I don't like using qualitative words like 'much' in a quantitative context, but yes, the change is logarithmic so the increase from 270 to 370 will be greater than from 370 to 470.
(Of course we're just talking about radiative forcing and disregarding feedbacks and other secondary effects. The actual global temperature change may be substantially different.)
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biffvernon
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I'll argue against that, it isn't CO2 and temperature with the logarithmic relationship but CO2 and radiative forcing. Temperature is much more complicated, hence the remaining uncertainly in climate sensitivity.snow hope wrote:As I have detailed before on here and nobody has argued against me, the relationship between CO2 increase and temperature increase is logarithmic in nature, ie. an increase from 300 to 400 parts per million (ppm) of CO2 with have a much smaller effect on temperature increase than an increase from 200 to 300 ppm would have.
270 to 370 will cause a larger increase in radiative forcing, but changes in radiative forcing certainly don't map proportionally onto the Earth's temperature. The Earth is a complex and dynamic system, some changes have more impact that others.snow hope wrote:Would it be fairer to say that, an increase in CO2 from 270ppm to 370ppm will cause a much greater increase in temperature than an increase from 370ppm to 470ppm?
For example, raise and icesheet's surface by 10C, from -15C to -5C and not a lot happens. Raise its temperature by just 6C from -5C to +1C and lots happens. The surface becomes wet, its albedo changes so it absorbs more incoming radiation, the surface lowers to a warmer altitude, the sea water receives a flux of cool, fresh water which impact ocean circulation etc...
For sake of the argument, assume the 10C rise was caused by going from 270 to 370 and the 6C rise was caused by going from 370 to 470. However, the 6C crossed the ice sheet's tipping point, and over time could trigger larger warming due to feedbacks.
Very few things in the Earth system are linear or just single relationships between two variables. I think one of the problems with climate science is that in an attempt to communicate to lay people too often it is simplified to the point where it becomes meaningless or at least easy to misrepresent.
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UndercoverElephant
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The feedback effects, and especially the mutually-reinforcing nature of most them, are very important.
Less ice means less solar energy reflected back from the surface.
Warmer ocean temperatures reduce phytoplankton activity in warm areas and lead to the release of clathrate methane in cold areas.
Warmer atmospheric temperatures increase water vapour content, and water vapour is a greenhouse gas itself.
Melting permafrost releases methane, another greenhouse gas.
All these things exacerbate the others.
A 2 degree rise due to human activity alone from the point we started seriously burning coal will probably be enough to set off feedback effects that will take the temperature several degrees higher.
I think we have to start take geo-engineering solutions to this problem seriously sooner rather than later. Just to cool things down a little bit...
Less ice means less solar energy reflected back from the surface.
Warmer ocean temperatures reduce phytoplankton activity in warm areas and lead to the release of clathrate methane in cold areas.
Warmer atmospheric temperatures increase water vapour content, and water vapour is a greenhouse gas itself.
Melting permafrost releases methane, another greenhouse gas.
All these things exacerbate the others.
A 2 degree rise due to human activity alone from the point we started seriously burning coal will probably be enough to set off feedback effects that will take the temperature several degrees higher.
I think we have to start take geo-engineering solutions to this problem seriously sooner rather than later. Just to cool things down a little bit...
We must deal with reality or it will deal with us.
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SleeperService
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I agree with nearly all this. I understood your comment to state that the messenger was as important as the message. That was what I found offensive.JavaScriptDonkey wrote:Only the lunatic fringe would argue that the increasing CO2 level isn't directly linked to the burning of fossil fuels.
Similarly it is hard to imagine anyone with any credibility arguing against the increasing temperature of atmosphere wrt recent records - not that I accept the validity of global averages as a method of measuring it.
The big questions are whether the two events are related and what else is going on. Greenhouse theory was manufactured from the basis that all global temperature change is a direct result of increasing CO2 concentrations.
That is a convenient theory but convenience doesn't guarantee accuracy.
I have my doubts about the scale of the relationship and suspect other phenomena are making their presence felt in the results.
As to your reference to offence I can only suggest you read what I wrote again. You have to judge arguments on the basis of their merits rather than from the jaded perspective of our own prejudices.
Although fossil fuel does seem, by far, the most likely reason for increased CO2, other factors haven't been discounted as you state. That's the edge that 'biased science' can exploit.
