Are we about to enter another mini ice age ?

[Methuselah]

You make a lot of asumptions in your posts claiming them to be facts. Such as above.

Solar induced global warming stopped years ago and if it was not for the fact of very

poor temperature measuring locations and heat island effects the cooling or lack of

warming would be far more evident.

If you do not believe this go look for yourself. There is plenty of written facts and

figures to back this up.

Not the strongest argument against AGW Theory, CC...If you could show that species are not really migrating polewards, you'd be on to something...

 

But, what really intrigues me, about the whole thing, is all those feedbacks that are still awaiting verification or refutation; especially so, given that cloud-feedback (which I'd always intuited as negative) increasingly appears to be positive, in nature...

 

I think it's fair to say that there is still plenty of work to be done; but dismissing all the data on the basis of something that has been known about, and factored-out, for many years seems a tad closed-minded to me?

Edited May 3, 2013 by Rybris Ponce

[knocker]

To be honest I know nothing about the subject, but if you google "temperature graph for the last million years"

And "co2 graph for the last million years", then look at the graphs, they show quite clearly that in many periods over the years it has been much hotter than at present, and much colder. And co2 ppm have been far higher, and far lower than at present.

Also the shorter timescale warming seems to have started hundreds of years ago, well before the industrial rev.

This maybee too simplistic for many, but, you can't look at recent temp changes and make a decision, you need to look at millions of years timescales. How long have sattalites been around? To me, the info they give is useless as ther is no data from the last 100000 years to compare with.

Personally I expect a general natural warming of the planet to continue for a few thousand years until the tipping point where we start to go into the next full ice age.

I'm sure many will shhot me down for being ignorant, but, why all this looking at the last hundred years? Look at the bigger timescales, its surely just common sense? Sorry for being slightly off topic..

 

I posted this in New Research.

 

Continental-scale temperature variability during the past two millennia

 

Abstract  

Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.

 

http://www.nature.co...l/ngeo1797.html

 

A comment on the paper.

 

http://www.carbonbri...nt-by-continent

[johnholmes]

I am generally quite pleased with this thread. Okay it is a diversion into the climate theory area but it is, so far, mercifully free from the constant bickering that goes on in there. Some very interesting posts from both sides and plenty to think about. I suspect if we were able to be a fly on the IPCC folks we MIGHT see some backing away from the highest possible earth temperature increases. If you read CAREFULLY their findings they do mention the possibility of a levelling off in rising temperatures but for the upward rise, to continue. I wonder if they might now prefer to print something along the lines of 'as more and more information becomes available we may have to reduce the expected increase in temperature levels over 10, 50 and 100 year time scales' ? To me as we read more, learn more, we have more and more variables and uncertainties.

But it does make for fascinating reading and hypothesising be it from the professionals or amateurs.

[Mr_Pessimistic]

Hi Mr_Pessimistic. There have been many studies that have looked back at global temperature change over the last few thousand years. The most recent I read, was by Marcott et al which examined temperature changes over the last 11,300 years. There generated this graph from their work

Hi, thanks for the graph, but, aside from the fact that that graph is only based on the last 10000 years, and not millions etc, the thing is, I've just had another google, and have found about 5 graphs all showing different data, soo.. which do we believe?? Its almost like the data produced seems to be based on which side of the fence you sit (I'm sure those that do the research will strongly dissagree with that though)..

If you get two sets of ice cores or the like showing different data, which is right? This seems to be the biggest problem with this arguement, unless I'm wrong and the older data is simply wrong, but the latest data is right? That's untill another study is done with, yet again, conflicting data?

[BornFromTheVoid]

I am generally quite pleased with this thread. Okay it is a diversion into the climate theory area but it is, so far, mercifully free from the constant bickering that goes on in there. Some very interesting posts from both sides and plenty to think about. I suspect if we were able to be a fly on the IPCC folks we MIGHT see some backing away from the highest possible earth temperature increases. If you read CAREFULLY their findings they do mention the possibility of a levelling off in rising temperatures but for the upward rise, to continue. I wonder if they might now prefer to print something along the lines of 'as more and more information becomes available we may have to reduce the expected increase in temperature levels over 10, 50 and 100 year time scales' ? To me as we read more, learn more, we have more and more variables and uncertainties.

But it does make for fascinating reading and hypothesising be it from the professionals or amateurs.

 

Your getting into the area of climate sensitivity John, which has quite a large potential range for doubling of CO2, between 1.5C and 4.5C roughly (going by the IPCC). It will be interesting to see what that range is like in the new assessment.

