Last year I posted an analysis of satellite observations of the 2007-08 global cooling event, showing evidence that it was due to a natural increase in low cloud cover. Here I will look at the bigger picture of what how the satellite-observed variations in Earth’s radiative budget compare to that expected from increasing carbon dioxide. Is there something that we can say about the relative roles of nature versus humanity based upon the evidence?
What we will find is evidence consistent with natural cloud variations being the dominant source of climate variability since 2000.
CERES Observations of Global Energy Budget Changes
The following graph shows the variations in the Earth’s global-average radiative energy balance as measured by the CERES instrument on NASA’s Terra satellite. These are variations in the imbalance between absorbed sunlight and emitted infrared radiation, the most fundamental quantity associated with global warming or global cooling. Also show (in red) are theoretically calculated changes in radiative forcing from increasing carbon dioxide as measured at Mauna Loa.
Since there is some uncertainty in the absolute accuracy of the CERES measurements, where one puts the zero line is also somewhat uncertain. Therefore, it’s the variations since 2000 which are believed to be pretty accurate, and the exact dividing line between Earth gaining energy and Earth losing energy is uncertain. Significantly, all of the downward trend is in the reflected sunlight portion, not the infrared portion of the variations. We similarly can not reference where the zero line should be for the CO2 forcing, but the reasons for this are more complex and I will not address them here.
In order to compare the variations in the CO2 forcing (in red) to the satellite observations, we need to account for the fact that the satellite observes forcing and feedback intermingled together. So, let’s remove a couple of estimates of feedback from the satellite measurements to do a more direct comparison.
Inferred Forcing Assuming High Climate Sensitivity (IPCC View)
Conceptually, the variations in the Earth’s radiative imbalance are a mixture of forcing (e.g. increasing CO2; clouds causing temperature changes), and feedback (e.g. temperature changes causing cloud changes). We can estimate the forcing part by subtracting out the feedback part.
First, let’s assume that the IPCC is correct that climate sensitivity is pretty high. In the following chart I have subtracted out an estimate of the feedback portion of the CERES measurements based upon the IPCC 20-model average feedback parameter of 1.4 W m-2 K-1 times the satellite AMSU-measured tropospheric temperature variations
As can be seen, the long-term trend in the CERES measurements is much larger than can be accounted for by increasing carbon dioxide alone, which is presumably buried somewhere in the satellite-measured signal. In fact, the satellite observed trend is in the reflected sunlight portion, not the infrared as we would expect for increasing CO2 (not shown).
Inferred Forcing Assuming Low Climate Sensitivity (”Skeptical” View)
There has been some published evidence (our 2007 GRL paper, Lindzen & Choi’s 2009 paper) to suggest the climate system is quite insensitive. Based upon that evidence, if we assume a net feedback parameter of 6 W m-2 K-1 is operating during this period of time, then removing that feedback signal using AMSU channel 5 yields the following history of radiative forcing:
As can be seen, the relative size of the natural forcings become larger since more forcing is required to cause the same temperature changes when the feedback fighting it is strong. Remember, the NET feedback (including the direct increase in emitted IR) is always acting against the forcing…it is the restoring force for the climate system.
What this Might Mean for Global Warming
The main point I am making here is that, no matter whether you assume the climate system is sensitive or insensitive, our best satellite measurements suggest that the climate system is perfectly capable of causing internally-generated radiative forcing larger than the “external” forcing due to increasing atmospheric carbon dioxide concentrations. Low cloud variations are the most likely source of this internal radiative forcing. It should be remembered that the satellite data are actually measured, whereas the CO2 forcing (red lines in the above graphs) is so small that it can only be computed theoretically.
The satellite observed trend toward less energy loss (or, if you prefer, more energy gain) is interesting since there was no net warming observed during this time. How could this be? Well, the satellite observed trend must be due to forcing only since there was no warming or cooling trend during this period for feedback to act upon. And the lack of warming from this substantial trend in the forcing suggests an insensitive climate system.
If one additionally entertains the possibility that there is still considerable “warming still in the pipeline” left from increasing CO2, as NASA’s Jim Hansen claims, then the need for some natural cooling mechanism to offset and thus produce no net warming becomes even stronger. Either that, or the climate system is so insensitive to increasing CO2 that there is essentially no warming left in the pipeline to be realized. (The less sensitive the climate system, the faster it reaches equilibrium when forced with a radiative imbalance.)
