Data prior to satellite or 1950's

[Thunderbomb1982]

As you all know, I am not a believer as greenhouse gasses being the sole property of global warming.  I think our Earth goes through cycles with sunspot activity.  Will a warming or cooling cycle last hundreds of years like the medieval warm period or the mini ice age? Who knows.  But what I have a hard time believing is the data that scientist today pull back form the 1800's and early to mid 1900's.  They say this data is accurate and yet they claim to have accurate maps of sea ice but yet there was no satellite until 1979.  But yet many global warming activists seem to prove the ice cover and temperature globally before then.  Why would people want to believe this? I mean if a scientist wants to make an ASSUMPTION that's one thing but to show data that seems to be nearly  accurate before this time is another thing. How can we think that global temperatures or ice cover taken in the year 1900 is even close to accurate?  If someone can give me proof I am all up to opinions but I just don't see how someone logically in the year (let's say 1920) could make an accurate assumption of sea ice cover or global temperatures. I understand that many colleges and congress wants everyone to believe in global warming and would be ousted if there was belief otherwise, but where is the real proof?  I mean I've seen where they say glaciers in Alaska have receded but yet to find the pictures were taken in different areas over years to make it seem true.  Hopefully I don't hear any of the members saying that there needs to be a "posting minimum" because that shows lack of intelligence and fear.  If you don't agree say why but please don't say there needs to be a posting minimum because I don't have a PHD or believe in the current global warming.  

[blizzard1024]

You raise some excellent points that I have had for many years which are at the heart of the debate on how much warming our planet has seen since the 1800s. How did they get such accurate and complete ocean temperatures and sea ice analysis in the late 1800s to the level of a tenth of a degree or square km ice coverage? They take a sparse and inconsistent dataset and compare with much more comprehensive datasets of today. First of all, CO2 by itself does provide some warming to the climate system this is where there is physical evidence.   Physics supports this and anyone who does not believe this is ignoring something that has been proven fairly well by radiative transfer. If you double C02 concentrations from pre-industrial levels it leads to an extra 3.7 w/m2 of radiative forcing to the troposphere. This alone equates to around 1.2C of warming of which could be drawn our over a long period of time due to the huge heat capacity of the oceans, like centuries. However, mainstream climate scientists believe there are positive feedbacks like the water vapor feedback which double to more than triple this warming and that is why they are so concerned. The water vapor feedback goes like this...if you warm the planet by any forcing you get more water vapor in the atmosphere from evaporation. Water vapor is the primary greenhouse gas and this will amplify the initial warming. That is where you hear about 2-4.5C of warming. However this really hasn't been proven and there is conflicting data of whether water vapor is increasing or even decreasing in the upper troposphere where it really matters. Plus the current slow rate of warming is well below the climate models suggesting a small or neutral water vapor feedback. The rate of warming is a big question mark since the late 1800s by any reasonable scientist or even lay person for the reasons you state. Climate scientists also are continually "adjusting" the temperature data making it cooler 100 years ago and warmer today despite urbanization.  There is also evidence that the sun was at its strongest based on beryllium studies in the late 20th century. Certainly there would be some lag effect from this into the 21st century because of the huge heat storage capacity of the oceans. There also is strong evidence that there was a little ice age that ended in the 1800s, so the small warming we have seen could easily be a rebound from this cool period. There also is strong evidence that the earth was warmer than today based on pollen studies 6000-8000 years ago suggesting today's climate is nothing unusual and within the bounds of the holocene epoch. The glacial records also show that CO2 levels lagged temperatures in ice cores meaning that temperatures would drop (or rise) first then hundreds of years later CO2 would drop(or rise) because colder (warmer) oceans absorb(outgas) CO2. This suggests CO2 is not the Earth's thermostat. Climate scientists still struggle to understand how the Earth goes in and out of ice ages meaning they don't fully understand the natural climate dynamics of our planet. 

So your skepticism is healthy and based on plain common sense. Good luck on this forum. The people aren't very nice to those who dare question or try to have a healthy debate on such valid questions that you raise. 

 

 

 

[chubbs]

This chart was recently posted on the arctic sea ice forum showing Captain Cooks depiction of the sea ice front in the Chukchi sea in August 1778. Cook sailed along the front for 11 days  between Alaska and Siberia. Per the chart the ice front in early December 2016 is well back from the Aug 1778 front.

