's wings had caused a chain of reactions in weather systems around the world that had resulted in changing the track of a depression a little, would you know it was the butterfly that had caused the deepression to move? The best that could be done would be to just trace back a few of those chain reactions and to consider them normal anomylous events. For something truly extreme to happen as a result of a butterfly, we'd be looking at quite some period of time between events - however incredibly long that might be. (or perhaps it's not that long - perhaps such events are things we consider to be normal, with the truly extreme things being rare. Perhaps in the end it'll all boil down to a simple frequency ratio that the whole planet works on - we'll never know in my opinion, which is really the beauty of Chaos)

It's all probability really, and isn't solely limited to creatures that have wings to flap. lol

Edited August 29, 2006 by crimsone

[Guest Viking141]

Returning to your earlier point about multiple events, Viking, here ar some thoughts.

Assuming the background of current GW:

reduced solar irradiance from the 11 -year cycle or, conceivably the 'Gliessberg minimum', might have a cooling effect of c. 1-1.2 C.

complex, little understood ocean circulation flux might, conceivably, reduce the speed/salinity/heat transport of the Gulf Stream to Northern Europe by 1-2C

The Arctic Oscillation may shift phase, from negative to positive, resulting in a cooling of higher latitutes, therefore us, by 1-2C

a large volcanic eruption might, in the short term (2-3 years), cause a cooling of 0.3C

alterations in cloud formation/reflectivity/albedo might have a cooling effect of 0.5-1C

All of this happening over a period of, say, thirty years.

Meanwhile, the increase of heat stored in the oceans and the atmosphere continues to rise, because of CO2, forcing a warming, in the same period, globally, of 1-2C

Consequence?

Plausible?

P

Hi P3

Plausible yes, anythings plausible. Consequences, dunno to be honest, Im a layman who's only just getting to grips with all this. Im sure theres omeone out there who could explain the consequences but it wont be me - im a bit of a novice in all this Im afraid, however it is one reason why I enjoy threads like this because Im learning so much.

Whilst my knowledge may be somewhat limited, however, I am absolutely convinced that the current warming phase does not necessarily mean more warming in the future. Asd I have said there could be things which alter all this entirely.

It has been suggested that something unexpected which could have a dramatic influence on our climate is unlikely (again with the human arrogance of "if I dont know about it then it doesnt exist") Im sorry but I disagree with that entirely.

Case in point. Remember a couple of years back the BBC drama and associated documentary "Supervolcano?" Up until recently, the existence of humungous volcanoes which could radically alter the planet and its climate for centuries into the future was neither widely accepted or understood. Nor was it understood that such beasts still exist (Yellowstone is just one of them), that they are still active and could potentially do the same again (as mentioned in the docu-drama Yellowstone is about due to blow its lid again some time soon if it sticks to its usual pattern of eruptions) has come as rather a nasty shock to the scientific community. Given that we have only really recognised the existence and potential impact of such volcanoes in the very recent past it strikes me as highly likely that there could be other things, other mechanisms that we are not yet aware of (as well as the ones that we are) which could potentially radically alter our climate.

What irritates me is this assumption by some that the future is cast in stone and that the only future we have to look forward to is one of continued warming and that the ONLY way that this will change is if we, the human race, change it by not burning fossil fuels etc. In a word BUNK! Yes we could make an impact if we do the above but when all is said and done, if there is one thing we can be absolutely sure about, the climate of this planet will change, one way or the other, either because of us or, more likely in my view, in spite of us. Its done it before and it will do it again and on this I can be sure because we do have the palaeoclimatic evidence in the Greenland Ice Cores etc to prove that it has happened before both when humans were around and when they were not.

[BLAST FROM THE PAST]

Viking

I see very much where you are coming from. Warming has been happening and it is the current trend. However, how can anyone say it WILL continue...absolute balony IMO. As we have been shown in the past warming starts and CO2 rises following in suit. Now say we are in a different position now ie we accept that the CO2 emissions we pump out are warming the planet, in the past CO2 has been higher, much higher than present day levels and we know that the planet has gone from ice age to warm phase to ice age etc etc. Assuming CO2 warms the atmosphere and the oceans as this goes on then the oceans absorb less CO2 and more is released and retained into the atmosphere, so the carbon sink diminishes and co2 increases and we warm and warm and warm.....then how the hell does the planet go into an iceage? Surely not CO2 is rising, carbon sinks diminish we warm warm warm...don't we? :lol: There is obviously something or a number of things far more important than CO2 forcing as things in the past have caused both CO2 and temps to plunge and indeed what plunges 1st temps or CO2? If its temps then CO2 is overidden. I like to go onto calls of cold sources no longer there winters will not produce. The arctic was betwen 1 and 2C warmer in the late 30s and 40s than now [average temp] yet the 40s produced the most cold winters than in any decade. Hmmm

