I just don't have the hubris to say today (or any in the last 30 years) is the "correct" average temperature for the earth
Not for the Earth perhaps, but certainly for us. Civilization arose in the last 10,000 years. Global Temperatures varied by +- 0.5C during that time. Those who appreciate the comforts that this stability has afforded are interested in preserving the status quo.
Who? Can you give an example? What are you even talking about? The Kyoto treaty is not scientists asking for trillions of dollars. Scientists do not stand to gain from carbon caps any more than you or I do. How does Kyoto possibly equate to scientists asking for trillions each year therefore they should provide access to data that they don't own?
You have also neatly avoided the point that the CRU results are highly replicated, often with freely available data. This point makes your argument somewhat moot.
First, since when did the CRU ask for trillions of dollars? Or even billions? Or even millions? Where do you come up with this?
Second, Why would you want to run the same process on the same data? Of course you would get the same results. This is science, not accounting. What you want to do is replicate the results. This means using the same method on different data and getting results that are equivalent. Better yet, use more data with a better process and get equivalent results. Simply running the same process on the same data is a waste of time, but does allow you to weave an interesting narrative on your blog.
Every team who has created a temperature reconstruction has found results with slightly more warming than the CRU. That includes teams that are using satellite data. It also includes teams like NASA and BEST who have released all of their data. Should we disregard the CRU data? Sure, if you want to. They don't include arctic stations. Since much of the warming is occurring in the Arctic the CRU data is of limited value.
That's the really funny thing about people who accuse the CRU of cooking their data. As owners of the reconstruction that shows the least warming, If anything, the CRU are hiding the incline.
Nothing I said was untrue. The whole "They're hiding the data!" meme is pure bunk. The CRU refused to negotiate licenses on behalf of the rent seekers, but that didn't stop scientists and hobbyists from accessing the data themselves. It seems like McIntyre and the other rent seekers are either extremely incompetent or are more interested in weaving narratives than in science. After all, it took only two days for the climategate investigators to replicate the CRU temperature reconstruction with freely available data.
Berkley Earth claims to have reacquired the data from scratch. That is, they claim to have taken it from the initial weather stations.
So it was available all along? Go figure. I guess all those rent seekers like Steve McIntyre were just blowing smoke when they whinged about being refused access. Meanwhile, the results have been replicated dozens of times by hobbyists and other scientists - most recently the Berkley team. In fact, the investigators into the hacked climate gate emails were able to replicate the results in just two days with the freely available data and the published literature.
Furthermore, were it available then the Berkley Earth program wouldn't have happened.
Errr, no. If it were not available then the Berkley Earth program wouldn't have happened. How could they have analyzed data that wasn't available??? Clearly the data is available - even if the CRU team isn't willing to host it.
...until they hit a tripping point in the arctic that'll release megatons of frozen methane which will lead to a catastrophic warming event.
These articles from realclimate.org suggest that the methane feedback is not catastrophic:
The worst-case methane scenario stands comparable to what CO2 can do. What CO2 will do, under business-as-usual, not in a wild blow-the-doors-off unpleasant surprise, but just in the absence of any pleasant surprises (like emission controls). At worst comparable to CO2 except that CO2 lasts essentially forever. - An Arctic methane worst-case scenario
The fact that the ice core records do not seem full of methane spikes due to high-latitude sources makes it seem like the real world is not as sensitive as we were able to set the model up to be. - Much ado about methane
Adding CO2 has an effect because there are non-overlapping areas of the absorption spectra between CO2 and other greenhouse gasses. Doubling CO2 will add a forcing of 3.7 W/m^2. This will warm the atmosphere somewhat. The warmer atmosphere will be able to hold additional water vapour. This will warm the planet much more as water vapour is a much more potent greenhouse gas. So you are right to worry about water vapour. This is expected to be one of the larger feedbacks from increased CO2.
We now have about 4% more water vapour in the atmosphere (relative to the 70's) as a result of global warming. This is not easily fixed. To reduce the amount of atmospheric water vapour you would need to lower the global mean temperature. Hotter air will hold more water vapour.
