Arguments
Global warming hiatus claims prebunked in 1980s and 1990s
Posted on 1 February 2017 by Ari Jokimäki
The recent global warming hiatus has been a subject of intensive studies during the last ten years. But it seems that there already was some research relating to the global warming hiatus during 1980s and 1990s (the earliest studies on the issue were actually back in the 1940s-1970s). This seems to have gone largely unnoticed in the scientific literature of current global warming hiatus, and it certainly seems to have gone unnoticed by climate mitigation opponents who have made claims on the global warming hiatus since at least 2006 and still continue to do so.
Some time ago I stumbled on a few old papers which discussed the temperature evolution of the 1940s to the 1970s. In the early 20th century there had been warming which seemed to have stopped around 1940 until it resumed again in the turn of 1970s and 1980s. Here I will use "global warming moratorium" to describe this early hiatus (the reason for this can be found below). Below I'll go through some of the papers in question.
Early studies on the 1940s-1970s global warming moratorium
Global surface temperature increased during the first half of the 20th century. In 1940s, this warming apparently stopped. Possibly the first to notice this was Kincer (1946):
Up to the end of 1945, records for 13 subsequent years have become available, and these are here presented, supplementary to the original data, to determine tendencies since 1932. They show that the general upward temperature trend continued for several years but that the more recent records indicate a leveling off, and even contain currently a suggestion of an impending reversal.
This was confirmed by Mitchell (1961, 1963), as described by Wigley et al. (1985):
Mitchell (1961, 1963) extended Willett's analysis beyond 1940, improved the method of area averaging, and found that the warming prior to 1940 had subsequently become a cooling trend (as suggested earlier by Kincer [1946]).
Later, Mitchell (1970) studied the effect of anthropogenic forcings (carbon dioxide and aerosols) on the temperature evolution of 20th century. Mitchell noted on the carbon dioxide forcing:
Changes of mean atmospheric temperature due to CO2, calculated by Manabe et al. as 0.3°C per 10% change in CO2, are sufficient to account for only about one third of the observed 0.6°C warming of the earth between 1880 and 1940, but will probably have become a dominant influence on the course of planetary average temperature changes by the end of this century.
And on the global warming moratorium:
Although changes of total atmospheric dust loading may possibly be sufficient to account for the observed 0.3°C-cooling of the earth since 1940, the human-derived contribution to these loading changes is inferred to have played a very minor role in the temperature decline.
Reitan (1974) extended the temperature analysis to 1968 and reported that the global warming moratorium had continued. Brinkmann (1976) extended the analysis to 1973 and saw the first signs of global warming moratorium ending and warming resuming.
Wigley et al. (1985) mention one further point worth noting about the global warming moratorium:
All seasons show the same long-term trends, trends that are also common to all other land-based data sets: a warming from the 1880s to around 1940, cooling to the mid-1960s/early-1970s (less obvious in winter), and subsequent warming, beginning later in summer and autumn than in spring and winter.
According to Wigley et al. (1985), the global warming moratorium remained largely unexplained, although there had been some relatively successful attempts to explain the short-term variability in the surface temperature by volcanic aerosols and solar variations, see for example the discussion and analysis in Hansen et al. (1981) and in Gilliland (1982).
Oceans and surface temperature studies in the 1980s
Watts (1985) used a simple model to suggest that changes in the rate of the deep water formation can have an effect to surface temperature:
...variations in the rate of formation of deep water can lead to fluctuations in the globally averaged surface temperature similar in magnitude to variations in the earth's surface-air temperature that have occurred during the last several hundred years.
Gaffin et al. (1986) got similar results:
The largest features of the northern hemispheric surface land temperature record can be simulated with our climate and deep ocean feedback formulation and CO2 forcing alone.
Jones et al. (1987) studied the rapidity of carbon dioxide induced climate change. Within this study, they also looked at how changes in deep water formation affected warming caused by carbon dioxide. They created a simulation, where there was a global warming caused by carbon dioxide, and then they turned off the deep water formation in the Northern Hemisphere (because the global warming moratorium was strongest in Northern Hemisphere). This resulted in surface cooling right after the deep water formation was stopped, and later warming continued again.
In the late 1980s and early 1990s there were some other similar studies also.
The global warming moratorium discussion of early 1990s
So, it seems that at the turn of 1980s and 1990s there had been several studies suggesting that oceans could have a considerable effect on the surface temperature. At this point, there was a discussion in the scientific literature on the global warming moratorium, and this discussion has some interesting resemblance to the current global warming hiatus discussion.