Scarcity is the new black
Yes, you are correct the logarithmic relationship is between CO2 and radiative forcing, but lets not forget that this forcing directly impacts the temperature, so whilst the CO2 and temperature relationionship is certainly more complex, it must still be of a logarithmic nature.clv101 wrote:I'll argue against that, it isn't CO2 and temperature with the logarithmic relationship but CO2 and radiative forcing. Temperature is much more complicated, hence the remaining uncertainly in climate sensitivity.snow hope wrote:As I have detailed before on here and nobody has argued against me, the relationship between CO2 increase and temperature increase is logarithmic in nature, ie. an increase from 300 to 400 parts per million (ppm) of CO2 with have a much smaller effect on temperature increase than an increase from 200 to 300 ppm would have.
These are good examples of what could happen, but when we introduce real values for the warming the IPCC said took place over the last century - that is about +0.6c - when CO2 did rise to 370ppm, then we see that the likelihood of the kind of changes you refer to above, if CO2 gets as high as 470ppm, is much less likely to happen.clv101 wrote:For example, raise and icesheet's surface by 10C, from -15C to -5C and not a lot happens. Raise its temperature by just 6C from -5C to +1C and lots happens. The surface becomes wet, its albedo changes so it absorbs more incoming radiation, the surface lowers to a warmer altitude, the sea water receives a flux of cool, fresh water which impact ocean circulation etc...
For sake of the argument, assume the 10C rise was caused by going from 270 to 370 and the 6C rise was caused by going from 370 to 470. However, the 6C crossed the ice sheet's tipping point, and over time could trigger larger warming due to feedbacks.
We have to look at the evidence of the recent summer Arctic melt in a realistic manner and not jump to unwarranted, catastrophic conclusions. The Arctic, even at the North Pole, has had stretches of open water in the middle of summer on many ocassions over the last few decades and indeed centuries.
Please have a read at this link, which I feel provides a lot of information and facts about the Arctic open waters during spring and summer over the 19th and 20th centuries.
http://www.john-daly.com/polar/arctic.htm
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biffvernon
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Yes, it takes it through that critical point every summer Biff...... and every autumn, winter and spring it freezes again and snows loads more. All normal. If you look at the stats for Greenland climate, you will see it was warmer in the 1940s that it is now.....biffvernon wrote:But when we look at what is actually happening.... we find that the surface temperature of the Greenland ice sheet has often risen by more than 0.6 degrees and what's more the temperature rise has taken it through that critical point that Chris describes where ice turns to water.
Real money is gold and silver
Greenland hasn't been following the AGW Theory predictions, that the arctic regions should warm faster than everywhere else.
"Moving to a consideration of more modern times, Chylek et al. (2004) analyzed the temperature histories of three coastal stations in southern and central Greenland that have almost uninterrupted temperature records between 1950 and 2000. In doing so, they discovered that "summer temperatures, which are most relevant to Greenland ice sheet melting rates, do not show any persistent increase during the last fifty years." In fact, working with the two stations with the longest records (both over a century in length), they determined that coastal Greenland's peak temperatures occurred between 1930 and 1940, and that the subsequent decrease in temperature was so substantial and sustained that current coastal temperatures "are about 1°C below their 1940 values." Furthermore, they note that "at the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2°C per decade since the beginning of the measurements in 1987." Hence, it would appear that Southern Greenland has not experienced any net warming over the most dramatic period of atmospheric CO2 increase on record. In fact, it has cooled during this period, and cooled significantly, in a place where CO2-induced warming is supposed to be greatest and most evident, and during a period of time when it is claimed that the earth experienced unprecedented warming.
At the start of the 20th century, however, Greenland was warming, as it emerged, along with the rest of the world, from the depths of the Little Ice Age. What is more, between 1920 and 1930, when the air's CO2 concentration rose by a mere 3 to 4 ppm, there was a phenomenal warming at all five coastal locations for which contemporary temperature records are available. In fact, in the words of Chylek et al., "average annual temperature rose between 2 and 4°C [and by as much as 6°C in the winter] in less than ten years." And this warming, as they note, "is also seen in the 18O/16O record of the Summit ice core (Steig et al., 1994; Stuiver et al., 1995)." Commenting on this dramatic temperature rise, which they call the great Greenland warming of the 1920s, Chylek et al. conclude that "since there was no significant increase in the atmospheric greenhouse gas concentration during that time, the Greenland warming of the 1920s demonstrates that a large and rapid temperature increase can occur over Greenland, and perhaps in other regions of the Arctic, due to internal climate variability ... without a significant anthropogenic influence."