Actually, in terms of surface area, more would be covered by glaciers than by water
Why do we have to choose between death by ice and death by fire? We've already released enough CO2 to prevent the next glacial period. If we stopped emitting CO2 then we could prevent the hell and high water that is predicted from continuing on with business as usual.
Wow, You are comparing the money spent on science vs the money spent on PR campaigns. The former is used to build and launch satellites, the latter is used to spread misinformation and confuse the public for personal gain.
Q: Given all these caveats, how robust are the results of your study?
I think our lower climate sensitivity estimate will hold up, provided the reconstructed LGM temperature data on which it is based hold up. Our finding of a warmer LGM will prove controversial among the scientific community and the data will be subject to much scrutiny. It remains to be seen whether this temperature data is consistent with everything else we know about that period of time (its climate, its vegetation, the size of its ice sheets, etc.).
I am less confident that our narrow uncertainty range really does exclude climate sensitivities above 3 C. This is something that could be overturned by future work. It certainly would stimulate a lot of rethinking among scientists if the result isn’t overturned. I can’t say I’m rooting strongly for either outcome, though. I’d be pleased to see our findings confirmed, but if they’re disproven, I’ll learn something from the way in which they are disproven, and this will improve my own research. Who knows, maybe I will disprove them myself.
Q: Can you briefly summarize which aspects of the study you and you coauthors contributed to?
I developed and conducted the statistical data-model comparison, in collaboration with lead author Andreas Schmittner. This corresponds to Figure 3 of the paper and most of sections 5, 6, and 7 of the supporting online material. Andreas designed and carried out the model simulations. Other coauthors worked on the temperature reconstructions, the assumptions about dust forcings, etc. I can’t tell you the exact partitioning of responsibility because I entered this project relatively late, after all the proxy reconstructions and model simulations had been completed.
Q: Your paper got a lot of positive attention from climate skeptic blogs like “Watts Up With That?”. What’s your reaction to all that?
I haven’t followed these blogs too closely, but I skimmed the comments on a few that were pointed out to me. The responses I saw were fairly predictable, veering from uncritical acceptance of our findings, to uncritical dismissal of any study that involves computer models or proxy data. But some comments did seem to find an appropriate middle ground of, well, skepticism.
Q. It’s a little funny, to me, that your paper was receiving such positive comments from skeptics while many of those same skeptics also support claims by Richard Lindzen and Roy Spencer purporting to find an essentially insensitive (~1C or less) or self-stabilizing climate. Does your paper support such incredibly low values for ECS?
Our analysis found a lower bound of 1.35 C for climate sensitivity (less than 5% probability of being below this bound). We tried a range of statistical and physical assumptions, and found sensitivities as low as 1.15 C, and as high as 4.65 C (if we analyze the land data). I don’t think sensitivities lower than our bound are consistent with either our study or paleoclimatic evidence in general.
Q: Any other thoughts on the skeptics’ reception of your paper?
One blog did surprise me. World Climate Report doctored our paper’s main figure when reporting on our study. This manipulated version of our figure was copied widely on other blogs. They deleted the data and legends for the land and ocean estimates of climate sensitivity, and presented only our combined land+ocean curve:
It seems that a couple of my mails have been highlighted by people wishing to take them out of context. Both related to a very early draft of the IPCC fourth assessment observations chapter that I was asked to review informally as part of the accepted report preparation pathway. This would have been in 2005 or 2006 not 2011. IPCC has several review cycles and numerous lead authors on each chapter to ensure balance and representivity. However, the very earliest drafts inevitably reflect the individual contributor’s perspectives. The review which I undertook was and still is intended to catch such cases and rectify before the formal reviews. I would note that none of the formal review versions retained the vast majority of the text that was being discussed in this email. In other words the process worked. I would note in passing that my understanding is that US FOIA precludes early drafts of papers and discussions thereof precisely because it is vital to be able to discuss fully and frankly scientific work prior to publication, peer review being a necessary but not adequate condition. It is good that scientists care about issues and imperative that they are allowed to discuss report and paper drafts openly if we want the best reports and papers possible.
