I’m always searching for better and simpler ways to explain the reason why I believe climate researchers have overestimated the sensitivity of our climate system to increasing carbon dioxide concentrations in the atmosphere.
What follows is a somewhat different take than I’ve used in the past. In the following cartoon, I’ve illustrated 2 different ways to interpret a hypothetical (but realistic) set of satellite observations that indicate (1) warming of 1 degree C in global average temperature, accompanied by (2) an increase of 1 Watt per sq. meter of extra radiant energy lost by the Earth to space.
The ‘consensus’ IPCC view, on the left, would be that the 1 deg. C increase in temperature was the cause of the 1 Watt increase in the Earth’s cooling rate. If true, that would mean that a doubling of atmospheric carbon dioxide by late in this century (a 4 Watt decrease in the Earth’s ability to cool) would eventually lead to 4 deg. C of global warming. Not good news.
But those who interpret satellite data in this way are being sloppy. For instance, they never bother to investigate exactly WHY the warming occurred in the first place. As shown on the right, natural cloud variations can do the job quite nicely. To get a net 1 Watt of extra loss you can (for instance) have a gain of 2 Watts of forcing from the cloud change causing the 1 deg. C of warming, and then a resulting feedback response to that warming of an extra 3 Watts.
The net result still ends up being a loss of 1 extra Watt, but in this scenario, a doubling of CO2 would cause little more than 1 deg. C of warming since the Earth is so much more efficient at cooling itself in response to a temperature increase.
Of course, you can choose other combinations of forcing and feedback, and end up deducing just about any amount of future warming you want. Note that the major uncertainty here is what caused the warming in the first place. Without knowing that, there is no way to know how sensitive the climate system is.
And that lack of knowledge has a very interesting consequence. If there is some forcing you are not aware of, you WILL end up overestimating climate sensitivity. In this business, the less you know about how the climate system works, the more fragile the climate system looks to you. This is why I spend so much time trying to separately identify cause (forcing) and effect (feedback) in our satellite measurements of natural climate variability.
As a result of this inherent uncertainty regarding causation, climate modelers are free to tune their models to produce just about any amount of global warming they want to. It will be difficult to prove them wrong, since there is as yet no unambiguous interpretation of the satellite data in this regard. They can simply assert that there are no natural causes of climate change, and as a result they will conclude that our climate system is precariously balanced on a knife edge. The two go hand-in-hand.
Their science thus enters the realm of faith. Of course, there is always an element of faith in scientific inquiry. Unfortunately, in the arena of climate research the level of faith is unusually high, and I get the impression most researchers are not even aware of its existence.
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As ever, Dr. Spencer, thank you for making the assumptions clear.
So long as the AGW hypothesis rests on the sandy foundation that there is just no other explanation than CO2 no actual science is being done. A scientific process would look at the variety of possible explanations and test each against the data and against each other.
What you describe as faith can also be described as a willful failure of imagination. Clouds, aerosols, the observed changes in current patterns, urban heat effects, solar activity (or inactivity) all have some impact. So, of course, does CO2 and water vapor and methane and, very possibly, CFCs.
Climate is complicated. The leaden certainty of the “climate scientists” rests upon the unjustified simplifications required to make their computer models work. The more we learn about climate the more unrealistic those simplifications appear. Which is progress.
A neat and simple explanation. But, because temperature is an intensive property, it would be useful to start off by explaining why the very idea of a global average temperature is complete nonsense.
I repeat – a global average temperature is complete nonsense.
Unfortunately, in the arena of climate research the level of faith is unusually high, and I get the impression most researchers are not even aware of its existence.
Dare I say it? The flat-earthers have come round again…
Bad pun, but it was such a fat pitch I had to swing at it.
“If there is some forcing you are not aware of, you WILL end up overestimating climate sensitivity.”
Dr Spencer, this is, of course, right but you then go on to assume an ‘if’ is a certainty. Indeed, you go one step further, assume and then accuse ‘are free to tune their models to produce just about any amount of global warming they want to.‘. That is worse than having a blind faith. It’s to have such conviction, such faith, you are right that you feel able to accuse others of crime in public and based on the most flimsy of ‘evidence’ – your feelings (well, you present no evidence).
Stick to the science, play the science. You don’t need to accuse the modeller if you can show them to be wrong. You clearly can’t.
As ever, I am at a loss to comprehend how AGW theory ever passed the scientific “laugh test”. The number of logical indicators of “negative feedback” to temperature forcing functions, not the least of which is the reconstructed history of the atmosphere, is simply overwhelming.
CH
“More Realistic View” ?
1 Watt net loss and 1 C warming? Does not make sense to me.
“They can simply assert that there are no natural causes of climate change,”
If you look at two different photos of the earth as seen from orbit you will see the cloud cover is never the same. This tells me that the amount of energy reaching the earth is constantly changing.