Working in West Greenland, Taurisano et al. (2004) found much the same thing that Chylek et al. did in Southern and Central Greenland, as their analyses of all pertinent regional data led them to conclude that "at all stations in the Nuuk Fjord, both the annual mean and the average temperature of the three summer months (June, July and August) exhibit a pattern in agreement with the trends observed at other stations in south and west Greenland (Humlum 1999; Hanna and Cappelen, 2003)." As they describe it, the temperature data "show that a warming trend occurred in the Nuuk fjord during the first 50 years of the 1900s, followed by a cooling over the second part of the century, when the average annual temperatures decreased by approximately 1.5°C." Coincident with this cooling trend there was also what they describe as "a remarkable increase in the number of snowfall days (+59 days)." What is more, they report that "not only did the cooling affect the winter months, as suggested by Hannna and Cappelen (2002), but also the summer mean," noting that "the summer cooling is rather important information for glaciological studies, due to the ablation-temperature relations." In discussing these observations, Taurisano et al. remark that the temperature data they studied "reveal a pattern which is common to most other stations in Greenland." Hence, we can be thankful that the part of the Northern Hemisphere that holds the lion's share of its ice has been cooling for the past half-century, and at a very significant rate, making it ever more unlikely that its horde of frozen water will be released to the world's oceans to raise havoc with global sea level any time soon. Moreover, because the annual number of snowfall days over much of Greenland has increased so dramatically over the same time period, it is possible that enhanced accumulation of snow on its huge ice sheet may be compensating for the melting of many of the world's mountain glaciers and keeping global sea level in check."
http://ff.org/centers/csspp/library/co2 ... trends.htm
"Moving to a consideration of more modern times, Chylek et al. (2004) analyzed the temperature histories of three coastal stations in southern and central Greenland that have almost uninterrupted temperature records between 1950 and 2000. In doing so, they discovered that "summer temperatures, which are most relevant to Greenland ice sheet melting rates, do not show any persistent increase during the last fifty years." In fact, working with the two stations with the longest records (both over a century in length), they determined that coastal Greenland's peak temperatures occurred between 1930 and 1940, and that the subsequent decrease in temperature was so substantial and sustained that current coastal temperatures "are about 1°C below their 1940 values." Furthermore, they note that "at the summit of the Greenland ice sheet the summer average temperature has decreased at the rate of 2.2°C per decade since the beginning of the measurements in 1987." Hence, it would appear that Southern Greenland has not experienced any net warming over the most dramatic period of atmospheric CO2 increase on record. In fact, it has cooled during this period, and cooled significantly, in a place where CO2-induced warming is supposed to be greatest and most evident, and during a period of time when it is claimed that the earth experienced unprecedented warming.
At the start of the 20th century, however, Greenland was warming, as it emerged, along with the rest of the world, from the depths of the Little Ice Age. What is more, between 1920 and 1930, when the air's CO2 concentration rose by a mere 3 to 4 ppm, there was a phenomenal warming at all five coastal locations for which contemporary temperature records are available. In fact, in the words of Chylek et al., "average annual temperature rose between 2 and 4°C [and by as much as 6°C in the winter] in less than ten years." And this warming, as they note, "is also seen in the 18O/16O record of the Summit ice core (Steig et al., 1994; Stuiver et al., 1995)." Commenting on this dramatic temperature rise, which they call the great Greenland warming of the 1920s, Chylek et al. conclude that "since there was no significant increase in the atmospheric greenhouse gas concentration during that time, the Greenland warming of the 1920s demonstrates that a large and rapid temperature increase can occur over Greenland, and perhaps in other regions of the Arctic, due to internal climate variability ... without a significant anthropogenic influence."
Working in West Greenland, Taurisano et al. (2004) found much the same thing that Chylek et al. did in Southern and Central Greenland, as their analyses of all pertinent regional data led them to conclude that "at all stations in the Nuuk Fjord, both the annual mean and the average temperature of the three summer months (June, July and August) exhibit a pattern in agreement with the trends observed at other stations in south and west Greenland (Humlum 1999; Hanna and Cappelen, 2003)." As they describe it, the temperature data "show that a warming trend occurred in the Nuuk fjord during the first 50 years of the 1900s, followed by a cooling over the second part of the century, when the average annual temperatures decreased by approximately 1.5°C." Coincident with this cooling trend there was also what they describe as "a remarkable increase in the number of snowfall days (+59 days)." What is more, they report that "not only did the cooling affect the winter months, as suggested by Hannna and Cappelen (2002), but also the summer mean," noting that "the summer cooling is rather important information for glaciological studies, due to the ablation-temperature relations." In discussing these observations, Taurisano et al. remark that the temperature data they studied "reveal a pattern which is common to most other stations in Greenland." Hence, we can be thankful that the part of the Northern Hemisphere that holds the lion's share of its ice has been cooling for the past half-century, and at a very significant rate, making it ever more unlikely that its horde of frozen water will be released to the world's oceans to raise havoc with global sea level any time soon. Moreover, because the annual number of snowfall days over much of Greenland has increased so dramatically over the same time period, it is possible that enhanced accumulation of snow on its huge ice sheet may be compensating for the melting of many of the world's mountain glaciers and keeping global sea level in check."
