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.
This paper is important because it actually measures the temperature change which has occurred (in the tropics) as a result of CO2/GHGs.
The 0.07C per decade warming should be compared to the global warming theory of 0.2C per decade (or only 35% of the warming predicted by the theory.)
This period, 1979 to 2007, was also the period of most rapid warming we have seen and yet warming is only 35% of that expected.
So wht is 35% times 3.0C = only 1.0C per doubling of CO2 (an inconsequential amount really)
Providing said scientific publication deigns to publish the item.
Mary Hinge (09:21:46) :
Old Man Winter (07:46:10) :
“One has to believe, in short, that the Maunder Minimum was not related to the sun, a very strange proposition.”
I thought the ‘Maunder Minimum’ was so called because of a prolonged period of a low number of sunspots […] surely the ‘Maunder Minimum’ has everything to do with the sun?
Mary, i interpreted his [admittedly obscure] statement as meaning that the LIA during the Maunder Minimum was not caused by the Sun, but who knows what he really meant [maybe he’ll clarify – although it doesn’t matter much].
My point was that you can’t have it both ways: MM -> cold LIA, and OM -> warm MWP. And that is actually also my response to Raven. Your mechanism would have to work in reverse during the OM [and actually the Spoerer Minimum – SM – too]. Of course, you could just postulate that it did and YAHF.
Mary;
Winds are caused by difference in temperature (or pressure) … p = f (T) … therefore, you are creating a “perpetuum mobile” in violation of the law of conservation of energy.
ANY value for superfical temperature of the sea, means nothing to amount of energy in the oceans.
Dear anna,
There are two models,
one predicts basically continuous increase of temperature, as long as we increase the output of greenhouse gases (and in addition predicts that we reach (or have reached) a tipping point, where an automatic further and very significant increase of temperature is triggered),
the other model predicts the sun’s influence to be dominant, which in the past 50 years has led to warming due to increased solar activity, under present circumstances, however, will lead to a significant cooling, if not something like a little ice age (pending Maunder-type minimum of solar activity).
These are the interesting times we live in, as Anthony is pointing out occasionally.
As a scientist, one would expect a scientific discussion, which, in the experience of my life-long scientific work, should at least be well-mannered.
Unfortunately, this is not the case.
Good science stands the test of time regardless of whether it is published in peer-reviewed journal. That said, this paper will not be taken seriously by policy makers unless and until it is published in a peer-reviewed journal.
I have some idea of why this might be, but I would like to hear from the authors their explanation of why they are publishing in E&E rather than GRL or some other more mainstream journal.
Mary Hinge: “The ‘little Girl’ is caused by increased easterly winds”
Where does the increase in wind come from?
Dr. Svalgaard: Why do you say the data appears smoothed, in figure A1?
Note that I am a layman, so be gentle….
Raven: “Many simple heaters work but adjusting the duty cycle of a fixed voltage pulse. It is possible to increase the temperature by increasing the width of the pulse and decrease it by reducing the width.”
Adjusting the duty cycle varies the average amount of power over time. Changing the length of the solar cycle simply changes the frequency without changing the duty cycle, so the average power over time remains (almost) constant.
Mike McMillan (23:22:20) :Didn’t know Kelvin degrees went below zero.
They can if they are deltas. That’s what “anomalies” are. I hate that word. It implies that the baseline is normal.
@Leif
I’m sure you are tired of answering this question..and I’m sure you have posted the answer here somewhere…but if I’m interpreting you correctly, you do not seem to beleive that solor cycles drive climate change..or do I misunderstand???
Obviously, climate changes over time…and obviously it was doing so for a long, long time before humans started setting fires…so SOMETHING is causing change…probably a mix of several somethings.
Equally, obviously, you could write a book on the topic…but, in simple words that a poor biologist can understand, what the heck do you think is really going on. I respect your posts and would greatly appreciate the time it will take you to answer.
most respectfully,
cdl
Les Johnson (10:52:49) :
Why do you say the data appears smoothed, in figure A1?
Note that I am a layman, so be gentle….
First the Figure just above it looks too smooth to be raw data, second, on A1, the points fall just next to one another forming long ‘lines’ or ‘rows’ of point, instead of showing the ‘lateral scatter’ that raw [real] data exhibits.
@Mary
Thanks for the sea-level rise graphs.
Gabriel
Leif Svalgaard: “The coincidence of the cold of the Little Ice Age with the Maunder Minimum of low solar activity must be tempered by the coincidence of the warmth of the Medieval Warm Period with the Oort Minimum of low solar activity”
Even Manns hockey stick displays a Little Ice Age so I guess there is more or less consensus about that. It is however my impression that no consensus has been reached as to the timing and possible global character of the Medieval Warm Period. What temperature reconstruction are you referring to and why do you believe it is valid?
Peter (10:57:40) : Adjusting the duty cycle varies the average amount of power over time. Changing the length of the solar cycle simply changes the frequency without changing the duty cycle, so the average power over time remains (almost) constant.