If you could pick any two identical periods of time and accurately measure the cloud cover it would be surprising to find the cover was the same.
How can this not be a natural cause of climate change.
Regarding the two different interpretations. One of the problems I have with the IPCC position is they present it as a choice between two possible explanations and then declare they have considered and rejected the natural explanation. This is an invalid “Argument from Ignorance.”(Aka argument to ignorance, argumentum ad ignorantiam ) (google it)
They are saying “I do not know how it could have a natural explanation so it must be anthropogenic.” In other words, “It must be true because it can’t be the other explanation”
It is a fallacy as it uses a lack of knowledge as if it were evidence.
The argument is invalid because there are not only two possible explanations. In reality there must be an infinite number of possible explanations and they cannot have considered them all.
Which brings me to the point I want to make. Whenever you find someone using an argument from ignorance you can be confident they have no valid evidence.
Their belief is based not on data predicted by their theory but on faith.
After all, if there was good evidence, Al Gore would have put it in the movie.
P Bratby
My sentiments exactly. The notion of a global average temp. is silly. It is a quantity we will NEVER know. It never stands still, changes dramatically in minutes and even in a few metres. To think that some wags believe they can determine average global temperatures from “proxy” data going back hundreds or thousands of years defies belief.
Peter Hearnden
We have a different understanding from reading the same article. That happens.
“natural cloud variations can do the job quite nicely”. and
“Of course, you can choose other combinations of forcing and feedback, and end up deducing just about any amount of future warming you want”.
I can’t see where Dr Spencer turned an if into a certainty. The only certainty he states is, “the major uncertainty here is what caused the warming in the first place. Without knowing that, there is no way to know how sensitive the climate system is”.
I don’t have a problem with the certainty that modellers are uncertain what caused the warming in the first place.
Peter Hearnden: Of course our knowledge is incomplete and there are lots of forcings and uncertainties we may be unaware of.
Trenberth (Mr ‘Earth’s Annual Global energy Budget’) was revealed in a climategate email to say:
“But the resulting evaporative cooling means the heat goes into atmosphere and should be radiated to space: so we should be able to track it with sky temperature data. That data is unfortunately wanting, and so too are the cloud data. The ocean data are also lacking, although some of that may be related to the ocean current changes, and burying heat at depth, where it is not picked up. If it is sequestered at depth then it comes back to haunt us later, and so we should know about it.” (Email #125552376)
Pretty conclusive ‘evidence’. How are these missing data dealt with in the models?
Not only is Roy Spencer debunking the myth of AGW he is also telling the truth about what evolution really is. It is Intelligent Design, folks!
A very clear way of explaining it – thanks.
I see some circular reasoning happening here in the IPCC camp. Because they can build a model with none of the natural factors and replicate warming with their assuming OTT feedback, they feel they are right, but its circular just reasonning if they dont seek to include the natural drivers to better estimate the co2 sensivity. This cirucular logic makes them feel right, as it all fits together. But give me 4 parameters and I could explain the warming without co2, fudging a model proves nothing!
Is it my false perception or is Dr Ray Spencer really the climate scientist with the best command of English? It seems he has a special ability to express clearly and succintly what ought to be complex scientific ideas. Since language and thought are related, I can only surmise that Dr Spencer’s elegance of language indicates an elgance of thought.
“Not only is Roy Spencer debunking the myth of AGW he is also telling the truth about what evolution really is. It is Intelligent Design, folks!”
Indeed! GW is so well organized it could not have been designed by chance!
So according to Philip Bratby, intensive properties can’t be averaged? What a bizarre notion. He seems very sure about it, though, for some reason. Perhaps he could explain whether the following concepts are “complete nonsense” or not: average velocity; average density; average pressure; average pH; average concentration? If they are, then naturally he should tell all the poor scientists who make daily use of some very simple maths to work out such averages. If they are not, then naturally he should explain why temperature is the only intensive variable that can’t be averaged. I look forward to hearing which of the two is the answer in Bratby-land.
lgl (00:44:42) :
“More Realistic View” ?
1 Watt net loss and 1 C warming? Does not make sense to me
This is based loosely on blackbody radiation. If something gets warmer, it radiates more energy. Thus, the 1c of warming would be associated with extra radiation into space – 1 watt in this case.
The question I have is that in the example on the right, the diagram shows an extra 3 watts radiated into space, but in the body of the text it says “The net result still ends up being a loss of 1 extra Watt.” I don’t follow that logic, which brings me onto:
sHx,
” It seems he has a special ability to express clearly and succintly what ought to be complex scientific ideas,”
Maybe if you are a climate scientist and understand the arguments, but I am always finding Dr. Spencer difficult to follow, compared to say Willis Eschenbach. But thats just me.