As to the tropical hotspot issue I raised it was correct in 2005/6! Here’s some headline news (if a second email tranche release also constitutes news then the bar is set very very low) science does not stand still. In the past five years there have been multiple new studies using satellites and weather balloons, including the thermal wind evidence. These studies have highlighted even more than was the case then the substantial uncertainty in tropical tropospheric temperature records. We never made these measurements for climate, they are bedevilled by non-climatic artifacts that are poorly understood. The observational evidence is so uncertain as to include anything from somewhat less warming than at the surface to substantial amplification of surface changes aloft. So, no there is no longer anywhere near as strong evidence for a lack of a tropical hotspot as was the case then. Although of course absence of evidence is not equivalent to evidence of absence for some kind of discrepancy between observations and models. The large observational uncertainty and strong inter-model consistency make the observational uncertainty a far more plausible explanation which was also the state of the science in 2005/6.
Also, to correct a mis-conception (zombie argument?) that the tropical upper-troposphere hotspot is somehow a unique signature of anthropogenic warming this is frankly baloney. The tropical troposphere is dominated by convective mixing processes. Although its not as simple as just a moist adiabatic lapse rate adjustment the net effect is that the tropical tropospheric column simply amplifies whatever changes occur at the surface. If it warms the troposphere warms with greater warming aloft. If it cools the troposphere cools at an increasing rate aloft. Models and observations concur on monthly to inter-annual timescales. So, a forcings run with a net +ve surface radiative effect will have a tropical hotspot and one with net -ve surface radiative effect will have a tropical coldspot. Single forcing model runs can easily verify this and show that the hotspot is no unique signature of CO2 forcing. It just doesn’t stack up physically. The unique anthropogenic signal is a warming troposphere / cooling stratosphere something that we see very clearly.
Finally, the caricature that has been painted of numerous of the principle actors but particularly Phil Jones are so divorced of reality and distorted. I do not know of a single person who has done more to try to advance data sharing of meteorological data for the last 15 years than Phil Jones (if you doubt me you could mine something useful instead of personal emails the GCOS report series to see how hard this really is to get to happen and ho
You are in favour of global treaties rather than local action I'm guessing? I tend to agree, but we're headed off a cliff. Someone's got to start pressing on the brake - even if they're not in the driver's seat.
There is quite a bit of nuance between what is said in each of these articles. There is no reason that each cannot be right. Global warming is irreversible. That was always true. Carbon added to the atmosphere today will still be there for my grandchildren. Damaging global warming is becoming irreversible. That is certainly true since we are starting to see damaging effects of global warming. Obama does have four years to address Global warming. That is the length of his term.
None of these preclude the idea that the decisions we make over the next five years may lock us into new infrastructure that will continue to produce carbon for decades. Nor do they preclude the possibility that that locked-in infrastructure will be enough to put us over the 2C tipping point.
It's difficult to cut through the noise and get down to what is really being said in each case - especially when the news coverage is typically hyperbolic. The best bet is to go to the source papers.
Climate is what you expect, weather is what you get. I've heard it put like this: Weather throws the punches but climate trains the boxer. So yes, a shift in weather patterns is a sign of a changing climate
British Columbia has had a revenue neutral carbon tax for a few years now. Their economy is still going strong, so I wouldn't panic. They too contribute very little to the global picture, but that can be said of 99% of the world. Ultimately China and the USA will need to step up.
Slashdot Mirror
I just don't have the hubris to say today (or any in the last 30 years) is the "correct" average temperature for the earth
Not for the Earth perhaps, but certainly for us. Civilization arose in the last 10,000 years. Global Temperatures varied by +- 0.5C during that time. Those who appreciate the comforts that this stability has afforded are interested in preserving the status quo.
Here is a reconstruction of the temperature during the Holocene: http://en.wikipedia.org/wiki/File:Holocene_Temperature_Variations.png
Who? Can you give an example? What are you even talking about? The Kyoto treaty is not scientists asking for trillions of dollars. Scientists do not stand to gain from carbon caps any more than you or I do. How does Kyoto possibly equate to scientists asking for trillions each year therefore they should provide access to data that they don't own?
You have also neatly avoided the point that the CRU results are highly replicated, often with freely available data. This point makes your argument somewhat moot.
First, since when did the CRU ask for trillions of dollars? Or even billions? Or even millions? Where do you come up with this?
