Regular readers may recall some of the posts here, here, here, and here, where the sea ice data presented by NSIDC and by Cryosphere today were brought into question. We finally have an end to this year’s arctic melt season, and our regular contributor on sea-ice, Steven Goddard, was able to ask Dr. Walt Meier, who operates the National Snow and Ice Data Center 10 questions, and they are presented here for you. I have had correspondence with Dr. Meier and found him straightforward and amiable. If only other scientists were so gracious with questions from the public. – Anthony
Questions from Steven Goddard:
Dr. Walt Meier from The US National Snow and Ice Data Center (NSIDC) has graciously agreed to answer 10 of my favorite Arctic questions. His much appreciated responses below are complete and unedited.
1. Many GISS stations north of 60 latitude show temperatures 70 years ago being nearly as warm as today. This pattern is seen from Coppermine, Canada (115W) all the way east to Dzardzan, Siberia (124E.) The 30 year satellite record seems to correspond to a period of warming, quite similar to a GISS reported period in the 1920s and 1930s. Is it possible that Arctic temperatures are cyclical rather than on a linear upwards trend?
No. Analysis of the temperatures does not support a cyclic explanation for the recent warming. The warming during the 1920s and 1930s was more regional in nature and focused on the Atlantic side of the Arctic (though there was warming in some other regions as well) and was most pronounced during winter. In contrast, the current warming is observed over almost the entire Arctic and is seen in all seasons. Another thing that is clear is that, the warming during the 1920s and 1930s was limited to the Arctic and lower latitude temperatures were not unusually warm. The recent warming in the Arctic, though amplified there, is part of a global trend where temperatures are rising in most regions of the earth. There are always natural variations in climate but the current warming in the Arctic is not explained by such variations.
2. The US Weather Bureau wrote a 1922 article describing drastic Arctic warming and ice loss. In that article, the author wrote that waters around Spitzbergen warmed 12C over just a few years and that ships were able to sail in open waters north of 81N. This agrees with the GISS record, which would seem to imply that the Arctic can and does experience significant warming unrelated to CO2. Do you believe that what we are seeing now is different from that event, and why?
Yes. The current warming is different from the conditions described in the article. The Weather Bureau article is specifically discussing the North Atlantic region around Spitsbergen, not the Arctic as a whole. The Arctic has historically shown regional variations in climate, with one region warmer than normal while another region was cooler, and then after a while flipping to the opposite conditions. As discussed above, the current warming is different in nature; it is pan-Arctic and is part of widespread warming over most of the earth.
3. A number of prominent papers, including one from Dr. James Hansen in 2003, describe the important role of man-made soot in Arctic melt and warming. Some have hypothesized that the majority of melt and warming is due to soot. How is this issue addressed by NSIDC?
NSIDC does not have any scientists who currently study the effect of soot on melt and warming. Soot, dust and other pollution can enhance melting by lower the albedo (reflectance of solar energy). However, it is not clear that soot has increased significantly in the Arctic. Russia is a major source of soot in the Arctic and Russian soot declined dramatically after the break-up of the former Soviet Union – just as sea ice decline was starting to accelerate. Furthermore, while soot on the snow/ice surface will enhance melt, soot and other aerosols in the atmosphere have a cooling effect that would slow melt. Thus, the effect of soot, while it may contribute in some way, cannot explain the dramatic rate of warming and melt seen in the Arctic seen over the past 30 years.
4. The NSIDC Sea Ice News and Analysis May 2008 report seems to have forecast more ice loss than has actually occurred, including forecasts of a possible “ice-free North Pole.” Please comment on this?
What NSIDC provided in its May report was “a simple estimate of the likelihood of breaking last year’s September record.” This gave an average estimate that was below 2007, but included a range that included a possibility of being above 2007. With the melt season in the Arctic ending for the year, the actual 2008 minimum is near the high end of this range. In its June report, NSIDC further commented on its minimum estimate by stating that much of the thin ice that usually melts in summer was much farther north than normal and thus would be less likely to melt.
In the May report, NSIDC also quoted a colleague, Sheldon Drobot at the University of Colorado, who used a more sophisticated forecast model to estimate a 59% chance of setting a new record low – far from a sure-thing. NSIDC also quoted colleague Ron Lindsey at the University of Washington, who used a physical model to estimate “a very low, but not extreme [i.e., not record-breaking], sea ice minimum.” He also made an important point, cautioning that “that sea ice conditions are now changing so rapidly that predictions based on relationships developed from the past 50 years of data may no longer apply.” Thus NSIDC’s report was a balanced assessment of the possibility of setting a new record, taking account of different methods and recognizing the uncertainty inherent any seasonal forecast, especially under conditions that had not been seen before.
