By William and Gavin
On Thursday March 8th, the UK TV Channel 4 aired a programme titled “The Great Global Warming Swindle”. We were hoping for important revelations and final proof that we have all been hornswoggled by the climate Illuminati, but it just repeated the usual specious claims we hear all the time. We feel swindled. Indeed we are not the only ones: Carl Wunsch (who was a surprise addition to the cast) was apparently misled into thinking this was going to be a balanced look at the issues (the producers have a history of doing this), but who found himself put into a very different context indeed [Update: a full letter from Wunsch appears as comment 109 on this post]
So what did they have to say for themselves?
CO2 doesn’t match the temperature record over the 20th C. True but not relevant, because it isn’t supposed to. The programme spent a long time agonising over what they presented as a sharp temperature fall for 4 decades from 1940 to 1980 (incidentally their graph looks rather odd and may have been carefully selected; on a more usual (and sourced!) plot the “4 decades of cooling” is rather less evident). They presented this as a major flaw in the theory, which is deeply deceptive, because as they and their interviewees must know, the 40-70 cooling type period is readily explained, in that the GCMs are quite happy to reproduce it, as largely caused by sulphate aerosols. See this for a wiki-pic, for example; or (all together now) the IPCC TAR SPM fig 4; or more up-to-date AR4 fig 4. So… they are lying to us by omission.
The troposphere should warm faster than the sfc, say the models and basic theory. As indeed it does – unless you’re wedded to the multiply-corrected Spencer+Christy version of the MSU series. Christy (naturally enough) features in this section, though he seems to have forgotten the US CCSP report, and the executive summary which he authored says Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human induced global warming. Specifically, surface data showed substantial global-average warming, while early versions of satellite and radiosonde data showed little or no warming above the surface. This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. New data sets have also been developed that do not show such discrepancies. See-also previous RC posts.
Temperature leads CO2 by 800 years in the ice cores. Not quite as true as they said, but basically correct; however they misinterpret it. The way they said this you would have thought that T and CO2 are anti-correlated; but if you overlay the full 400/800 kyr of ice core record, you can’t even see the lag because its so small. The correct interpretation of this is well known: that there is a T-CO2 feedback: see RC again for more.
All the previous parts of the programme were leading up to “so if it isn’t CO2, what is it?” to which their answer is “solar”. The section was curiously weak, and largely lead by pictures of people on beaches. It was somewhat surprising that they didn’t feature Svensmark at all; other stuff we’ve commented on before. Note that the graph they used as “proof” of the excellent solar-T connection turns out to have some problems: see figure 1c of Damon and Laut.
Along the way the programme ticked off most of the other obligatory skeptic talking points: even down to Medieval English vineyards and that old favourite, volcanoes emitting more CO2 than humans.
It ended with politics, with a segment blaming the lack of African development on the environmental movement. We don’t want to get into the politics, but should point out what the programme didn’t: that Kyoto exempts developing nations.
[Also: other discussion at InTheGreen, Stoat, The Guardian and
Media lens.]
[Update: What Martin Durkin really thinks!]
[Update for our german readers: A german version of the “swindle” film was shown on June 11 on German TV (RTL); here is a german commentary by stefan.]
> Richard S. Courtney
Several show up; would you be this gentleman?
“Dr. Richard S. Courtney, climate and atmospheric science consultant”
http://www.canada.com/nationalpost/financialpost/story.html?id=3711460e-bd5a-475d-a6be-4db87559d605
Or this gentleman?
“Richard S. Courtney, Ph.D., ESEF – European Science and Environment Forum, UK, EU.”
personal.inet.fi/koti/hameranta/appendix.htm
Or one of those at a US academic address? Hard to be sure who we’re hearing from here, with so many people of the same name.
Re: #248
Dear All except Richard,
Richard’s characterization of the history of earth’s temperature still isn’t right, and his assertion without evidence still doesn’t hold water. I pointed him to GISS and HadCRU, but he protests that we haven’t provided any evidence. He probably hasn’t been there or he’d be admitting at least some of his misstatements.
Instead he has the gall to accuse us of insulting him, when one of my original objections was his having insulted the moderators of the blog, in most smug and snarky fashion. And he has been exposed as a shill for the coal industry.
This is clearly an attempt to provoke us. It can’t be taken seriously as an attempt to deny global warming; his post is far too amateurish to be any good at that. So my advice to all the regulars is: do not feed the troll. Let him have the last word if he wants it, but give him all the response he deserves: none.
