This is an interesting paper from our good friend Dr. John Christy of UAH and D. H. Douglas. In it, a bold claim is made about the likelihood that the atmosphere no longer shows the characteristic of CO2 radiative forcing, and that the effect apparently peaked around 1998. Here is figure 1 from the paper:
From the paper: “The global values of ΔT in Figure 1 show for the period Jan 1979 to Jan 2008 that the anomalies reached a maximum in 1998 which has not been exceeded by later values.”
Here is how the abstract reads:
“The global atmospheric temperature anomalies of Earth reached a maximum in 1998 which has not been exceeded during the subsequent 10 years. The global anomalies are calculated from the average of climate effects occurring in the tropical and the extratropical latitude bands. El Nino/La Nina effects in the tropical band are shown to explain the 1998 maximum while variations in the background of the global anomalies largely come from climate effects in the northern extratropics. These effects do not have the signature associated with CO2 climate forcing. However, the data show a small underlying positive trend that is consistent with CO2 climate forcing with no-feedback.”
You can read the paper and the link below. which provides a new perspective on the role of CO2 as a radiative climate forcing.
Douglass, D.H., and J.R. Christy, 2008: Limits on CO2 Climate Forcing from Recent Temperature Data of Earth.
I’m sure this will raise the ire of a number of people, but at the same time, what else have we to explain the nearly flat response in global temperature in the last 10 years?
h/t Dr. Roger Pielke, Sr.
Duscany (18:30:51) :
“Maybe no one can find any “missing heat” deep in the ocean, Matti Virtanen, because there’s no heat there to be found.”
Don’t forget that only 10% of the oceans waters are in surface currents, that leaves 90% that have little measurements (virtually none below 2km, the average sea depth is 3.5km) We know that the sea levels have risen, this can only either be from melting of land ice or from thermal expansion. These are the facts, you decide.
Dee Norris (03:04:45) :
“My understanding of Leif’s position is that he is saying that he does not see any acceptable mechanism to demonstrate that the sun had a major role in historic climate change.”
You also missed out Leif’s position that there is no evidence either. Read his points on the Maunder and Oort Minimums.
@Mary:
Please don’t tell me what I missed or didn’t miss.
No evidence does not mean the evidence does not exist. Leif chooses his words very carefully.
I ask people on this blog to be very wary of Leif Svalgaard’s arguments.
He is very knowledgeable about the Sun and solar activity. He is a highly respected researcher in this field and, unlike many in his field, he goes out
of his way to try and explain quiet technical and difficult material in a manner
that is (mostly) understandable to the lay person.
However, the fact that he is so knowlegeable about the Sun and influneces upon the Earth does not mean that he is font of all wisdom on this topic.
There are plausibe alternative ideas on this topic to those held by Dr. Svalgaard.
While his expertise on solar phenomenon cannot be faulted, and few would argue that many of his arguments are not based on firm scientfic principles,
he is not an expert in all of fields of science.
There are many respected scientists who would argue that he has not taken into account all the factors that are involved in solar activity and climate.
Mary Hinge,
Before you accept Leif’s world view as gospel, you might want to look at
one alternative ideas at:
http://www.lavoisier.com.au/articles/greenhouse-science/solar-cycles/IanwilsonForum2008.pdf
Old Man Winter (07:46:10) :
“With respect to Dr. Svalgaard’s claim that “the Sun is not a major climate driver,” Shaviv, the de la Fuente Marcoses, and Svensmark have established beyond a shadow of a doubt that huge spikes of cosmic rays increased cloud cover on Earth twice, once 2.3 billion years ago and once 700 million years ago, during periods of unusually high star formation in the vicinity of the Milky Way. The stellar baby booms produced frozen seas at the equator and total glaciation of the continents, a condition referred to as Snowball Earth.”
A more plausible theory for the ‘Snowball Earth’ (though ‘Slushball Earth may be more accurate) for 2.3 billion years ago is the increase of oxygen and the subsequent rapid decrease of methane in the atmosphere of the time.
The event 700 mya again involves changes in greenhouse gasses, this time CO2. The equatorially placed continents of the time would have facilitated the rapid weathering of calcium and magnesium silicate rocks. This forms carbonates and removes CO2 from the atmosphere.
Unlike the cosmic ray theory which is, at best still a weak theory, the changes in geology are solid evidence that make the atmospheric change theory a much stronger and testable one.
Interesting discussion about how atmosphere is heated up by different wavelengths.
There are a few things said that I do not understand fully.
About the calculation that 99.95% of UV/X-ray are absorbed in atmossphere.
Even though it gets absorbed very high up in the atmosphere it is still heating it up. Almost all the energy from those dangerous wavelengths are absorbed in the atmosphere.
Leif said:
“It doesn’t matter how much the thermosphere and stratosphere is heated by UV as there is no way of getting that heat to the ground [hot air does not sink. but rises]. Also the heat content is very small as the density of the air decreases by a factor of a thousand for each 50 km step in altitude.”
I understand that the “heated” air high up in the stratosphere cant reach us via convection or conduction but still the energy that that layer of atmosphere absorb must go somewhere or the air will be turned into glowing plasma in time.
