Forecasting the Earth’s Temperature
by David Whitehouse via Benny Peiser’s CCnet
The recent spate of scientific papers that are attempting to predict what the earth’s temperature might be in the coming decades, and also explain the current global temperature standstill, are very interesting because of the methods used to analyse temperature variations, and because they illustrate the limitations of our knowledge.
Recall that only one or two annual data points ago many scientists, as well as the most vocal ‘campaigners,’ dismissed the very idea that the world’s average annual temperature had not changed in the past decade. Today it is an observational fact that can no longer be ignored. We should also not forget that nobody anticipated it. Now, post facto, scientists are looking for an explanation, and in doing so we are seeing AGW in a new light.
The main conclusion, and perhaps it’s no surprise, to be drawn about what will happen to global temperatures is that nobody knows.
The other conclusion to be drawn is that without exception the papers assume a constantly increasing AGW in line with the increase of CO2. This means that any forecast will ultimately lead to rising temperatures as AGW is forever upward and natural variations have their limits. But there is another way of looking at the data. Instead of assuming an increasing AGW why not look for evidence of it in the actual data. In other words let the data have primacy over the theory.
Lean and Ride try to isolate and analyse the various factors that affect decadal changes in the temperature record; El Nino, volcanic aerosols, solar irradiance and AGW. Their formula that links these factors together into a time series is quite simple (indeed there is nothing complicated about any of the papers looking at future temperature trends) though in the actual research paper there is not enough information to follow through their calculations completely.
El Nino typically produces 0.2 deg C warming, volcanic aerosols 0.3 deg C cooling on short timescales, solar irradiance 0.1 deg C (I will come back to this figure in a subsequent post) and the IPCC estimate of AGW is 0.1 deg C per decade.
It should also be noted that natural forces are able to produce a 0.5 deg C increase, although over a longer period. The 0.5 deg C warming observed between say 1850 and 1940 is not due to AGW.
The temperature increase since 1980 is in fact smaller than the rise seen between 1850 – 1940, approx 0.4 deg C. This took place in less than two decades and was followed by the current standstill. A fact often overlooked is that this recent temperature increase was much greater than that due to the postulated AGW effect (0.1 deg C per decade). It must have included natural increases of a greater magnitude.
This is curious. If the recent temperature standstill, 2002-2008, is due to natural factors counteracting AGW, and AGW was only a minor component of the 1980 -1998 temperature rise, then one could logically take the viewpoint that the increase could be due to a conspiracy of natural factors forcing the temperature up rather than keeping the temperature down post 2002. One cannot have one rule for the period 2002 – 2008 and another for 1980 -1998!
Lean and Rind estimate that 73% of the temperature variability observed in recent decades is natural. However, looking at the observed range of natural variants, and their uncertainties, one could make a case that the AGW component, which has only possibly shown itself between 1980 – 98, is not a required part of the dataset. Indeed, if one did not have in the back of one’s mind the rising CO2 concentration and the physics of the greenhouse effect, one could make out a good case for reproducing the post 1980 temperature dataset with no AGW!
Natural variations dominate any supposed AGW component over timescales of 3 – 4 decades. If that is so then how should be regard 18 years of warming and decades of standstills or cooling in an AGW context? At what point do we question the hypothesis of CO2 induced warming?
Lean and Rind (2009) look at the various factors known to cause variability in the earths temperature over decadal timescales. They come to the conclusion that between 2009-14 global temperatures will rise quickly by 0.15 deg C – faster than the 0.1 deg C per decade deduced as AGW by the IPCC. Then, in the period 2014-19, there will be only a 0.03 deg C increase. They believe this will be chiefly because of the effect of solar irradiance changes over the solar cycle. Lean and Rind see the 2014-19 period as being similar to the 2002-8 temperature standstill which they say has been caused by a decline in solar irradiance counteracting AGW.
This should case some of the more strident commentators to reflect. Many papers have been published dismissing the sun as a significant factor in AGW. The gist of them is that solar effects dominated up to 1950, but recently it has been swamped by AGW. Now however, we see that the previously dismissed tiny solar effect is able to hold AGW in check for well over a decade – in fact forcing a temperature standstill of duration comparable to the recent warming spell.
