This is a continuation of a remarkable thread that has now received 10,000 comments running to well over a million words. Unfortunately its size has become a problem and this is the reason for the move.
The history of the New Statesman thread goes back to December 2007 when Dr David Whitehouse wrote a very influential article for that publication posing the question Has Global Warming Stopped? Later, Mark Lynas, the magazine’s environment correspondent, wrote a furious reply, Has Global Warming Really Stopped?
By the time the New Statesman closed the blogs associated with these articles they had received just over 3000 comments, many from people who had become regular contributors to a wide-ranging discussion of the evidence for anthropogenic climate change, its implications for public policy and the economy. At that stage I provided a new home for the discussion at Harmless Sky.
Comments are now closed on the old thread. If you want to refer to comments there then it is easy to do so by left-clicking on the comment number, selecting ‘Copy Link Location’ and then setting up a link in the normal way.
Here’s to the next 10,000 comments.
Useful links:
Dr David Whitehouse’s article can be found here with 1289 comments.
Mark Lynas’ attempted refutation can be found here with 1715 comments.
The original Continuation of the New Statesman Whitehouse/Lynas blogs thread is here with 10,000 comments.
Max,
Ok just checking about sea level rise after the ice age! You never know with you guys. You might well be arguing that rising seas somehow caused the Earth to warm! That may be one to bear in mind for the future :-)
Potentilla
If you are lurking out there, it would be nice if you could join-in over at WUWT with your hydrology expertise at this particular point, concerning Himalaya glacier melt and its hydrology :
http://wattsupwiththat.com/2010/09/12/pacing-the-glacial/#comment-482463
The thread is about glaciology in general, and I’m having fun there, but a tad behind at the moment in responses.
Brute
I enjoy your posts, and thought that your prose in 1697 in particular took away the boredom of most responses to the teasing from “Anagram S.P. Pete”. (Erh; I’m a bit left of you though sometimes!)
PeterM
Your statement about “rising sea level causing the Earth to warm” brings up an interesting point.
Vostok ice core studies tell us:
CO2 levels rose from around 180 to 280 ppm over the 20,000 years since the glacial maximum of the last Ice Age.
At the same time temperature rose around 9C.
Question (multiple choice):
1. increased CO2 caused the temperature to rise
2. increased temperature caused the CO2 to rise
3. there is no causal link – the two were independent
4. None of the above (please explain)
Max
Bob_FJ and Brute
You’ll both be pleased to know that there are many celebrities who are helping to “save the planet”. Here are some of the favorites:
http://www.allamericanspeakers.com/Green_Celebrities_&_Green_Speakers.php
While this is an “All American” talent site, you’ll also be delighted to hear that global crises are also being tackled by the stars:
And:
But the most reassuring news of all is:
Rejoice! We’re saved!
Max
Max,
I’ll have to pass, for now, on your “ice age” question due to lack of time. It is, I think, “none of the above”.
Maybe you could explain why yourself, and I’ll get back to it over the weekend?
PeterM
I’d go for answer 2 (increased temperature caused the CO2 to rise), since the temperature increase came before the CO2 increase (as the record shows was the case in earlier warming/cooling cycles).
But I’d be curious to hear your explanation to “none of the above”.
Max
But why did the temperature rise in the first place? And, furthermore, if warming did lead to a CO2 level increase did that feedback into even greater warming?
Subject: A Holman-Moody prepped ’64 Fairlane goes to the Nurburgring
http://www.dogfightmag.com/2010/08/a-1964-fairlane-hits-nurburgring/
Just goes to show no matter when or where, the good old American V8 will rise to the occasion and kick some Euro-ass.
Whoops……..
Sorry, wrong site.
Max, Reur 1799, as to how wealthy celebrities are saving the world:
I was somewhat fascinated by the simple brevity of:
(Although I read somewhere that biodiesel may be “dirtier” than regular diesel unless the engine is specifically designed for its use)
However, the crowning excellence of silliness was, in my opinion:
So, what do they propose to do in Yellowstone? Sit upon the potentially catastrophic volcanic eruption point, and stop it from happening with their combined mass?
Thanks for the laugh Max!
PeterM
You ask regarding the 20,000-year warming to today:
We do not know for sure what caused the temperature to rise in the first place.
Wiki seems to like the mathematically derived Milankovi? theory that variations in eccentricity, axial tilt, and precession of the Earth’s orbit have determined climatic patterns on Earth. This sounds perfectly reasonable to me, although problems with cycle inconsistencies have been noted.
