Do you agree that the debate is over...

[ORH_wxman]

No I think i took your point. IMO the headline is fine. It works considered in terms of what headlines subs ledes and folds are trying to do, how lay readers read, who the audience likely is, what phrasing like "the debate" probably means in context to that audience, and the strategy adopted by e.g. fhe Heartland Institute ("500 Scientists Whose Research Contradicts Man-Made Global Warming Scares") to influence that context.

Given all that the headline improves the public's view of fhe consensus science, avoids being diverted into niceties intended to accomodate contrarian agitprop, and pursues the correct policy action.

By analogy given all the controversies in evolutionary biology there isn't much mistaking in the USA what someone means when they say the media needs to address the controversy, schools should teach the controversy, etc. or what's being said when a media institution out and out says there is no debate or controversy. Darwin was in fact wrong about a helluva lot, but:

edit or with media and NWS weather products the headline and sub are not being written for either pros or enthusiasts, but for everyone's idiot cousin Colton who's gonna repost it on Facebook. Cousin Colton, the one with all the knives and whose living room is decorated with "historic flags"

 

 

We will agree to disagree on this point.

[chubbs]

There is plenty of work to do on climate change and its impact but the basics are well understood. The mechanism and range of magnitude is well established. Sure models could be off somewhat but not by an order of magnitude. Consensus estimates of the long-term average AGW  impact haven't changed much in 40+ years. The observations are in general consistent with theory and models. Not only temperature and its distribution in the atmosphere but the shrinking cryosphere and rising ocean levels. Both long-term and short-term variability is also recognized. Climate has varied in the past and will continue to vary in the future with large magnitude but on a much longer timescale than AGW. . Recently there has been better understanding of the role of variation in  ocean currents and upwelling in producing short-term variability. It is now understood that AGW will proceed in an erratic and uneven fashion that is unpredictable in the short-term but easily detectable over multi-decade periods.

 

The amounts of fossil fuel that are likely to be economically accessible are also known.to at least an order of magnitude. There is enough to produce significant AGW but not enough to get much beyond the next 50-200 years. Already renewable technologies have largely closed the cost gap to generate electricity.  Eventually use of fossil fuels will wane its just a matter of time.

[FloridaJohn]

the ice core data in my opinion is the most damning evidence that CO2 does NOT have the leverage on the climate system since it is totally in-sync with the ice core derived temperatures with a LAG of several hundred years. It did not drive the climate to change in the past...its concentration followed global temperature.

By this logic, one could say that in the past forest fires were started due to natural causes, so therefore, man cannot be responible for forest fires today. Clearly, that is not the case. Forest fires can be started both by nautural causes (i.e. lightning) and also by man-made causes (i.e. campfires).

When comparing historic rises in CO2 to the modern-day rise in CO2, one needs to look at the cause of the rise in addition to the amount of CO2. In the past, CO2 was introduced into the atmosphere by a general warming of the globe. The intial warming was primarily caused by slight changes in the orbit of the earth around the sun. As the earth warmed, CO2 locked in the earth was released into the atmosphere. This CO2 then worked to enhance, or amplify, the general warming trend.

In current times, humans are burning fossil fuels and releasing CO2 into the atmosphere. The source of the CO2 is not a natural process, humans are circumventing that in a quest for cheap energy. This CO2 in the atmosphere is working to warm the earth, just like it did in the past. If you look at the earth's orbit, you will see that we are not "coming out of an ice age," but rather entering into the long gradual slide into the next ice age. The natural climate should be cooling down now, not warming up.

In summary, when comparing CO2 levels now to the past, you have to compare the source of the CO2 in the past to the source of CO2 today and see if they are the same.

[TerryM]

The debate is far from over. One only has to follow the debates of William Nye to realise that as long as there are dollars to be made in denying science someone will come along and try to dupe the stupes. Find a cycle that is longer than the life span of the Ellesmere Ice Shelf, then we can talk of "cycles".

Terry

[blizzard1024]

The debate is far from over. One only has to follow the debates of William Nye to realise that as long as there are dollars to be made in denying science someone will come along and try to dupe the stupes. Find a cycle that is longer than the life span of the Ellesmere Ice Shelf, then we can talk of "cycles".

Terry

 

This ice shelf started breaking up 100 years ago. How could increasing CO2 possibly be to blame here?  We exited the Little Ice Age 150 years ago or so when glaciers advanced. Many glaciers started retreating far before CO2 could have done anything to the climate system. 