At least the predictions from the various papers are testable. Lean and Rind (2009) predict rapid warming. Looking at the other forecasts for near-future temperature changes we have Smith et al (2007) predicting warming, and Keenlyside et al (2008) predicting cooling.
At this point I am reminded that James Hansen ‘raised the alarm’ about global warming in 1988 when he had less than a decade of noisy global warming data on which to base his concern. The amount of warming he observed between 1980 and 1988 was far smaller than known natural variations and far larger than the IPCC would go on to say was due to AGW during that period. So whatever the eventual outcome of the AGW debate, logically Hansen had no scientific case.
There are considerable uncertainties in our understanding of natural factors that affect the earth’s temperature record. Given the IPCC’s estimate of the strength of the postulated AGW warming, it is clear that those uncertainties are larger than the AGW effect that may have been observed.
References:
Lean and Rind 2009, Geophys Res Lett 36, L15708
Smith et al Science 2007, 317, 796 – 799
Keenlyside et al 2008, Nature 453, 84 – 88
If my model is anywhere near the mark we will see a slight rise of around 0.1C in temp if solar cycle 24 gets going, followed by a 20-30 year slight fall of around 0.2C – 0.3C as the oceans cool due to generally low solar activity.
Considering UAH already fell around 0.2C from 2005 to now, this is not drastic as far as I can see.
Of course, I am probably completely wrong. 🙂
Tom P (19:21:37) : But the fact remains that while there have been plenty of assertions on this site that we are experiencing global cooling, nobody is willing to bet against me on this.
Reply: I said I will take your bet. In fact. I propose you double it. Use 200 pounds as your base. ~ ctm
Well, I’d be willing to “take the bet” on the same terms as ctm were it not for two things:
1) The gubmint has been cracking down lately on ‘online gambling’ and I’m not willing to take THAT bet.
2) The logistics of dealing with the bet are not worth the potential gains.
(Basically, I make $10,000 sized bets in trades and expect an overhead cost of $15 round trip with a time overhead of about 10 minutes or less and a cycle time of a week to 6 months with no legality risk. Your bet is too inefficient to interest me. Other than that, the odds look favorable to my side.)
So don’t read any great truth into the lack of takers. It’s just not a very interesting proposition.
Reply: Gee thanks, bragging about how much more money you have than I do. Well…nyeah. ~ ctm
Leif Svalgaard (22:46:54) : In astrophysics, one defines an ‘effective temperature’ of a body X as the temperature of that blackbody that radiates as much X. Makes perfect sense.
THAT I would agree with. Surely we can park something at geosync that can get a “visual integration” of the X radiated from the earth? (Might need 2, one front and one back…). Why go through all the hokum of measuring thousands of points and averaging if you can get a single data point that has meaning?
Since one is not averaging intensive variables, but instead taking a measurement of one thing (radiated energy in the field of view) one has a valid metric. Basically, you are measuring the emissions for a “single pot of water”.
A different question is how well we can measure the effective temperature with the thermometer network we have.
I fear the answer is “not well”. A further question is how to tease out any historical baseline from the sparse (in some cases non-existent) historical thermometer data… I can say that the GIStemp code is not up to the task.
interested spectator (21:16:03) :
NASA is predicting that solar cycle 25 will be one of the weakest in CENTURIES
They also predicted that cycle 24 would be one of the strongest in centuries…
I’m tempted to predict it will be one of the most mediocre in centuries, just to complete the set 😎
Oh what the heck:
It will be one of the most mediocre in centuries. Indistinguished.
You heard it here first (and you will forget it here first too, I’d wager… 😉
ctm
Your reply to EM Smith.
But you keep telling us you are a virtual moderator comprised merely of pixels-not flesh and bones-what could you possibly want with money?
tonyb
Reply: You’re think of Evan, but after a year of mental health recovery I am stepping back into entrepreneurship. So we’ll see. ~ charles the moderator
Reply: Gee thanks, bragging about how much more money you have than I do. Well…nyeah. ~ ctm
Urk. I um, er. It wasn’t meant to be bragging…
BTW, one can make a $10,000 sized bet using options for about $100 “real money” … (A $100 stock can have options trading for about $1 that are ‘interesting’ – and a lot of options at 5 to 10 cents that are almost guaranteed to lose – and that means that $100 will control 100 shares of a $100 stock, so you are swinging about $10,000 of stock with a $100 option buy. So you, too, can make $10,000 size bets on less than you are betting now.