There is also good paleoclimate data showing that arctic sea ice began decreasing in the 1800s (see 2nd link below). 

http://forum.arctic-sea-ice.net/index.php/topic,1611.msg95659.html#new

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiMvNqXmdjQAhUGYyYKHSJyCvsQFgglMAE&url=https%3A%2F%2Fwww.geo.umass.edu%2Ffaculty%2Fjbg%2FPubs%2FPolyak%20etal%20seaice%20QSR10%20inpress.pdf&usg=AFQjCNFKr_Ob0xC8CwN1-IuZvT3rPN9WgQ&cad=rja

[blizzard1024]

3 hours ago, chubbs said:

This chart was recently posted on the arctic sea ice forum showing Captain Cooks depiction of the sea ice front in the Chukchi sea in August 1778. Cook sailed along the front for 11 days  between Alaska and Siberia. Per the chart the ice front in early December 2016 is well back from the Aug 1778 front.

There is also good paleoclimate data showing that arctic sea ice began decreasing in the 1800s (see 2nd link below). 

http://forum.arctic-sea-ice.net/index.php/topic,1611.msg95659.html#new

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiMvNqXmdjQAhUGYyYKHSJyCvsQFgglMAE&url=https%3A%2F%2Fwww.geo.umass.edu%2Ffaculty%2Fjbg%2FPubs%2FPolyak%20etal%20seaice%20QSR10%20inpress.pdf&usg=AFQjCNFKr_Ob0xC8CwN1-IuZvT3rPN9WgQ&cad=rja

So we have two dates and an ice edge. I don't think this proves much about areal extent in the long run. It is all anecdotal and not as precise as satellite measurements. apples to oranges....sorry. 

[Fantom X]

5 hours ago, blizzard1024 said:

You raise some excellent points that I have had for many years which are at the heart of the debate on how much warming our planet has seen since the 1800s. How did they get such accurate and complete ocean temperatures and sea ice analysis in the late 1800s to the level of a tenth of a degree or square km ice coverage? They take a sparse and inconsistent dataset and compare with much more comprehensive datasets of today. First of all, CO2 by itself does provide some warming to the climate system this is where there is physical evidence.   Physics supports this and anyone who does not believe this is ignoring something that has been proven fairly well by radiative transfer. If you double C02 concentrations from pre-industrial levels it leads to an extra 3.7 w/m2 of radiative forcing to the troposphere. This alone equates to around 1.2C of warming of which could be drawn our over a long period of time due to the huge heat capacity of the oceans, like centuries. However, mainstream climate scientists believe there are positive feedbacks like the water vapor feedback which double to more than triple this warming and that is why they are so concerned. The water vapor feedback goes like this...if you warm the planet by any forcing you get more water vapor in the atmosphere from evaporation. Water vapor is the primary greenhouse gas and this will amplify the initial warming. That is where you hear about 2-4.5C of warming. However this really hasn't been proven and there is conflicting data of whether water vapor is increasing or even decreasing in the upper troposphere where it really matters. Plus the current slow rate of warming is well below the climate models suggesting a small or neutral water vapor feedback. The rate of warming is a big question mark since the late 1800s by any reasonable scientist or even lay person for the reasons you state. Climate scientists also are continually "adjusting" the temperature data making it cooler 100 years ago and warmer today despite urbanization.  There is also evidence that the sun was at its strongest based on beryllium studies in the late 20th century. Certainly there would be some lag effect from this into the 21st century because of the huge heat storage capacity of the oceans. There also is strong evidence that there was a little ice age that ended in the 1800s, so the small warming we have seen could easily be a rebound from this cool period. There also is strong evidence that the earth was warmer than today based on pollen studies 6000-8000 years ago suggesting today's climate is nothing unusual and within the bounds of the holocene epoch. The glacial records also show that CO2 levels lagged temperatures in ice cores meaning that temperatures would drop (or rise) first then hundreds of years later CO2 would drop(or rise) because colder (warmer) oceans absorb(outgas) CO2. This suggests CO2 is not the Earth's thermostat. Climate scientists still struggle to understand how the Earth goes in and out of ice ages meaning they don't fully understand the natural climate dynamics of our planet. 