Watts and Morantine (1991), in an editorial of Springer's journal Climatic Change, reviewed the research which I already have discussed above. They noted the possibility of energy transfer between the surface and the deep ocean and concluded:
It is entirely possible that the greenhouse gas climate change signal is alive and well and hiding in the ocean intermediate waters, having reached there because of increased upwelling, or by some other mechanism that could effectively transport heat from the upper layers of the ocean into the huge thermal reservoir of the intermediate and deep ocean.
Kellogg (1993) revisited the issue, also in the same journal, with a letter named as "An Apparent Moratorium on the Greenhouse Warming Due to the Deep Ocean". Kellogg described some new observational evidence for the ocean's role in the issue. Based on this he suggested:
...oceans could sequester a significant part of the incremental greenhouse-generated heat over a period of a few decades, a period during which the surface warming would be curtailed.
Kellogg also discussed some issues relating to timing of the global warming moratorium and what would have happened if oceans wouldn't have had a role in the surface temperature. Relating to the current global warming hiatus discussion, Kellogg made an interesting note:
One of the arguments most frequently advanced by the skeptics is that the observed warming in this century should have been larger, based on climate models that do not take account of ocean circulations, and that there should theoretically have been no such 'moratorium' between 1940 and 1975.
Kellogg then notes that if the oceans played a role, there wouldn't be such a problem.
Watts and Morantine (1993) also revisited the issue (perhaps the journal sent them Kellogg's letter and asked for their response). There were couple of additional interesting points in their response relating to current discussion on global warming hiatus. They noted on the significance of the moratorium:
In a recent article by Galbraith and Green (1992), a series of statistical tests were performed on the global average temperature time series from 1880 to 1988 (Hansen and Lebedeff, 1987). A statistically significant trend that can be approximated by a linear term was found, and the deviation from this trend during the period between 1940 and 1970 was found to fall within the range of sample fluctuation.
And:
Even though the surface temperature of the Earth is an important piece of information, the distribution of thermal energy is a three-dimensional problem.
What I have shown here is just a sample of all papers that were studying the issue. The research on the issue also continued after the papers presented here.
The significance for current hiatus discussion
It is clear that before the 2000s there had been lot of research on the subject of short-term variability of surface temperature in a presence of a long-term warming trend. The research back then also pointed to probable causes of the short-term variability.
Apparently, the first claims of global warming hiatus after 1998 were made in 2006 by well-known climate change mitigation opponents. This was obviously far too soon statistically to make those claims, and there was no indication that the claims were made with knowledge of the earlier discussion and research on the subject. It also should be noted, that the claims in question were not made in the scientific literature but in the popular media (a situation that has continued after that and largely continues even today).
However, lots and lots of papers have been published on the recent global warming hiatus. I have sampled the reference lists of some of them and it seems that also the scientific community has largely forgotten that the issue has already been studied. This seems a bit unfortunate and makes one wonder if we will have forgotten the current research when the next moratorium or pause or hiatus or whatever happens.
References:
Waltraud A.R. Brinkmann (1976), Surface temperature trend for the Northern Hemisphere-updated, Quaternary Research, Volume 6, Issue 3, September 1976, Pages 355-358, doi:10.1016/0033-5894(67)90002-6. http://www.sciencedirect.com/science/article/pii/0033589467900026
Gaffin, S. R., M. I. Hoffert, and T. Volk (1986), Nonlinear coupling between surface temperature and ocean upwelling as an agent in historical climate variations, J. Geophys. Res., 91(C3), 3944–3950, doi:10.1029/JC091iC03p03944.
http://onlinelibrary.wiley.com/doi/10.1029/JC091iC03p03944/full
Gilliland, R.L. (1982), Solar, volcanic, and CO2 forcing of recent climatic changes, Climatic Change, 4: 111. doi:10.1007/BF00140585.
http://rd.springer.com/article/10.1007/BF00140585
J. Hansen, D. Johnson, A. Lacis, S. Lebedeff, P. Lee, D. Rind, G. Russell (1981) Climate Impact of Increasing Atmospheric Carbon Dioxide, Science 28 Aug 1981: Vol. 213, Issue 4511, pp. 957-966, DOI: 10.1126/science.213.4511.957.