Longwinded way to say you don’t need a lot of money to bet big, only to pay off 8-{ big and options let you control the payoff side of the bet…
Reply: I was jerking your chain, but I am kicking myself for not putting down a couple of grand on calls for Ford when it was $1 ~ charles the day late and dollar short moderator (who knew how well the Escape was doing in the marketplace)
FORECAST ?
SEE:
http://sites.google.com/site/earthquakepredictionbyjac/Home/greenhouse-effect
http://sites.google.com/site/earthquakepredictionbyjac/Home/greenhouse-effect/KLIMAT2.eml?attredirects=0
Jacek Dunajewski
RW: “yet atmospheric CO2 concentrations started rising in about 1750. CO2 did not suddenly become a greenhouse gas at some point after 1940.”
I see it coming. Next claim will be that all the warming we have seen since the LIA is due to man.
Charlie: Thanks for the link to Lean and Rind (2009). It makes the same basic error that Lean and Rind (2008) makes. It assumes the relationship between ENSO and global temperature variations is linear. It is not. This was illustrated in my post “Regression Analyses Do Not Capture The Multiyear Aftereffects Of Significant El Nino Events”
http://bobtisdale.blogspot.com/2009/07/regression-analyses-do-not-capture.html
Refer also to my posts:
“Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1”
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of.html
“Can El Nino Events Explain All of the Global Warming Since 1976? – Part 2”
http://bobtisdale.blogspot.com/2009/01/can-el-nino-events-explain-all-of_11.html
“RSS MSU TLT Time-Latitude Plots…Show Climate Responses That Cannot Be Easily Illustrated With Time-Series Graphs Alone”
http://bobtisdale.blogspot.com/2009/06/rss-msu-tlt-time-latitude-plots.html
One can always, always fit a function to past data and desired future projections. Once the AGW advocates are done retrofitting their models, they will still predict calamity. This is the single point of failure in the current political situation: politicians do not understand that one can always create a model for the past – and that this says nothing about the model’s ability to predict the future.
Regarding testability: the only meaningful test is this: write down specific predictions for the future. Wait till the future gets here. Do the predictions match, yes or no? Unfortunately, when the answer turns out to be “no”, they just weasel-word their way out of it and retrofit their model again…
Nick Stokes (16:06:32) :
“………..This is completely wrong, and reverts to the common fallacy that AGW is based on an examination of the temperature record. It isn’t. It has always been based on an analysis of the greenhouse effect, and the accumulation of GHGs. Hansen’s paper was based on that too. That’s why he gave his physics-based projections citing varied GHG emission scenarios.”
I’m delighted to learn this because the major argument I was given by a luminary of the British government in reply to a letter from me to the PM was to do with the temperature record.
I, and most here I would guess, have few problems with “greehouse theory”, what troubles me is the invocation of “climate catastrophe”, which in my opinion is a step too far.
E.M. Smith – you have horribly misunderstood some basic physics. Averaging intensive variables is trivial. Your example about taste is meaningless. Taste is not a quantifiable physical property.
Leif
“In astrophysics, one defines an ‘effective temperature’ of a body X as the temperature of that blackbody that radiates as much X. Makes perfect sense. A different question is how well we can measure the effective temperature with the thermometer network we have.”
.
It makes about as much sense as saying that given some constant power P , I choose an arbitrary function f0 among the infinity of functions solving
[Integral over some arbitrary space-time domain (fdx) = P] .
There where it stops making any sense is when people begin to infer from :
[Integral over some arbitrary space-time domain (fdx)] = [Integral over same arbitrary domain (gdx)] => f = g what is obviously wrong .
Or in other words and that is actually the point of E.M.Smith , f0 may solve [Integral over some arbitrary space-time domain (fdx)] = P but it clearly doesn’t solve any differential equations representing the laws of physics like f.ex Navier Stokes .
Not even remotely because f0 in our case here describes an isothermal and isotropic body while the real body (described by the function g) is anything but isothermal and isotropic .
There is a word for that and this word is UNPHYSICAL .
So nobody is really interested in a solution F0 for the Earth (the global average temperature) because it is unphysical e.g doesn’t represent even approximately the physics of the Earth . Its only property is that its integral gives by definition the total emitted power while getting everything else wrong .