So your skepticism is healthy and based on plain common sense. Good luck on this forum. The people aren't very nice to those who dare question or try to have a healthy debate on such valid questions that you raise. 

 

 

 

Excellent post

[chubbs]

Here is the paleo data.

http://www.nature.com/nature/journal/v479/n7374/full/nature10581.html

 

[blizzard1024]

"Here we use a network of high-resolution terrestrial proxies from the circum-Arctic region to reconstruct past extents of summer sea ice, and show that—although extensive uncertainties remain, especially before the sixteenth century—both the duration and magnitude of the current decline in sea ice seem to be unprecedented for the past 1,450 years. "   Emphasis is mine.  Of course, it is pay walled so I can't read it. Our tax dollars pay for this research and then we have to
repay for it.  such BS. 

 

[blizzard1024]

Paper finds Medieval Warm Period in Arctic was much warmer than the present

 

A paper published in Polar Research finds that temperatures at two sites in the Arctic were much warmer than at the end of the 20th century. At one site, Longyearbyen, the11-year running-mean peak winter temperature was a remarkable 9C warmer than at the end of the record in 2000. At the 2nd site, Vardo, the11-year running-mean peak winter temperature was about 3.3C warmer than at the end of the record in 2000. As the NIPCC Report explains,

Not only is there nothing unusual, unnatural or unprecedented about the most recent surface air temperatures at Longyearbyen and Vardo, it is pretty clear that it was significantly warmer at both locations during the peak warmth of the Medieval Warm Period, when there was way less CO2 in the atmosphere than there is today. And this observation suggests - as do many others from all around the world - that anthropogenic CO2 emissions are not the great threat to humanity and the biosphere that climate alarmists claim them to be, for something in the environment appears to be effectively counteracting whatever "greenhouse effect" they may produce.

Reference: Divine, D., Isaksson, E., Martma, T., Meijer, H.A.J., Moore, J., Pohjola, V., van de Wal, R.S.W. and Godtliebsen, F. 2011. Thousand years of winter surface air temperature variations in Svalbard and northern Norway reconstructed from ice-core data. Polar Research 30: 10.3402/polar.v30i0.7379.

In introducing the purpose for their study, Divine et al. (2011) write that "the recent rapid climate and environmental changes in the Arctic, for instance, sea-ice retreat (e.g., Comiso et al., 2008) and ice-sheet melting (e.g., van den Broeke et al., 2009), require a focus on long-term variability in this area in order to view these recent changes in the long-term context," which is truly essential if one desires to know just how unusual, unnatural or unprecedented the recent warming of the Arctic has been.

Working with ice cores extracted from Svalbard at Lomonosovfonna in 1997 (Isaksson et al., 2001) and at Holtedahlfonna in 2005 (Sjorgren et al., 2007), Divine et al. used the δ18O data derived from them to reconstruct 1200-year winter (Dec-Jan-Feb) surface air temperature histories for nearby Longyearbyen (78.25°N, 15.47°E) and farther-afield Vardo (70.54°N, 30.61°E, in northern Norway), by calibrating (scaling) the δ18O data to corresponding historically-observed temperatures at the two locations, which for Longyearbyen were first collected in 1911 and for Vardo have been extended back to 1840 as a result of the work of Polyakov et al. (2003).

The winter surface air temperature reconstructions, which are depicted in the figure below, begin at the peak warmth of the Medieval Warm Period at approximately AD 800, and they decline fairly steadily to the coldest period of the Little Ice Age at approximately AD 1830, after which they rise into the 1930s, decline, and then rise again, to terminate just slightly lower than their 1930s' peaks near the end of the 1990s.

[so_whats_happening]

On 12/4/2016 at 7:00 AM, chubbs said:

Here is the paleo data.

http://www.nature.com/nature/journal/v479/n7374/full/nature10581.html

 

Hmmm thats weird why would we be seeing ice gains in years with temps warmer also ice losses in years with relatively low SAT anoms or little change from those temp fluctuations and then BAM. Honestly not 100% sure myself, but something is not making sense with it solely just following CO2 as many state something else seems at play here. I would love to post more in this portion of the forum but I feel, as I have seen here and other threads, people try to discredit your own thoughts on the topic at hand. While I do believe some of the responses were needed since not much factual data was presented in some posts but ideas are that ideas. How are we to grow as a science commmunity if we continue to bash each other for presenting different ideas. 