http://ff.org/centers/csspp/library/co2 ... trends.htm
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biffvernon
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Oh come on, Snowhope, you can't really think getting your science from Frontiers of Freedom is sensible.
http://ff.org/index.php?option=com_cont ... &Itemid=69
http://ff.org/index.php?option=com_cont ... &Itemid=69
It was just a fecking google search!!! 
and links to data from elsewhere that is properly referenced. There is plenty of data out there that pours cold water on your favourite theory. 
And that is not where I get my science from. It is common knowledge that Greenland bucks the AGW Theory predictions, other than to you of course.....
I am getting pretty sick and tired of your accusations of sources of information and links Biff.
If you can't win your discussions with facts, you resort to rubbishing the sources of information.
and links to data from elsewhere that is properly referenced. There is plenty of data out there that pours cold water on your favourite theory. And that is not where I get my science from. It is common knowledge that Greenland bucks the AGW Theory predictions, other than to you of course..... I am getting pretty sick and tired of your accusations of sources of information and links Biff.
If you can't win your discussions with facts, you resort to rubbishing the sources of information.
Real money is gold and silver
Right, recovering from that ridicule thrown at me (yeah I know I was a bit over-sensitive - sorry), here is another paper (scientific and peer-reviewed) that states,
"The estimated average
Greenland snow temperature over the past 4000 years
was −30.7°C with a standard deviation of 1.0°C and exhibited
a long‐term decrease of roughly 1.5°C, which is consistent
with earlier studies. The current decadal average surface temperature
(2001–2010) at the GISP2 site is −29.9°C. The
record indicates that warmer temperatures were the norm in
the earlier part of the past 4000 years, including century‐long
intervals nearly 1°C warmer than the present decade (2001–
2010). Therefore, we conclude that the current decadal mean
temperature in Greenland has not exceeded the envelope of
natural variability over the past 4000 years, a period that
seems to include part of the Holocene Thermal Maximum.
http://www.leif.org/EOS/2011GL049444.pdf
I note that the average temperature of the last decade is +0.8c above the last 4000 years average and is more than 1c cooler than century long periods in the past 4000 years...... I think the facts speak for themselves here.
I wonder if this paper is acceptable? Or whether it has any authors who are funded by oil companies, or who are right-wing or were photographed picking their nose.......
I am sure I will find out soon. 
"The estimated average
Greenland snow temperature over the past 4000 years
was −30.7°C with a standard deviation of 1.0°C and exhibited
a long‐term decrease of roughly 1.5°C, which is consistent
with earlier studies. The current decadal average surface temperature
(2001–2010) at the GISP2 site is −29.9°C. The
record indicates that warmer temperatures were the norm in
the earlier part of the past 4000 years, including century‐long
intervals nearly 1°C warmer than the present decade (2001–
2010). Therefore, we conclude that the current decadal mean
temperature in Greenland has not exceeded the envelope of
natural variability over the past 4000 years, a period that
seems to include part of the Holocene Thermal Maximum.
http://www.leif.org/EOS/2011GL049444.pdf
I note that the average temperature of the last decade is +0.8c above the last 4000 years average and is more than 1c cooler than century long periods in the past 4000 years...... I think the facts speak for themselves here.
I wonder if this paper is acceptable? Or whether it has any authors who are funded by oil companies, or who are right-wing or were photographed picking their nose.......
I am sure I will find out soon. Real money is gold and silver
AGW
Snow, I've found the best policy for me is to act as if AGW is happening (even if I can't KNOW for sure), because it could very well be happening, and because these actions of mine also coincide well with my other actions to mitigate against energy depletion, over-consumption of resources, production of waste, etc.
I believe you are very much on board with peak oil, etc. and so I was just wanting to ask if you currently act in ways that assume no AGW (merrily producing loads of CO2), or is the argument for you more about trying to find out for sure, while continuing to act in a carbon-reducing manner? If that makes sense...
Just curious.