http://science.sciencemag.org/content/213/4511/957
P. D. Jones, T. M. L. Wigley, , S. C. B. Raper (1986), The Rapidity of CO2-Induced Climatic Change: Observations, Model Results and Palaeoclimatic Implications, in Abrupt Climatic Change, Volume 216 of the series NATO ASI Series pp 47-55.
http://rd.springer.com/chapter/10.1007/978-94-009-3993-6_4
Kellogg, W.W. (1993), An apparent moratorium on the greenhouse warming due to the deep ocean, Climatic Change 25: 85. doi:10.1007/BF01094085.
http://rd.springer.com/article/10.1007%2FBF01094085
Kincer, J. B. (1946), Our changing climate, Eos Trans. AGU, 27(3), 342–347, doi:10.1029/TR027i003p00342.
http://onlinelibrary.wiley.com/doi/10.1029/TR027i003p00342/abstract
Mitchell, J. M. (1961), RECENT SECULAR CHANGES OF GLOBAL TEMPERATURE. Annals of the New York Academy of Sciences, 95: 235–250. doi:10.1111/j.1749-6632.1961.tb50036.x
http://onlinelibrary.wiley.com/doi/10.1111/j.1749-6632.1961.tb50036.x/abstract
J. Murray Mitchell Jr. (1970), A Preliminary Evaluation of Atmospheric Pollution as a Cause of the Global Temperature Fluctuation of the Past Century, 139-155. In, S.F. Singer (ed.), Global Effects of Environmental Pollution. Springer Verlag, New York, New York.
http://rd.springer.com/chapter/10.1007/978-94-010-3290-2_15
Clayton H. Reitan (1974), A climatic model of solar radiation and temperature change, Quaternary Research, Volume 4, Issue 1, March 1974, Pages 25–38, http://dx.doi.org/10.1016/0033-5894(74)90061-1.
http://www.sciencedirect.com/science/article/pii/0033589474900611
Watts, R. G. (1985), Global climate variation due to fluctuations in the rate of deep water formation, J. Geophys. Res., 90(D5), 8067–8070, doi:10.1029/JD090iD05p08067.
http://onlinelibrary.wiley.com/doi/10.1029/JD090iD05p08067/full
Watts, R.G. & Morantine, M.C. (1991), Is the greenhouse gas-climate signal hiding in the deep ocean?, Climatic Change 18: iii. doi:10.1007/BF00142966.
http://rd.springer.com/article/10.1007%2FBF00142966
Wigley, T.M.L., Angell, J.K. and Jones, P.D., 1985. Analysis of the temperature record. In: M.C. MacCracken and F.M. Luther (Eds.), Detecting the Climatic Effects of Increasing Carbon Dioxide, (DOE/ER-0235), U.S. Department of Energy, Carbon Dioxide Research Division, Washington, D.C., 55-90.
http://archives.aaas.org/docs/Detecting_Climate_Effects_Increasing_CO2.pdf
Tamino claimed several times that the hiatus is statistically not even there (e.g. here). How does the SkS team weigh in in this issue?
Alexandre, unfortunately there is a lot of confusion about this topic due to use of jargon and loose terminology rather than actual disagreements among scientists. I agree with Tamino (enter "pause" in the search field of his site) and others that there has been no hiatus/pause/slowdown in "the trend" of surface temperature, given that I and those other people define "the trend" to mean the "long term" trend in surface temperature. There is no doubt among those people that the surface temperature has, does, and always will vary around that long term trend, as "short term" trends that are too short to reasonably imply any change in the underlying long term trend.
Some scientists have investigated the causes of "the pause/hiatus/slowdown," unfortunately using those terms instead of being clear that they were discussing one of (or some of) those short term trends, not the underlying long term trend.
Excellent history. I find this pause issue pretty interesting, just as a lay person observer. I think a lot of this depends on how you define a hiatus or pause.
For example, I'm looking at the NASA Giss surface temperature record, and clearly there was a slowdown in surface temperatures from roughly 2002 - 2010, (just eye balling the graph)and there were also previous slowdowns like this. I see this as a slowdown or pause of at least some kind. I would suggest the general public see this as a pause, and it would be most unwise to say to them its not a pause, or you come across as claiming white is black. It's important not to let the denialist people spook you into making wild claims. Of course you can say with validity that this "pause" was not statistically significant.