 

 

[chubbs]

Here is the most recent proxy data for Arctic temperature (open). Note that the most recent adjustment was to warm the early part of the proxy data. This data includes the Svalbard ice cores that were hyped in the denier blog above. Yes it was relatively warm in the arctic 2000 years ago, but it was cold with extensive sea ice when the modern warming began roughly 200 years ago. Warm conditions in the past don't give me much comfort since they highlight how sensitive the climate is to changes in forcing.

http://www.nature.com/articles/sdata201426

[LithiaWx]

Deniers have replaced the alarmists.  Both suck but deniers are the worst. 

[skierinvermont]

On 12/4/2016 at 7:41 AM, blizzard1024 said:

"Here we use a network of high-resolution terrestrial proxies from the circum-Arctic region to reconstruct past extents of summer sea ice, and show that—although extensive uncertainties remain, especially before the sixteenth century—both the duration and magnitude of the current decline in sea ice seem to be unprecedented for the past 1,450 years. "   Emphasis is mine.  Of course, it is pay walled so I can't read it. Our tax dollars pay for this research and then we have to
repay for it.  such BS. 

 

I found full free text on google in less than one minute. Quit whining and actually try. Your phony outrage and bias are the only thing that are BS here.

[skierinvermont]

19 hours ago, so_whats_happening said:

Hmmm thats weird why would we be seeing ice gains in years with temps warmer also ice losses in years with relatively low SAT anoms or little change from those temp fluctuations and then BAM. Honestly not 100% sure myself, but something is not making sense with it solely just following CO2 as many state something else seems at play here. I would love to post more in this portion of the forum but I feel, as I have seen here and other threads, people try to discredit your own thoughts on the topic at hand. While I do believe some of the responses were needed since not much factual data was presented in some posts but ideas are that ideas. How are we to grow as a science commmunity if we continue to bash each other for presenting different ideas. 

 

 

Of course there are other factors that affect sea ice than temperature. And of course there are other factors that affect temperature than CO2. That's why there's no perfect correlation on the graph. Temperature reconstructions have been around a long time and have a lot of different methods and data and peer-reviews backing them up. The temperature fluctuations prior to 1900 were small and the uncertainty in the sea ice data much higher so it would be hard to detect any correlation. There is some tendency in the graph for the first half of the graph was warmer and less ice. But the temperature fluctuations are less.

 

Intuitively it makes sense that the unprecedented warmth lately would have less sea ice. But the sea ice data has pretty large uncertainty with it. The temperature reconstructions have significant but lower uncertainty. The temperature data corroborates the ice data somewhat. It certainly doesn't prove it -that's not the point. All we can say is the high ice cooler temperatures prior to 1900 and low ice warm temperatures after 1900 "agree" with each other.

 

The point is not to find some perfect correlation in fairly rough temperature and ice reconstructions.

[blizzard1024]

Temperature fluctuations were small before 1900?? Based on proxy data?? We are comparing apples to oranges when you put proxy data against 

real temperature data. i.e Mann's hockey stick graph that has been thoroughly discredited.  Plus sea ice minimum extent is pretty stable like in the

warm 1930s for example???  Its only after we started monitoring sea ice with satellites after the cool 1970s period (AMO related) that sea ice is declining. 

That is too much of a coincidence for me when common sense is applied to climate science.  Once the AMO goes back to the cold phase you will

see Arctic sea ice recover. Maybe it doesn't recover as much as it did by the 1970s but it will recover. The CO2 forcing is overstated and has some small

influence. Everybody with common sense outside the climate change science "group think" folks who need funding can see this. That is why so many METs

are skeptical. we know how the atmosphere really works and how poor models are.  I can go on but as another poster above states...

On 12/5/2016 at 3:42 PM, so_whats_happening said:

How are we to grow as a science commmunity if we continue to bash each other for presenting different ideas. 

 If you don't believe the Earths climate is so delicate that an extra 3-4W/m2 of IR downwelling (from CO2) will throw the climate into chaos you aren't treated with any respect. So according to many on this forum a 1% change in the terrestrial greenhouse effect is enough to throw the climate out of balance. SMH.... I will stop now. 