Any way you look at it, the evidence for internally-forced climate change is pretty clear. Based upon this satellite evidence alone, I do not see how the IPCC can continue to ignore internally-forced variations in the climate system. The evidence for its existence is there for all to see, and in my opinion, the IPCC’s lack of diagnostic skill in this matter verges on scientific malpractice.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
It’s dicey to trust James Hansen’s predictions of a pipeline since his predictions in the past have been wrong in the past. Track record counts.
as solar minimum was approached (=high gcrs=cooling=svensmark) the plots above show earth gaining excess energy.
I do not, I admit, understand how more energy = cooling
The plots show CO2 line doing the correct thing more co2=earth gaining excess energy so the plots are named correctly.
Yes in broad terms, however, I think everyone accepts (apart from IPCC and AGWers who believe in ONLY one GOD – the GOD of man-made CO2) that the whole climate system is complex and NOT SIMPLY EXPLAINED BY ANY ONE SINGLE FACTOR.
Therefore the physical response from physical mechanisms of one particular factor may be masked or swamped by another factor as the atmosphere responds to the combined effects of MANY FACTORS.
So in theory (or until proven WRONG): Trenbeth, Svensmark and Spencer may ALL be correct to some degree!!!!
Eric Barnes (21:14:53) :
Leif, broadly characterizing people wins you no points. Maybe you could be a little more charitable with your thoughts?
I’m not fishing for points. Just making an observation. Science results from being critical, not charitable.
“Leif Svalgaard (17:26:56) :
Henry chance (14:16:46) :
Joe Romm has just announced this is an anti-science blog
That is quite possibly an overblown claim, but there is a large amount of pseudo-science being peddled.”
Leif refers to people with alternative views on cosmology here. Leif is our local expert for the sun’s activity for all those who don’t know.
Leif, you should really explain it some more when you drop the anti-science word. You’ll confuse newcomers otherwise.
“(The less sensitive the climate system, the faster it reaches equilibrium when forced with a radiative imbalance.)”
Given all the talk recently about oceans and overpowering the “anthropogenic signal”, I would argue that oceans must have been contributing before hand to a rate at least equal to half of the rate observed if nature’s version of ‘overpowering’ the signal means flattening the signal out. If it were contributing less than half, then the ‘signal’ could overpower the natural process, and if it were contributing more than half… well, I guess we’ll find that part out in the next ten years, huh?
Leif Svalgaard (21:47:03) :
Science results from being critical, not charitable.
I actually think what he meant by being ‘charitable with your thoughts’ was to share them, as in why do you think pseudo-science is peddled here. I believe you are referring to electric universe stuff, but I am not really sure either.
bc browser (21:18:03) :
I am lost
Seems to me “pipeline” “latency” and “clmate sensitivy” are all similar concepts here. When you add additional new energy into a complicated system like a planet, it Kicks off all sorts of processes. Icreased heating, incresed negative feeback loops, increased radiance to space. Still those processes have to damp out until we reach a new quilibriium. Pipeline, latency and climate sensitivity are wll words the the same thing – how long after the input energy changes does the temp go up? Hansen seems to think a few yesrs, Pielk is saying decades. The more the various feedbsck loops cancel each other out, the longer it will take and the lower the end result temp delta.
My personsal feeling is the timescsale is even bigger than what Pielke thinks, about 150 years. My opinion comes not from scientific analysis. I noticed that the reconstruction of the solar constant to 1000 AD looked almost identical to tempersature reconstructions, but with the time scale slid sideways by 150 years. Here are some exasmples:
http://knowledgedrift.files.wordpress.com/2010/01/europe-vs-solar-forcing1.png
http://knowledgedrift.files.wordpress.com/2010/01/china-vs-solar-forcing2.png
and even displayed sgainst the 9 construction spasghetti graph from IPCC
http://knowledgedrift.files.wordpress.com/2010/01/ipcc-vs-solar-forcing-3.png
I freely admit that I cut graphs and did a so so job of getting scale right, but you csn see what I mean. The effective solar radiance we are talking about here is about .85 watts/m2 , half of what IPCC claims is the current level from co2. Since CO2 was very stable going back to 1000 AD, it was a steady state actor not influencing equilibrium before 1900. In brief, the pipeline is being proposed as a delay of a few years, Pielke is saying a number of decades, and I, with the sophisticated tools of cut and paste at my disposal, think it is 150 years. If you check my graph, we should see a cooling trend start early in this decade based on drop in solar radiance 150 years ago. Who know Paint was a climate model tool?