Re #248: Richard S. Courtney — I encourage you to read
W.F. Ruddiman
Earth’s Climate: Past and Future
to aid in correcting your misinformed condition.
Can anyone give answers to someone puzzled by the Channel 4 programme. No doubt these questions are fully answered on other parts of the site, but there are probably plenty of people who are visiting the site for the first time – seeking more understanding after seeing the Channel 4 programme. Please indulge my ignorance – I suspect that I am not going to be the only visitor to this site in that condition.
What percentage of CO2 emissions into the atmosphere are anthropogenic? The programme said it was quite a small proportion compared to the total emitted in other ways? Is that true? I have noticed the volcano effect being discounted but what about the rest?
The programme said that CO2 was only a small part of the greenhouse gases and that water vapour was much more important. Is this true and if so is it relevant?
I have read some of the links about the “800 year lag” and find the responses unconvincing. Am I right in saying that over 420,000 years in every warming/cooling cycle CO2 has always followed the pattern set by temperature. Imagine a cycle that lasts 10,000 years. For 800 years (plus or minus 200 years)after the temperature has started rising the CO2 in the atmosphere is actually falling. For 4,200 years they both rise; then for 800 years temperature is falling while CO2 levels continue to rise. There then follows another 4,200 years while both temperature and CO2 fall before the cycle starts again.
Now obviously something has caused the temperature variation to start in a particular direction – and it cannot have been CO2. It appears that in the past global warming always began when CO2 was at a relatively low level and dropping for 800 years, and that global cooling started when CO2 was always at a relatively high level and rising for another 800 years.
I am a simple mathematician who never thought of himself as a sceptic, still less a denialist. Can those who know far than I do about this subject explain these difficulties?
In terms of net contribution, zero, because that forms part of the carbon cycle – http://www.grida.no/climate/vital/13.htm .
In the natural process, for roughly the last 10K years until the industrial revolution, every giga tonne of carbon going into the atmosphere was balanced by one coming out. Since we began burning fossil fuels in ernest over 150 years ago, the atmospheric concentration that was relatively stable for the previous several thousand years (http://www.brighton73.freeserve.co.uk/gw/paleo/20000yrfig.htm ) has now risen by over 35% (http://en.wikipedia.org/wiki/Image:Carbon_History_and_Flux-2.png ).
A good place to go for information like this is http://gristmill.grist.org/skeptics.
Re #254: Dave Rado — Both of your links appear to be broken.
There were more than two links in my last message, but the others didn’t display as links because I had put brackets round them.
The gristmill site appears to be down temporarily but the following article answers your question and the links from it do all work:
http://illconsidered.blogspot.com/2006/03/natural-emissions-dwarf-humans.html
Dave R., your links accidentally include the periods following them, that’s the problem — David B, just copy all but the dot at the end and paste that into your browser, to follow the links.
http://www.grida.no/climate/vital/13.htm
http://gristmill.grist.org/skeptics
See also the last several threads here on what’s known about T/CO2: http://www.scienceblogs.com/stoat/
Re: #254 (Patrick Hadley)
I don’t know the numbers, but I do know that the anthropogenic emissions of CO2 are far smaller than those from other sources (except volcanos, which are tiny by comparison). For example, emissions from the oceans each year are about 90 GT.
But all the other sources absorb as much as they emit; they’re in equilibrium. Of course the “documentary” failed to mention this. The net contribution from those other sources is zero.
And in fact, even that is not quite true. Lately, the ocean is taking more than it gives; the oceans are absorbing about half the CO2 emitted by humans, and are acidifying as a consequence. Many consider this a great threat to marine ecosystems.
We know for certain that the rise in CO2 is due to the burning of fossil fuels. Fossil-fuel carbon has a different isotopic composition than other sources; it’s depleted in C-13 (because its origin is organic plant matter) and depleted in C-14 (because it’s been buried underground for millions of years). The isotopic composition of carbon in atmospheric CO2 is changing in exactly the way we’d expect if — and only if — the source is the burning of fossil fuels.
This is another example of the disingenuous nature of the “documentary.” It’s true that H2O is the dominant greenhouse gas in the atmosphere. But that doesn’t mean that the effect of CO2 (and CH4, N2O, etc.) is negligible. The most disingenuous part is that many of the participants know this.