[so_whats_happening]

9 hours ago, blizzard1024 said:

Temperature fluctuations were small before 1900?? Based on proxy data?? We are comparing apples to oranges when you put proxy data against 

real temperature data. i.e Mann's hockey stick graph that has been thoroughly discredited.  Plus sea ice minimum extent is pretty stable like in the

warm 1930s for example???  Its only after we started monitoring sea ice with satellites after the cool 1970s period (AMO related) that sea ice is declining. 

That is too much of a coincidence for me when common sense is applied to climate science.  Once the AMO goes back to the cold phase you will

see Arctic sea ice recover. Maybe it doesn't recover as much as it did by the 1970s but it will recover. The CO2 forcing is overstated and has some small

influence. Everybody with common sense outside the climate change science "group think" folks who need funding can see this. That is why so many METs

are skeptical. we know how the atmosphere really works and how poor models are.  I can go on but as another poster above states...

 If you don't believe the Earths climate is so delicate that an extra 3-4W/m2 of IR downwelling (from CO2) will throw the climate into chaos you aren't treated with any respect. So according to many on this forum a 1% change in the terrestrial greenhouse effect is enough to throw the climate out of balance. SMH.... I will stop now. 

I hear you about this there is always reason to question opinions that is just how the science community works. Things have been questioned all throughout history some stays some changes but not to say peer reviewed articles should be thrown out the window as ideas but those same ideas they present should not be the sole reason behind our thinking. Honestly I do not feel I would ever have a chance at a job if these people knew everything that was to occur 100%. lol

 

Honestly again I get there is a lag in temp and co2 correlation I get it will not go exactly as planned that as temp roses the sea ice will not react exactly to this but again I digress there seems to be something, other then what many are truly thinking is co2 release, causing what is occurring in our climate. Now to say co2 is not having some effect ehhh that's going a little far but to also say it is the sole reason  for our climate changing is also going a little to far.

[blizzard1024]

CO2 lagging the temperatures in ice cores clearly shows that it is not the main player in our climate. So the narrative goes as such, temperatures go up in the NH from orbital parameters, this causes melting of the NH land ice sheets and freshens the the north Atlantic which shuts down the thermohaline circulation. This warms the southern Oceans which then outgass CO2 which now leads to the warming in the NH. This is a very convoluted argument that has been published in a peer reviewed journal. How can CO2 after not causing any changes in the climate suddenly be activated for a time driving the climate and then go back to not driving the initial changes? There are times in the ice core records that CO2 is rising and temperatures are falling and vice-versa. It makes little sense. The oceans are more soluble when the atmosphere is cold during ice ages and they absorb CO2. That is why there is a strong correlation and a lag effect. That makes intuitive sense. CO2 passively follows the Earth's temperatures and has a small effect on the climate system. Its a minor component.   

[chubbs]

On 12/7/2016 at 6:42 PM, blizzard1024 said:

CO2 lagging the temperatures in ice cores clearly shows that it is not the main player in our climate. So the narrative goes as such, temperatures go up in the NH from orbital parameters, this causes melting of the NH land ice sheets and freshens the the north Atlantic which shuts down the thermohaline circulation. This warms the southern Oceans which then outgass CO2 which now leads to the warming in the NH. This is a very convoluted argument that has been published in a peer reviewed journal. How can CO2 after not causing any changes in the climate suddenly be activated for a time driving the climate and then go back to not driving the initial changes? There are times in the ice core records that CO2 is rising and temperatures are falling and vice-versa. It makes little sense. The oceans are more soluble when the atmosphere is cold during ice ages and they absorb CO2. That is why there is a strong correlation and a lag effect. That makes intuitive sense. CO2 passively follows the Earth's temperatures and has a small effect on the climate system. Its a minor component.   