 

Hi, thanks for the graph, but, aside from the fact that that graph is only based on the last 10000 years, and not millions etc, the thing is, I've just had another google, and have found about 5 graphs all showing different data, soo.. which do we believe?? Its almost like the data produced seems to be based on which side of the fence you sit (I'm sure those that do the research will strongly dissagree with that though)..

If you get two sets of ice cores or the like showing different data, which is right? This seems to be the biggest problem with this arguement, unless I'm wrong and the older data is simply wrong, but the latest data is right? That's untill another study is done with, yet again, conflicting data?

 

Would you mind linking to some of those other graphs?

I didn't think there had been any other detailed studies of the last 10k years or so, at least not on a global scale.

 

Different ice cores and different proxy measurements (tree rings, sediment cores, etc) will reflect the climate of that area, which doesn't require any being more right than others.

It's through combining many different proxy measurements from many locations that you can begin to assemble a global picture of temperature change.

Edited May 3, 2013 by BornFromTheVoid

[Mr_Pessimistic]

I posted this in New Research.

 

Continental-scale temperature variability during the past two millennia

 

Abstract  

Past global climate changes had strong regional expression. To elucidate their spatio-temporal pattern, we reconstructed past temperatures for seven continental-scale regions during the past one to two millennia. The most coherent feature in nearly all of the regional temperature reconstructions is a long-term cooling trend, which ended late in the nineteenth century. At multi-decadal to centennial scales, temperature variability shows distinctly different regional patterns, with more similarity within each hemisphere than between them. There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age, but all reconstructions show generally cold conditions between ad 1580 and 1880, punctuated in some regions by warm decades during the eighteenth century. The transition to these colder conditions occurred earlier in the Arctic, Europe and Asia than in North America or the Southern Hemisphere regions. Recent warming reversed the long-term cooling; during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.

 

http://www.nature.co...l/ngeo1797.html

 

A comment on the paper.

 

http://www.carbonbri...nt-by-continent

Hi, again, we are talking about only the last couple of thousand years, just a tiny time in the earths history.. if the cooling pattern stated was the result of natural things such as volcanic activity (as stated)etc, then this has to end at some point and a rebound effect may well be likely, hence the rise from the 70s -2000s, of which that rebound affect is now settling down. But a rise in just the last 30 years or so, a worry to us or caused by us? I highly doubt it myself. I'm sure if one looks further back in time there have been many times in the past wjere the earth has been cooling on average for a while, only for that cooling to stop and the temperature to rise relatively quickly or slowly as the case may be, but for this time to be any different?, I would be v supprised if that were the case..

[knocker]

I would be surprised because we are passing the 400ppm so I can't see a little ice age around the corner. Upto 1950 I believe the later graphs have already been posted.

Temperature and CO2 concentration in the atmosphere over the past 400 000 years

 

Over the last 400,000 years the Earth's climate has been unstable, with very significant temperature changes, going from a warm climate to an ice age in as rapidly as a few decades. These rapid changes suggest that climate may be quite sensitive to internal or external climate forcings and feedbacks. As can be seen from the blue curve, temperatures have been less variable during the last 10 000 years. Based on the incomplete evidence available, it is unlikely that global mean temperatures have varied by more than 1°C in a century during this period. The information presented on this graph indicates a strong correlation between carbon dioxide content in the atmosphere and temperature. A possible scenario: anthropogenic emissions of GHGs could bring the climate to a state where it reverts to the highly unstable climate of the pre-ice age period. Rather than a linear evolution, the climate follows a non-linear path with sudden and dramatic surprises when GHG levels reach an as-yet unknown trigger point.

 

http://www.grida.no/publications/vg/climate/page/3057.aspx

Edited May 3, 2013 by knocker

[Mr_Pessimistic]

Your getting into the area of climate sensitivity John, which has quite a large potential range for doubling of CO2, between 1.5C and 4.5C roughly (going by the IPCC). It will be interesting to see what that range is like in the new assessment.

 

 

Would you mind linking to some of those other graphs?

I didn't think there had been any other detailed studies of the last 10k years or so, at least not on a global scale.

 

Different ice cores and different proxy measurements (tree rings, sediment cores, etc) will reflect the climate of that area, which doesn't require imply any being more right than others.

It's through combining many different proxy measurements from many locations that you can begin to assemble a global picture of temperature change.