As to CO2 playing a role, there is no empirical evidence supporting this postulation. Earlier Vostok cycles also show that CO2 lagged temperature by several centuries, with temperature shifting to cooling at high CO2 levels and to warming at low CO2 levels.
Realize that ice core data are dicey in any case. Wiki tells us
Different dating methods makes comparison and interpretation difficult.
But the record certainly does not support the postulation that CO2 contributed to the warming. I’d say that’s a “red herring” that would not pass the “Occam’s razor” test.
Max
Bob_FJ
The “Barenaked Ladies” may be ill-informed about the relative environmental impact of diesel versus bio-fuel, as you point out, but you can’t fault them for at least trying to do the right thing to save our planet.
As to “Cameron Diaz and a group of her close, personal friends” averting another volcanic eruption by sitting on the crater with their combined mass, I can’t vouch for the “close, personal friends”, but Diaz’ “mass” around the seat region is at least pleasant to contemplate.
Could be a great photo op.
Max
Max,
Yes, the Milankovitch theory is thought to offer the best explanation for periodic ace ages. However, the effect on solar forcing is quite small and doesn’t explain why temperatures should vary by 5 or 6 degrees.
The favoured scientific opinion is that positive feedbacks come into play which amplify a smaller signal into a larger one. In other words, as the Earth started to warm by a small amount, the ocean warmed and released CO2. This in turn caused the Earth to warm some more until a new equilibrium was reached.
You in your wisdom have rejected the idea that CO2 can play any significant part in the process. So, if you have one, what’s your explanation?
PeterM
Use your head (1789).
An increase from 180 to 280 ppm CO2 as occurred over the 20,000 years since the last glacial maximum is no big deal.
If you calculate the GH warming resulting from this, you get:
– 0.6C (with no feedbacks)
– 0.3 to 0.4C with net negative feedback, as was determined recently by actual physical ERBE and CERES satellite observations by Lindzen and Choi plus Spencer et al.
– 2.0C if you use the exaggerated and outdated (pre-Spencer et al.) IPCC model assumptions on cloud feedbacks
It warmed by 9C over this period, so the effect of CO2 was peanuts, in any case.
I’m afraid you’ve got to look elsewhere, Peter.
Max
PeterM
You made a strange statement (1789) regarding the impact of the sun on climate change since the last glacial maximum:
the effect on solar forcing is quite small and doesn’t explain why temperatures should vary by 5 or 6 degrees.
Just how large is the impact of changes in solar irradiance on our climate?
I know that IPCC essentially writes of solar forcing as negligible, but I have shown you links to several solar studies concluding that the unusually high level of 20th century solar activity is estimated to have caused roughly half of the observed 0.7C warming over the 20th century.
I’m sure you have also seen the White et al. study showing a response of global upper ocean temperatures to changing solar irradiance.
http://tenaya.ucsd.edu/~dettinge/white1.pdf
Using two independent data sets, the authors show global-average upper ocean temperature responses to changing solar irradiance on decadal and interdecadal scales, based on data collected over three different upper ocean basins (i.e. Atlantic, Pacific, Indian), on two different timescales (i.e. decadal and interdecadal), over the 95 years from 1900 to 1994.
Without getting into the details of the Milankovitch theory, I wouldn’t write off the impact of the sun on climate changes as “quite small” (as IPCC has done), Peter, (if that’s what you meant).
Max
Max,
You are confusing solar irradiance with solar forcing.
Yes, all heat, or nearly all, comes from the sun but a change in forcing doesn’t mean than the sun itself is changing.
The periodic nature of the glacial/interglacial periods does point to the validity of the theory that the Earth’s climate is modulated by changes in the Earth’s orbit.
However, the theory only fits if a small forcing is amplified by positive feedbacks to produce a large temperature change.
Unless you, of course know any different, :-)
PeterM
You seem to assume that climate science “knows it all”, therefore if a known forcing cannot achieve the observed warming by itself it must have been caused by a feedback to that known forcing rather than by some unknown forcing.
This is as silly as the IPCC statement that “our models can only explain the late 20th century warming if we include anthropogenic forcing”.
These are “arguments from ignorance”, Peter.
We may not know for sure what the real cause was, but it is virtually certain (IPCC wordsmithing) that CO2 was not the cause of the post-glacial warming of the past 20,000 years, for many reasons, but primarily because the warming came before the CO2 increase.
Come up with something better, Peter.