It’s hard to say about every cycle, because the timing is hard to pin down with sufficient precision. From what I’ve seen, in some cycles, CO2 appears to be stable (not declining) during the approx. 800yr lag, in some cycles it appears to decline.
As to why CO2 doesn’t rise until after temperature begins to rise, consider that it has to! CO2 doesn’t increase for no reason. One of the things that can make it rise is warming of the oceans (which reduces the solubility of CO2). There is also indication that the melting of ice sheets can release CO2 trapped in the ice.
None of which alters the fact that CO2 is a greenhouse gas and contributes to the net warming. I’ve seen estimates that greenhouse gases are responsible for about half the net warming during a deglaciation.
What starts the warming is probably (correct me if I’m wrong, guys) the melting of ice sheets. Ice is highly reflective, so reducing ice coverage reduces the albedo (reflectivity) of the earth, allowing more of the incoming solar energy to be absorbed, and therefore available to the climate system.
What starts the melting is changes in the orbit and tilt of earth. This redistributes incoming solar energy so that more of it strikes high latitudes, which causes melting of high-latitude ice.
And again, the 800yr lag is probable but highly uncertain. I’m not sure that all warmings are accompanied by 800yr of CO2 falling (I think some of them have CO2 stable), or that all coolings are accompanied by CO2 rising. Anybody know the details?
I too am just a simple (but not always modest) mathematician.
1. So Richard Courtney is ‘a shill for the coal industry’. Fine. This means his papers need not be examined for their science? It is automatically wrong?
2. Thousands of scientists now make a living from the billions of dollars available to study global warming. There is no money available from govt for the opposite. Suppose the situation were reversed? What then?
Was Richard Lindzen swindled by the producers of the appropriately named documentary or did he voluntarily mislead the viewers? In the middle of a section about changes in tropical storms with global warming he was shown commenting that global warming theory predicts a decrease in equator-to-pole temperature difference which implies a decrease in storm strength and frequency. A true statement but one that, as he certainly knows, applies to midlatitude storms and has no direct relevance to tropical storm activity. I would like to think that the comments were inappropriately positioned by the documentary producers who seem to specialize in the particular activity. It would be sad for our field if they were knowingly made in that context.
Re #254: I think this question needs further comment:
[The programme said that CO2 was only a small part of the greenhouse gases and that water vapour was much more important. Is this true and if so is it relevant?]
This illustrates one of Heinlein’s classic ways to lie: tell the truth, just not all of it :-) What they don’t tell you is that 3/4 of the Earth’s surface is covered with water. Water goes quickly between vapor & liquid/solid, so that the atmosphere is always going to have as much as local conditions permit. It’s mainly that existing water vapor that keeps the Earth at its fairly comfortable temperature, instead of somewhere below freezing. (You can find more accurate numbers if you look around this site.)
Unlike water vapor, CO2 sticks around for a long time, centuries or more, so the amounts humans add keep accumulating over the years. And here’s the real kicker: if increased CO2 warms the planet a little bit, that causes more water to evaporate from the oceans. Since water vapor is a greenhouse gas, the reality is that it acts to amplify any temperature increase caused by CO2, just the opposite of what the program would have you believe.
Re #216, 226: [You are cartainly correct that there was plenty of life in the Cretaceous, and it was very much warmer…]
Many other things were different then: the composition of the atmosphere was different, there’s evidence for higher atmospheric pressures, the continents were arranged differently, etc. One thing to remember, though, is that whatever conditions prevailed during the Cretaceous (or most other periods) took millions of years to develop. The plants and animals had time enough to evolve to suit the conditions.
You also might reflect on the fact that an awful lot of the species that were living happily in Cretaceous conditions are now extinct.
The UK Independent newspaper has discovered where that temperature graph came from. In summary: they used out-of-date data and got the scale on the bottom of the graph completely wrong – the temperature series actually ended “in the early 1980s”.
Oh, dear. There are further revelations in the article .
BBC Radio4’s Today programme just had a climate scientist (not sure who) on phone interview to challenge a Channel 4 representative. The C4 guy defended the whole programme and said he didn’t see how Carl Wunsch was misrepresented at all. When the scientist challenged him on specific points, he refused to address them and started talking about the sun and that minority opinions need to be represented. The climate scientist didn’t come across too well on the radio interview though, perhaps because he wanted to cover too much ground in so little time. The scientific jargon and reiterating the ICPP conclusion quickly loses the listener such that at the end of the ten minute piece they think there is still a debate, and that the C4 programme has some scientific merit.