This red herring has been around the blogs for a while. The science is clear however, CO2 does not trigger ice age cycles but plays an important role as an amplifier. When I went to school 40 years ago orbital forcing was a one of several possible explanations for ice age cycles, but the weak orbital forcing puzzled scientists. Now it is known that amplifying feedbacks play a critical role. On a global basis, orbital forcing is an order of magnitude weaker than the GHG forcing that you complain about. Orbital forcing mainly shifts solar energy from S to N hemisphere or tropics to poles without impacting total forcing.  Without GHG you can not explain the magnitude or the global  timing synchronization of ice age cycles. Scientists already understood the role of CO2 before the ice cores were drilled. The early ice cores indicated that CO2 lagged temperature in Antarctica by roughly 800 years. However more recent data indicates that the existing ice cores probably overestimate the timing difference due to air migration within snow as ice is forming. The 2013 paper below, which used heavy N isotopes to more accurately time CO2, found that there was no timing lag between temperature and CO2 in Antarctica in the last deglacial warming.  There is still uncertainty about how ice age cycles are triggered and evolve. It is unclear why the very weak 100,000 eccentricity cycle times the recent ice ages. Ice sheet dynamics, ocean currents and carbon cycles all play important roles but the details are uncertain. There is still important science to be done, because all of these feedbacks are active in the current warming, which is much more rapid than the ice-age warming depicted below. You would be better served by broadening your information sources instead of relying on blog articles which cherry-pick information to fit a narrative.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwj8puXL0unQAhXC6iYKHVOtDqQQFgguMAI&url=https%3A%2F%2Fepic.awi.de%2F32547%2F1%2Fparrenin2013s_accepted_all.pdf&usg=AFQjCNH569hSF2GM4HbRyDbrxapWT8HrDA&cad=rja

[blizzard1024]

7 hours ago, chubbs said:

This red herring has been around the blogs for a while. The science is clear however, CO2 does not trigger ice age cycles but plays an important role as an amplifier. When I went to school 40 years ago orbital forcing was a one of several possible explanations for ice age cycles, but the weak orbital forcing puzzled scientists. Now it is known that amplifying feedbacks play a critical role. On a global basis, orbital forcing is an order of magnitude weaker than the GHG forcing that you complain about. Orbital forcing mainly shifts solar energy from S to N hemisphere or tropics to poles without impacting total forcing.  Without GHG you can not explain the magnitude or the global  timing synchronization of ice age cycles. Scientists already understood the role of CO2 before the ice cores were drilled. The early ice cores indicated that CO2 lagged temperature in Antarctica by roughly 800 years. However more recent data indicates that the existing ice cores probably overestimate the timing difference due to air migration within snow as ice is forming. The 2013 paper below, which used heavy N isotopes to more accurately time CO2, found that there was no timing lag between temperature and CO2 in Antarctica in the last deglacial warming.  There is still uncertainty about how ice age cycles are triggered and evolve. It is unclear why the very weak 100,000 eccentricity cycle times the recent ice ages. Ice sheet dynamics, ocean currents and carbon cycles all play important roles but the details are uncertain. There is still important science to be done, because all of these feedbacks are active in the current warming, which is much more rapid than the ice-age warming depicted below. You would be better served by broadening your information sources instead of relying on blog articles which cherry-pick information to fit a narrative.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0ahUKEwj8puXL0unQAhXC6iYKHVOtDqQQFgguMAI&url=https%3A%2F%2Fepic.awi.de%2F32547%2F1%2Fparrenin2013s_accepted_all.pdf&usg=AFQjCNH569hSF2GM4HbRyDbrxapWT8HrDA&cad=rja

I agree that climate scientists don't fully understand the natural changes in climate and this needs more study. No doubt. But the GHG forcing

is still small as CO2 changes only 100 ppm between glacial and interglacial cycles. If there is an amplifying effect from water vapor then it must

be a logarithmic effect otherwise the climate would spiral out of control. Has anyone quantified the water vapor feedback in terms of total CO2 vs total water vapor in the

atmosphere?? There should at least be an empirical relationship.  

[chubbs]

52 minutes ago, blizzard1024 said:

I agree that climate scientists don't fully understand the natural changes in climate and this needs more study. No doubt. But the GHG forcing

is still small as CO2 changes only 100 ppm between glacial and interglacial cycles. If there is an amplifying effect from water vapor then it must

be a logarithmic effect otherwise the climate would spiral out of control. Has anyone quantified the water vapor feedback in terms of total CO2 vs total water vapor in the

atmosphere?? There should at least be an empirical relationship.  

A rough estimate follows: assuming 2xCO2 = 3C given time for ocean warming. Each degree C increases water vapor by roughly 7% per the Clausius Clapeyron equation so 2xCO2 would increase water vapor by roughly 23% (1.07^3). Note that CO2 concentrations were much lower during the last glaciation so a fixed amount of CO2 had a bigger impact due to the log relationship with forcing; 160-->280 ppm is almost a doubling and would have the same impact as 280-->490 ppm.