Max
PS The White et al. study shows a strong observed correlation between solar activity and ocean temperature over several tropical oceans using two independent temperature records. Since solar warming of the tropical oceans is where most of our planet’s incoming energy comes from, this demonstrates that changes in solar activity lead to changes in our planets warming (contrary to the IPCC assumption that solar forcing has been essentially insignificant in driving changes in our planet’s climate). Get it?
Max,
You, yourself, need to do a bit better than ape the tactics of creationists in criticising established science. They too, depending on the context, make accusations of scientists either being “know-alls” or “know nothings”. The truth is somewhere in between of course.
Feedbacks, in principle, are quite straightforward. As the Earth started to slightly warm 20,000 years ago due a tiny change in its orbital conditions, several other changes ocurred too. Ice caps shrank leading to an increase in the Earth’s albedo or reflectivity. This lead to even greater warming. CO2 was released by the oceans into the atmosphere. This too led to increased warming. Atmospheric water vapour content increased in the warmer climate. Yes, you’ve guessed, this in turn led to increased warming too.
Its not that hard to understand , is it?
Elroy,
What’s the problem?
Whatever it is, I’ll explain it……..
Hmmmmm……another name change. This should remove all uncertainty.
White House: Global Warming Out, ‘Global Climate Disruption’ In
http://www.foxnews.com/politics/2010/09/16/white-house-global-warming-global-climate-disruption/
Whew! I’m really sweating this one. Another prediction from a global warming “expert” scientist…….I’d better brush up on my interplanetary language skills.
Retired NORAD Officer’s New Book Predicts a Tentative Worldwide UFO Display on October 13, 2010
“A newly-published book by a retired NORAD officer predicts October 13, 2010 as the tentative date for a fleet of extraterrestrial vehicles to hover for hours over the earth’s principal cities. Author says the event to be the first in a series intended to avert a planetary catastrophe resulting from increasing levels of carbon-dioxide in the earth’s atmosphere dangerously approaching a “critical mass.” ”
http://news.yahoo.com/s/prweb/20100914/bs_prweb/prweb4491804_1
Brute #1797 and Max.
If Brute wants an answer as to why they want to change the name from global warming I suggest he revisits the article a colleague and myself wrote here concerning global cooling trends.
http://wattsupwiththat.com/2010/09/04/in-search-of-cooling-trends/
Then go to slide 19 20 21 22 of presentation 7.1 which is from the Exeter Climate conference at the Met office just concluded.
http://www.surfacetemperatures.org/exeterworkshop2010
Our studies cover different time periods but you can see the similarities. There are substantial long lived and ongoing cooling trends happening all over the weorld. It is masked by Homogenisation, adjustments, and that the natural warming cycle and the unnatural UHI signal are greater in total than the areas that are cooling.
Hence the ‘average’ is a slightly warmer world which crowds out the places cooler than average. Global warming is simply not a correct term for something that isn’t happening globally.
Co2 is obviously affecting the US in different ways to much of the rest of the world as it seems to be cooling rather than warming you, Brute :)
tonyb
PeterM
Yes, Peter. All those many things may very well have happened as you write (1795).
And we also believe from paleoclimate records that the increase in CO2 levels followed the temperature rise by several centuries, falsifying the hypothesis that CO2 caused the warming.
Whether CO2 amplified the warming by a few percentage points due to the GH effect, is a point of debate, but we know from the GH theory that it could not have been a major contributing factor with a rise from 180 to 280 ppmv over 20,000 years.
But we have discussed the 20,000-year period since the glacial maximum of the last Ice Age at nauseam, and it is clear that we (i.e. climate science today) are not sure about all the interrelated processes and forces, which caused the gradual warming and melting of the massive ice sheet.
We have also shown that the 120 meter SL rise that resulted from the slow melting of the massive ice sheet of 20,000 years ago bears no resemblance to today’s condition.
But let’s move on to a more pertinent topic: the predictions for the next decades. In its 2007 AR4 report (data up to 2006), IPCC conceded, “cloud feedbacks remain the largest source of uncertainty”. Yet all this “uncertainty” did not stop IPCC from citing models that all showed a strongly positive net feedback from clouds, strong enough to result in an increase of the assumed average 2xCO2 climate sensitivity of 1.3C (out of 3.2C)!
However, as Spencer et al. have since shown based on actual real time physical observations over the tropics from CERES satellites reported after IPCC issued its AR4 report, the net cloud feedback with warming is strongly negative, rather than strongly positive. In itself, these results would reduce the 2xCO2 climate sensitivity to somewhere below 1C.
In a later study also covering the tropics, Lindzen and Choi confirmed a net negative total feedback with warming, based on physical observations of ERBE satellites. (Links to both studies have been cited previously).