Of course if I am right, and the CO2 trapping heat thing is right, some folks in sbout 2100 ought to be getting a problem coming their way.
[quote tfp svensmark says -ve
spencer says +ve
trenberth says our observing system is inadequate.
Who is being honest here? [/quote]
I don’t think Svensmark and Trenberth are taking about the same thing.
Svensmark talks about how low level clouds cool the Earth. That’s pretty much an accepted fact. Svensmark’s contribution to it is that GCRs seem to play a role in forming low level clouds. But whether they do or not, low level clouds are still considered to cause cooling.
Trenberth was talking about how the CERES satellite was showing significantly more warming than could be accounted for from other forms of measurements. And that the instruments (probably the CERES satellite, if I understand him correctly) where not up to their task.
So I think there is little doubt in the main messages of these two men. Low level clouds cool. Our instruments aren’t reliable when it comes to measuring temperature.
Both are true and the statements don’t conflict one another.
So both men are right. And both are talking about different things.
The pair of blue lines is actual and trend?
davidmhoffer (22:58:15) :
What does all that energy do for 150 years? Hide in the ocean?
“Syl (17:15:53) :
pft (16:46:47) :
As I read it there’s less reflected sunlight (trend) which means fewer, not more, clouds. There are ups and downs, of course. And you can detect the 2007/2008 La Nina where the reflected sunlight went up (more clouds).”
After rereading this I agree, thanks.
magicjava (23:01:12) :
I don’t think Svensmark and Trenberth are taking about the same thing
OK
1. Svensmark says GCRs create more low cloud at solar minimum (i.e. NOW)
2. Spencer’s plots show earth gaining excess energy over the solar minimum.
Both 1 and 2 cannot be correct.
I know Trenberth is not talking about clouds. He simply said the data Spencer used is wrong or the earth is stroring energy but there is no measurement that can allow choice of either one.
For making this comment he and AGW have been trashed by the anti-AGW blogs
It does not add up!
GCR-climate connection – GCR’s increase low cloud cover via increased CCN production (via increased atmospheric ionization), which acts as a cooling effect on the climate.
IPCC
6.11.2.2 Cosmic rays and clouds
Svensmark and Friis-Christensen (1997) demonstrated a high degree of correlation between total cloud cover, from the ISCCP C2 data set, and cosmic ray flux between 1984 and 1991.
Unfortunately this ‘high degree of correlation’ didn’t really exist, it was due to the fortuitous mixing of the ISCCP data and the DMSP data to hide the decline in the former by S & F-C.
See for example:
Kristjansson, J.E., Kristiansen, J., Journal of Geophysical Research 105 (D9), 11851–11863, (2000).
[snip – we don’t allow discussions of chemtrails on this website]
((Richard111 (10:22:06) :
There must be a theoretical explanation for the existence of the “pipeline”.
James Hansen seems to believe it exists. Anybody?))
the ‘pipeline’ is what connects the Hooka to your lips, maybe???
regards
Phil. (06:11:48) :
Unfortunately this ‘high degree of correlation’ didn’t really exist, it was due to the fortuitous mixing of the ISCCP data and the DMSP data to hide the decline in the former by S & F-C
Ah! so Svensmark is wrong and Spencer’s satellite is correct.
So now all we have to do is find where all the excess energy is going, since it hasn’t increased temperatures for a few years.
It really is a TRAVESTY that we don not have instrumentation to show us where it has gone!
Thanks for your replies.. the only problem I have with saying rocks store heat in relation to nature is the fact that, if left to nature, we wouldn’t have the amount of ‘rocks’ (rock, concrete, brick, asphalt surfaces all exposed) that we have today.
Anyway, thanks again. It’s nice to know people are looking at all the variables that mankind ‘adds’ to nature. I, for one, can’t seem to wrap my head around the science using ONE factor, CO2, and finding some ‘correlation’ then turn that into causation… even when the correlation barely exists… then, saying it is BAD for earth, as if there is a manual for the earths ‘gasses’…
Keep up the great work, everyone.
***************
Henry chance (14:16:46) :
Joe Romm has just announced this is an anti-science blog. Joe romm is financed by convicted felon George Soros according to a post over there. Climate progress.
**************
The fact that Joe Romm has a physics degree does not mean he isn’t a political hack. He is a political hack. JMO.