For the first time in our records, the North Pole was covered by seasonal ice (i.e., ice that grew since the end of the previous summer). Since seasonal ice is thinner than multiyear ice (i.e., ice that has survived at least one melt season) and vulnerable to melting completely, there was a possibility that the ice edge could recede beyond the pole and leaving the pole completely ice-free. This would be fundamentally different from events in the past where a crack in the ice might temporarily expose some open water at the pole in the midst of surrounding ice. It would mean completely ice-free conditions at the geographic North Pole (just the pole, not the entire Arctic Ocean). The remarkable thing was not whether the North Pole would be ice-free or not; it was that this year, for the first time in a long time it was possible. This does not bode well for the long-term health of the sea ice
The fact that the initial analysis of potential minimum ice extent and an ice-free pole did not come to pass reflects a cooler and cloudier summer that wasn’t as conducive to ice loss as it might have been. There will always be natural variations, with cooler than normal conditions possible for a time. However, despite the lack of extreme conditions, the minimum extent in 2008 is the second lowest ever and very close to last year. Most importantly, the 2008 minimum reinforces the long-term declining trend that is not due to natural climate fluctuations.
5. The June 2008 NSIDC web site entry mentioned that it is difficult to melt first year ice at very high latitudes. Is it possible that there is a lower practical bound to ice extent, based on the very short melt season and low angle of the sun near the North Pole?
It is unlikely that there is a lower bound to sea ice extent. One of the things that helped save this year from setting a record was that the seasonal ice was so far north and did not melt as much as seasonal ice at lower latitudes would. The North Pole, being the location that last sees the sun rise and first sees the sun set, has the longest “polar night” and shortest “polar day.” Thus, it receives the least amount of solar radiation in the Arctic. So there is less energy and less time to melt ice at the pole. However there is a feedback where the more ice that is melted, the easier it is to melt still more ice. This is because the exposed ocean absorbs more heat than the ice and that heat can further melt the ice. Eventually, we will get to a state where there is enough heat absorbed during the summer, even at the shorter summer near the pole, to completely melt the sea ice. Climate models have also shown that under warmer conditions, the Arctic sea ice will completely melt during summer.
6. GISS records show most of Greenland cooler today than 70 years ago. Why should we be concerned?
We should be concerned because the warming in Greenland of 70 years ago was part of the regional warming in the North Atlantic region discussed in questions 1 and 2 above. Seventy years ago one might expect temperatures to eventually cool as the regional climate fluctuated from a warmer state to a cooler state. The current Greenland warming, while not yet quite matching the temperatures of 70 years ago, is part of a global warming signal that for the foreseeable future will continue to increase temperatures (with of course occasional short-term fluctuations), in Greenland and around the world. This will eventually, over the coming centuries, lead to significant melting of the Greenland ice sheet and sea level rise with accompanying impacts on coastal regions.
7. Antarctica seems to be gaining sea ice, and eastern Antarctica is apparently cooling. Ocean temperatures in most of the Southern Hemisphere don’t seem to be changing much. How does this fit in to models which predicted symmetric NH/SH warming (i.e. Hansen 1980)? Shouldn’t we expect to see broad warming of southern hemisphere waters?
No. Hansen’s model of 1980 is no longer relevant as climate models have improved considerably in the past 28 years. Current models show a delayed warming in the Antarctic region in agreement with observations. A delayed warming is expected from our understanding of the climate processes. Antarctic is a continent surrounded on all sides by an ocean. Strong ocean currents and winds swirl around the continent. These act as a barrier to heat coming down from lower latitudes. The winds and currents have strengthened in recent years, partly in response to the ozone hole. But while most of the Antarctic has cooled, the one part of Antarctica that does interact with the lower latitudes, the Antarctic Peninsula – the “thumb” of the continent that sticks up toward South America – is a region that has undergone some of the most dramatic warming over the past decades.
Likewise, Antarctic sea ice is also insulated from the warming because of the isolated nature of Antarctica and the strong circumpolar winds and currents. There are increasing trends in Antarctic sea ice extent, but they are fairly small and there is so much variability in the Antarctic sea ice from year to year that is difficult to ascribe any significance to the trends – they could simply be an artifact of natural variability. Even if the increasing trend is real, this is not unexpected in response to slightly cooler temperatures.