I have a lump of material at xC and another lump of material at yC. What is the average temperature of the material?
Ditto density and the othet intensive properties?
Perhaps there is something missing?
Phillip Bratby (00:24:33) :
A neat and simple explanation. But, because temperature is an intensive property, it would be useful to start off by explaining why the very idea of a global average temperature is complete nonsense.
I repeat – a global average temperature is complete nonsense.
Ok – call it global temperature index if it makes you feel any better. We’re not interested in the actual global average temperature, we’re interested in whether in by how much it’s changed. The various datasets do a reasonable job of providing that information.
To use the lake analogy. I can tell whether the level of a lake has risen or fallen without knowing exactly how much water is in the lake.
“I have a lump of material at xC and another lump of material at yC. What is the average temperature of the material?
Ditto density and the othet intensive properties?
Perhaps there is something missing?”
C’mon, Philip, stop playing silly B’s. We have vastly more than two data points for the atmosphere.
Wrt other comments. I explained my pov in my post and I don’t see the need to expand on that.
John Finn, I disagree. If the global average temperature is nonsense, then so too is the derivative.
Your lake analogy is OK for the lake, because the lake has a single level. But the earth does not have a single temperature.
Peter Hearnden. It doesn’t matter how many points you have. The average is still meaningless. BTW, what’s the average temperature of the air over Dartmoor this morning? Let’s say at 2metres agl. Or over the bottom 10metres. I wonder if it’s warmer in the valleys than on the tors?
hunter (01:50:41) :
I agreed with Phillip Bratby so I’ll try to answer, I’m sure he may have a different point.
The discussion is not whether “numbers” or data can be averaged. The point is the data.The temperature from any part(s) of the world can be averaged, but that average DOES NOT and CANNOT give a correct figure for the globes temperature on any given day week or year.
eg I live on a 20 acre farm. If I wanted to know what the average temp of my farm is what do I do? Take some measurements and then average them? The result is useless. The temperature variations on my farm at any given moment are huge. Some areas can be 30deg C in the summer afternoon, other areas can be as low as 25deg C at the very same time. Some areas reach maximum temp. for the day at 3pm other areas reach max at 2.30pm or 3.30pm
Now extrapolate this to a global scale (James Hansen came up with dividing the planet into 5deg by 5deg sectors) Imagine the variables in a 5×5 grid. Whatever “averaging” results is totally and absolutely useless (and thats before the infamous smoothings).
All the above even before we consider temp variations due to other localised causes. (Even a 10sqm area can have it’s own micro-climate)
NO ONE knows what the average temp. of the globe is, and no one will know into the foreseeable future. period.
hunter (01:50:41)
I think Philip Bratby is making the claim that the climate is so variable over short distances that one would need temperature measuring stations in a grid pattern every few 100 metres to obtain enough data to even consider making a worthwhile average.
As an example consider the differences in climate between Milford Sound and Queenstown, New Zealand. (http://en.wikipedia.org/wiki/Milford_Sound http://en.wikipedia.org/wiki/Queenstown,_New_Zealand. I hope that these wpedia entries have not been fiddled with :-).) These two places are less than 50Km apart on the same latitude but Queenstown is 354m higher than Milford Sound with an extensive mountain range between them. If there is such a massive difference between two places this close together how can any-one attempt to average the temperature of the entire planet without having far more datum points than are currently used. Also the datum points for the oceans are few and far between, usually on inhabited islands and not therefore a measure of oceanic temperatures. The oceans are ~70% of the Earth’s surface area with virtually zero measuring stations. Satellite data measures (I think) in 50Km diameter circles so these would give wildly inaccurate local temperatures, if they were measuring ground level temps. which of course they do not do.
I’ll add to my comment above by saying the radiation budget of the planet is a whole different kettle of fish. That we may get a handle on at some time in the future.
hunter (01:50:41) :
So according to Philip Bratby, intensive properties can’t be averaged? What a bizarre notion.
Hunter, consider A + B = C
If A & B are extensive variables, say A = 1 and B = 1, the C= 2.
If A & B are intensive variables, using the same assumptions above, then C=1.
Bratby is correct.
QED
Since we are on the 40% way to doubling and the most sensitive areas – Arctic and Antarctic – show just natural AMO-related variations and present temperatures equal to 40ties (Arctic) or nothing at all (Antarctic), hereby I declare CO2 as innocent in full extent.
http://climexp.knmi.nl/data/icrutem3_hadsst2_0-360E_66-90N_na.png
http://climexp.knmi.nl/data/itlt_0-360E_-66–90N_na.png
Cay any “leading climate scientist” explain, why the polar areas with cold and dry air and therefore the most sensitive to CO2 increase, do not react at all on “increased greenhouse effect”?