I believe you are very much on board with peak oil, etc. and so I was just wanting to ask if you currently act in ways that assume no AGW (merrily producing loads of CO2), or is the argument for you more about trying to find out for sure, while continuing to act in a carbon-reducing manner? If that makes sense...
Just curious.
I like to know the truth.
I have found myself searching for that over the last 10 years and becoming more and more aware of the fact that we are not informed of the truth. In fact the wool is drawn over our eyes intentionally.
I am unconvinced that AGW is happening. I have made the analogy elsewhere, that if I urinate into the Irish Sea, than I am raising the temperature of the sea, but it is negligable as regards measuring the temperature of the ocean.
I am completely on-board that Peak Oil has happened and that this has/will have increasingly major implications for our current way of life and I am trying to mitigate that as best I can.
I am not particularly concerned about emitting CO2 as I don't think this is a "poison" as we are increasingly encouraged to believe. I am much more concerned about the polluting of our atmosphere with fumes of any kind, including diesel and petrol fumes. Nevertheless I would much rather reduce my carbon footprint than increase it. I believe that homo sapiens are in overshoot and that sadly a die-off will occur over the coming decades and civilisation will become less complex. This will be a good thing for the rest of the animal kingdom.
I don't believe the Govt about much to be honest. And this is after about 35 years of interest in politics and watching from the sidelines. I don't believe them about Peak Oil and I don't believe them about AGW either. It amazes me that so many people who don't believe them about Peak Oil, do believe them about Climate Change...... hmmmmm.
We aren't much more intelligent than yeast. 
I have found myself searching for that over the last 10 years and becoming more and more aware of the fact that we are not informed of the truth. In fact the wool is drawn over our eyes intentionally.
I am unconvinced that AGW is happening. I have made the analogy elsewhere, that if I urinate into the Irish Sea, than I am raising the temperature of the sea, but it is negligable as regards measuring the temperature of the ocean.
I am completely on-board that Peak Oil has happened and that this has/will have increasingly major implications for our current way of life and I am trying to mitigate that as best I can.
I am not particularly concerned about emitting CO2 as I don't think this is a "poison" as we are increasingly encouraged to believe. I am much more concerned about the polluting of our atmosphere with fumes of any kind, including diesel and petrol fumes. Nevertheless I would much rather reduce my carbon footprint than increase it. I believe that homo sapiens are in overshoot and that sadly a die-off will occur over the coming decades and civilisation will become less complex. This will be a good thing for the rest of the animal kingdom.
I don't believe the Govt about much to be honest. And this is after about 35 years of interest in politics and watching from the sidelines. I don't believe them about Peak Oil and I don't believe them about AGW either. It amazes me that so many people who don't believe them about Peak Oil, do believe them about Climate Change...... hmmmmm.
We aren't much more intelligent than yeast.
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biffvernon
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For sure - no one is suggesting otherwise, or themselves striving for anything less.snow hope wrote:I like to know the truth.
In search for truth I find it very hard to see how you can remain unconvinced that AGW is happening - the balance is evidence is pretty much incontravertable. It's also worth pointing out that pretty much no government remains unconvinced AGW is happening, and there's even close agreement of 2C warming being too much and how much emission that relates to. That much is largely settled at the international level. The debate is all around how emission cuts should be distributed between countries and how they should be funded. Your position is a decade old in terms of international politics. If every government in the would is now convinced, why do you remain unconvinced?snow hope wrote:I am unconvinced that AGW is happening.
This is a poor analogy - there are many many systems (in fact for complex systems it's probable more likely than not) where small changes have disproportionate effects. We shouldn't assume linear relationships - they tend to be quite rare!snow hope wrote:I have made the analogy elsewhere, that if I urinate into the Irish Sea, than I am raising the temperature of the sea, but it is negligable as regards measuring the temperature of the ocean.
This is interesting - the evidence for peak oil having happened is far far weaker than the evidence that AGW is happening. I'm not saying I disagree with you, but it's clear you aren't holding each position to the same level of evidence.snow hope wrote:I am completely on-board that Peak Oil has happened and that this has/will have increasingly major implications for our current way of life and I am trying to mitigate that as best I can.
It looks like your adopting an 'anti-government' or 'anti-mainstream' position, despite the relative evidence for each position. I disagree with the government on peak oil, but largely agree with them on climate change. This should not be seen as an amazing position - the government (all government's around the world) aren't all fools!snow hope wrote:I don't believe them about Peak Oil and I don't believe them about AGW either. It amazes me that so many people who don't believe them about Peak Oil, do believe them about Climate Change...... hmmmmm.