This is in stark contrast with the Arctic where there are strong decreasing trends that cannot be explained by natural variability. These decreasing Arctic trends are seen throughout every region in every season. Because much of the Arctic has been covered by multiyear ice that doesn’t melt during the summer, the downward trend in the summer and the loss of the multiyear ice has a particularly big impact on climate. In contrast, the Antarctic has very little multiyear sea ice and most of the ice cover melts away completely each summer. So the impact of any Antarctic sea ice trends on climate is less than in the Arctic. There is currently one clearly significant sea ice trend in the Antarctic; it is in the region bordering the Antarctic Peninsula, and it is a declining trend.
Because the changes in Antarctic sea ice are not yet significant in terms of climate change, they do not receive the same attention as the changes in the Arctic. It doesn’t mean that Antarctic sea ice is uninteresting, unimportant, or unworthy of scientific study. In fact, there is a lot of research being conducted on Antarctic sea ice and several scientific papers have been recently published on the topic.
8. In January, 2008 the Northern Hemisphere broke the record for the greatest snow extent ever recorded. What caused this?
The large amount of snow was due to weather and short-term climate fluctuations. Extreme weather events, even extreme cold and snow, will still happen in a warmer world. There is always natural variability. Weather extremes are always a part of climate and always will be. In fact, the latest IPCC report predicts more extreme weather due to global warming. It is important to remember that weather is not climate. The extreme January 2008 snowfall is not a significant factor in long-term climate change. One cold, snowy month does not make a climate trend and a cold January last year does not negate a decades-long pattern of warming. This is true of unusually warm events – one heat wave or one low sea ice year does not “prove” global warming. It is the 30-year significant downward trend in Arctic sea ice extent, which has accelerated in recent years, that is the important indicator of climate change.
9. Sea Surface Temperatures are running low near southern Alaska, and portions of Alaska are coming off one of their coldest summers on record. Will this affect ice during the coming winter?
It is possible that this year there could be an earlier freeze-up and more ice off of southern Alaska in the Bering Sea due to the colder temperatures. But again, this represents short-term variability and says nothing about long-term climate change. I would also note that in the Bering Sea winds often control the location of the ice edge more than temperature. Winds blowing from the north will push the ice edge southward and result in more ice cover. Winds blowing from the south will push the edge northward and result in less total ice.
10. As a result of being bombarded by disaster stories from the press and politicians, it often becomes difficult to filter out the serious science from organisations like NSIDC. In your own words, what does the public need to know about the Arctic and its future?
I agree that the media and politicians sometimes sensationalize stories on global warming. At NSIDC we stick to the science and report our near-real-time analyses as accurately as possible. Scientists at NSIDC, like the rest of the scientific community, publish our research results in peer-reviewed science journals.
There is no doubt that the Arctic is undergoing dramatic change. Sea ice is declining rapidly, Greenland is experience greater melt, snow is melting earlier, glaciers are receding, permafrost is thawing, flora and fauna are migrating northward. The traditional knowledge of native peoples, passed down through generations, is no longer valid. Coastal regions once protected by the sea ice cover are now being eroded by pounding surf from storms whipped up over the ice-free ocean. These dramatic changes are Arctic-wide and are a harbinger of what is to come in the rest of the world. Such wide-ranging change cannot be explained through natural processes. There is a clear human fingerprint, through greenhouse gas emissions, on the changing climate of the Arctic.
Changes in the Arctic will impact the rest of the world. Because the Arctic is largely ice-covered year-round, it acts as a “refrigerator” for the earth, keeping the Arctic and the rest of the earth cooler than it would be without ice. The contrast between the cold Arctic and the warmer lower latitudes plays an important role in the direction and strength of winds and currents. These in turn affect weather patterns. Removing summer sea ice in the Arctic will alter these patterns. How exactly they will change is still an unresolved question, but the impacts will be felt well beyond the Arctic.
The significant changes in the Arctic are key pieces of evidence for global warming, but the observations from Arctic are complemented by evidence from around the world. That evidence is reported in the Intergovernmental Panel on Climate Change and thousands of peer-reviewed scientific journal articles.
Let me close by putting Arctic change and climate science within the broader scientific framework. Skepticism is the hallmark of science. A good scientist is skeptical. A good scientist understands that no theory can be “proven”. Most theories develop slowly and all scientific theories are subject to rejection or modification in light of new evidence, including the theory of anthropogenic climate change. Since the first thoughts of a possible human influence on climate over a hundred years ago, more and more evidence has accumulated and the idea gradually gained credibility. So much evidence has now been gathered from multiple disciplines that there is a clear consensus among scientists that humans are significantly altering the climate. That consensus is based on hard evidence. And some of the most important pieces of evidence are coming from the Arctic.
