"Canada's Prime Minister Stephen Harper has just completed his seventh annual foray to the Arctic. The PM's annual northern tours have traditionally focused on a combination of announcements affecting economic development, environmental protection, and defense readiness. The ever-shrinking ice cap is bringing new challenges to Canadian policy makers, particularly with regard to the...
Quotes from Climategate 2.0 Emails
"There are two things I'm going to say though :
1) Keith didn't mention in his Science piece but both of us think that you're on very dodgy ground with this long-term decline in temperatures on the 1000 year timescale. What the real world has done over the last 6000 years and what it ought to have done given our understandding of Milankovic forcing are two very different things. I don't think the world was much warmer 6000 years ago - in a global sense compared to the average of the last 1000 years, but this is my opinion and I may change it given more evidence.
2) The errors don't include all the possible factors. Even though the tree-ring chronologies used have robust rbar statistics for the whole 1000 years (ie they lose nothing because core numbers stay high throughout), they have lost low frequency because of standardization. We've all tried with RCS/very stiff splines/hardly any detrending to keep this to a minimum, but until we know it is minimal it is still worth mentioning. It is better we (I mean all of us here) put the caveats in ourselves than let others put them in for us."
"You are the only guy who may know what was and is going on in the northern forests. ...
Another problem: the ring density and width in the last several decades are both decreasing which at any other time would be interpretted as a sign of cooling. So why is it shown in the WMO report as an unprecedented warming?
As you properly discuss in your papers we just do not know how exactly do the tree rings relate to weather. In my understanding we are left with the following options:
1) The calibrations of the rings to temperature prior to 1950 are biased, possibly due to the poor coverage of temperature stations.
2) Something other than the temperature influenced the trees in the last several decades and we do not know what."
"I do think that the Medieval Warm Period was a far more significant event than has been recognized previously, as much because the high-resolution data to evaluate it had not been available before. That is much less so the case now. It is even showing up strongly now in long SH tree-ring series. However, there is still the question of how strong this event was in the tropics. I maintain that we do not have the proxies to tell us that now. The tropical ice core data are very difficult to interpret as temperature proxies (far worse than tree rings for sure and maybe even unrelated to temperatures in any simple linear sense as is often assumed), so I do not believe that they can be used alone as records to test for the existence of a Medieval Warm Period in the tropics. That being the case, there are really no other high-resolution records from the tropics to use, and the teleconnections between long extra-tropical proxies and the tropics are, I believe, far too tenuous and probably unstable to use to sort out this issue.
So, at this stage I would argue that the Medieval Warm Period was probably a global extra-tropical event, at the very least, with warmth that was persistent and probably comparable to much of what we have experienced in the 20th century. However, I would not claim (and nor would Jan) that it exceeded the warmth of the late 20th century. We simply do not have the precision or the proxy replication to say that yet. This being said, I do find the dismissal of the Medieval Warm Period as a meaningful global event to be grossly premature and probably wrong."
"I will be sure not to bring this up to Mike [Mann]. As you know, he thinks that CRU is out to get him in some sense. So, a very carefully worded and described bit by you and Keith will be important. I am afraid that Mike is defending something that increasingly can not be defended. He is investing too much personal stuff in this and not letting the science move ahead. I am afraid that he is losing out in the process. That is too bad."
"Malcolm's comments are really quite irritating - given that we (you and I) have pioneered an honest approach to making explicit the problems. It is not as though we don't know. Mike [Mann] could be a lot more open about the real uncertainty of his early temperature estimates (as we discussed in our first perspectives piece)."
"I think that we have to stop being so aggressive in defending our series and try to understand the strengths and weaknesses of each in order to improve them. That is the way that science is supposed to work. I must admit to being really irritated over the criticism of the ECS tree-ring data standardized using the RCS method."