Second, Why would you want to run the same process on the same data? Of course you would get the same results. This is science, not accounting. What you want to do is replicate the results. This means using the same method on different data and getting results that are equivalent. Better yet, use more data with a better process and get equivalent results. Simply running the same process on the same data is a waste of time, but does allow you to weave an interesting narrative on your blog.
Every team who has created a temperature reconstruction has found results with slightly more warming than the CRU. That includes teams that are using satellite data. It also includes teams like NASA and BEST who have released all of their data. Should we disregard the CRU data? Sure, if you want to. They don't include arctic stations. Since much of the warming is occurring in the Arctic the CRU data is of limited value.
That's the really funny thing about people who accuse the CRU of cooking their data. As owners of the reconstruction that shows the least warming, If anything, the CRU are hiding the incline.
Nothing I said was untrue. The whole "They're hiding the data!" meme is pure bunk. The CRU refused to negotiate licenses on behalf of the rent seekers, but that didn't stop scientists and hobbyists from accessing the data themselves. It seems like McIntyre and the other rent seekers are either extremely incompetent or are more interested in weaving narratives than in science. After all, it took only two days for the climategate investigators to replicate the CRU temperature reconstruction with freely available data.
Berkley Earth claims to have reacquired the data from scratch. That is, they claim to have taken it from the initial weather stations.
So it was available all along? Go figure. I guess all those rent seekers like Steve McIntyre were just blowing smoke when they whinged about being refused access. Meanwhile, the results have been replicated dozens of times by hobbyists and other scientists - most recently the Berkley team. In fact, the investigators into the hacked climate gate emails were able to replicate the results in just two days with the freely available data and the published literature.
Furthermore, were it available then the Berkley Earth program wouldn't have happened.
Errr, no. If it were not available then the Berkley Earth program wouldn't have happened. How could they have analyzed data that wasn't available??? Clearly the data is available - even if the CRU team isn't willing to host it.
Why do we have to choose between dirty energy and no energy? These false dichotomies are preventing constructive dialogue.
...until they hit a tripping point in the arctic that'll release megatons of frozen methane which will lead to a catastrophic warming event.
These articles from realclimate.org suggest that the methane feedback is not catastrophic:
The worst-case methane scenario stands comparable to what CO2 can do. What CO2 will do, under business-as-usual, not in a wild blow-the-doors-off unpleasant surprise, but just in the absence of any pleasant surprises (like emission controls). At worst comparable to CO2 except that CO2 lasts essentially forever. - An Arctic methane worst-case scenario
The fact that the ice core records do not seem full of methane spikes due to high-latitude sources makes it seem like the real world is not as sensitive as we were able to set the model up to be. - Much ado about methane
Adding CO2 has an effect because there are non-overlapping areas of the absorption spectra between CO2 and other greenhouse gasses. Doubling CO2 will add a forcing of 3.7 W/m^2. This will warm the atmosphere somewhat. The warmer atmosphere will be able to hold additional water vapour. This will warm the planet much more as water vapour is a much more potent greenhouse gas. So you are right to worry about water vapour. This is expected to be one of the larger feedbacks from increased CO2.
We now have about 4% more water vapour in the atmosphere (relative to the 70's) as a result of global warming. This is not easily fixed. To reduce the amount of atmospheric water vapour you would need to lower the global mean temperature. Hotter air will hold more water vapour.
Actually, in terms of surface area, more would be covered by glaciers than by water
Why do we have to choose between death by ice and death by fire? We've already released enough CO2 to prevent the next glacial period. If we stopped emitting CO2 then we could prevent the hell and high water that is predicted from continuing on with business as usual.
Fire and Ice: Permafrost Melt Spews Combustible Methane
Great news! Another victory for the 1 percent!
Wow, You are comparing the money spent on science vs the money spent on PR campaigns. The former is used to build and launch satellites, the latter is used to spread misinformation and confuse the public for personal gain.
Here are further comments from the author: http://newscience.planet3.org/2011/11/24/interview-with-nathan-urban-on-his-new-paper-climate-sensitivity-estimated-from-temperature-reconstructions-of-the-last-glacial-maximum/
Q: Given all these caveats, how robust are the results of your study?