Mr. Goddard, through his demonstrated skeptical and curious nature, clearly has the soul of a scientist. I thank him for his invitation to share my knowledge of sea ice and Arctic climate. I also thank Anthony Watts for publishing my responses. It is through such dialogue that the public will hopefully better understand the unequivocal evidence for anthropogenic global warming so that informed decisions can be made to address the impacts that are already being seen in the Arctic and that will soon be felt around the world. And thanks to Stephanie Renfrow and Ted Scambos at NSIDC, and Jim Overland at the NOAA Pacific Marine Environmental Laboratory for their helpful comments.
Thanks once again to Dr. Walt Meier from NSIDC. He has spent a lot of time answering these questions and many others, and has been extremely responsive and courteous throughout the process.
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Jeff:
My ‘refutation’ of AGW at
http://www.tech-know.eu/uploads/AGW_hypothesis_disproved.pdf
concludes
The above list provides a complete refutation of the AGW-hypothesis according to the normal rules of science: i.e.
Nothing the hypothesis predicts is observed in the empirical data and the opposite of the hypothesis’ predictions is observed in the empirical data.
That conclusion is simply true.
But you assert:
“Your “refutation” would only be valid if the claim was that nothing besides GHG was controlling climate. Unfortunately, no one is making this claim, so your post is meaningless. IIRC, this is know as a “strawman argument”.
Well, no. I never pose straw men, and I have not in this case. As is my practice, I made clear statements that can be disputed by counter-argument and/or evidence. You have disputed none of my statements but, instead, you made the erroneous assertion that I posed a straw man. And the error of your assertion is easy to demonstrate.
The AGW hypothesis predicts that AGW will “control” climate such that global warming is inevitable. AGW will dominate other effects so global warming is an inevitable result of increased GHGs (notably carbon dioxide) in the atmosphere. If other effects than AGW were “controlling climate” then they would dominate AGW and, therefore, AGW would not occur.
My refutation at the above URL consists of two points that are listed as 5 items.
Firstly, no prediction – n.b. not one – of the AGW hypothesis is observed in the data. That could be
(a) because AGW is absent
or
(b) because AGW is so trivial that other climate effects overwhelm its effects.
But the AGW hypothesis asserts that AGW will dominate global climate change. Hence, AGW is falsified whether or not other climate effects are happening.
Secondly, the warm hot spot in the troposphere is absent: in fact, cooling is present in that region of the troposphere. But that pattern has to be present if AGW induced by enhanced GH is present.
It matters not whether other effects “control climate” because the absence of the ‘hot spot’ demonstrates the absence of AGW.
Richard
Dodgy Geezer:
“I had a marathon discussion on another board where the rule seemed to be that 30 years was the shortest period which would be accepted – this seems rather long,”
30 years has the standard used by climatologists since long before anyone thought of global warming, though I don’t know the justification for it.
“If the current warming is NOT unusual, the theory fails. ”
To claim that if the change attributed to CO2 is less than that caused by natural forcings is proof that the change could not have actually been caused by CO2 seems to me to require randomness in climate change. Otherwise, the change attributed to CO2 must have been caused by one or more natural forcing mechanisms and it should in principle be possible to identify those mechanisms.
Mr Jeff said (17:05:32) :
“FatBigot:
“Everyone should care what was published in Energy and Environment IF what was published advanced understanding of the subject.”
Energy and Environment is not a legitimate scientific journal and papers are not peer-reviewed. Only 26 libraries in the entire world even bother to subscribe to it. Its chief editor openly admits to advancing a political objective. It is more of an op-ed journal than a research journal.”
Thank you for proving my point Mr Jeff.
The most valuable question in any critical analysis is “so what”?
So what if E&E is not a “legitimate scientific journal” (whatever that is supposed to mean)? So what if it is not peer-reviewed? So what if only 26 libraries subscribe to it? So what if its chief editor has a political agenda? So what if it contains more opinion pieces than research pieces? None of that tells us anything about the value of a particular article featured in the journal. Only examination of the article itself can tell us that.
I played cricket about 15 years ago against a team we had beaten every year I can remember. They were always easy opponents until that year when they featured a guest player (a friend of one of the regular players) someone who had just retired from professional cricket and had played for England the previous year. If someone asked on Friday “does X Cricket Club have any good players” the answer would have been a resounding “no”. At 2pm on Saturday when the match started the answer suddenly became “actually they’ve got one player who is better than all of us combined.”