[blizzard1024]

Yes the CC equation would be the place to start. This works well for the lower troposphere where vapor pressures have been rising with rising temperatures. But higher water vapor in the lower troposphere actually would lead to a net cooling of the bulk atmosphere. You need higher vapor pressure in the upper troposphere and that's where it really counts. Measurements up there are uncertain. Dessler suggests it is moistening but the AIRS satellite data used in his study is not meant for long term trends. Paltridge et al 2009 suggests it is drying a little but again the radiosonde data set used is not meant for long term trends. The fact that climate scientists don't fully understand  how the Earth goes from Glacial to Interglacial cycles shows a lack of knowledge in fundamental processes of the climate system. Therefore the current warming we have seen could easily be natural. Its hard to understand how another factor kicks off a cooling or warming and then the feedbacks take over. Whatever kicks off the initial warming or cooling during an glacial or interglacial must be a major factor in our climate. Plus how do clouds factor in? GCMs don't handle clouds and they have a huge effect on the radiative balance of our planet.  Also tropical convection is a huge factor in the earth's net heat balance and again GCMs don't handle thunderstorms. Too many uncertainties in the natural climate system and a reliance on feedbacks to amplify a small amount of warming from increased CO2 is just not enough for the world to jeopardize its economy by abandoning fossil fuels before renewables are ready to take over the energy generation. Its does make a lot of sense to switch over to renewables in the future when the technology is cheap enough. Because burning fossil fuels still leads to pollution. Solar is making a lot of progress. We shall see. So I do agree with you guys on this at least. 

[chubbs]

11 hours ago, blizzard1024 said:

Yes the CC equation would be the place to start. This works well for the lower troposphere where vapor pressures have been rising with rising temperatures. But higher water vapor in the lower troposphere actually would lead to a net cooling of the bulk atmosphere. You need higher vapor pressure in the upper troposphere and that's where it really counts. Measurements up there are uncertain. Dessler suggests it is moistening but the AIRS satellite data used in his study is not meant for long term trends. Paltridge et al 2009 suggests it is drying a little but again the radiosonde data set used is not meant for long term trends. The fact that climate scientists don't fully understand  how the Earth goes from Glacial to Interglacial cycles shows a lack of knowledge in fundamental processes of the climate system. Therefore the current warming we have seen could easily be natural. Its hard to understand how another factor kicks off a cooling or warming and then the feedbacks take over. Whatever kicks off the initial warming or cooling during an glacial or interglacial must be a major factor in our climate. Plus how do clouds factor in? GCMs don't handle clouds and they have a huge effect on the radiative balance of our planet.  Also tropical convection is a huge factor in the earth's net heat balance and again GCMs don't handle thunderstorms. Too many uncertainties in the natural climate system and a reliance on feedbacks to amplify a small amount of warming from increased CO2 is just not enough for the world to jeopardize its economy by abandoning fossil fuels before renewables are ready to take over the energy generation. Its does make a lot of sense to switch over to renewables in the future when the technology is cheap enough. Because burning fossil fuels still leads to pollution. Solar is making a lot of progress. We shall see. So I do agree with you guys on this at least. 

 

I don't see any strong evidence that natural variability is contributing. In addition to the 1C of warming there is also 0.6 to 1 w/m2 of current global heat imbalance that must be explained. The sun is weak. ENSO, PDO, AMO etc., can't explain the magnitude or timing of the warming. On-the-other-hand the timing fit of temperature vs GHG+aerosal forcing is quite good with net forcing increasing rapidly after 1970. So GHG can explain all of the warming and the current heat imbalance while no natural factor can explain a significant portion. I feel we are jeopardizing the economy by ignoring GHG. Currently coal and other fossil fuels are getting a free ride for the future economic costs they are causing. This is producing a sub-optimal energy system both use and consumption.  Yes the costs are minimal now, but they will escalate rapidly at some point and persist for a very long time. It is going to take decades to wean ourselves off GHG and so changes to the economy will be slow. The first steps involve shifting away from high-carbon fuels like coal, improving energy efficiency and getting non-carbon energy up to economic scale. If done right the impacts on the economy will be minimal and have a big payback in the future. A conservative solution based on carbon pricing would allow the free market to pick winners and losers.