I really wish Gavin would put as much effort into getting the oddities with the GISTEMP dataset fixed rather than writing coffee table books and trying new models to show the sun has little impact.
This paper gets extra points for using the word “robust”. – Anthony
Solar trends and global warming (PDF here)
R. E. Benestad
Climate Division, Norwegian Meteorological Institute, Oslo, Norway
G. A. Schmidt
NASA Goddard Institute for Space Studies, New York, New York, USA
We use a suite of global climate model simulations for the 20th century to assess the contribution of solar forcing to the past trends in the global mean temperature. In particular, we examine how robust different published methodologies are at detecting and attributing solar-related climate change in the presence of intrinsic climate variability and multiple forcings.
We demonstrate that naive application of linear analytical methods such as regression gives nonrobust results. We also demonstrate that the methodologies used by Scafetta and West (2005, 2006a, 2006b, 2007, 2008) are not robust to
these same factors and that their error bars are significantly larger than reported. Our analysis shows that the most likely contribution from solar forcing a global warming is 7 ± 1% for the 20th century and is negligible for warming since 1980.
Received 17 December 2008; accepted 13 May 2009; published 21 July 2009.
Citation: Benestad, R. E., and G. A. Schmidt (2009), Solar trends and
global warming, J. Geophys. Res., 114, D14101,
doi:10.1029/2008JD011639.
hat tip to Leif Svalgaard
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Also Phil, I would be interested to know the temperature value that CO2 forcing asymptotically approaches, sans feedback.
Adam from Kansas (20:25:37) :
Ball of ice without CO2? Is that trying to say the Sun has no power to warm the Earth, last I checked it gets well over 100 degrees on the part of the moon baking in the Sun, any ice on the back side of the moon would melt when it recieves direct sunlight. If you stand outside and feel the warmth of sunlight hitting your face, you know the Sun has warming power.
The Moon’s albedo is ~0.12, snow is about 0.8, snow and ice seems to do well enough in the direct sunlight in the Himalayas. White coral sand on tropical beaches stays relatively cool to the touch for the same reason.
Also, what are the clear differences between those two ice datasets, regardless of which one you believe it doesn’t show ice even close to being below 2007.
The OP referred to 2008! Currently the Arctic seaice extent is dropping fast, another 120,000 km^2 today, already passed 2008 and will probably be 2nd only to 2007 in a day or so. With the current rate of drift the NP webcam will be floating in the ocean in early Sept.
Steven Hill (17:02:17) :
Well, it appears that the arctic is not melting as much as 2008,
Hey Anthony,
Can I be the spelling marm tonite. Perhaps you are tired and need some coffee, cause gaving’s name is spelled wrong:) 🙂 🙂
Reply: Thanks, I fixed it, and the word coffe as well. ~ charles the moderator
It’s amazing how pathetic the science of global warming is. It makes you shake your head!!
Ok so Gavin is pontificating that solar influence is at an irrelevant level in the context of AGW.
Of course he is. The guy has gambled his credibility, reputation and career on AGW.
Gavin and AGW relies upon the solar influence having a minor role in global temperature trends.
That’s a huge conflict of interest creating extreme bias which has already eroded his credibility.
He’s an untrustworthy activist with personal interests at stake .
The worst source for anything authentic and reliable.
His deleting and even doctoring commenter’s posts on his blog is one of many red flags which should render him unfit for publicly funded influence at any level.
So his latest pretense of impartial and honest science should be met with disgust and disregard.
Steve S (22:20:50) : which has already eroded his credibility.
I didn’t know of his original credibility in an pre-eroded state.
He was who then?
So the sun is irrelevent in the context of AGW is it? Here’s a very simple, but I believe effective, thought experiment…
Suppose one hot summer’s day, I decide to pull that cosmic string which is – conveniently – connected to the on/off switch for the sun. 8 minutes later, the planet that was on the daylight side of the Earth, suddenly notices… ” E’re – the sun’s been switched off, cor blimey!” (Cockney accent added for dramatic effect).
I wonder how long it would take for the Earth to start getting intolerably cold, and whether the fraction of a percent of human-introduced carbon dioxide would make a blind bit of difference.
Also, “planet” should be “population” in my above post. Bleh.
Phil. (21:33:34)
The OP referred to 2008! Currently the Arctic seaice extent is dropping fast, another 120,000 km^2 today, already passed 2008 and will probably be 2nd only to 2007 in a day or so. With the current rate of drift the NP webcam will be floating in the ocean in early Sept.
The rather monotonous consistency of the drift patterns of the Arctic webcams over each of the years it has been deployed seems to me to strongly suggest that the primary driver of sea ice loss in the Arctic has not been in situ melting, but the relative strength of the Cross Polar Drift. Each of the sites that have persisted for up to a year has ended up in pretty much the same location at about lat 72-68 off the East coast of Greenland. The ice pinger data at this years site is showing only minor loss of thickness even though it has already moved to lat 85.
Adam from Kansas (20:25:37) :
We need the whole atmosphere, including the CO2.
Plants need food and we need plants.
Besides, on the moon, the diurnal is cyrogenic freeze to vaporized roast
We went there, too..
BTW, if you watch the Arctic ice animation that Jeff id made a while back the flow pattern is quite apparent.
Kevin Cave (22:38:16) :
Now that is something the ancients got very worried about. The Sun getting eaten.