I wouldn’t know Energy and Environment from a bar of soap, what I do know is that one can only judge the quality of an article published in a journal by reading the article. Maybe the article in E&E was rubbish, maybe it was Einstein on stilts, one cannot judge its merit by knowing nothing about it other than where it was published.
Dodgy Geezer says:
Certainly, a good way to go is to determine not only the trendlines but also the errorbars on the trendlines. To do that correctly though, you have to take into account the correlation in the data…which an excellent data analyst like Tamino can do but can get dicey for the rest of us mortals.
Barring that, however, there are still some things one can do to determine if the trend is “real”. For example, one can check how robust the trend is to such things as changing the start or end years by one or two years, changing which data set you use (GISS or HADCRUT, for example), or eliminating one year of data. (For example, if your entire conclusion changes if you eliminate the year 1998, then the conclusion is probably not very robust!) I have done these sort of checks for the GISS and HADCRUT data and what you find is that for the yearly data ending in 2007, there is strong sensitivity to the data set used and how many years are included out to be about 10 years or so. After that, it starts to settle down and once you get out to 15 years or so, the trends seem to be quite robust.
Another thing to look at is what the climate models project. As I have noted already above in this thread, this post at RealClimate http://www.realclimate.org/index.php/archives/2008/05/what-the-ipcc-models-really-say/langswitch_lang/in shows how different runs of climate models show strong variations in the trends over a period of, say, 8 years…with many even showing negative trends…despite the fact that greenhouse gas forcings in the models are steadily increasing. So, in fact, having occasional periods of this length showing cooling is not only possible but expected!
Jeff and John Phillips:
You wrongly assert that E&E does not subject papers for publication to peer review. And you impugn the academic qualifications of E&E’s Editor who is a lady with superior academic record that of the Editor of Nature.
Being a member of the large Editorial Board of E&E, I can confirm that papers published in E&E are submitted for peer review.
E&E’s excellent and courageous Editor, Sonja Boehmer-Christiansen, oversees the peer review process with assistance from members of E&E’s Editorial Board.
The peer review process required by E&E is more severe than that of several ‘leading’ journals. E&E submits a paper for review by a range of peers whose publication records suggest that some would be favourable to the paper while others would be unfavourable. Several journals that publish papers (e.g. pertinent to AGW) have a selection of frequently-used reviewers with a smaller range of scientific views. The results of review comments can induce rejection of a paper but almost always call for amendment of a paper prior to its acceptance for publication by E&E.
The severity of E&E’s peer review process is a response to the repeated untrue assertion that peer review is not conducted by E&E.
Richard
A-CO2-GW is dead. Can we move on now?
All may not be lost though, if the great hoax can act to tweak the curiosity of the next generation to study physics, biology, geology, statistics, etc. And don’t forget sociology and psychology.
I tried to read every post, but couldn’t and have to post.
Thin Ice – Which is the thinest?
a) baby ice
b) reputations of certain climate scientists
c) reputations of certain scientific journals
d) reputations of certain political bodies
e) reputations of data adjustments
Richard S Courtney claims:
Yes…They have been. For example, one prediction is that the troposphere will warm while the stratosphere cools, which is very different than what would occur if the warming were due to an increase in solar irradiance, and matches what has been observed. Another is that the arctic will warm faster than it warms closer to the equator. A third is that the day – night temperature differences will tend to decrease.
No. As I have said a million times on this website and will probably have to say a million times more, the amplification of temperature trends or fluctuations as you go up in the tropical troposphere is NOT a prediction specific to AGW as the mechanism causing the warming. It is a prediction that follows from the basic physics of moist adiabatic lapse rate theory and is expected independent of the mechanism causing the warming.
And, in fact, when one looks at temperature fluctuations that occur on the timescales of months to a few years, you do in fact see this amplification. Where you don’t see it is in SOME of the data sets for the overall trend on multidecadal timescales. However, what you see varies strongly from data set to data set and these data sets have problems that make their overall multidecadal trends extremely problematic. For example, the radiosonde data sets are very sparse in the tropics and there are known issues with instrumentation that likely are causing a significant cooling bias over time (namely, better shielding from the sun). As one understands the problems in the data sets and starts to try to correct them, they seem to come into better agreement with what the modeling predicts (which, I repeat, is not a prediction specific to AGW but is a prediction of how temperature trends or fluctuations of any sort should tend to be amplified as one goes up in the tropical atmosphere on the basis of some pretty simple physics). See here: http://www.realclimate.org/index.php/archives/2008/05/tropical-tropopshere-ii/langswitch_lang/in
So, to make a long story short, the data and model agree on the timescales over which the data is expected to be reliable. The data and model disagree (with the data deviating from what is seen on the shorter timescales) for the longterm trends, which is exactly where the data has known problems. And, even if this deviation is real, it does not speak directly to what is causing the warming trend since the amplification is not a prediction specific to AGW as the warming mechanism.