I think it would be valid to say theres been no 'pause' in terms of the underlying greenhouse effect, or total energy accumulation, because that is what the evidence shows. But you should be specific that theres no pause in terms of energy accumulation, and not simply say there was no pause of any kind.
The real issue to me is what caused the pause in surface temperatures? The most likely explanation is natural variation or noise.
Given the greenhouse effect should in theory and assuming it is the only climate forcing agent, cause a straight line, it can only be natural variation. Foster and Rhamstorf subtracted all known natural cycles from the temperature record and were left with something getting near a straight line, reinforcing the natural variation theory. There was nothing to suggest something totally unknown was at play.
The sunspot cycle is known to be a factor that can supress or exaggerate temperatures for a period.
Ocean cycles clearly affect surface temperatures, because el nino and la nina years stand out. It appears there were a lot of la ninas and weak el ninos during the slow period, which suggests some sort of ocean process. My understanding is energy went into the deep oceans, and it's hard to measure this affect on temperatures at that depth, so hence the generally flat global temperatures.
Clearly the pause is now over, which suggests this ocean phenomenon has reversed and may be cyclical. But do we know for sure, could you get quite a long pause? It seems to me these ocean cycles are not well understood. However the ocean can't by definition act as some sort of heat sink forever, and that heat is going to come out, or alternatively the ocean would stop absorbing so much heat. Given the big jump in temperatures over the last three years it must be one or the other?
The IPCC back about 1990 also predicted slow periods of about 10 years, due to natural variation, and we have seen a slow period of about 6 - 10 years depending on what graph you look at. This prediction surely reinforces that the IPCC is a reliable authority. Rather than playing down the pause, I would highlight this. Don't let the denialists frame the debate and make the definitions.
Wonderful article. A few weeks ago I was having a conversation with someone I know who is a long-time AGW denier who frequently waffles on exactly the position he takes.
In that conversation he denied that anyone has claimed there was/is a pause in warming.
Ari Jokimäki observes that "apparently, the first claims of global warming hiatus after 1998 were made in 2006 by well-known climate change mitigation opponents."
Of course there is the distinction between the science literature and the popular literature.
I would like to see an attempt made to create a complete bibliography of the leading denier articles that claimed there was/is a pause in warming.
The historical record of this travesty should be preserved.
The common practice for evaluating climate data has always been to look at a 30-year set of data (along with all the previous history that is available). That was always the way that the Canadian Building Code climate data for design was updated every 10 years, a new most recent 30 year set of data being the basis for location specific design values (along with the full history of data for each location).
An appropriate way to look at the trend of the data is the 30-year rolling average.
There has been no pause/hiatus in the 30-year riolling average. Evene the 40 year satellite data would show a fairly steady rise of the 10 years of 30-year rolling average.
Looking at shorter sets of data (or cherry-picking bits of detail from the historical record) is the only way to create the impression of justification for claims that warming due to increased CO2 is not continuing to occur, or the rate of warming has dramatically changed from a previous rate in a way that is inconsistent with the current best understanding of climate science.
A deep dive comes up with a fascinating report. Thanks for this; great stuff.
@5 OPOF, I have great difficulty explaining this to people, I'm guessing because 30 years in some cases a significant fraction of their lives. Even people with some matematical training are happy to pick a couple of yeaars to prove their point but to ignore long term trends. Personally I hope that the models and trends are shown to be erroneous, but the evidence is stacked against that I believe.
Pause for thought.
There was this now infamous comment in a leaked e-mail from the University of East Anglia, “no upward trend” has to continue for a total of 15 years before we get worried."
Personally, I'm more worried by the fact that there wasn't nor isn't a pause in the surface trend, or indeed the lower troposphere, but that aside, such an off the cuff remark never intended for public consumption did for many provide a source of authority to (falsely) validate the significance of a short term weakening of the surface trend.
uncletimrob@7,
There is another way of talking about the 30-year trend in surface temperature data.
The monthly surface temeprature values vary significantly even from month to month. This can be seen in the scatter of the monthly value dots on any data presentation. So if there was indeed no significant continuing warming trend any new monthly average temperature should have a significant chance of being cooler than the value 360 months earlier.
Prior to the 1980s that was indeed the case. The rate of CO2 increase and the resulting warming was less than the more recent rate (and things like particulate from lousy burning of fossil fuels dampened the warming). Since the 1980s there are significantly fewer cases where a monthly value is lower than the value 360 months before.