[ORH_wxman]

This ice shelf started breaking up 100 years ago. How could increasing CO2 possibly be to blame here?  We exited the Little Ice Age 150 years ago or so when glaciers advanced. Many glaciers started retreating far before CO2 could have done anything to the climate system. 

 

 

CO2 accelerated the process once it started warming us more.

[Jonger]

This ice shelf started breaking up 100 years ago. How could increasing CO2 possibly be to blame here? We exited the Little Ice Age 150 years ago or so when glaciers advanced. Many glaciers started retreating far before CO2 could have done anything to the climate system.

In Vaders voice:

You don't you know the power of 15ppm co2!

[sokolow]

This ice shelf started breaking up 100 years ago. How could increasing CO2 possibly be to blame here? We exited the Little Ice Age 150 years ago or so when glaciers advanced. Many glaciers started retreating far before CO2 could have done anything to the climate system.

This is of the reasons I re-asked the question up above as: when do human activities cause (plausibly detectable, noticeable, significant, dominant) effect on (local, regional, global) climate or environment on (annual, decadal, century) scales -- so with the land ice question, its: when do CO2 and temperature become a contributing factor in conjucntion with all the other things regional to local (precipitation, radiation, orientation) that affect glacier mass balance. And in fact there's a recent argument out there that the reason European alpine glaciers fall off a cliff mid 19th century is partially on account of albedo effects from industrial particulate ash. Oerlemans otoh claimed in his glacier inventory paper of the early oughts that what we call the LIA actually terminated and marked temperature rise began at the start of the 19th century, and he leaves it open to detection and attribution investigators to sort out why that is. Like we talked about before, glaciers are complex.

OK so given all that if we're going to toss it out there in terms of attribution that human GHG industrial activities are having an effect on worldwide temperatures, when does that effect become pronounced for land ice -- distinct even among all the other possible sources of variation.

I would say the latter half of the 20th century is when changes in land ice show a coherent, global, marked, and accelerating loss of length and mass.

From the 2007 UNEP report on land ice w/ Zemp and Haeberli lead authors.

Though even then changes in industrial emissions -- regulation in the West, economic collapse in the Eastern bloc -- likely play a part.

[TerryM]

I'm not sure why the dating of when the Ellesmere shelves began their retreat is pertinent. The important fact is that by carbon dating of driftwood at the head of fjords we can accurately date the last time they were ice free. When dates in excess of 5k are found it shows that the ice had continuously been in place since that early date. Any "cycle" describing polar ice extent therefore has to have a periodicity that exceeds 5k yr.

Since this far exceeds the cycles postulated it proves the unnatural nature of the recent retreat of Arctic fast ice. The addition of CO2 to the atmosphere is the accepted causal driver.

Terry

[blizzard1024]

I'm not sure why the dating of when the Ellesmere shelves began their retreat is pertinent. The important fact is that by carbon dating of driftwood at the head of fjords we can accurately date the last time they were ice free. When dates in excess of 5k are found it shows that the ice had continuously been in place since that early date. Any "cycle" describing polar ice extent therefore has to have a periodicity that exceeds 5k yr.

Since this far exceeds the cycles postulated it proves the unnatural nature of the recent retreat of Arctic fast ice. The addition of CO2 to the atmosphere is the accepted causal driver.

Terry

 

That's a fair statement in my opinion. I agree with ORH_wxman that CO2 increases could be leading to some additional warming and hastening ice loss but most land glaciers were in retreat before significant CO2 increases started.  I don't doubt that CO2 increases leads to external positive TOA radiative forcing.  I don't believe the climate was in stasis or ever is in stasis with or without CO2 changes. It is always warming and cooling and likely was warming prior to significant CO2 increases. 

[StudentOfClimatology]

No debate with arms into the realm of theoretical physics is ever "over". That doesn't mean a proposed solution is not significantly favored over another. In this case, the evidence of significant anthropogenic forcing on the climate system since 1950 is very well established in the observational data, which is why so many scientists have reached the same conclusion.

That doesn't mean it's a 100% certainty, though, and the IPCC acknowledges that in the AR5 report. People claiming 100% certainty on anything at the subatomic level are politically driven whack-jobs and should be ignored completely. I have zero respect for those who politicize science.