Brendan H: “”Dodgy Geezer: “In support of this aim, and in recognition of Dr. Meier’s attitude, I think that Anthony should make a particular effort to weed insulting, off-topic, or plain ‘denial’ posts from this thread.”
Well said. The peanut gallery should be closed on threads like this. It’s not as if they’re saying anything new or original, and there are plenty of other threads for mindless politicking. “”
As a probable member of your peanut gallery, I take quick offense of your nobler than thou attitude. You have your peer reviewed articles and conferences to do your discussions, we do not. Why not restrict every thread to just those that can prove they have accredited knowledge of the thread subject? If you do not want to read a comment, then don’t. You know which posters to overlook. I think this blog is well moderated. It is read by many of us because we can make the comments, it allows us a venue to ask what we never get a chance to ask even if we show a lack of knowledge on the subject. Sometimes you need the common man view point, even if it is not quite right. Sometimes we even get a reply that enlightens us or makes us understand something we didn’t know. If a person of knowledge cannot communicate that knowledge to the average person, what good is it? Besides that, you just never know what might trigger a different train of thought in someone.
Jeff (17:05:32) :
So’s this blog, at least the 1st and 3rd sentences. No, I don’t think the moderators qualify as peer reviewers. Yet we seem to have people posting stuff on this thread faster than I can read it!
The Driver says: “The wake from an icebreakers’ massive propellers, especially when the ship is near stationary as a result of resistance from the ice-pack, is far reaching in width and depth. More than sufficient to disturb the surface haloclines. There are a lot of these vessels now, making many crossings per year. They accompany every ship attempting passage through the Soviet polar regions. It is mandatory. The Soviets have the largest, and the largest fleet of, icebreakers. Some are converted for tourism and visit the pole often every season. Satellites show that, recently at least, the Soviet side of the Arctic suffers the greatest reduction of sea ice. Broken ice is more susceptible to melting.”
Any way them smarty-pants Russians might have polluted the Arctic with their spent nuclear fuel rods and discarded nuclear-submarine reactors in order to help spur the melting and open up a treasure trove of natural resources they intended to claim for themselves? Or, barring that, if you can bar that, slicing and dicing the ice with their ice breakers for the same purpose?
Several of the above comments query the difference between weather and climate with some comments pertaining to the classical ’30-year’ period. The confusion is exemplified by the IPCC that provides the following definition of “climate” in its Glossary.
“Climate
Climate in a narrow sense is usually defined as the “average weather” or more rigorously as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These relevant quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system. ‘Climate’ is defined as an average condition over 30 years of ‘weather’ components such as temperature, pressure, humidity, precipitation, cloudiness, major wind direction, etc.”
There is a clear ambiguity in this definition. Its first sentence says “climate” is “average weather” that may be assessed “over a period of time ranging from months to thousands or millions of years”. But the final sentence of the above definition asserts that “climate” is “defined as an average condition over 30 years of ‘weather’ components”.
So, which is true, any period of time “ranging from months to thousands or millions of years” or “30 years”?
The ambiguity arises from confusion of “climate” and the “classical period of climate”. (And there are several examples of times when the confusion of “climate” and the “classical period of climate” has enabled inconvenient data to be ignored; i.e. a form of ‘cherry picking’).
“Climate” is “the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years”, and the IPCC uses this definition. For example, the IPCC used this definition in its 1994 WGI report when it considered two adjacent 5-year periods to observe change in climate.
Also, for example, there is a typical climate for January in England obtained by averaging the weather parameters (i.e. temperature, preciptation, etc.) of Januarys in England over several years. A ‘January climate’ has a length of one month.
Any number of years can be averaged for a climate value. HadCRUT3, GISS, etc. data sets report annual global temperature (i.e. climate data obtained over each of a series of years: one year climate data) but often add 5 or 10 year running means to graphical presentations of their data.
But 30 years was adopted as an arbitrary standard (i.e. the “classical period of climate”) in the year of the International Geophysical Year (the IGY was in 1958 and it was thought that 30 years of climate data had then been amassed). This “classical period” permits a base-line for comparison of climate data.