What real climate scientists need to highlight are the omissions and distortions that demonstrate beyond reasonable doubt that the intent was to mislead, and not to present alternative scientific explanations. Failing to mention sulphate aerosols had a big part to play in 1940-1970, distorting the graphs, outright lies like the ice cores being the only evidence of a link between CO2 and T, using scientists quotes out of context, using out of date data (satellites and radiosondes) when the recent datasets don’t support the controversy, accusing modellers of using exagerated CO2 increases, limiting icecap footage to the 1990s and not 2000s when the north pole turned liquid, to name but a few.
Dear All
You will be pleased to learn that the UK paper The Independent has today published a full one page article taking some of the points raised here and highlighting the inaccuracies in the programme. Its nice to get some coverage like this in the media as it is a rare event to publish corrections. You can read the article here: http://news.independent.co.uk/environment/climate_change/article2355956.ece In the newspaper they publish 3 graphs from the programme, alongside the corrected versions.
And I just LOVE these comments from the producer:
Mr Durkin admitted that his graphics team had extended the time axis along the bottom of the graph to the year 2000. “There was a fluff there,” he said.
The original Nasa data was very wiggly-lined and we wanted the simplest line we could find,” Mr Durkin said.
Enough said!
The Channel 4 documentary was brilliant at pointing out how the alarmism has become an industry. It could have looked further into how damaging following this political agenda of anti-development will be and how much less developed and well off we would be without following the climate-hysteria political agenda.
J, Denmark
Re#259 Tamino states:
“I don’t know the numbers, but I do know that the anthropogenic emissions of CO2 are far smaller than those from other sources (except volcanos, which are tiny by comparison). For example, emissions from the oceans each year are about 90 GT.
But all the other sources absorb as much as they emit; they’re in equilibrium. Of course the “documentary” failed to mention this. The net contribution from those other sources is zero.
And in fact, even that is not quite true. Lately, the ocean is taking more than it gives; the oceans are absorbing about half the CO2 emitted by humans, and are acidifying as a consequence. Many consider this a great threat to marine ecosystems.”
Maybe I’m missing something here. So the oceans emit 90 GT CO2 per year. Anthropenic emissions of CO2 are 6.5 GT per year. So just how can it be that ‘the ocean is taking more than it gives’?? Or do you mean that the oceans emit AND THEN RE-ABSORB 90 GT per year PLUS THEN they have to absorb half of the anthropogenic output ON TOP??
I’m assuming you guys have seen/heard of this 2002 paper (its the first thing I found when looking for a current annual figure for anthropogenic CO2 output).
http://www.climatechangeissues.com/files/s…e/defreitas.pdf
Interestingly, it makes – amongst others – the following points:
*Anthropogenic (human) CO2 contributes 6.5 Gt to the atmosphere per year.
*Biomass absorbs 10 Gt per year, which is three times the net increase from fossil fuels.
*CO2 increase is levelling off due to increased plant growth absorbing CO2.
*CO2 increase is variable and in 1992 was zero.
*Anthropogenic CO2 contributes 3% of the natural Carbon Cycle.
This is less than 1% of the atmospheric reservoir of 750 Gt CO2.
*The CO2 increase is following a 300 year global warming trend.
*The well known Vostok Ice Core data shows that CO2 increases lag 600 years behind temperature increases.
I know and appreciate that the above paper is from a petroleum geology journal, but it looks to me (as a non-scientific though nonetheless PhD-educated individual) to be well written and referenced. Just how many of the extracted statements above are actually incorrect and/or irrelevant?
OK, so petroleum companies are obviously dollar-driven, but I don’t think there’s any hiding from the fact that the current green shift in politics is to no small extent driven by politicians’ egos/political ‘band-wagoning’ and, way more importantly, the need to raise ‘green’ taxes to address some horrendous governmental financial defecits in Western economies. There is similarly little doubt that AGW scientists also require funding dollars and public recognition/kudos! So given the obvious and inescapable dichotomy between the oil-driven powers-that-be and green-tax-dollar and ego-driven politicians (both of who can easliy manipulate and distort the findings [e.g. the IPCC’s ‘Summary Reports’] of the scientists they associate themselves with – none of whom would surely claim to FULLY understand the myriad intricacies of our climate with its many positive and [far less talked about in AGW circles so it seems to me….] negative feedbacks), just what is the average lay-person out there like me supposed to believe is REALLY going on??