I think our lower climate sensitivity estimate will hold up, provided the reconstructed LGM temperature data on which it is based hold up. Our finding of a warmer LGM will prove controversial among the scientific community and the data will be subject to much scrutiny. It remains to be seen whether this temperature data is consistent with everything else we know about that period of time (its climate, its vegetation, the size of its ice sheets, etc.).
I am less confident that our narrow uncertainty range really does exclude climate sensitivities above 3 C. This is something that could be overturned by future work. It certainly would stimulate a lot of rethinking among scientists if the result isn’t overturned. I can’t say I’m rooting strongly for either outcome, though. I’d be pleased to see our findings confirmed, but if they’re disproven, I’ll learn something from the way in which they are disproven, and this will improve my own research. Who knows, maybe I will disprove them myself.
Q: Can you briefly summarize which aspects of the study you and you coauthors contributed to?
I developed and conducted the statistical data-model comparison, in collaboration with lead author Andreas Schmittner. This corresponds to Figure 3 of the paper and most of sections 5, 6, and 7 of the supporting online material. Andreas designed and carried out the model simulations. Other coauthors worked on the temperature reconstructions, the assumptions about dust forcings, etc. I can’t tell you the exact partitioning of responsibility because I entered this project relatively late, after all the proxy reconstructions and model simulations had been completed.
Q: Your paper got a lot of positive attention from climate skeptic blogs like “Watts Up With That?”. What’s your reaction to all that?
I haven’t followed these blogs too closely, but I skimmed the comments on a few that were pointed out to me. The responses I saw were fairly predictable, veering from uncritical acceptance of our findings, to uncritical dismissal of any study that involves computer models or proxy data. But some comments did seem to find an appropriate middle ground of, well, skepticism.
Here is an interview with the author of the paper: http://newscience.planet3.org/2011/11/24/interview-with-nathan-urban-on-his-new-paper-climate-sensitivity-estimated-from-temperature-reconstructions-of-the-last-glacial-maximum/
Q. It’s a little funny, to me, that your paper was receiving such positive comments from skeptics while many of those same skeptics also support claims by Richard Lindzen and Roy Spencer purporting to find an essentially insensitive (~1C or less) or self-stabilizing climate. Does your paper support such incredibly low values for ECS?
Our analysis found a lower bound of 1.35 C for climate sensitivity (less than 5% probability of being below this bound). We tried a range of statistical and physical assumptions, and found sensitivities as low as 1.15 C, and as high as 4.65 C (if we analyze the land data). I don’t think sensitivities lower than our bound are consistent with either our study or paleoclimatic evidence in general.
Q: Any other thoughts on the skeptics’ reception of your paper?
One blog did surprise me. World Climate Report doctored our paper’s main figure when reporting on our study. This manipulated version of our figure was copied widely on other blogs. They deleted the data and legends for the land and ocean estimates of climate sensitivity, and presented only our combined land+ocean curve:
Here's Peter Thorne at realclimate.org:
It seems that a couple of my mails have been highlighted by people wishing to take them out of context. Both related to a very early draft of the IPCC fourth assessment observations chapter that I was asked to review informally as part of the accepted report preparation pathway. This would have been in 2005 or 2006 not 2011. IPCC has several review cycles and numerous lead authors on each chapter to ensure balance and representivity. However, the very earliest drafts inevitably reflect the individual contributor’s perspectives. The review which I undertook was and still is intended to catch such cases and rectify before the formal reviews. I would note that none of the formal review versions retained the vast majority of the text that was being discussed in this email. In other words the process worked. I would note in passing that my understanding is that US FOIA precludes early drafts of papers and discussions thereof precisely because it is vital to be able to discuss fully and frankly scientific work prior to publication, peer review being a necessary but not adequate condition. It is good that scientists care about issues and imperative that they are allowed to discuss report and paper drafts openly if we want the best reports and papers possible.