Here are a number of graphs from a simple google search:

http://www.google.co.uk/imgres?imgurl=http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png&imgrefurl=http://joannenova.com.au/2010/02/the-big-picture-65-million-years-of-temperature-swings/&h=493&w=829&sz=159&tbnid=SOadANpetBK6qM:&tbnh=87&tbnw=147&prev=/search%3Fq%3Dtemperature%2Bgraph%2Bfor%2Bthe%2Blast%2Bmillion%2Byears%26tbm%3Disch%26tbo%3Du&zoom=1&q=temperature+graph+for+the+last+million+years&usg=__3L7cvdVt6wqYnBBUaznmxqxfzkc=&docid=UrLd2hoOeD7sWM&hl=en&sa=X&ei=hqaDUa_CDYKp0QW85YDoCw&ved=0CCwQ9QEwAA

Also, the graph you posted does not show any 'spikes' that would have been shown if modern technology was around years ago. It only shows a recent spike, and to me, that is a bit missleading..

[Interitus]

My opinion on things is how the PDO behaves as that can have an impact on global temperatures and how the Enso behaves too. What we have had since 2007 is mainly a Nina driven regime and the PDO in a negative phase. If this trend continues yes we will probably get substantially cooler, its not just solar driven as there are other players too.

 

With this and the Alaska paper Jethro linked to, the PDO undoubtedly affects the northern hemisphere more widely than regions adjacent to the north Pacific.

However in this chicken and egg scenario the strongest correlation was found with the AO leading conditions of the PDO by 7-8 years. The AO affects the strength of the Aleutian low (which is suggested as the main coupling of AO & PDO) and thence to north Pacific SST which then feeds back into the PDO -

paper http://csb.scichina.com:8080/kxtbe/fileup/PDF/06ky0075.pdf

 

Similar research then shows that the dominant decadal variability of north Pacific SST leads the tropical Pacific variability (which may be independent of ENSO) by 5-7 years - ftp://apapane.soest.hawaii.edu/users/niklas/2002JD002817.pdf

[Mr_Pessimistic]

actually, the graphs i posted are probably not from multiple sources from around the world, but i guess if you were to take an average from the places these graphs were taken from, it would still show the same..

Here are a number of graphs from a simple google search:

http://www.google.co.uk/imgres?imgurl=http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png&imgrefurl=http://joannenova.com.au/2010/02/the-big-picture-65-million-years-of-temperature-swings/&h=493&w=829&sz=159&tbnid=SOadANpetBK6qM:&tbnh=87&tbnw=147&prev=/search%3Fq%3Dtemperature%2Bgraph%2Bfor%2Bthe%2Blast%2Bmillion%2Byears%26tbm%3Disch%26tbo%3Du&zoom=1&q=temperature+graph+for+the+last+million+years&usg=__3L7cvdVt6wqYnBBUaznmxqxfzkc=&docid=UrLd2hoOeD7sWM&hl=en&sa=X&ei=hqaDUa_CDYKp0QW85YDoCw&ved=0CCwQ9QEwAA

Also, the graph you posted does not show any 'spikes' that would have been shown if modern technology was around years ago. It only shows a recent spike, and to me, that is a bit missleading..

[BornFromTheVoid]

Here are a number of graphs from a simple google search:

http://www.google.co.uk/imgres?imgurl=http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png&imgrefurl=http://joannenova.com.au/2010/02/the-big-picture-65-million-years-of-temperature-swings/&h=493&w=829&sz=159&tbnid=SOadANpetBK6qM:&tbnh=87&tbnw=147&prev=/search%3Fq%3Dtemperature%2Bgraph%2Bfor%2Bthe%2Blast%2Bmillion%2Byears%26tbm%3Disch%26tbo%3Du&zoom=1&q=temperature+graph+for+the+last+million+years&usg=__3L7cvdVt6wqYnBBUaznmxqxfzkc=&docid=UrLd2hoOeD7sWM&hl=en&sa=X&ei=hqaDUa_CDYKp0QW85YDoCw&ved=0CCwQ9QEwAA

Also, the graph you posted does not show any 'spikes' that would have been shown if modern technology was around years ago. It only shows a recent spike, and to me, that is a bit missleading..

 

Reconstructions of global temperatures in the last few thousand to 12,000 years have been quite consistent with each other. When you take ice cores or whatever other proxy measurement from a single location, it will likely be quite different to the global mean, with much more local variability, which is what you see in the graph you linked to.

For example, the globe has not recorded a below average month since the 80s (NCDC), but the variability of temperature in somewhere like the UK is massive in comparison, with some months several degrees above average and some several several degrees below.

[Mr_Pessimistic]

Reconstructions of global temperatures in the last few thousand to 12,000 years have been quite consistent with each other. When you take ice cores or whatever other proxy measurement from a single location, it will likely be quite different to the global mean, with much more local variability, which is what you see in the graph you linked to.