Mike
The UK paper The Independent today printed its results of an investigation into the suspicious datasets and graphs used in the programme. It also put its points to the programme’s director, Martin Durkin:
http://news.independent.co.uk/environment/climate_change/article2355956.ece
My personal favourite – when asked why the programme’s global temperature graph, credited as sourced by NASA, bore no relation to NASA’s actual temperature graph, Durkin replied “The original Nasa data was very wiggly-lined and we wanted the simplest line we could find”. That turned out to be out of date infromation compliled on a old climate sceptic website. So, er, not NASA then.
[[re postings 236, 237 and 238. I correctly and accurately said there is no evidence for man-made global warming; none, not any of any kind. The responses say there is some such evidence but cite no such evidence (which is not surprising because there is none). However, the responses do provide insults (as is usual from global warming fanatics).]]
The evidence for anthropogenic global warming is as follows:
1. CO2 has increased 40% since the industrial revolution started.
2. The new CO2 is overwhelmingly from fossil fuels, not the biosphere, because it is deficient in carbon-14.
3. More CO2 in the atmosphere warms the ground, all else held equal.
4. Proposed alternatives such as Solar luminosity increase and modulation by galactic cosmic rays don’t stand up to scrutiny.
What more evidence do you want? Just repeating “there’s no evidence” won’t make it so.
RE 259:>>We know for certain that the rise in CO2 is due to the burning of fossil fuels. Fossil-fuel carbon has a different isotopic composition than other sources; it’s depleted in C-13 (because its origin is organic plant matter) and depleted in C-14 (because it’s been buried underground for millions of years).>>
I’m a bit worried about this certainty. I can think of three reasons for the Suess effect where the atmosphere shows more light isotope carnbon than expected — well, two-ish.: more C4 plankton; more C3 plankton converting to C4 metabolism; methanophages gettng their teeth into slightly warmer methane hydrates as ocean currents change in the deeps. The latter, BTW, might explain the CO2 rise after 800 years problem, if that is the ocean currents respond in a very slow rate to warming of the atmosphere. The C4 metabolism doesn’t fractionate carbon in the same way as C3, which means a falling dead C4 phyto takes with it into the depths an unexpectedly large amount of heavy isotopes — in effect it pumps down the heavy stuff.
‘It’s all we can think of’ is not a good response to answering a problem. ‘It’s the only thing we can think of at the moment. Anyone got any other ideas?’ is how I’d like this discussion to go, but too many people have nailed their flags to the mast and are determined to go down all guns blazing for that to be a realistic hope.
I didn’t think much of the science on the Channel 4 programme, but I’m dubious of much of the stuff I’m told elsewhere. I’d like to see a few more ‘get your hands dirty’ scientists (ie real ones) being funded by both sides, not because I think either side is wrong, but because I don’t think science should be carried out by PR or in a massaged computer. Numbers, we need more real world numbers.
You can do anything without numbers: I have invented a non-numerical explanation of global warming at http://www.floodswclimbers.co.uk. There are no numbers so I felt free to handwave to my heart’s content. However, it hangs together rather well. It even puts the blame, or most of it, on excessive oil consumption, car drivers and washing machines.
JF
[[What percentage of CO2 emissions into the atmosphere are anthropogenic? The programme said it was quite a small proportion compared to the total emitted in other ways? Is that true? I have noticed the volcano effect being discounted but what about the rest?]]
It’s true, much more is already circulating in the biosphere than human technology emits. But the natural carbon dioxide is balanced by things like the respiration/photosynthesis cycle. We’re adding extra that the system can’t take out in a reasonable amount of time, and as a result, CO2 has increased 40% since the industrial revolution began. And the new CO2 is mostly from fossil fuels, not the biosphere, because it’s deficient in carbon-14 (i.e., very old).
[[The programme said that CO2 was only a small part of the greenhouse gases and that water vapour was much more important. Is this true and if so is it relevant?]]
True yes, relevant no. H2O is a stronger greenhouse gas than CO2 and is present in greater quantities. But the amount of water vapor in the air is set by the ambient temperature and the relative humidity, not by anything we do. The average residence time of a molecule of water vapor in the atmosphere is 9 days; for carbon dioxide it’s more like 200 years. We could double water vapor tomorrow and almost all the excess would have rained out in less than a month. Carbon dioxide, however, will stay up there a long, long time.
[[1. So Richard Courtney is ‘a shill for the coal industry’. Fine. This means his papers need not be examined for their science? It is automatically wrong?]]