[sokolow]

I have zero respect for those who politicize science.

Most if not all science is either politicized or the object of politics and that's normal and fine.

I mean think about if you said "I have zero respect for those who think human subject research should be subject to national and international legislative limits" or "I have zero respect for anyone who considers the commercial or national security implications of their research" or " "I despise the NSF for reviewing grant apps instead of picking them at random out of a hat" or "NAGPRA is just superstition about spooky old bones" or "geology is of no political interest to the residents of the valley of the Vajont or Snake River plain"

[StudentOfClimatology]

Most if not all science is either politicized or the object of politics and that's normal and fine.

Two completely different orders of operation there. Politics should be the object of science, not the other way around. Otherwise the exxonmobils of the world will have their tentacles right in the research process, which will only lead to bad things. This is already happening, come to think of it.

So yeah, I don't respect those who mold science around political belief systems, and never will.

[sokolow]

Two completely different orders of operation there. Politics should be the object of science, not the other way around. Otherwise the exxonmobils of the world will have their tentacles right in the research process, which will only lead to bad things. This is already happening, come to think of it.So yeah, I don't respect those who mold science around political belief systems, and never will.

Oh. Well I don't see any particular need to indict Szilard or Einstein for setting out on a deliberate campaign to direct nuclear physics to the production of atomic bombs in order to preempt Germany, and I deeply respect the postwar scientists' movement - Oppenheimer in particular - to internationalize nulcear research, subject it to multilateral control, direct it to peaceful ends, and block further research and development of nuclear & radiological weapons.

Edit and if Heisenberg and company did in fact falsify their research to sabotage the German bomb program, that's also laudable.

That's kind of the most obvious example, but more broadly speaking polio vaccination and smallpox eradication were public health and political projects; WHO's whole mission is politically directed and it engages in deliberate propaganda to achieve it. That's fine.

The two orders are reciprocally related and inseperable.

[StudentOfClimatology]

How is any of that relevant to my point regards to the thread topic? I think you're misunderstanding what I'm trying to say here.

When exploring science within a partial theoretical domain, political and/or religious ideologies often dictate the way people reach their conclusions. I do not respect those who let their ideological world-views cloud their objectivity.

[AvantHiatus]

How is any of that relevant to my point regards to the thread topic? I think you're misunderstanding what I'm trying to say here.

When exploring science within a partial theoretical domain, political and/or religious ideologies often dictate the way people reach their conclusions. I do not respect those who let their ideological world-views cloud their objectivity.

Climate Change goes beyond the science, it will become more politicized as millions experience famine and are flooded out across the world. Such an issue cannot be handled with a cold, calculated analytic perspective.

 

We must apply some sense of emotional consideration to completely understand why we must act to reduce the threat of climate change. Otherwise, climate change is just a set of numbers experienced by said date, etc etc.

 

Scientists are not public servants or activists but they should inspire others to do so in their place. In the end, people just want the key takeaway points and not the details, which by themselves retain no value and in which their sum culminate together into a theory.

 

Your mindset also reflects a greater problem in society and the academic community of focusing on left-brain concepts over right-brain insights. Both are equally valuable.

[Jonger]

Climate Change goes beyond the science, it will become more politicized as millions experience famine and are flooded out across the world. Such an issue cannot be handled with a cold, calculated analytic perspective.

 

We must apply some sense of emotional consideration to completely understand why we must act to reduce the threat of climate change. Otherwise, climate change is just a set of numbers experienced by said date, etc etc.

 

Scientists are not public servants or activists but they should inspire others to do so in their place. In the end, people just want the key takeaway points and not the details, which by themselves retain no value and in which their sum culminate together into a theory.

 

Your mindset also reflects a greater problem in society and the academic community of focusing on left-brain concepts over right-brain insights. Both are equally valuable.

 

Do you agree with trumping up warming to accelerate the process of getting off fossil fuels?

[blizzard1024]

No debate with arms into the realm of theoretical physics is ever "over". That doesn't mean a proposed solution is not significantly favored over another. In this case, the evidence of significant anthropogenic forcing on the climate system since 1950 is very well established in the observational data, which is why so many scientists have reached the same conclusion.

That doesn't mean it's a 100% certainty, though, and the IPCC acknowledges that in the AR5 report. People claiming 100% certainty on anything at the subatomic level are politically driven whack-jobs and should be ignored completely. I have zero respect for those who politicize science.