It is not very sensible to theorize about patterns of global warming or cooling without having regard to two major geophysical processes:
• the Earth’s variable rotation and its relationship with global temperature; and
• the Lunar Nodal Cycle and its relationship with the climate of the Arctic and the Pacific Decadal Oscillation.
In relation to the Earth’s rotation there is considerable evidence that decadal length variations in the rate of the Earth’s rotation result in periods of global cooling or warming.
Lambeck and Cazenave (1976), “Long Term Variations in the Length of Day and Climatic Change” published in 1976 in the Geophysical Journal of the Royal Astronomical Society Vol 26 Issue No 3 pps 555 to 573, reported that there is an established relationship between the Earth’s decadal variable rotation and climate dynamics.
As LoD shortens, (i.e. the Earth rotates faster) the planet warms; in contrast, as LoD lengthens, the planet cools. There is a time lag of most likely six years between the change in the Earth’s rotation and global temperature changes.
Their paper is available here: http://rses.anu.edu.au/people/lambeck_k/pdf/37.pdf
Their paper warrants careful study.
Lambeck and Cazenave (1976) found that:
“The long-period (greater than about 10 yr) variations in the length-of-day (LoD) observed since 1820 show a marked similarity with variations observed in various climatic indices; periods of acceleration of the Earth corresponding to years of increasing intensity of the zonal circulation and to global-surface warming: periods of deceleration corresponding to years of decreasing zonal-circulation intensity and to a global decrease in surface temperatures. The long-period atmospheric excitation functions for near-surface geostrophic winds, for changes in the atmospheric mass distribution and for eustatic variations in sea level have been evaluated and correlate well with the observed changes in the LoD.“
Lambeck and Cazenave (1976) argued that the cooling of that the planet experienced in the 1960s arose from a slowing of the Earth’s rotation.
They wrote:
“if the hypothesis [that decadal rotation decrease (increase) results in planetary cooling (warming)] is accepted then the continuing deceleration of[the rotating Earth] for the last 10 yr suggests that the present period of decreasing average global temperature will continue for at least another 5-10 yr.”
Lambeck and Cazenave (1976) predicted that the cooling would come to an end by the mid 1970s and be followed by a period of global warming because they had discovered that the planet’s rate of rotation had begun to accelerate from 1972.
They wrote:
“Perhaps a slight comfort in this gloomy trend is that in 1972 the LoD showed a sharp positive acceleration that has persisted until the present, although it is impossible to say if this trend will continue as it did at the turn of the century or whether it is only a small perturbation in the more general decelerating trend.”
How this comes about is a matter of continuing debate and research. It does seem reasonably well established that the proximal causes are changes in the behaviour of the Earth’s inner cores and the way these cores are coupled dynamically and electromagnetically to the rest of the Earth.
However, there is growing evidence that coupling between various forms of solar activity and the inner cores is one of the determinants of the variable behaviour of the cores.
Regardless of this, the relationship established by Lambeck and Cazenave has been corroborated by others and disconfirmed by no one. Keep in mind that Lambeck and Cazenave found the correlation between LoD and average global temperature is a statistically significant 0.91 using time series some 150 years long with good quality data.
It could be, as Kurt Lambeck argues in his book, The Earth’s Variable Rotation: Geophysical causes and consequences, Cambridge University Press 1980, pps 279 – 282, that both arise from a third cause (about which he did not speculate).
It could be that the same solar activity contributes to the global climate variations in addition to the ways in which rotational change over a decade brings about climate change.
Richard Gross of the JPL at the California Institute of Technology produces a report each year that presents the most recent data about the rotation of the Earth. The title of the report is Combinations of Earth Orientation Measurements: SPACE2007, COMB2007, and POLE2007. See here http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/41279/1/09-18.pdf
Fig 4 (d) which is the graph of Length of Day from 1960 to 2007 below with the smaller variations smoothed out.
{Looks like the lovely garph didn’t copy into the Leave a comment box, but you can find it in the pdf}
The graph shows that LoD has been shortening (rotation speeding up) since 1970, except that the planet’s rotation slowed just a little between 1988 and 1994. It then began to speed up, de-accelerating again just a little in 2006. There is just a hint of speeding up again in 2007.