Today, we have a Sun that has gone eerily quiet, and we know it.
Gavin gets two more points for inventing the word “nonrobust”.
I like that propaganda diagram, it is narrow and high to create a steep slope and its limits is set sp that the temperature curve hits the roof before it reaches the end instead of fitting it well within the limits.
Should the solar forcing curve be interpreted as how much the TSI has contributed to the gloobal warming, i.e 0.1 to 0.2C during the 20th century?
I always thought “Robust” was a word used to describe spaghetti sauce.
Phil. (20:21:13) :
Bill Illis (18:47:20) :
Let’s recalculate gavin’s number (using his own assumptions) since he has to use a climate model to do his simple calculations.
Total solar irradiance change from 1900 to 2000 according to Lean 2004 – 2.0 watts/m^2.
Except as you know very well, because Lief has posted on here multiple times, Lean has revised that figure downwards. Of course that doesn’t suit your agenda so you keep going back to the repudiated data.
Recanted data more like.
The real issue is the degradation of the sensors on the satellites measuring TSI. Something I’m going to try to find out more about. Scafetta seems to be on the case, per Nogw’s several posts linking his EPA presentation.
I’m approaching the issue the other way about to see what the world would look like if the solar signal has the terrestrial amplification Nir Shaviv calculated, and allowing for some sensor degradation on the radiometers.
Should have some preliminary results later today.
Sneak preview:
http://s630.photobucket.com/albums/uu21/stroller-2009/?action=view¤t=ssnc-pdo-amo.gif
The only solar forcing that Gavin has ever included in any of his models is Total Solar Insolation (TSI). He does not include any solar-magnetic effects, which is how solar activity is hypothesized by Svensmark and others to affect global temperature.
TSI varies by less than .1% over time. Solar activity ranges from fifty years of near zero sunspots (the Maunder Minimum), to the “grand maximum” solar activity between the 1930’s and 2003.
In other words, just more of the same omitted variable fraud that Gavin Schmidt has been engaging in his entire career. Search GCR in Gavin’s paper and you’ll see that he only mentions it to give his rationales for why he doesn’t bother to include it. The guy is the ultimate charlatan.
@RW:
“Between 1905 and 1940, CO2 concentrations rose from about 297ppm to about 311ppm. It would be perverse to call a 5% rise “almost constant”. ”
-5% increase of much less important GHG than water vapor is negligible.
“Using all four major measures of global temperature, we can see that the warming since 1980 is not negligible. What data did you use to reach this erroneous conclusion?”
-Had not been there two volcanic events in 1984/1991 and natural El Nino, the trend would be flat. Today temperature is on the level of 80ties.
-Start doing more research. Yesterday it was late.
I would ask 2 questions.
1. Why does the graph stop at 2002
2. Does Solar forcing mean direct solar irradiance or does it include secondary effects of the solar cycle i.e. magnetic field influencing cosmic rays influencing cloud formation influencing albedo etc.
Global Climate Modeling. Getting it wrong for 20 years… and counting!
But don’t worry – we’ll get it right eventually!
RW (16:34:16) :
Between 1905 and 1940, CO2 concentrations rose from about 297ppm to about 311ppm. It would be perverse to call a 5% rise “almost constant”.
An increase from 297ppm to 311ppm gives a forcing of ~0.25 w/m2. Given the uncertainty of the measurements before 1958 and in the context of climate variability over a 35 year period, ‘almost constant’ is a fair description.
Note that using your figures the CO2 forcing since 1940 is more than 4 times the pre-1940 forcing yet the magnitude of the warming is of similar order.
And as is rather well known, the early part of the 20th century saw a lull in volcanic activity, …..
Ah yes – the “lull in volcanic activity”. This is where something not happening causes temperatures to rise at an unprecedented rate. Though, of course, there was Krakatoa in 1883 and the other one (can’t remember it’s name) in 1902 yet within a few years temperatures began to rocket.
Mind, though, it’s now been 18 years since last major volcano. The Pinatubo eruption in 1991 was the last eruption to have a climatic effect. Perhaps the ‘lull’ in volcanic activity has caused whatever temperature increase we’ve seen since then.
and an increase in solar output.
Gavin’s just shown there was no increase in solar output.
The combination of these three effects accounts for the observed warming.
The combination of these 3 effects before 1940 amounts to diddly squat.
Just how much research had you done into this, before posting here?
More than you.
The term ‘forcing’ sounds very Orwellian to me.
Has some new major source of energy other than the Sun been discovered in the Solar System?
Quote, Gavin, “we examine how robust different published methodologies are”
Hypocrisy writ large when you consider that Gavin and co have been busted several times for exploiting far less robust methodologies themselves to give the desired result. e.g., Mann’s hockey stick, Steig’s smearing etc.
We can take this study with a large pinch of salt, because it is the same old, same old story.
OK I haven’t read this stuff, but why the obsession with the second half of the 20th century? Did it not get more warmerer in the first half of the 20th? DId it not get warmerer still in the 19th century? … oh, wait, the temperature of the planet was constant until 1950. I forgot; silly me.
As Barry pointed out before the graph shows the temp in 2/10th of degrees and shows solar variation in full unit.
I think that if the solar variation was plotted within the border of 1365 and 1367, would show a better correlation.
BTW- what is the R^2 for the solar temp when compared to the co2 R^2 of 0.07 from a post a few days ago.