 

There should be debate on how much man has contributed to the recent warming. That's the problem.  How come these scientists ignore the ocean cycles like the PDO and AMO and their contributions to the global temperature?  If you superimpose these two cycles, you can describe most of the warming since 1950 without invoking external forcing from CO2 increases. In addition, there were periods in the Medieval Warm Period and even during the Little Ice Age based on paleoclimate proxy data that saw periods of warming on the order of 100 years and periods of cooling at the same intervals. How do we know that the last 60 years is unusual? We have much finer resolution data now that we did then as inferred from the proxy data. How do these scientists explain these multi-century variations in the proxy data which did not have the influence of increasing CO2? 

 

This graph below shows the variations in the Greenland temperatures based on ice core data and you can see periods of warming and cooling locally. It warmed over Greenland about 1-2C over a couple hundreds years leading up to several warm periods including the Minonian....Roman and Medieval warm periods. The resolution of ice core data is much lower than today's high res data so I bet during these warm periods, arctic sea ice was decreasing, glaciers were retreating etc.  How do we know that the last 60 years were unprecedented??  These previous warm periods no doubt saw tremendous changes in the Arctic which globally sees the wildest swings in temperature.

 

 

The only thing that climate scientists can hang their hat on are computer model simulations which lead to this conclusion that anthropogenic CO2 increases are dominating the climate system now. Models are not reality, especially atmospheric models.

[AvantHiatus]

Do you agree with trumping up warming to accelerate the process of getting off fossil fuels?

Yes, to some extent but I also don't believe the theory of global warming is a lie; ie the dangers are exactly as advertised. Kind of ironic but take what you want from it. There will never be more than enough reason to end fossil fuel dependence then what we have now, it's a double-edged sword.

 

As the years go by, it seems we will not take deeper action until the bigger events start happening and also after many people have already died.

 

This is similar to the tombstone mentality, which is traditionally used for aircraft accidents but can also be applied to AGW-based problems.

 

 

Tombstone mentality is an aviation informal term that notes air safety is often improved only after somebody has died, which points out a fatal defect.

Strictly speaking, tombstone mentality decisions are examples where there is no incentive for an economic actor to be a 'first mover' and promote safety. Sometimes this is a result of market pressures (nobody wants to pay for extra safety, despite their talk), or, it may be a result of legal disincentives such as product liability lawsuits (if a design change is made that is not government approved and somebody is injured, even if the design change was not the reason for the injury, the company may be liable).

[sokolow]

Do you agree with trumping up warming to accelerate the process of getting off fossil fuels?

Rabinowitch and crew came away from the Manhattan project with some important realizations. First: science and its technological products were so powerful they posed an existential threat to humanity. Second: military, civilian, business, and media leaders are not scientific researchers, do not think like scientists, and don't share their priorities. Neither do other academic disciplines or the lay public.

So if the community of scientists is going to build bridges between these groups, it needs to adopt rhetoric and media strategies that make use of powerful symbols and blunt language. Hence the Doomsday Clock:

CHICAGO — The Science and Security Board of the Bulletin of Atomic Scientists today called on the United States and Russia to restart negotiations on reducing their nuclear arsenals, to lower alert levels for their nuclear weapons, and to scrap their missile defense programs.

The Board also implored world leaders to take immediate action to combat climate change as it announced that the minute hand of the Bulletin’s iconic Doomsday Clock will remain at five minutes to midnight because “the risk of civilization-threatening technological catastrophe remains high.”

...

“The science on climate change is clear, and many people around the world already are suffering from destructive storms, water and food insecurity, and extreme temperatures,” the Board wrote. “It is no longer possible to prevent all climate change, but you can limit further suffering—if you act now.”

Hawks called this "scaremongering" back in the Cold War; Adenauer derided the Göttinger 18 as a 'pack of panic-making sorcerer's apprentices ignorant of politics'. Rabinowitch himself even said that the BAS had in effect become a 'conspiracy to frighten men into rationality' with attendant drawbacks.

The BAS and climate science generally are in the same position of being accused of trumping up the issue now:

http://thebulletin.org/how-many-hiroshimas-does-it-take-describe-climate-change

[sokolow]

How is any of that relevant to my point regards to the thread topic? I think you're misunderstanding what I'm trying to say here.