AS I understand it the only way earth can loose energy is via IR radiation.
If so all that energy that get absorbed high up in the atmosphere must escape earth via radiation.
Now to my questions:
– What is the wavelength of the IR radiation from the air in stratosphere?
– Does the air in the stratosphere reemit the absorbed UV and X-ray energy at wavelengths that can reach troposphere/surface?
– Which direcation does it radiate its absorbed energy? Doesn’t it radiate it in any random direction and thus something like 40-45% of the energy absorbed high up in the stratosphere would be raidated in a direction that will bring the energy to or closer to the surface and the rest, 55-60% would be radiated directly back out into space?
– If this is how it works, wouldn’t Mike Ramsey’s 0.96% contribution to heating rather be like 0.4%(still 400% larger contribution than the 0.1% number) incase the absorbed UV/x-ray can be remited at wavelenghts that can reach troposphere or surface?
Mary Hinge, sea level is dropping and this can only be from thermal contraction or ice accumulation. In this case, I think it is both, since the globe, oceans and atmospheres, is cooling.
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Old Man Winter (03:19:41) :
“The Little Ice Age was not produced by internal variations, as Dr. Svalgaard has suggested at various times. It was produced by Svensmark clouds during a series of significant solar minima, most notably Maunder.”
Then why isn’t the LIA more than a local phenomenon, if it was caused by SC then surely it would be global. This suggests that the LIA and MWP were more to do with the Atlantic currents (we know these are variable) than climate change due to SC which is a pretty weak theory
Dee Norris (03:35:16) :
“No evidence does not mean the evidence does not exist. Leif chooses his words very carefully.”
I shall re-phrase “Available evidence shows that there is no correlation between sunspot activity and the LIA and MWP”
Leif Svalgaard (21:49:25) :
[snip]
The air is transparent to visual and infrared radiation so that shines through to be finally absorbed by ground and sea [what is not reflected back out]. The heated ground heats the air just next to it by conduction, casing the heated air to rise by convection heating the troposphere from below.
I agree with the comment about visual. The air is not transparent to infrared. Isn’t that the crux of the global warming concern?
It doesn’t matter how much the thermosphere and stratosphere is heated by UV as there is no way of getting that heat to the ground [hot air does not sink. but rises].
After that UV and X-Ray radiation is absorbed, the energy is reemitted as long wave infrared (IR). Some of that infrared radiates back out into space as a component of the Outgoing long wave radiation (OLR). The rest, called the long wave (LW) downward atmospheric radiation, heats the earth’s surface.
Also the heat content is very small as the density of the air decreases by a factor of a thousand for each 50 km step in altitude.
All (99.95%) of the incoming radiation with wavelength shorter than 300 nm is absorbed by that atmosphere. That energy has to go somewhere.
Mike Ramsey
kim (04:12:34) :
“Mary Hinge, sea level is dropping and this can only be from thermal contraction or ice accumulation. In this case, I think it is both, since the globe, oceans and atmospheres, is cooling.”
Plese look at this graph and you will see that sea-level is rising and has been rising 50% faster than the average of the 20th century, at a rate 0f 3.3mm a year. http://www.cmar.csiro.au/sealevel/sl_hist_last_15.html
Therefore, as sea level measured to be rising, logically you must think this is from thermal expansion or land ice melt, yes?
Mary, I wonder if you could point to your evidence that the LIA was local? If it is Antarctic temps, don’t bother. The cloud-seeding provided by cosmic rays during solar minima actually warms Antarctica. In every case, when Greenland ice cores show substantial cooling Antarctica warms, and vice-versa. This has to do with the albedo of snow and ice, which is even higher than that of clouds. Antarctica is separated, temperature-wise, from the rest of the world by powerful currents encircling it and a vortex in the atmosphere above that. During periods of relatively high numbers of clouds, e.g. the Little Ice Age, Antarctica trends warm.
The same phenomenon exists over Greenland, but is generally overwhelmed by Atlantic weather systems and ocean temps.
So, rather than disproving that the Little Ice Age was global, Antarctic warmth actually corroborates it, if you know what governs Antarctica’s temperatures.
Mary Hinge: “Available evidence shows that there is no correlation between sunspot activity and the LIA and MWP”
Yeah sure Mary, I’ll go along with that if you go along with: “There is no evidence that man-made CO2 is the primary cause of temperature rise in the last century.”
And the temperature rise has stopped in the last ten years, the CO2 models say it should continue to go up. But hey the science is settled, no need to reexamine anything, lest people like Mary come “[snip]”. Onward CO2 soldiers!
Warning: Them thar be fightin’ words that were [snipped]. Lets avoid the Ad Hominems. – Anne
Speaking of sea level…
http://sealevel.colorado.edu/
No new measurements til the end of 2008…
Would like to know what the problem is, precisely.
Mary Hinge (04:30:10) :
That graph covers part of the last PDO warm phase and the barest beginning of the current PDO cool phase. There are hints in that graph that ocean levels have stopped rising. The Argos system is reporting that the ocean has cooled slightly in the last year or so, and CO2 levels at Mauna Loa have been making some atypical jogs, though some of those have been identified as measurement processing shortcomings.