"I believe you criticised the inclusion of the 2000 (Eurasian) tree-ring series (since reiterated by Malcolm). Fair enough, though again misguided in my opinion if on the basis of 'contains few data' or 'has weak climate response'. I was perfectly happy to drop it ( I never suggested its inclusion in the first place), but I find it somewhat ironic that it should be replaced with the latest (Mann and Jones) series that contains the same three series plus a mixture of other far more dubious (not to say bad ) series - I agree with the remarks you made re some of these (particularly the Chinese series) in your recent email to someone. I consider that this new series (plus the illustration of the Western US series in the EOS) piece will 'stimulate further discussion' in the field, both between we palaeo-types and the Sceptics. I and Tim have been left to submit this and the balance of pressure seems to be to submit as is - if we remove the suspicious Chinese series we would have to delay things further (Ellen is hassling for us to submit) and, anyway, it is still contained in the Long series. I am of the opinion that the points made in the piece still stand - and by signing on, we are not individually sanctioning all the curves or data used in the illustrations (There are genuine problems with ALL of them)."
"Reading your letter in the EDP today makes me wonder who your source inside the Tyndall Centre was supplying you with such exaggerated evidence? Surely it wasn't me, was it? Treating Dick Lindzen with the esteem of flat-earthers; could this claim have been inserted by politicians seeking to make a dramatic point to their audience? Or was it really what the experts in the Tyndall Centre think? Perhaps we need an enquiry.
Don't worry - I'm not thinking of committing suicide should I be exposed as the source of this story; but then again, it couldn't have been me, could it?
I didn't say that after all; all I said was that we are well aware of Dick Lindzen and his arguments (in fact, Dick Lindzen is a pretty smart meteorologist who just takes a more cautious view of the scientific evidence for human causes of global warming; similar in caution in some ways to David Kelly even)."
"[W]e have been concerned that people often use the melting glacier on kilimanjaro as an example of impacts of man-made warming. you may have seen some stories countering this on the sceptics websites.
I got philip brohan to look at temps there (see attached) and there isnt any convincing consistent recent warming in the station data. but your gridded CRUtem2V does show a recent warming. presumably that is because (as philip suggests) the gridded stuff has influences from quite a large radius, and hence may reflect warming at stations a long way from kilimanjaro?
would you agree that there is no convincing evidence for kilimanjaro glacier melt being due to recent warming (let alone man-made warming)?"
"Hi Keith - great (!) to hear from you - hope you had a good holiday. Your reward (ha) is the attached paper and comment below from Konrad. He can supply data if needed for a synthetic figure, but we can add this later once the Science paper he mentions (w/ us a co-authors among millions, I assume) gets vetted more. Your call.
I'm still not convinced about the AO recon, and am worried about the late 20th century 'coolness' in the proxy recon that's not in the instrumental, but it's a nice piece of work in any case."
"The statistical efforts (yours, others) to retain more long period variability in the dendro series have led to greater variability in the reconstructions, all toward a cooler past in the 16th-17th centuries. There is no a priori reason that the improved dendro series should have led to a cooler past; retention of more long period variability might conceivably have led to a warmer past, but it did not. That makes me think that the 16th-17th centuries were indeed cooler than the hockey stick portrays."
"There is little effective communication in the main text of the uncertainty that is inherent in these measures due to the poor quality of the underlying data and metadata and to the choices made - 'structural uncertainty'. ...
What, rightly or wrongly, I get out of the current draft on an initial read is:
'We don't like UAH. We don't believe radiosondes over the satellite period, but do over the longer period (paradox). We believe Fu et al. is correct. There is no longer any problem whatsoever.'
I don't think this simple message is actually remotely supported by the science. Therefore at the very least efforts are required to balance the text so that this is not the message communicated. I don't think we should be scared of admitting that we just don't know, if indeed we just don't know (which I believe is a fair reflection of the state of the science). ...
So to state boldly that trends agree and therefore all is well is again our living in a fools paradise."
"Although I agree that GHGs are important in the 19th/20th century (especially since the 1970s), if the weighting of solar forcing was stronger in the models, surely this would diminish the significance of GHGs.