The key factor to concentrate on is the decadal rotational changes.
The table below summarises LoD variations over the last fifty years, the predicted climate consequence and the period in which that consequence would occur, given a lag time of five years, other things being equal. As the determinants of climate dynamics are multivariate, non-linear and non-stationary and include elements of randomness, it is not realistic to say that the predicted climate consequence necessarily follows.
Time period of rotation LoD Rotation Climate temperature Climate period (5yr lag)
Pre 1960 – 1972 lengthen slower cooling 1960 – 1977
1972 – 1987 shorten faster warming 1977 -1992
1987 – 1994 lengthen slower cooling 1992 – 1999
1994 – 2002 shorten faster warming 1999 – 2007
2002 – present lengthen slower cooling 2007 – ?
{looks like the formatting vanished when I copied a word document into the “Leave a comment” box}.
L&C noted that the significance in the “lag suggests that the LOD observations can be used as an indicator of future climatic trends, in particular of the surface warmings.”
Prediction of the LoD time series is an area of specialized research conducted by a relatively small number of scientists. Gambis and Bizouard (2003) see slide 18 of http://www.ien.it/luc/cesio/itu/gambis.pdf predict that LoD will lengthen during 2000 and 2010 resulting in global cooling from around 2006 to 2016 according to the relationship established by Lambeck and Cazenave.
As has been shown in previous posts there is a well established relationship between the Lunar Nodal Cycle, the climate of the Arctic and the Pacific Decadal Oscillations. The LNC peak of 2006 brought on the negative PDO which is now cooling North America.
Here is another recent paper about the LNC by Renato Ramos da Silva and Roni Avissar “The impacts of the Luni-Solar oscillation on the Arctic oscillation”, Geophys. Res. Lett., 32, L22703, doi:10.1029/2005GL023418; here is the Abstract:
“The Arctic Oscillation (AO) has a major impact on climate variability in the extra tropical regions of the Northern Hemisphere. In this study, we show that specific alignments between the Sun, the Moon and the Earth known as the Luni-Solar Oscillation (LSO) that occur at frequencies of nearly 9 and 18 years are unambiguously correlated with the AO since the mid-1960’s. The occurrence of the LSO peaks is predictable and, as a result, it improves climate predictability. Furthermore, we hypothesize that the recent observed increase in the AO amplitude maybe due to ice melting in the Arctic and SST increases at northern latitudes combined with the recent LSO peaks.”
The authors conclude with this interesting observation:
“Finally, we note that the current generation of global climate models that are broadly used to produce various climate change scenarios do not account for long-term tidal dynamic effects. This may be a significant flaw worth investigating carefully.”
TomVonk (03:38:42) :
So nobody is really interested in a solution F0 for the Earth (the global average temperature) because it is unphysical e.g doesn’t represent even approximately the physics of the Earth.
Of course it does. Just like it makes a lot of sense to say that the average family has 2 1/3 children. Nothing unphysical about it. The problem comes when you try to make rhetoric out of it.
So RW…
The “expected rise” over the last decade was also 0.2 C. How has the reality on the ground compared to that one? Since it was wrong both in sign and magnitude is it ok if I not assume that everything in the computer fantasy games called models is the absolute truth?
What do the trends look like if we remove the “corrections” that are obviously incorrect? What would we have if we made some realistic attempt at correcting for UHI and land use changes?
GeoS
How delighfully naive you are to believe that any part of the AGW hypothesis is based on actual facts and figures. The following is an exchange I had with Joel Shore over on another thread a couple of days ago. This isn’t a dig at Joel who I always find a pleasant well informed promoter of AGW-it is the system that undepins it that is wrong, as the exhange articulates.
“From TonyB
Hi Joel
Good to see you over here again. You’ll be setting WUWT as your home page before you know it 🙂
You said;
“Of course, our understanding of AGW is based on a lot more than just current temperature trends. It is, for example, based on the temperature difference and estimated difference in forcings between the last glacial maximum and now. So, any new competing hypotheses will (at least eventually) also have to explain this empirical data in addition to the current temperature trends.”
I appreciate you were being simplistic, but to broaden it out you obviously know that our understanding of AGW is based on a lot of hypothetical data.