Matbe you guys missed this post
sportpunter (12:47:52) :
Maybe you should check out this webpage: http://gustofhotair.blogspot.com/
which shows s significant decrease in cloud cover in the last 50 years. This decrease in cloud cover occurs only during the day, with steady rates at night. Temperatures have not been increasing at night but only during the day. Cloud cover is shown to be strongly related to temperature, and it will show that 75% of all warming is caused by cloud cover and proper statistical analysis of temperature.
It shows a practical application of the theory that shows less clouds = higher temperatures (In the day)
From previous posts, it sounds like Australia should be de-salinating Water and pumping it to in land reservoirs to cool their country down a bit. They also need it for drinking water and irrigation so it is a win win situation.
Much better than paying Carbon Taxes to make others rich
Dave F (23:05:32) :
What does all that energy do for 150 years? Hide in the ocean
It isnt hiding. when you transfer energy to something via a steady input it will rise to a new temperature, but it doesn’t get there in a single jump, or a straight line. It follows a logarythmic curve that is 5 time constants long. So, if the new temp is a rise of one degree, 63% of the rise would occur in one time constant, 63% of what is left in the second time constant (about 85% of the total) and so on. Here is a picture that is illustrative
http://knowledgedrift.files.wordpress.com/2010/01/time-constant-explanation2.png
So when someone says LOOK temperature of the earth started going up at exactly the same time as XYZ happened, they are proposing a time constant of 0. As Mr Einstein once quipped, that’s not right, that’s not even wrong. Hansen is suggesting that the time constant is perhaps a few years meaning that the increased energy input that started due to co2 increases in 1940 will result in a new temperature, but we may only be part way through the first one or two time constants, meaning that there is more temp rise “in the pipeline”. Pielke is saying that due to negative feedbacks and other issues, the time constant is perhaps decades and the total change may take 75 years. Given that the solar energy fluctuates by about 0.85 watts/m2, about half of what IPCC is claiming as a positive CO2 increase so far, and there were negligible greenhouse gases increased before 1900, we should be able to “see” the solar variation in the millenial temperature reconstructions and work backwards to determine what 5 time constants is. Using the incredible climate modeling tools of copy, paste, paint and resize, I concluded 150 years. If Pielke is right, the current cooling trend over the last few years would be attributed to a reduction in energy input about 75 years ago. I propose 150 because if you take as look at:
http://knowledgedrift.files.wordpress.com/2010/01/solar-constant-6.png
you see there was a solar max about 1850 implying a cooling trend starting about 2000 give or take a few years, which is what we are seeing. There was a major solar min about 1700 implying that we we should have seen a general warming trend starting in about 1850. Actual temp records indicate 1830 was the low. There was a solar max about 1600 implying a peak about 1750. IPCC has about 9 temp reconstructions in their report, all showing a hump at about 1750.
This is really important to understand because the bulk of the climate models are built on the assumption that the time constant is a few years at best. Perhaps a decade. But they are built on very detailed information from just the last few decades. If the time constant is larger than the data set time span as Pielke (and I) suggest, then it would be near impossible to build a mathematical model that was precise.
August is good month in lincoln, uk. for high temperatures. Temperatures get higher if there a lot of sunshine and little rain in one month but even higher if the previous month had a lot of sunshine and little rain .Could evaporation be causing a build up of water vapour over time in the atmosphere raising temperatures higher?
Re: boballab (14:55:24)
I would be interested in hearing how you think N. American farming practices affected Earth orientation parameters in the ’30s.
davidmhoffer (22:58:15)
Thanks for your comments; good points. I am still digesting your article on Theory of Earth Temperature Regulation. What I was getting from Roy Spencer’s article was that Trenberth could actually be onto something except that what we were seeing was a very fuzzy object in the distance. We think it is coming toward us but don’t know how far it is, how fast it is moving, how big it is and what’s it made of. Hardly grounds for preparing a sensible, evasive action. Oceans, biomass, ice melt were just the first few things that came to my mind but I am sure there are many more potential cooling mechanisms, acting in synch or in sequence and the one mentioned in your article via north and south poles sounds very plausible. I am just hoping that after all the excitement of the last year we’ll reach that “tipping point” when most scientists, including those involved in the climategate, will stop wasting their considerable intelligence and energy on what to say and instead focus on the clues. I tend to side with Lomborg on this one. We need some time and we have that time.
sportpunter (12:47:52) ” http://gustofhotair.blogspot.com/ “
It will be interesting to see what he comes up with if he starts using methods beyond whole-record trend analysis.