The satellite data also has very few cases where a monthly value is cooler than the value 360 months prior. Of course it is such a short data set that it is difficult to justify any interpretation of the satellite data set as Trumping what is seen in data sets with longer durations of data. But that does not justify delaying actions to reduce the rate of CO2 increase until there is more satellite data.
An additional point about climate variability and the importance of considering 30 year periods of data: When climate design data is developed for the Canadian Buidling Code any data gathering location with less than 30 years of data is considered to be a marginally accurate basis for design requirements. And even at a location with 30 years of data the nearest location with more than 30 years of data is referred to when trying to decide what would be reasonable.
Art Vandelay @8, yes the leaked emails were most unfortunate. Rotten luck really. They were so open to manipulation.
I work in technology not science, but I know that the term "tric and hide the decline" were not sinister, and were shorthand for completely legitimate processes as various investigations have found, but they are created a bad impression.
Regarding temperatures my understanding is similar to OPOF that you need 30 years of data to get beyond natural variation. Basically the IPCC only confirmed we were altering the climate when they had a 30 year warming trend.
I also understand that the IPCC says any pause or slowdown less then 15 years is just natural varaition and temporary, over 15 years and we would need to be asking questions. The slowdown a few years back was nearer 6- 10 years so doesn't bother me, and I just fail to see why some people say it wasn't a pause.
My understanding is that all powerful natural variation operates on quite short cycles, up to about 15 years, but there are longer term cycles like the PDO that work on longer cycles, but are unlikely to slow warming significantly as far as I understand.
I would also be worried if there were no pauses or "blips". You would not expect the climate to warm in a precisely straight line from CO2, as there are just obviously natural influences modulating this.
However the pause around the 1950s was quite long, and has not been well explained as yet. It seems to correspond to a slow period in solar activity and aerosols from industry, but as far as I'm aware neither really explain this period according to the article above. Were there ocean processes at work?
Yes threr is global warming. There are natural causes of GW other than human produced GHGs
Again proponeents of GW are reaching for any any unproven or untestable hypothesizes to support global warming continues unabeatted Obviously theer was pause in GW between 1945 and 196 as there was between 1998 and 2013. But these paises are denied. Now we GW sup[porter are latching onto theories re the ocean currents and cycles w/o any data to support these supposed studies.
They ignore that between 1934 and 1944 the global temp increse 0.45 C.
A much bigger change than we just experienced since 2011.
Why did the global temp incr so much bewteen 1934 & 1944 would be good to know ansd compare to what is happening today.
Obviously the sun influences cvlimate on earth as it did during the LIA, ie the suns rotation slowed . but items ike this are debunked as bad science, while theories of deep welling in the ocean are accepted.
[PS] Deleted rampant offtopic sloganeering. This appears to be a pattern. Multiple comments policy infringements. In particular, note the requirement for backing your claims with evidence. Things like "science ignores" are patently false as even a cursory reading of IPCC reports would tell you. Furthermore please use the search function to find appropriate topics and dont bother with gish-gallops of long-debunked talking points.
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Clearly any slowdown in global temperatures of any length, or pause raises the question of solar influences. My understanding is that there are three solar cycles influencing the climate, and that they cannot significantly slow down the projected warming from greenhouse gases. I would be interested if the experts could tell me if I have got this about right as below.
Firstly the suns energy output varies in an 11 year cycle, but not very much and only causes a fraction of a degree of change. Given the short period of the cycle it cannot really slow down longer term warming from greenhouse gases.
Secondly we have a longer solar cycle of about 50 years (from the article on this website called "It's The Sun") but this only changes temperatures by about 1 degree maximum. It was responsible for the Maunder minimum in the 1800's where global temperatures dropped about half a degree. We base knowledge of this cycle partly on historical evidence as well as scientific calculation.
It does appear we are now in a cooling phase of this cycle, but it is calculated to have negligible affect. Given this cycle only has a small affect on temperatures and in the suns energy output, it can't really significantly slow down warming from greenhouse gases and won't save us, and could equally speed it up slightly anyway later this century.
Thirdly we have changes in solar insolation due to regular changes in the earths orbit that can alter temperatures by a degree or two, but this cycle is 100,000 years preiodicity and we are in a stable part of the cycle, and will remain there for about 10 - 20,000 years. (This stuff is mainstream science and not controversial so I won't to provide a link). This cycle is therefore not capable of impacting on warming from greenhouse gases over the next few thousands of years, so won't save us and is irrelevent to the debate.