Changing the length of the period changes the duty cycle.
%duty = Pon/(Pon+Poff).
or average/time = P(t)/period
Perhaps you meant something else?
Fernando Mafili (10:26:15) :
“Winds are caused by difference in temperature (or pressure) … p = f (T) … therefore, you are creating a “perpetuum mobile” in violation of the law of conservation of energy.
ANY value for superfical temperature of the sea, means nothing to amount of energy in the oceans.”
I think you are missing one fundamental factor, the difference in temperature/pressure over the Americas, i.e not over the sea, helping to generate the winds. This allows the same cooling effect of blowing on a cup of coffee to cool it down i.e to remove energy from it via evaporation.
Correction:
Changing the length of the period changes the duty cycle.
%duty = Pon*Ton / (Pon * Ton + Poff * Toff) = averaged normalized power over time. (P=power; T=time)
Though “duty cycle” usually is reserved for binary states.
Leif Svalgaard (10:06:22) :
In full agreement with you on this one. I was just saying that the MM itself was a solar phenomenon.
Werner Weber (10:31:58) :
“Dear anna,
There are two models,
one predicts basically continuous increase of temperature, as long as we increase the output of greenhouse gases (and in addition predicts that we reach (or have reached) a tipping point, where an automatic further and very significant increase of temperature is triggered),
the other model predicts the sun’s influence to be dominant, which in the past 50 years has led to warming due to increased solar activity, under present circumstances, however, will lead to a significant cooling, if not something like a little ice age (pending Maunder-type minimum of solar activity).”
Sorry, but there are many models, called GCM models, creating spaghetti graphs of temperatures for the future. If in these models the albedo, for example, is adjusted it will give equally well cooling spaghetti as now it is giving warming ones . If in this models you put strong feedbacks, you get the CO2 scenario, in varying strengths. As Keenlyside et al have shown you can fit the present stasis with these models. Who was it who said give me three parameters and I will fit you an elephant? It is just that the project of the AGW crowd is to fit for rising temperatures, no matter what.
True, there are statistical correlations with the sun and its sunspots and maybe with cosmic rays, they give rise to other models.
Craig D. Lattig (11:49:49) :
I’m sure you are tired of answering this question..and I’m sure you have posted the answer here somewhere…but if I’m interpreting you correctly, you do not seem to believe that solar cycles drive climate change..or do I misunderstand???
I never tire [and I have posted it a lot of times, try google]
It is a question of ‘how much’, not of ‘if’. There is surely a solar signal because the Sun is changing what it throws at us, but [and this is the crux of the matter] the solar change is very tiny and the climate signal seems to be very tiny too [otherwise this would not up for discussion, just like nobody discusses anymore if sunspots cause aurorae]. The latest research seems to indicate the the Sun changes a lot less than we thought just a few years ago.
Equally, obviously, you could write a book on the topic
There are already a lot, but I am ‘working’ on a book with a somewhat broader subject: ‘What we know about the Sun’s activity and its effects, and how we know it’ But is is a long-term project that may never be finished.
Chris H,
I believe the graph you displayed is based on errors.
“Discovering these three types of errors in calculating oceanic heat content anomalies allows for some skepticism about how much our oceans are really warming as well as the magnitude of the thermosteric contribution to sea level rise.
Considering the meteorological and societal impacts of accelerated sea level rise, it is very important to not only find and assess all sources of error in measuring oceanic heat content anomalies, but to reduce the amount of error that is present.
Optimal accuracy of calculations of heat content will lead to better diagnosis and modeling of sea level rise. ”
http://209.85.173.104/search?q=cache:2WBG28MWBDQJ:www.atmos.umd.edu/theses_archive/2007/asantor/Scholarly_Paper.doc+heat+content+700m+layer&hl=en&ct=clnk&cd=10
@Leif
Thank you for the reply and the “where to look”.
Best of luck with the book!!!
cdl
Dr. Svalgaard:
I thought that was the point, on figure 1A, that the data between RSS and UAH correlated well, if the data was separated into two temporal segments. He also gives references as to why he separates into those particular temporal segments.
To my eye, while the data is close to linear, it still follows a tight cloud along the slope.
To my mind, it should, as two measuring instruments, if both are accurate, should be close, without agreeing exactly.
Leif
“The latest research seems to indicate the the Sun changes a lot less than we thought just a few years ago.”
But we also know that the amount of sunlight that reaches the earth does fluctuate a great deal. And present papers have shown a big increase in sunlight reaching the earth from the early 1990s on.
http://www.nasa.gov/centers/goddard/news/topstory/2007/aerosol_dimming.html
“The Baseline Surface Radiation Network (BSRN) has been collecting surface measurements. BSRN was started in the early 1990s and updated the archives in this time. Analysis of recent data reveals that the surface of the planet has brightened by about 4% in the past decade. The brightening trend is corroborated by other data, including satellite analyses.”
http://en.wikipedia.org/wiki/Global_dimming#Recent_reversal_of_the_trend
4% more sunshine per decade is a lot.