When exploring science within a partial theoretical domain, political and/or religious ideologies often dictate the way people reach their conclusions. I do not respect those who let their ideological world-views cloud their objectivity.

Its relevant because the aspirational disciplinary ideal of an objective science doesn't describe peoples' motivations as researchers or capture the problem of the setting the science-advocacy boundary in politically contentious / regulatory arenas such as arms control or environmental policy.

edit basically what Weatherguy said translated into socsci speak.

[StudentOfClimatology]

There should be debate on how much man has contributed to the recent warming. That's the problem. How come these scientists ignore the ocean cycles like the PDO and AMO and their contributions to the global temperature? If you superimpose these two cycles, you can describe most of the warming since 1950 without invoking external forcing from CO2 increases. In addition, there were periods in the Medieval Warm Period and even during the Little Ice Age based on paleoclimate proxy data that saw periods of warming on the order of 100 years and periods of cooling at the same intervals. How do we know that the last 60 years is unusual? We have much finer resolution data now that we did then as inferred from the proxy data. How do these scientists explain these multi-century variations in the proxy data which did not have the influence of increasing CO2?

This graph below shows the variations in the Greenland temperatures based on ice core data and you can see periods of warming and cooling locally. It warmed over Greenland about 1-2C over a couple hundreds years leading up to several warm periods including the Minonian....Roman and Medieval warm periods. The resolution of ice core data is much lower than today's high res data so I bet during these warm periods, arctic sea ice was decreasing, glaciers were retreating etc. How do we know that the last 60 years were unprecedented?? These previous warm periods no doubt saw tremendous changes in the Arctic which globally sees the wildest swings in temperature.

greenland-ice-core-temperature-and-co2-11000-bp.jpg

The only thing that climate scientists can hang their hat on are computer model simulations which lead to this conclusion that anthropogenic CO2 increases are dominating the climate system now. Models are not reality, especially atmospheric models.

1. The AMO and PDO are disregarded because no viable hypothesis has been put forth to explain how they can swing the planetary energy budget on a multi-decadal timescale. My ears are open if you can give me an *verifiable* explanation, but from what I've learned, their effects are negligible.

2. I am studying paleoclimatology, and I can say without a doubt that the GISP2 graph you posted is horribly misleading, because the viable GISP isotope ratios cut off in the depth of the little ice age. All of the best proxy evidence and instrumental data reveals that we've warmed rapidly over the past 300 years. In fact temperatures today likely exceed those of the Medieval Warm Period, and are only slightly cooler than those of the Roman Warm Period.

http://geoweb.princeton.edu/people/bender/lab/downloads/Petit_et_al_1999_copy.pdf

[TerryM]

Why would anyone choose to cite ice core data in preference to data that preserves a marker for the whole of the arctic basin? 

When driftwood from Siberia is trapped by ice in Ellesmere's fjords it demonstrates that the ice wasn't present at that time, that ice has been present since that time and that the Arctic Ocean was not ice free at that time (or the driftwood would have sunk). To have this information available and to then post a graph from a particular ice core in Greenland to prove that things were warmer in the intervening years is disingenuous.

When a lake freezes on Mount Hood it doesn't prove that the State of Washington is below freezing temperature. When ice at  particular drill site in Greenland indicates a warm summer it doesn't indicate that the Arctic was warmer that summer.

Any cyclic activity between the deposit of the driftwood and the present loss of the ice shelves is obviously of a lesser magnitude and therefore can not be used to disprove AGW. If things had been warmer in any of the intervening cycles the driftwood simply would have vanished.

A better example of ideology trumping scientific rigor would be difficult to find.

Terry

[StudentOfClimatology]

Why would anyone choose to cite ice core data in preference to data that preserves a marker for the whole of the arctic basin?

When driftwood from Siberia is trapped by ice in Ellesmere's fjords it demonstrates that the ice wasn't present at that time, that ice has been present since that time and that the Arctic Ocean was not ice free at that time (or the driftwood would have sunk). To have this information available and to then post a graph from a particular ice core in Greenland to prove that things were warmer in the intervening years is disingenuous.

When a lake freezes on Mount Hood it doesn't prove that the State of Washington is below freezing temperature. When ice at particular drill site in Greenland indicates a warm summer it doesn't indicate that the Arctic was warmer that summer.

Any cyclic activity between the deposit of the driftwood and the present loss of the ice shelves is obviously of a lesser magnitude and therefore can not be used to disprove AGW. If things had been warmer in any of the intervening cycles the driftwood simply would have vanished.