When you parse temperatures, sea level rises etc etc that go back some 150 years or more, to hundredths of a degree or mm, this must surely be in the hope (rather than certainty) that we had accurate data back then that can be parsed and sliced so minutely and therefore has some scientific validity.
Do not certain things worry you about much of this data;
* The notion that 20 stations comprise our 1850 global temperature data and they have changed in numbers and locations ever since? (don’t get me started on whether a GT has any meaning)
* That our global sea level (AArgghh!) is based on highly extrapolated (i.e. non existent) data back to 1700 that relies on three northern European tide gauges?
* That SST were measured in a very haphazard way over a tiny portion of the globes water surface and only highly specific local ones should be given any credence?
* That ice melts and re-freezes with monotonous regularity in the arctic and that current events are not out of the ordinary?
Is there not a scintilla of doubt in your mind that relying on -at best- often highly dubious if not actually meaningless information, is not a sensible way to run a railroad?
Ps That 8 out of 10 letters reference was the first time I have seen you make a joke, keep it up!
PPs Don’t tell Flanagan, but I quite like him posting here as well 🙂
Best regards
tonyb
From Joel Shore (15:31:33) :
TonyB: What you have identified are the kinds of issues that one deals with in science all of the time. Data is seldom available without some (often severe) data quality issues. I don’t know what to tell you except that the way one deals with it is the way that climate scientists have been dealing with it: by having different independent analyses done on the data sets, by making estimates of the errors introduced due to various known data issues, by looking at different measures of a similar thing (e.g., in addition to direct air thermometer measurements, there are ocean temperature measurements, measurements of the advance and retreat of glacials, borehole temperature measurements, and various temperature proxy measurements).
Work at the forefront of science is seldom as easy and straightforward as presented in science textbooks. This is probably one of the main reasons why scientists and “lay people” tend to reach rather different conclusions regarding the strength of the evidence in a field such as climate science where lay people are motivated to investigate the science.
If other fields of science were subjected to the similar sort of study by lay people that climate science has been, I think that these people would find similar deficiencies…and they would probably be left believing hardly any of the theories of modern science. And yet, I think these theories have been very important and successful in advancing our knowledge, and the reason I think that is the case is that, while each individual piece of data or each experiment may have its problems, the whole set of data and experiments taken together generally have a high degree of redundancy that means that the overall picture that emerges is more likely to be correct than one would expect by looking at each experiment in isolation.
To be honest, I have spent almost my entire career as a computational physicist being continually surprised at how well the models that I use agree with the experimental data in spite of the fact that I can almost always identify many concerns that I have with either the data or the model (e.g., many things that the model is ignoring).
From TonyB (16:37:11) to Joel
Thanks for your candour. However it is explained away, much of the theoretical information presented is contradicted by observations from the real world. It seems to me that climate science has standards not as rigorous as those applied to other sciences and the burden of proof falls far short of what should be expected.
This is probably the first science born in the computer age and many believe the models to be more accurate than we can in reality currently achieve.
According to the IPCC, Climate Change 2007: The Physical Science Basis “The set of available models may share fundamental inadequacies, the effects of which cannot be quantified.”
best wishes”
As I say, this is not a dig at Joel, but I do think it demonstrates the uphill task we have when we point to actual facts and figures to demonstrate our case. These apparently do not count as much as we thought they did.
tonyb
E.M.Smith (16:50:59) :
Nick Stokes (16:06:32) :
This is completely wrong, and reverts to the common fallacy that AGW is based on an examination of the temperature record. It isn’t. It has always been based on an analysis of the greenhouse effect, and the accumulation of GHGs. Hansen’s paper was based on that too. That’s why he gave his physics-based projections citing varied GHG emission scenarios.
“So it has always been based on a fantasy about gasses and models and projections, oh my! Ok, got it…
It’s so much easier to understand when you leave the data out and accept that it has always been confirmation bias and self delusion.”
Well then:
“The data don’t matter. We’re not basing our recommendations [for reductions in carbon dioxide emissions] upon the data. We’re basing them upon the climate models”
Chris Folland
UK Meteorological Office
“The “expected rise” over the last decade was also 0.2 C. How has the reality on the ground compared to that one? ”
Using GISS data, the mean global temperature anomaly from 1999-2008: 0.49°C. Mean global temperature from 1989-1998: 0.31°C. So, the last decade has been 0.18°C warmer than the one preceding it. If you prefer the creationist dataset, UAH gives anomalies of 0.04 and 0.20, giving an increase of 0.16°C.