What papers? All I’ve seen is posts here insulting climatologists.
Can I suggest a resolution to the temperature CO2 lag debate. Concede the point that in the past, variations in the amount of solar energy impinging on earth have caused temperature changes. That the increases have caused CO2 to be released into the atmosphere. That the amount of CO2 released did not initiate global warming and it was susequently reabsorbed as the earth cooled.
Instead, emphasize that we are at the top of one of these natural temperature cycles and at the same time we have released massive amounts of CO2 in the atmosphere, presumably with a lot more to follow in 800 years time. All the evidence suggests this was an incredibly bad idea. Incidentally most of the rebuttals appearing in the UK press are leaving out this point altogether and nit-picking about graphs. Also suggest Mr Gore clarifies this point in his film.
re: 260. “2. Thousands of scientists now make a living from the billions of dollars available to study global warming. There is no money available from govt for the opposite.”
This is a horribly biased, disingenuous point, probably intentional. The Bush adminstration is anything but willing to support climate research aside from things such as “clean coal technologies” (corporate handouts). In fact, the adminstration has put serious restrictions on the information government scientists can release/say about global warming. It has to be approved by political operatives first. That is common knowledge. The large sums of money are coming from the oil and coal corporations such as Exxon/Mobil who pay not only certain scientists (not many are climate researchers of course!) but PR firms to come up with misleading information, cherry-picked data, character assasinations, web blogs/postings, non peer-reviewed papers on the web and op-ed pages to simply confuse the public. Even if it means repeating items that have been long proven to be utterly false. Or making up new ones.
Finally, please understand what “science” means. It is not a case of “opposite” research. The data are there for anyone to review. Science includes hypotheses, testing those hypotheses with data, analyzing the data for trends, publishing the results for peer-review, drawing conclusions and new hypotheses for further analyses and testing. You do not start with a conclusion or an “opposite” to prove a point. That is not science. Fortunately, climate research follows the scientific method. The science is strong and sound.
Re #260 “Thousands of scientists now make a living from the billions of dollars available to study global warming. There is no money available from govt for the opposite.”
Actually, I think money is generally made available to study climate change – “global warming” is a popular rather than a scientific term. However, setting that aside, the opposite of “global warming” is presumably “global cooling”. It now seems to be admitted even by most of those who deny that human activity is responsible that mean temperatures have increased in recent decades – i.e. that “global warming”, in the sense that phrase is generally used, has happened. Wouldn’t it be rather silly of any funder of science to fund extensive studies of global cooling, which (at least recently) hasn’t?
Hi Chaps,
Wikipedia has a section on the Channel 4 tripe and says it needs “cleanup”.
http://en.wikipedia.org/wiki/The_Great_Global_Warming_Swindle
I don’t know how to do that but if you do go for it.
Regards
Mike
re. #271, the climatologists whose articles are on this site are not being funded by any side, so why don’t you read their hard scientific articles on this site – there are hundreds – and the peer reviewed literature that they link to?
Apols in advance if this an old chestnut to say the least, but it often gets banded around amongst ordinary non-scientific folk out there anyway…… namely; what happened to all the talk by scientists a couple or three decades ago about us rapidly approaching a Mini-Ice Age?? What WAS all that about? The fact that such scientific musings were rampant not that long ago goes a long way to undermining what AGW scientists are saying NOW in the minds of many lay-people at least.
Mike
re: 271 and the source of atmospheric CO2
So what happens to the CO2 that’s derived from the burning of fossil fuels? Does it just disappear? Occams Razor. We can account for the increase by calculating the amount of fossil fuels.
Re: #268 (Mike Forster)
That’s exactly what I mean.
I think that’s correct.
Correct, but biomass also emits that amount per year. That’s why the graph of CO2 concentration shows an annual cycle; plants take in CO2 during the northern-hemisphere growing season and release it back later in the year. Check out the Keeling Curve and you’ll see what I mean.
Absolutely false. Look at the above graph again. Does it look like it’s levelling off? In fact since 2000 the CO2 concentration has been increasing more rapidly than ever — at about 2.1 ppmv/year.
It is variable, and in 1992 was near zero. Many have attributed that to the collapse of the economy of the former Soviet Union.
Less than 3% of the gross is easy to believe. What is not mentioned is that the other players in the cycle both emit and absorb, and are in equilibrium. Their NET contribution is zero (except the ocean, which is a net absorber now). It’s the human burning of fossil fuels that’s causing the increase.