If say that the Gleissberg minima produces a cooling of 1-2C then that would reduce the global temp by 0.4 to 1.4C from now and that would take us back some way as we only warmed 0.6c over the last century so bearing in mind what winters were experienced during that century One can quote that the accelerated warming over past 30 years...fine but 1998 has not been exceeded [allegedly matched in 05] but this year don't look like it will either and short term is of no use to us. One can also counter the potential effects of Gleissberg minima by saying we will warm further...we will have to see.......................................and that sums it up we will have to see

BFTP

[snowsure]

Re your lottery, and choice of words. Yes, it's potential, but only in so much as p>0. On a scale of 0<=p<=1, the p in your case, for a single purchase, is around 18,000,000:1. I'd have to check the numbers but it puts it in the ball park with the ods of dying in a plane crash - so long and against as to really not be worth thinking about at all as an outcome.

Your physics teacher is actually incorrect, if not necessarily wrong. Taking a forward view of time, and assuming that it is infinite, then it is fairly easy to prove that anything and everything will happen, because infinity x zero = 1. Therefore, over an infiinite period, even things with a probability = 0 become certain. Isn't that bizarre? Gosh, even Daniel's Ice Age might be along "soon" based on that timescale.

I thought it was 14,000,000:1 for a lottery win?

However my Mathematics teacher would disagree with your infinity X zero=1 attempt (which I have assumed you got from re-arranging 1/0 = infinity)

L'Hopitals rule is invoked making your statement incorrect.

Still this is a weather forum. We aren't bothered by a few little incorrect odds and mathematical procedures are we?

Sorry for breaking up the great debate that is happening at the minute. Had a day in Hawes today. 12oC at 1pm and showery. Looks like autumn is impatient this year. Coupled with reports of a growing cold zone near the arctic this could put a spoke in the GW vehicle for a little while.

Speaking of inertia in the climate system; how long have the Anthro effects been building in the system to cause the current climate shift? If I said it is analogous to trying to lift a brick with an elastic band would you know what I mean?

[parmenides3]

I think some of you may have missed the point of my previous post. :lol:

All of the things I mentioned are distinct possibilities; indeed, there are good reasons to believe that three of them may already be on the way. We cannot predict a volcanic eruption, but we all know that, in the next thirty years, it would be surprising if there wasn't at least one decent-sized eruption. Apart from Mayon, which is currently on alert status 4, a good contender might be Kilauea, which is busy, and bulging badly at the moment.

What I was trying to do was show, as Viking has suggested, that a combination of three or four such forcings would, almost certainly, lead to a cooling of our climate, in the order of 3-4C.

In the short term (30 years), the rate of warming from GW would be insufficient to compensate for this. In the longer term, it probably would.

So I wasn't being sarcastic, I was proposing a scenario which could, plausibly, lead to a substantial local cooling. If anyone feels it is not plausible, please challenge me.

But, and it is a big but, none of this changes the fact of GW. None of it changes the science which shows, other things being equal, that we, humans, are contributing to a net warming of the climate which is not recorded in 650,000 years of records or proxies at the rate it is currently going. (I'll try to respond to BFTP's post later). And none of it changes, as far as I can tell, the conclusion that, even if we can't necessarily stop the climate from changing, one way or the other, for us to do nothing about greenhouse gases would be wrong. And if none of the above does happen, and warming still continues, which is currently considered to be the single most likely scenario, then surely we must do something about it.

Now, onto the palaeo record...

P

[Thundery wintry showers]

And none of it changes, as far as I can tell, the conclusion that, even if we can't necessarily stop the climate from changing, one way or the other, for us to do nothing about greenhouse gases would be wrong. And if none of the above does happen, and warming still continues, which is currently considered to be the single most likely scenario, then surely we must do something about it.

That's pretty much the conclusion I always end up arriving at in these debates- it certainly seems to me that the evidence is sufficiently large for it to be worth doing something about it.