“Since it was wrong both in sign and magnitude…”
Try again and give us a more accurate description of how +0.16 and +0.18 compare to +0.2
“Ron Mexico:
So, Hansen’s projections are physics based, eh? Fair enough. Einstein (full disclosure – I ain’t no Einstein) liked his Gedankens, here’s one: I live on a platform suspended in the sky, an area of the sky that never has wind, & have done enough ball throwing to figure out that v=a*t & d=.5*a*t*t & the gravitational acceleration constant a is 9.8 m/sec.”
I am sure that Einstein had many ideas, but you do not have to make a “square plural” of der Gedanke (sing.)/ die Gedanken (pl.). But you should square the sec in g. Otherwise it is a pleasure to see somebody calculating in “metric units”.
James F. Evans (10:15:36) :
“Instead of assuming an increasing AGW why not look for evidence of it in the actual data. In other words let the data have primacy over the theory.”
Imagine that!
Data over theory.
Sadly, in scientific discipline after scientific discipline, theory trumps data.
The imagnination and desires of men have a firm grip on Science.
No surprise there.
But when theory trumps data, one can not claim the state of Science is “clearly healthy!” with a straignt face and retain credibility.
But perhaps after this experience with the inscrutible Sun men will be humble and more open-minded and less attached to figments of imagnination flickering on the cave wall.
Kudos to you. The notion that we can have science absent “good” data is paranormal science. The facts are there, the data points have been inconsistent and moved in many instants while in others the local geology has changed dramatically, from rural to urban, thus artifactually changing the database. The database derived from our satelites is juvenile and flawed by external influences and marred by poor design, temp. buoys that float freely, give me a break. The more I study and read the less I am convinced that we know about this and that we understand even less than that. When I superimpose these thoughts on the history of remarkable climate change on this earth I am forced to the conclusion that the only hot air involved here is from the proponents of AGW, in support of their theory and their funding.
What i want to know is will the lack of warming or any of the science which has questioned AGW have an influence on the next IPCC assessment?
RW (11:57:26) :
This whole piece is a tiresome mixture of half-truths, untruths, misunderstandings and simple mistakes.
What is becoming very clear is that he whole business of evemn measuring the global temperature has become “a tiresome mixture of half-truths, untruths, misunderstandings and simple mistakes” as you put it.
There is no “current global temperature standstill”. The trend in temperatures from x-present is not statistically different from the trend from x-1998, or x-2002, or x-2005, or whichever date you want to cherry pick. Yet again, you allow yourself to be fooled by weather. Will this ever stop?
What do you call it when the temperature stops rising? If to want to masage the data, you can. With a decade of little or no risies, you still get a flat part of the curve, in fact they mostly seem to be going down (hockey sticks notwithstanding).
There is no “IPCC estimate of AGW”. The quantification of the expected temperature rise is far more complicated than the single number you wrongly attribute. In fact, in this and the next few decades, the expected warming from the rise in CO2 would be about 0.2°C, not 0.1°C.
The IPCC has definitely predicted the effects of the presumed AGW. It is repeated to us, with alarming increases, on a regular basis by media. True, it is far more complicated, but the media portray it as figures. Ane thay are wrong, I agree. That means we should challenge these assertions, I am sure you can agree.
“The 0.5 deg C warming observed between say 1850 and 1940 is not due to AGW” – and yet atmospheric CO2 concentrations started rising in about 1750. CO2 did not suddenly become a greenhouse gas at some point after 1940.
1750? From what, exactly? we were not burning fossil fuels back then, so I assume you assert CO2 increase is not caused by us then? I’m not sure I understand the logic of this.
Rik Gheysens (12:25:51) :
It seems me that the authors in this new paper (2009) have an opinion that is opposite to that of 2008. Then they argued: “According to this analysis, solar forcing contributed negligible long-term warming in the past 25 years and 10% of the warming in the past 100 years.”
Now, they state:”But as a result of declining solar activity in the subsequent five years [from 2014 to 2019], average temperature in 2019 is only 0.03±0.01 C warmer than in 2014. This lack of overall warming is analogous to the period from 2002 to 2008 when decreasing solar irradiance also countered much of the anthropogenic warming.”