Jeez - I sound like a sceptic - this is not my intension.
I guess, ultimately, what troubles me is that of the myriad of NH recons out there now, they generally show a MWP [Medieval Warm Period] that is NOT as warm as the late 20th century. I have no trouble with this - however, the solar activity of the MWP (excluding the Oort minimum) is also generally not as high as the recent period. I know correlation does not mean causation, but it seems to me that by weighting the solar irradiance more strongly in the models, then much of the 19th to mid 20th century warming can be explained from the sun alone."
"The whole Macintyre issue got me thinking about over-fitting and the potential bias of screening against the target climate parameter.
Therefore, I thought I'd play around with some randomly generated time-series and see if I could 'reconstruct' northern hemisphere temperatures. ...
The reconstructions clearly show a 'hockey-stick' trend. I guess this is precisely the phenomenon that Macintyre has been going on about.
"My guess is that anything that the 4 of us all can find consensus on, is probably a good reflection of what the consensus is within the leaders in this field, and you could certaintly use that as ammunition in your deliberations with Peck and Susan..."
"And I also see your problem: what we are finding out now makes the IPCC process look somewhat unsophisticated back in 1990, so it is a diplomatic conundrum how to be completely truthful in reporting this, as we need to be as scientists, without providing the skeptics undue fodder for attacking IPCC. But maybe we're too concerned - the skeptics can't really attack IPCC easily in this case without shooting themselves in the foot."
"Well I have my own article on where the heck is global warming? We are asking that here in Boulder where we have broken records the past two days for the coldest days on record. We had 4 inches of snow. The high the last 2 days was below 30F and the normal is 69F, and it smashed the previous records for these days by 10F. The low was about 18F and also a record low, well below the previous record low. This is January weather (see the Rockies baseball playoff game was canceled on saturday and then played last night in below freezing weather). ...
The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't. The CERES data published in the August BAMS 09 supplement on ... shows there should be even more warming: but the data are surely wrong. Our observing system is inadequate."
"The whole issue of whether or not the MWP was more spatially heterogeneous or not is a huge 'red herring' in my opinion anyway. A growing body of evidence clearly shows that hydroclimatic variability during the putative MWP (more appropriately and inclusively called the 'Medieval Climate Anomaly' or MCA period) was more regionally extreme (mainly in terms of the frequency and duration of megadroughts) than anything we have seen in the 20th century, except perhaps for the Sahel. So in certain ways the MCA period may have been more climatically extreme than in modern times. The problem is that we have been too fixated on temperature, especially hemispheric and global average temperature, and IPCC is enormously guilty of that. So the fact that evidence for 'warming' in tree-ring records during the putative MWP is not as strong and spatially homogeneous as one would like might simply be due to the fact that it was bloody dry too in certain regions, with more spatial variability imposed on growth due to regional drought variability even if it were truly as warm as today. The Calvin cycle and evapotranspiration demand surely prevail here: warm-dry means less tree growth and a reduced expression of what the true warmth was during the MWP."
"I hope you're not right about the lack of warming lasting till about 2020. I'd rather hoped to see the earlier Met Office press release with Doug's paper that said something like - half the years to 2014 would exceed the warmest year currently on record, 1998!
Still a way to go before 2014.
I seem to be getting an email a week from skeptics saying where's the warming gone. I know the warming is on the decadal scale, but it would be nice to wear their smug grins away."
"In any case, if the sulfate hypothesis is right, then your prediction of warming might end up being wrong. I think we have been too readily explaining the slow changes over past decade as a result of variability--that explanation is wearing thin. I would just suggest, as a backup to your prediction, that you also do some checking on the sulfate issue, just so you might have a quantified explanation in case the prediction is wrong. Otherwise, the Skeptics will be all over us--the world is really cooling, the models are no good, etc.
And all this just as the US is about ready to get serious on the issue."