Spencer has reviewed the L&C study, concurring with the finding of a net negative feedback in our climate system, but disagreeing on the strength of this net negative feedback.
http://www.drroyspencer.com/2009/11/some-comments-on-the-lindzen-and-choi-2009-feedback-study/
In his re-analysis of the ERBE satellite data series used by L&C, Spencer extended it to cover all time periods rather than just those showing the largest temperature change. Spencer found that the feedback parameter was around +2 W/m^2K, rather than the much higher values up to +6 W/m^2K found by L&C.
What is the impact of this?
The graph below shows how this is related.
http://farm5.static.flickr.com/4148/4996556497_748599aa5e_b.jpg
The “no feedback” feedback parameter is 0. The theoretical 2xCO2 climate sensitivity with no feedbacks according to IPCC (Myhre et al.) is around 0.9C.
All the IPCC climate models assume a strongly negative feedback parameter of between –2.2 and –3.2 W/m^2K (the 11 models cited in L&C showed an average of –2.5 W/m^2K). In other words, the models assume that as our planet warms at the surface, the amount of energy radiated into space diminishes (due to net positive feedback, primarily from water vapor and clouds, causing a stronger GH effect, which traps more LW energy). This results in a very sensitive climate system, in fact one that is unstable. As shown on the graph, this assumption results in a 2xCO2 climate sensitivity in the range of 2.0 to 4.5C.
The actual observations do not support these assumptions and conclusions. In fact, the Spencer re-analysis of L&C found a feedback parameter of +2 W/m^2K, which correlates with a 2xCO2 climate sensitivity of 0.6C. This confirms that the planet radiates more total net SW plus LW energy into space as it warms, resulting in a net negative feedback.
This compares with the original L&C finding of a very strong feedback parameter of up to +6 W/m^2K, which correlates with a 2xCO2 climate sensitivity of 0.4C.
Although the observations clearly show that the IPCC model assumption of a strong net positive feedback (and a resulting unstable climate system) is not supported by the actual observations, Spencer cautions:
With the closing comment:
So we have a 2xCO2 climate sensitivity that probably lies somewhere between 0.6 and 0.8C, as compared to that assumed by the IPCC models of 2.0 to 4.5C.
This means that the GH warming we can theoretically expect between today and 2100 (with an estimated CO2 increase from 390 to 560 ppmv) probably lies within the range of 0.3 to 0.4C, rather than 1.0 to 2.3C, as calculated using the range for 2xCO2 climate sensitivity assumed by the IPCC climate models.
Any comments?
Max
TonyB and Brute
Brand name changes
“Man-made global warming” sounded great back in the 1990s, when the surface as well as the satellite temperature record showed that the atmosphere was warming. The crude spot measurements of the ocean also seemed to show warming, and life was good for the warming doomsayers.
Around 1998, when we had a “really hot” year (i.e. a barely measurable small fraction of a degree warmer than previous years), caused by a very strong El Niño, the “MMGW” (or “AGW”) brand sounded like a winner.
But then something bad happened – it stopped warming.
Whether one takes the record starting in the “very warm” year of 1998 or after 2000, the surface record (with all its manipulations and “massaging”) showed slight cooling; the satellite record (without all the manipulations and much better global coverage) showed even more cooling.
Even worse, when accurate measurements of upper ocean temperature were installed in 2003, these also showed cooling of the oceans.
So the whole planet was cooling!
Ouch!
At first the logical thing to do was to say that the cooling is just an insignificant “blip”, but after several years including some really cold winters in Europe, North America and Asia, this strategy no longer worked.
It was time for a “brand” change.
“AGW” was changed to “Anthropogenic Climate Change” and all extremes (hot, cold, wet or dry) were now blamed on the newly branded phenomenon. A stroke of genius!
Everyone knows that climate “changes”. Always has. But now the changes – especially extreme changes, whatever they might be, could be blamed on human greenhouse gas emissions. Obviously “time to act now!”
Floods in Pakistan? Blame ACC.
Harsh and severe winters across northern hemisphere? Ditto.
Drought and dust storms in China? Must be due to ACC, as well.
Bushfires in southern Australia? No question.
Massive fish freezing in South America? Absolutely!
Fires in Russia? Same.
Etc.
This is the dream of every huckster: THE UNIVERSAL PRODUCT!
Problem is, people are not stupid (at least not all people). Most have already been taken in by some sort of “snake oil salesmen” in the past and recognize a bamboozle when they see one. This one is no different.
Max