For example, the HadCRUT3, GISS, etc. data sets of annual mean global temperature each report global temperature changes as differences from a 30-year average. These differences are called ‘temperature anomalies’ and they permit direct comparisons between the data sets. However, if 30 years were used as the minimum time period for assessing global climate then we would only have 4 data points for global climate – as indicated by these data sets – because they estimate mean global temperature since about ~1860.
Indeed, 30 years is a problematic climate length because it is not a multiple of the solar 11 year sunspot cycle or the 22 year Hale cycle.
The important point is that any number of years can be averaged provided that the end dates of the averaging and the averaged data points are specified.
Richard
Until the ‘scientific consensus’ is well defined and engages in real dialogue, then the most laudable independent thoughts and efforts are in vain.
Real Dialogue:
Civil and inquisitive debate, well sourced study, sharing of data and code, proposed publication and discussion request , is non-political, be web orginized, etc.
The non-political is oh so important. This rubs both ways for us all.
I am lucky, I have a code to go by. My professional registration requires that any and all my political and commercial interests are on the table. But what governs my recommendations are public safety. It is also in the code.
I am dumbfounded sometimes when I read of scientific reports with no data or calcs submitted. Any calc I do, any observation I make are submitted for review of anybody concerned. In fact, I welcome any review.
Of course, I am not a climatologist, but I learned my maths and sciences. Get an engineer to stamp the IPCC report, put his reputaion and registration on the line.
This is all respectfully submitted, and I learn every time I log on here.
Richard S. Courtney:
“Jeff and John Phillips:
You wrongly assert that E&E does not subject papers for publication to peer review. .
Being a member of the large Editorial Board of E&E, I can confirm that papers published in E&E are submitted for peer review. ”
And the Journal of 9/11 Studies is also “peer-reviewed”.
Energy and Environment is not listed in the Journal Citation Reports (which checks 7,500 journals) and is carried by only a couple dozen libraries.
Phil. (18:53:08) Hah, you illustrate your method perfectly. I, and we, talk about ice extent, and you counter with ice area. You are a sophist rather than a seeker of truth. You’ve been called repeatedly on this sort of behaviour over at climateaudit.org. As I said, your sins are of omission rather than commission; you very rarely say something factually wrong, it’s what you don’t say, but could, that indicts your intentions.
============================================
You mean this kind of heat?
http://www.int.iol.co.za/index.php?set_id=1&click_id=14&art_id=vn20080921084615870C810928
It seems that all warming is global and all cooling is local. So S. Africa must have been moved south when we weren’t looking?
Joel Shore (19:02:02) Sure, you take 20 different models and run them a bunch of times and you’ll have runs that show a temperature decline. The mass of them do not. The mass of them expect rising temperature with rising CO2. No one has verified or validated a General Climate Model. To pretend otherwise is hallucinatory.
Can you explain why Tamino, an apparently excellent statistician, went so badly into the tank over the Hockey Stick, only finally, grudgingly, admitting error when the expert he cited called him on it. Might it have anything to do with his self applied nickname, ‘Hansen’s Bulldog’? There are many things to admire about bulldogs, but scientific objectivity is not one of them.
And please, enough with RealClimate. It is well known that when the editors there cannot handle skeptical contributions they just don’t appear on the board. That venue is a splendid example of the sort of echo chamber that Wegman decried in climate science.
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Wow.
What intense posts – both sides – on this issue.
This demonstrates a fact:
Anthropogenic causation of climate change is NOT a fact – but still, merely, a hypothesis.
Qudo’s to you, Mr. Watts.
Your fantastic site has succeeded in becoming the magnet of honest discussion from all those who have an investment in climate science. It will be here (and/or climateaudit.org) that the truth – whatever it will be – will be found.
More power to the “Watts”! 🙂
-Alan
Oops. I missed another paper in Smokey’s list that was published in a legitimate journal, the one by McKitrick and Micheals in the Journal of Geophysical Research. It claims that up to half of global warming can be explained by urbanization and land use changes. If it explained all the warming, then it would falsify the GHG theory. But it doesn’t.
I also glanced at Lindzen’s paper in the Bulletin of the American Meteorological Society. This paper questions the probability of large temperature changes from the increase in CO2 but Lindzen does not deny that CO2 can lead to some amount of warming. So no falsification in this paper.
Also, I missed the 2 papers in Climate Research, First, Idso’s paper. Idso thinks that vegetation will absorb some of the CO2 and thus limit the warming, but he allows that there could be some warming due to the increased CO2. His paper is a bit dated (1998) and he mentions the possible role of increasing insolation as a cause of warming, a mechanism that has since been shown to be insufficient. Once again, no falsification.