A better example of ideology trumping scientific rigor would be difficult to find.

Terry

The isotope ratios within ice cores do not reflect atmospheric temperatures solely over the extraction site. That claim was invented by a few rogue skeptic bloggers arguing for a lower climate sensitivity.

The GISP isotope ratios represent Northern Hemispheric SSTs above ~ 20N. There are 3 naturally occurring O^2 isotopes (with different atomic masses)..^16/O, ^17/O, and ^18/O. The ^16/O isotope is the most frequently occurring, featuring the slightest atomic mass, followed by ^18/O which is two neutrons heavier than ^16/O. Hence it takes more energy to vaporize H-2_^18/O than H-2_^16/O. So, the first H^2O created through evaporation is highly enriched in H-2_^16/O. As warmer airmasses are propelled poleward by the Hadley and Ferrel circulations, H^2O condenses and precipitates. The atomically heavier H-2_^18/O within the droplets is the first to leave the column, leaving a greater ratio of H-2_^16/O, so the colder the airmass gets, the further the 18/O-16/O is lowered.

The temperatures required for these processes are well known. So you have to look toward the SSTs in the subtropics/mid-latitudes..all of which will affect the isotope ratios stored in the ice cores.

[StudentOfClimatology]

Climate Change goes beyond the science, it will become more politicized as millions experience famine and are flooded out across the world. Such an issue cannot be handled with a cold, calculated analytic perspective.

We must apply some sense of emotional consideration to completely understand why we must act to reduce the threat of climate change. Otherwise, climate change is just a set of numbers experienced by said date, etc etc.

Scientists are not public servants or activists but they should inspire others to do so in their place. In the end, people just want the key takeaway points and not the details, which by themselves retain no value and in which their sum culminate together into a theory.

Your mindset also reflects a greater problem in society and the academic community of focusing on left-brain concepts over right-brain insights. Both are equally valuable.

Exactly. Billions of lives are possibly hanging in the balance as sea levels continue to rise, and circulation patterns are thrown out of whack forcing droughts, starvation, and possibly much more.

This is no time to lose objectivity and act on our beliefs and emotions. We humans have a knack for screwing things up by doing just that. Look at every war in history and tell me politics and emotions were not the culprit..

The clashing of politics and emotions account for almost all violent death in history, while scientific advance (in of itself) is the only reason the human population is growing, and has saved more lives than wars have taken altogether throughout history.

It's the power of knowledge and truth. This what we must strive to grasp before anything else.

As Albert Einstein famously said: "There are only two things I know of that are infinite...the universe, and human stupidity. And I'm not sure about the former".

[ORH_wxman]

Its relevant because the aspirational disciplinary ideal of an objective science doesn't describe peoples' motivations as researchers or capture the problem of the setting the science-advocacy boundary in politically contentious / regulatory arenas such as arms control or environmental policy.

edit basically what Weatherguy said translated into socsci speak.

 

 

The problem with his explanation is that you cannot accurately attribute "The tombstones" so to speak with AGW.

 

The uncertainties are well documented in the peer reviewed science. You make policy decisions based on money and risk. There's probably an awful lot of different opinions on just how much risk is worth the price of different actions levels. However, none of this gives any excuse for poor science or to let these political biases get in the way of the scientific method. 

 

Hopefully the science is what dominates these discussions and not politics.

[blizzard1024]

The isotope ratios within ice cores do not reflect atmospheric temperatures solely over the extraction site. That claim was invented by a few rogue skeptic bloggers arguing for a lower climate sensitivity.

The GISP isotope ratios represent Northern Hemispheric SSTs above ~ 20N. There are 3 naturally occurring O^2 isotopes (with different atomic masses)..^16/O, ^17/O, and ^18/O. The ^16/O isotope is the most frequently occurring, featuring the slightest atomic mass, followed by ^18/O which is two neutrons heavier than ^16/O. Hence it takes more energy to vaporize H-2_^18/O than H-2_^16/O. So, the first H^2O created through evaporation is highly enriched in H-2_^16/O. As warmer airmasses are propelled poleward by the Hadley and Ferrel circulations, H^2O condenses and precipitates. The atomically heavier H-2_^18/O within the droplets is the first to leave the column, leaving a greater ratio of H-2_^16/O, so the colder the airmass gets, the further the 18/O-16/O is lowered.