The last two years of that graph say “Chill out, there’s no crisis at the moment, watch, earn, and understand.” Then few decades will be fascinating, sit back and take some time to appreciate this golden era of climatology.
OK, The temperatures are adjusted and homogenized. The Mauna Loa CO2 station is manned by someone who is preparing for cap and trade. The AIRS team have been working for over five years to get a “CO2 product” out. (two more weeks?) The sea level numbers are unavailable until the end of the year.
With the billions and billions we taxpayers have kicked in to this climate investigation, don’t we deserve better?
Good old Ric and his tiny trends! The graph only covers the last 15 years as that is how long the measuring system has been in place.
Ric Werme
“There are hints in that graph that ocean levels have stopped rising”
Nice word ‘Hints’! More to do with VERY short term deviations, ‘noise’ some may call it. Look at the unadjusted graph and check out the annual maxima and minima abd you will see that the meaningful trend is definately up.
Old Man Winter (04:46:06) :
“Mary, I wonder if you could point to your evidence that the LIA was local?”
Proxy temperatures do not show the events on a global scale….and there have been a lot of them!
“So, rather than disproving that the Little Ice Age was global, Antarctic warmth actually corroborates it, if you know what governs Antarctica’s temperatures”
So global cooling causes warming is what you are saying. So why is it when evidence comes to light that global warming can cause cooling there is such a cause of commotion on this blog!
Ninderthana (03:46:19) :
An interesting document, a skillfull mix of the science we know and wild speculation. If true maybe there is more to Astrology than we realise! Nice moon picture though.
Ric, just for you, the trend over the last few hundred years http://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html
@Mary:
The reason there is no available evidence of a correlation between sunspot activity and LIA or MWP is because no one was counting sunspots at the time. However, there is a correlation to solar activity using 10-Be isotope concentrations in ice cores as a proxy.
Also, the Dalton Minimum does show a correlation between temperature and solar activity using both 10-Be and Sunspot concentrations.
Mike Bryant (05:24:49) :
“No new measurements til the end of 2008…
Would like to know what the problem is, precisely.”
Seems to be a local issue at Colorado, could explain why they haven’t updated their graph since February whereas the CSIRO graph goes to May.
Dee Norris (06:02:00) :
I’m not going to discussa point that Leif has covered so well earlier in the post, if you want answers then I suggest you refer to his previous points on this very matter
But correlation does not imply causation. I’ve already read your stated point previously in this thread that you believe the absence of evidence does not imply evidence of absence, but you are making a broad leap when you suggest that, in the lack of evidence of a mechanism to with which to construct a cause-and-effect relationship, such a relationship exists. As a matter of fact, it is inconsistent to be a skeptic and hold this viewpoint – a skeptic should be rational, and it isn’t rational to violate Occam’s Razor and suggest that although there isn’t evidence for it, such a connection between the sun and the climate does indeed exist.
Skeptics – particularly the ones who consider themselves scientists – do not get a free pass on the principle of parsimony. It is incompatible with the foundation of their perspective.
Reply – My viewpoint is that there is a correlation. If my viewpoint was that there was evidence supporting causation, I would have stated it. – Dee Norris
Jerker Andersson,
Does the air in the stratosphere reemit the absorbed UV and X-ray energy at wavelengths that can reach troposphere/surface?
Take a look at Figure 2. here
http://met.hu/doc/idojaras/vol111001_01.pdf
I must warn you that Ferenc was writing for folks like Leif rather than John Q Public. The physics can be daunting to the uninitiated.
Mike Ramsey
Bruce (17:12:40) : who said “The graph of ocean heat content shows more ocean warming from 1968 to 1980 as from 1980 to say 1992.
Yet we know the temperature was cold in the 1970s.”
Try looking at the latest (2008) corrected OHC analysis, which I mentioned in a later post:
http://www.realclimate.org/images/ohc_domingues.jpg
Which happens to match the HADCRUT global temperatures quite well:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1947/mean:72
OTOH, sea level rises (= average ocean temperature) since 1880…
http://www.globalwarmingart.com/images/thumb/0/0f/Recent_Sea_Level_Rise.png/700px-Recent_Sea_Level_Rise.png
…seem to lack of lot of the bumps seen by HADCRUT since 1880:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1875/mean:132/plot/hadcrut3vgl/from:1880/mean:12
But that can perhaps be attributed to the atmosphere holding *much* less heat than the oceans, and so that the atmosphere is presumably prone to much greater variations in temperature. Which is why I suggest looking at ocean temperature/level is in the first place.
counters (06:39:32) :
Yeah, but there’s this annoying 200 years of correlation taunting to explain it. We’re entering a period where we may finally figure out what’s going on. Or not. It’ll be a fun ride, no point in jumping to conclusions yet. Nor is there any point in saying that “CO2 is going up, it works (details omitted), therefore the temperature is going up.” Besides, there’s a better correlation between PDO and temperature, and a direct link to boot.
Science didn’t figure out how aspirin worked until the 1980s. Didn’t stop doctors from using it.
@Mary:
I wasn’t looking for answers, but thank you for your concern.