Also, Soon, et al., in Climate Research. (This was not the paper that led to the resignation of half of the editors.) This paper raises questions about the accuracy of the models (it’s not clear that the authors have experience with GCMs) and floats some ideas, but does little more than claim that the models aren’t accurate enough to prove that there has been any warming due to CO2. I found no claim that AGW isn’t happening or can’t happen. Again, no falsification here.
So how many papers do I have to read before I find one that even purports to falsify AGW?
Being a member of the large Editorial Board of E&E, I can confirm that papers published in E&E are submitted for peer review.
We are honoured to have an editorial board member of E&E contributing here, and I apologise for incorrectly characterising E&E as not peer-reviewed. For the purposes of identification, are you the same Richard Courtney who also serves as Technical Editor of the coal industry journal CoalTrans International ? Presumably you disqualify yourself from any editorial decisions involving, er, Energy or Environment, on the grounds of conflict of interest?
And are you the Dr Richard Courtney who signed this open letter? http://www.john-daly.com/guests/openletter.htm
If so would you share with us the title of your PhD thesis and the awarding body? Before I spend time reading your refutation of AGW, what exactly are your academic credentials, publications please?
Perhaps you could confirm that the title IPCC Expert Reviewer can be used by anyone asked to view the draft report or who submitted a comment, even unsolicited, to the review process?
regards and thanks
If the current cooling trend is a sign of AGW, what would have to happen to signal the IPCC to stop pushing AGW?
And still it cools
Yah, it cools a bit, then it warms a bit, then it cools… as Dr Courtney reminds us, the classic averaging period to discern the long term climate signal is thirty years and over this period all the global temperature series show a warming trend in line with that predicted by AGW.
Any shorter period, e.g. ‘we’ve had a decade of cooling’ is too prone to short – term noise, eg from El Nino. For example, according to UAH the global temperatures were
Jan 1997 -0.065C
Jan 2007 0.594C
So the ‘decade of cooling’ seems to have been preceded by a ‘decade of warming’. Cherry-picking? Of course,- it warms a bit, it cools a bit, it warms a bit …
Kim said
“On the basis of van Loon’s prediction of a mild winter and a cold summer I’ll predict now that this winter’s Arctic ice maximum will not exceed last winter’s and that next summer’s melt will be even less than this year. I also believe the value of the Arctic ice as a proxy for global temperature will overwhelm the strong local effects on ice. I believe that because the temperature drop over the last year has been so dramatic.”
I’m confused again by your statements Kim. If last years extent maxima was “tremendous” due to dramatic cooler global weather, that this summers extent was larger also because of this and finally that the next year or so will also be affected by this cooler global condition then how will a mild winter suddenly appear to reduce this winters maxima? For consistency you’d have to say the maximum should be a lot larger would you not?
Looking at the data last years maxima was no larger than the average and this years total melt has been larger than 2007, so neither, to me, show any global cooling effect at all.
Regards
Andy
Get 2,500 professional engineers to sign off on the IPCC.
No, that’s not good enough.
Get a consensus of registered ‘engineers’ and ‘geologists’ who agree this science is settled.
Also, lets do some blind studies, eh? Throw the data and theories out there. Throw back some verifiable hypotheses.
I contend you all are on the cutting edge of a young, fun and complex science. If you admit the vastness of what is climate, the scales which we try to measure, and how much there is to learn, then drop the politics and try and control bias, then serious science can flourish.
I am also convinced that serious science can eventually be practiced on the web, and that the talent and knowledge out there is substantial and growing.
REMEMBER: All your talents are put forth are all voluntarily, are they not?
All this knowledge, available with a few clicks. It is truly amazing.
Like Kevin Bacon as Jack said, “I represent the government of the United States without passion or prejudice.” Let us all try to let our science discourse be without passion or prejudice.
But we can still have fun, right Tom?
a,b,c,d or e?
Cheers to all! and good science.
kim (20:54:59) :
Phil. (18:53:08) Hah, you illustrate your method perfectly. I, and we, talk about ice extent, and you counter with ice area
Actually you don’t, you waffle on about ‘ice’, why anyone would want to use extent as an indicator of the amount of ice or the rate of melting or freezing is a mystery since it’s clearly unsuitable for that role. The message that the increased ice extent tells us is that this year the ice is more fragmented and spread out than last year. Talking about ‘sins of omission’, why didn’t you point out that the ice area was virtually indistinguishable from last year’s minimum? Don’t you think you should have mentioned it?