The temperatures required for these processes are well known. So you have to look toward the SSTs in the subtropics/mid-latitudes..all of which will affect the isotope ratios stored in the ice cores.

 

Yes this is well known paleoclimatology stuff. But the isotopes are a marker for temperature and that is the point. I don't care if it is Greenland temperature or the SSTs of the midlatitudes/sub-tropics.  The point is that is shows temperature variations from this ice core data.  Clearly there are swings in temperature for centuries...both warming and cooling. I am not as concerned about the actual temperature...it is the trend that matters. Maybe it is warmer now than it was earlier in this graph. The point is that if the past showed periods of warming and cooling on the order of centuries than what makes this warm period so special? We could be in the middle of a 200 year warm cycle for all we know. This also has nothing to do with skeptics or "deniers" which is the way you like to insult people.  

[blizzard1024]

Why would anyone choose to cite ice core data in preference to data that preserves a marker for the whole of the arctic basin? 

When driftwood from Siberia is trapped by ice in Ellesmere's fjords it demonstrates that the ice wasn't present at that time, that ice has been present since that time and that the Arctic Ocean was not ice free at that time (or the driftwood would have sunk). To have this information available and to then post a graph from a particular ice core in Greenland to prove that things were warmer in the intervening years is disingenuous.

When a lake freezes on Mount Hood it doesn't prove that the State of Washington is below freezing temperature. When ice at  particular drill site in Greenland indicates a warm summer it doesn't indicate that the Arctic was warmer that summer.

Any cyclic activity between the deposit of the driftwood and the present loss of the ice shelves is obviously of a lesser magnitude and therefore can not be used to disprove AGW. If things had been warmer in any of the intervening cycles the driftwood simply would have vanished.

A better example of ideology trumping scientific rigor would be difficult to find.

Terry

 

Terry,

 

You have peaked my interest in this driftwood. I would like to read more about this. Do you have any references that are not paywalled??  The problem with trying to learn about climate science (and most sciences!!) is that the good papers are

all paywalled... if not that is fine.  I will do my best to find this stuff.  My thoughts with the above post and in general is that

we have had 1-2 century long warmings and coolings in the past so why is this one different? That's all. The magnitude of

that data does not matter as much as the trends. Anyway. Thanks. 

[AvantHiatus]

Yes this is well known paleoclimatology stuff. But the isotopes are a marker for temperature and that is the point. I don't care if it is Greenland temperature or the SSTs of the midlatitudes/sub-tropics.  The point is that is shows temperature variations from this ice core data.  Clearly there are swings in temperature for centuries...both warming and cooling. I am not as concerned about the actual temperature...it is the trend that matters. Maybe it is warmer now than it was earlier in this graph. The point is that if the past showed periods of warming and cooling on the order of centuries than what makes this warm period so special? We could be in the middle of a 200 year warm cycle for all we know. This also has nothing to do with skeptics or "deniers" which is the way you like to insult people.  

It really depends on how much "faith" you put into the science behind climate sensitivity and CO2. If you are a climate scientist or atmosphereic scientist you must be willing to accept that whatever warm cycle was occuring is now amplified by the expanding CO2 concentrations. The real debate is mostly how long it will take to reach that 3-4C+ above baseline.

 

This is why I am constantly rehashing paleoclimate along with others, the extreme warming scenarios will be inevitable if we keep pumping out CO2....it's quite simple. The aspect that trips most skeptics up is the fact that CO2 follows temperature in the climate record. However, unlike in the past, CO2 is now being released very quickly. Fast enough to act as a primary driver and the lag time between temperature and CO2 will be substantial because the oceans are currently in a state that reflects mid 20th century CO2 levels.

 

However the global state change will most likely take place on century-based timescales instead of millenniums due to the CO2 processes breaking out of the background/historic state and rising towards around 800 ppm by 2100 as a result of continued emissions and positive feedbacks.

 

 

 

CO2 didn't initiate warming from past ice ages but it did amplify the warming.  In fact, about 90% of the global warming followed the CO2 increase.

[Jonger]

There is no proof co2 enhanced past warming, its all speculation, co2 always trailed warm periods. Its very possible a shift in climate caused a massive die-off and co2 release. It would have taken a while for newly adapted foliage to begin to keep up with the natural rate of co2 emission.