Have they been overtaken by events??
No, no, no, you just don’t understand. If it’s warming, it’s AGW, if it’s cooling, it’s the Sun. Or it’s weather. Or it aerosols. Or it’s bad data. or it’s something else we may not have thought of……..
Tom P (13:19:29) :
I’m willing to bet against you on these terms that we are cooling. Are you on (in a currency multiple of your choice)?
I would love to take you or anyone up on that, apart from the massive problem that I cannot trust the data. When it is analysed by amateurs, and when they can even get a hold of it, we get clear signals denying any warming, whereas when it is analysed by ‘professionals’ it is massaged to ‘prove’ a foregone conclusion.
Shame about that.
RW (15:07:00) :
“There is no “Global Mean Temperature”. It’s an artificial construct that is completely meaningless.”
Oh, god, not this again… it’s so depressing to see so many people fall for this tragic nonsense. What does “temperature” mean to you? Only if you think the answer is “nothing, ever” is your previous statement logically possible.
I’m sorry, but you are completely wrong, and I rarely say that.
The idea of a global mean temperature is so deeply flawed with hidden misunderstandings that it is effectively meaningless. When you are trying to capture a trend of 0.01C a year, it is laughable.
My random thoughts on it are:
Quite frankly, there are a huge number of problems with trying to measure the temperature of the world. I mean, you can’t just stick a thermometer into a convenient orifice and wait.
There is land and sea and air.
Which part do we measure? Presumably we should measure all of them. Should we weight the results according to the thermal capacity of each of these mediums? Should we consider the relative volume of each? When we talk of the land, presumably that is just the surface.
Land is all at different levels.
Do we measure the surface wherever it is? In theory we should. There will be considerable differences depending on the make up of the land. Clay, sand and chalk, for example, will have different heat retention properties.
The air is at different temperatures all the way through, and constantly moving. Where should we measure. How should we weight the various measurements we do take? Do we have to take humidity into account (wet air has a higher thermal capacity). How should we compare measurements at high humidity to measurements at low humidity?
The seas are deep, and at varying depths. Where should we measure? The top few hunderd meters? What about after storms when the lower, colder waters may be (and most often are in my experience) brought to the surface.
Assume we manage to find compromises for all of these variables. I assume somone has, however good or poor they must be, because temperatures are published and we are told they are valid.
OK, then, how far apart are the measurements taken. In a uniform grid? Obviously not. If most are concentrated in one place (eg the US), how do we weight these against the others?
How do we take the spreading urban sprawl and its associated warming of the envoronment into account? How do we filter the data to remove this bias?
The number of active stations seems to vary constanatly. A huge number of stations in the former USSR went offline when the USSR collpased in 1990. Interestingly, it seems that a whole lot more went offline in China, Turkey and Australia at about the same time. I have no firm idea why.
How can we relate the measurements after 1990 to those before?
OK, so we manage, somehow, to achieve that. Since graphs are shown with no display of this fracture in the continuous record, we have to assume someone is managing that and adjusting the data to compensate.
So what we probably need is the temperature taken at a constant height in the air, and at a constant depth in the sea, every hour of every day, at regularly spaced relatively small distances. Given this, we could probably be fairly sure of temperature changes and trends over time.
What we have is measurements taken at inconsitently spacings, with random geographic distribution (probably weighted toward the US), at varying heights.
But some argue that the trend is important, not the absolute temperature. This is a good point.
The problem them becomes when you measure. Let’s look at when the measurements are taken. There is a strong ‘time of day’ bias in some records, especially older ones. It depended on when someone decided to wander out and read the thermometer as to what temperature was recorded. That does not sound very accurate.
So we then have Max/Min thermoemeters. That should be better, shouldn’t it? Well, perhaps not. Imagine the temperature stays at 10C all night, and most of the day. In the afternoon the clouds part, the sun comes out, and the temperature reaches 20C in a couple of hours before it rains, dropping it to 10C again sharply.
The record shows 10C – 20C. Is that an average temperature of 15C? I think you can see it is not.
There is pretty clearly a huge amount of ‘manipulation’ of this data required before meanigful results are available. What is not clear is what is done to the raw data, and why. That makes many mistrustful of any ‘global’ or ‘average’ figures, and therefore trends. They do have a good point.