As to the tropical hotspot issue I raised it was correct in 2005/6! Here’s some headline news (if a second email tranche release also constitutes news then the bar is set very very low) science does not stand still. In the past five years there have been multiple new studies using satellites and weather balloons, including the thermal wind evidence. These studies have highlighted even more than was the case then the substantial uncertainty in tropical tropospheric temperature records. We never made these measurements for climate, they are bedevilled by non-climatic artifacts that are poorly understood. The observational evidence is so uncertain as to include anything from somewhat less warming than at the surface to substantial amplification of surface changes aloft. So, no there is no longer anywhere near as strong evidence for a lack of a tropical hotspot as was the case then. Although of course absence of evidence is not equivalent to evidence of absence for some kind of discrepancy between observations and models. The large observational uncertainty and strong inter-model consistency make the observational uncertainty a far more plausible explanation which was also the state of the science in 2005/6.
Also, to correct a mis-conception (zombie argument?) that the tropical upper-troposphere hotspot is somehow a unique signature of anthropogenic warming this is frankly baloney. The tropical troposphere is dominated by convective mixing processes. Although its not as simple as just a moist adiabatic lapse rate adjustment the net effect is that the tropical tropospheric column simply amplifies whatever changes occur at the surface. If it warms the troposphere warms with greater warming aloft. If it cools the troposphere cools at an increasing rate aloft. Models and observations concur on monthly to inter-annual timescales. So, a forcings run with a net +ve surface radiative effect will have a tropical hotspot and one with net -ve surface radiative effect will have a tropical coldspot. Single forcing model runs can easily verify this and show that the hotspot is no unique signature of CO2 forcing. It just doesn’t stack up physically. The unique anthropogenic signal is a warming troposphere / cooling stratosphere something that we see very clearly.
Finally, the caricature that has been painted of numerous of the principle actors but particularly Phil Jones are so divorced of reality and distorted. I do not know of a single person who has done more to try to advance data sharing of meteorological data for the last 15 years than Phil Jones (if you doubt me you could mine something useful instead of personal emails the GCOS report series to see how hard this really is to get to happen and ho
Climate scientists are providing context to the leaked emails here: http://www.realclimate.org/?comments_popup=9931
Well, call your local politician and demand real progress in Durban this month: http://unfccc.int/2860.php
Indeed! Every decade has seen cooling since 1973! The following graph must bee seen to be believed! http://planet3.org/2011/11/08/a-picture-is-worth-a-thousand-words-a-graph-more-so/
You are in favour of global treaties rather than local action I'm guessing? I tend to agree, but we're headed off a cliff. Someone's got to start pressing on the brake - even if they're not in the driver's seat.
There is quite a bit of nuance between what is said in each of these articles. There is no reason that each cannot be right. Global warming is irreversible. That was always true. Carbon added to the atmosphere today will still be there for my grandchildren. Damaging global warming is becoming irreversible. That is certainly true since we are starting to see damaging effects of global warming. Obama does have four years to address Global warming. That is the length of his term.
None of these preclude the idea that the decisions we make over the next five years may lock us into new infrastructure that will continue to produce carbon for decades. Nor do they preclude the possibility that that locked-in infrastructure will be enough to put us over the 2C tipping point.
It's difficult to cut through the noise and get down to what is really being said in each case - especially when the news coverage is typically hyperbolic. The best bet is to go to the source papers.
Great graphic! I'd love to see this animated so that you could see countries shrink or grow over time as their relative emissions change.
Climate is what you expect, weather is what you get. I've heard it put like this: Weather throws the punches but climate trains the boxer. So yes, a shift in weather patterns is a sign of a changing climate
The following graph shows that the ration of US record hot to record cold temperatures has increased steadily up to the point where it was 2:1 in the 2000's: http://www.ucar.edu/news/releases/2009/images/temps_2.jpg
In 2011 it was much worse than that - and this is during a moderately strong la-nina (which drives temperatures down): http://4.bp.blogspot.com/-5baWZYXDlCo/Tjhrbi97kpI/AAAAAAAACSg/YYzIk2KsANo/s1600/temp.records.073111.jpg
British Columbia has had a revenue neutral carbon tax for a few years now. Their economy is still going strong, so I wouldn't panic. They too contribute very little to the global picture, but that can be said of 99% of the world. Ultimately China and the USA will need to step up.
A new graph by the team at SKS shows that the entire globe has actually been cooling - decade after decade - since at least 1973! http://www.skepticalscience.com/pics/SkepticsvRealistsv3.gif