For example, the globe has not recorded a below average month since the 80s (NCDC), but the variability of temperature in somewhere like the UK is massive in comparison, with some months several degrees above average and some several several degrees below.

yes, i see youre point, but to get a good average could take thousands of readings? as 73 (i think you said 73) may not be enough, if , say, half of the readings contain big local variations..    but also, as i said, the graph you posted pretty much shows the earth was warmer, has been cooling, and is now starting to warm again, probably as part of a natural cycle.  the recent spike imo should be ignored, as previous spikes have been due to lack of detailed data from centuries gone by, if you get what i mean? as im sure the data used to plot the older part of the graph would have contained many spikes showing even warmer/colder periods..  i think people are worring for nothing.  and if sea levels are going to rise, this will take many years, plenty of time for people to move away from the coasts etc..  we have to adapt to conditions, we will never be able to change them, simple as that..

[cheeky_monkey]

  i think people are worring for nothing.  and if sea levels are going to rise, this will take many years, plenty of time for people to move away from the coasts etc..  we have to adapt to conditions, we will never be able to change them, simple as that..

its not as simple as that..dont forget huge areas of world food production are in low lying areas that would be underwater due to rises in sea levels.

[Mr_Pessimistic]

its not as simple as that..dont forget huge areas of world food production are in low lying areas that would be underwater due to rises in sea levels.

yes, i know its not a nice thought, but does anyone that actually beleives in agw actually think that we will be able to stop it?  because i think they are living in a dream world if they think we will.. its simply not going to happen, the only answer would be a new technology  of some sorts. and untill this happens, and if temps do continue to rise, we will simply have to get used to the fact that we need to adapt to the conditions rather than argue about them..  expecially if they continue to rise and natural forces are actually the drivers..

[BornFromTheVoid]

yes, i see youre point, but to get a good average could take thousands of readings? as 73 (i think you said 73) may not be enough, if , say, half of the readings contain big local variations..    but also, as i said, the graph you posted pretty much shows the earth was warmer, has been cooling, and is now starting to warm again, probably as part of a natural cycle.  the recent spike imo should be ignored, as previous spikes have been due to lack of detailed data from centuries gone by, if you get what i mean? as im sure the data used to plot the older part of the graph would have contained many spikes showing even warmer/colder periods..  i think people are worring for nothing.  and if sea levels are going to rise, this will take many years, plenty of time for people to move away from the coasts etc..  we have to adapt to conditions, we will never be able to change them, simple as that..

 

True that short term fluctuations in temperature spikes (and drops) are smoothed out of the long term graph. What the study does show, is the long term cooling trend that the Earth was experiencing since 7k years ago. There may have been short term us and downs during that time, but the trend was clear.

 

For a temperature increase like the one we've seen (since the late 1800s) not to show up on the Marcott graph, would have required an immediate drop in temperature globally on the same scale as the increase we've seen since the industrial revolution. The only thing that could come close to that is the Younger Dryas event, but the effects of that seemed concentrated in the northern hemisphere, with some warming occurring in around Antarctica during that time. An abrupt shut down in the thermohaline circulation doesn't appear at all likely at the moment either, so i doubt we could see such a temperature drop.

[Mr_Pessimistic]

interesting read relating to what we are both discussing:

http://www.esd.ornl.gov/projects/qen/transit.html

[jethro]

Interesting though the conversation is folks, it's not exactly on topic and drifting far too far into the realms of climate change. There's a huge climate area on the forum, loads of different topics, I'm sure one of them would fit the bill to continue your conversations.

Please take all climate discussion to here: http://forum.netweather.tv/forum/105-climate-and-environment/

[cooling climate]

Interesting though the conversation is folks, it's not exactly on topic and drifting far too far into the realms of climate change. There's a huge climate area on the forum, loads of different topics, I'm sure one of them would fit the bill to continue your conversations.

Please take all climate discussion to here: http://forum.netweather.tv/forum/105-climate-and-environment/

I have tried logging into the climate discussion area but it I keep getting the message sorry you do not have

permission for that. In other words it does not recognise me as a member.

I have tried getting in touch with the administrator but the it will not accept my e-mail saying the server does

not support the required http methods.

Can you help. Thanks.

[jethro]

I have tried logging into the climate discussion area but it I keep getting the message sorry you do not have

permission for that. In other words it does not recognise me as a member.

I have tried getting in touch with the administrator but the it will not accept my e-mail saying the server does

not support the required http methods.

Can you help. Thanks.

Yes, of course. Will get back to you via PM.