Fred Singer talked about a long term solar cycle. I can't remember the name, but this cycle has been discredited as it doesn't cause a net change in global temperature.
So in conclusion my understanding is changes in solar energy output from the sun have been extensively researched, and are extremely unlikely to significantly slow down future warming from CO2.
One of my wishes is that someone with better statistical and graphic skills than I will update Hansen's 1988 scenarios with 2016 data. At about 1c above baseline, I think we passed, at least briefly, above scenario B and not far off from scenario A.
Presenting this in a graphic form would stick a stake in the heart of the "models are wrong" argument if Hansen absolutely nailed predictions 30 years into the future... which he pretty much accomplished.
[PS] The Hansen 1988 predictions are discussed in detail here. Take a look at the article and please have any followups on that thread please.
At @ 8,
Pause for thought.
There was this now infamous comment in a leaked e-mail from the University of East Anglia, “no upward trend” has to continue for a total of 15 years before we get worried."
The email was written in 2009, so a continued 15 years of no warming takes us to... 2024. Often misconstrued as 15 years only, but the language is quite clear.
Alexandre @ 1,
Tamino claimed several times that the hiatus is statistically not even there (e.g. here). How does the SkS team weigh in in this issue?
To be clear, the OP is about the 'pause' from the 40s to the 70s, Tamino on the recent slowdown.
While SkS have examined the so-called pause from a variety of angles, Tamino's take is that calling a pause is statistically invalid.
bobbyj, made a quick reply in the Hansen 88 thread.
https://skepticalscience.com/Hansen-1988-prediction-advanced.htm#120318
[PS] Thank you for your cooperation. Most appreciated.
The claims by Dr John Bates, a climate scientist (it seems actually a meteorologist) formerly responsible for NOAA’s climate archive, (https://judithcurry.com/2017/02/04/climate-scientists-versus-climate-data/) do bring a sense of unease about this discussion on "the pause". Dr Bates says this: "The most serious example of a climate scientist not archiving or documenting a critical climate dataset was the study of Tom Karl et al. 2015 (hereafter referred to as the Karl study or K15), purporting to show no ‘hiatus’ in global warming in the 2000s The most serious example of a climate scientist not archiving or documenting a critical climate dataset was the study of Tom Karl et al. 2015 (hereafter referred to as the Karl study or K15), purporting to show no ‘hiatus’ in global warming in the 2000s" Dr Bates goes on to say:
"I questioned another co-author about why they choose to use a 90% confidence threshold for evaluating the statistical significance of surface temperature trends, instead of the standard for significance of 95% — he also expressed reluctance and did not defend the decision. A NOAA NCEI supervisor remarked how it was eye-opening to watch Karl work the co-authors, mostly subtly but sometimes not, pushing choices to emphasize warming. Gradually, in the months after K15 came out, the evidence kept mounting that Tom Karl constantly had his ‘thumb on the scale’—in the documentation, scientific choices, and release of datasets—in an effort to discredit the notion of a global warming hiatus and rush to time the publication of the paper to influence national and international deliberations on climate policy."
Are these comments valid? They seem to be and if so do lead to questions about the veracity of some authors.
Haze: Bates's claims are without merit. Eli Rabbett provides context (especially the supposed rushing to publication and lack of archiving) for the detailed rebuttal that was posted by Peter Thorne who (unlike Bates) was directly involved with the people and processes of the actual science-doing.
Variable Variability has a devastating rebuttal of fake journalist David Rose’s even more outlandish accounting of Bates's claims. The Great White Con has more. Also regarding Rose's baselines deception: And Then There's Physics.
Zeke described how the recent study by he and coauthors solidly backed the conclusions of the Karl et al. paper.
@18 There is a saying "that lies are round the world before truth is even out of bed" The current publicity on the Dr Bates' comments exemplifies what that saying means. Yesterday the Australian published a piece, written by Matt Ridley and first published in the UK Times. The number of people reading that piece both here and in the UK plus those reading the piece by David Rose in the deplorable Daily Mail headlined "Exposed: How world leaders were duped into investing billions over manipulated global warming data", far, far exceeds the number that will read the denuciations to which you refer. In consequence these pieces will have far, far more effect on the general public's view of the validity of climate science and the credibility of climate scientists
Of course climate change is real. Of course the GMT is increasing. We are in the tail end of yet another interglacial warm up!
Science would be so much better off if they could actually scientifically mathematically analyze how the 100,000 year glacier cycle... the most powerful naturally occurring climate forcing event... will react to the man caused introduction of greenhouse gasses.
The ability to do that would provide the missing link that appears to mitigate that introduction... since the average earth temperature is not following the doubling of CO2 from 200ppm to 400ppm, but IS following the 100,000 year glacial cycle and is currently several degrees COOLER than the highs of the past 400,000 years of glacial cycles.
The peer reviewed data chart on the U.S. Government's NOAA web site graphically illustrates this fact.
https://www.ncdc.noaa.gov/paleo/abrupt/data2.html
Science is obviously making progress in identifying previously unstudied causes and effects to the changing conditions surrounding climate change. Unfortunately the complexities of the eath's climate system continue to remain elusive.
As the understanding and the math become available to be able to integrate more and more of the interactions that continue to be studied, we will eventually be able to more accurately identify the way the 100,000 year glacial cycle will react.
New studies help to approach that end, such as all the climate change hysteria about the melting of the glaciers, sea ice, and ice caps, studies are showing that the influx of this fresh water into the oceans may be responsible for the mitigation of the warming effect caused by greenhouse gasses. This is just one event over the past million years that has contributed to the transition from the interglacial warm up to the glacial cool down. There are many other unknown, less obvious, and unstudied events in play.
This information is not discussed by the global warming alarmists and is available on the U.S. Government NOAA web site.
https://www.ncdc.noaa.gov/paleo/abrupt/model-abrupt.html
The recent IPCC prediction that the temperature will rise at least another 2 degrees is refreshing in that it follows the pattern of the 100,000 year glacial cyle nicely. Given the rate of increase since the 1880's we should reach that mark in another couple of hundred years or so.
stephenwv @20.
I think you rather exaggerate the power of the milankovitch cycles which drove the recent 100ky ice age cycles. There is much more power in the changing ice-cover that has a big impact on albedo and thus how much solar energy is reflected back into space. And the climatic change also sets off even greater changes in GHG forcing. So it does not take much science to assert that the next ice age, which would begin with a reduction of Northern Hemisphere temperatures (a process that had been in play over recent Holocene millenia but which has now dramatically reversed), will require a re-reversal of NH ice loss, a reversal of the global warming and a reversal of the positive anthropogenic GHG forcing. None of those essential processes are likely now to happen due to AGW.
And note that the 'cycle' is not itself very strong but the product of other underlying cycles. Had glaciation been allowed to continue its course, the depths of the NH cooling over the next 100ky would have been far less than in previous glacial events as this graph of 65N summer 30ky bp - 70ky ap insolation shows.
Concerning your link to the Dome Fuji Ice Core Preliminary Temperature Reconstruction, while previous peak interglacial temperatures within the reconstruction have been warmer than Holocene temperatures, it is perhaps more interesting to consider that the latest reconstruction temperatures (from a millenium ago) which after 10ky of the holocene had not fallen from the peak interglacial temperature.That was not the case 10ky after the other peak interglacials. Indeed, the temperature reconstruction shows the most recent temperatures on a par with this stage in previous interglacial periods. And since the time of that latest data in the reconstructed temperature, there has been significant warming (in recent decades) in Antarctica.
A 2ºC global temperature rise will not be the "refreshing" event that you suggest. For a start it will increase sea level by twenty feet, as occurred during the Eemian (which, if you examine the data you cite, was not "several degrees" warmer than a millenium ago). Much of the problem with such a 2ºC rise (assuming that is all it will be) will be because, contrary to your unsupported assertions, it will arrive thirty/forty times more quickly than the last ice age ended.
Further to that, unless you are ready to throw conservation of energy of the window (in which case this isnt the site for you), you cannot increase the ocean heat content (or surface temperature) without changing the energy flow. We have a pretty good handle on these energy flows (and the obvious one is the increasing re-radiation from GHG). Where precisely do you think the energy flow is changing if this is a normal ice age cycle? Where does the directly measured increase in surface radiation disappears to if you think something else is the warming? I would note, that without the GHG, the orbital forcings should have us slowly cooling not warming.
Not sure why you think GHG theory isnt performing..
@Art Vandelay,
What was Phil Jones "worried" about? If global warming were to stop, why would that cause someone to "worry?" Why wouldn't they "celebrate?"