If by “following” they mean “started after,” then OK. If by “following” they mean “is caused by,” then that’s just not true.
This appears to be true, and there’s been quite a lot of discussion about that on this thread already.
I for one find it astounding that anyone is still contending that the CO2 increase is not due to human activity. For at least 650,000 years, CO2 concentration never rose above 300 ppmv. In fact since the holocene (the last 11,000 years) it’s been very stable at around 280 ppmv — despite the large numbers involved in the carbon cycle that denialists like to point out dwarf human emissions. But those parts of the cycle are in equilibrium, taking as much as they give — how else could CO2 concentration be stable? Then — since the start of the industrial revolution — CO2 has risen by 35% to its present value just over 382 ppmv. And of course, there’s that isotope thing.
Just how stupid do they think we are?
Re: #271 (Julian Flood)
Your alternatives might explain the C-13 depletion by an origin other than fossil fuels, but won’t explain the C-14 depletion.
If that is the extent of the rebuttal, I would think the film has made its case.
If one is to believe in AGW, one needs evidence. The rebuttal concedes that there isn’t much. Unrebutted is the fact that the temperature CO2 correlation in the ice cores is not evidence for AGW, although it had been held out as convincing (at least by Gore), and that the temperature record of the 20th century is not much evidence for AGW, both because the temperature rise is completely unremarkable in historic context,
and because the warming is punctuated by untimely drops. The rebuttal’s claim that this isn’t relevant is telling– it may not be disproof, but the assumption of the rebutters appears to be, we don’t need evidence for AGW. The fact that the models can match anything is one of the problems, not a victory! An attempt was made to rebut the claim of the film that the satellite and radisonde data is contradictory to AGW. The rebuttal skips over the fact (as I understand it) that everybody agrees agreement is lousy over the tropics– and the tropics comprise half the atmosphere. I’m left thinking the satellite data may not disprove AGW (as one scientist claimed in the film) but it seems apparent that it is mixed evidence. Also largely unrebutted is the films claim that solar/cosmic rays provide a better explanation for the evidence than GHG theories.
Also unrebutted is the claim of the film that the IPCC is heavily politicized, and engaged in egregious violations of academic protocol. As a viewer of both film and this rebuttal, I am left wondering: are there in fact any serious scientists who would stand up and say in print they believe there is 90% confidence that humans have been responsible for more than half the warming?
At my website, I have previously posted a summary of what I understand to be the changes in evidence and scientific understanding since 2001. It appears to me that they are rather damaging to the theory of AGW, so that our confidence should have declined rather than risen. If there is something I am missing, I would appreciate knowing what it is.
“The Earth has been warming out of the Little Ice Age for the 300 years since then. Around 1700, Londoners used to have “Ice Fairs” on the frozen Thames each year. The last Ice Fair was held in 1814, and the Thames has not frozen solid since.”
Richard S Courtney: Comment 233.
Hubert Lamb and other historians have also found that the Thames also froze in 923 & 998.
The Thames froze for seven weeks in 1061 and was completely frozen over during the severe winters of 1149/50, 1204/05, 1269/70 and 1281/82, 1309/10, 1407/08, 1409/10 1434/35, early 1506, 1513/14, 1516/17 and 1536/37. That’s throughout the entire Medieval Warm Period, however you wish to date its start and finish.
The river Thames no longer freezes because of work done in the 19th century to widen the arches under London bridges and to improve ships’ passage along the river resulted in salty water extending further upstream and a faster flow rate along the river channel.
[[what happened to all the talk by scientists a couple or three decades ago about us rapidly approaching a Mini-Ice Age?? What WAS all that about? ]]
The short answer is that it wasn’t by scientists, but by journalists. There was never a scientific consensus behind imminent global cooling.
Re 102: “There is NO controversy in the scientific community–just the normal process of consensus with some cranks who cling to dissent for their own contrarian reasons. It is the media and public who manufacture the controversy.”
Ray Ladbury
cf.
“Dissent is the native activity of the scientist, and it has got him into a good deal of trouble in the last years. But if that is cut off, what is left will not be a scientist. And I doubt whether it will be a man.”
Jacob Bronowski
Most scientists go along with the idea that within science dissent/scepticism is how things move on: if there’s no controversy perhaps we should all start fearing for the climate science field itself.
Finding consensus where it truly exists in a complex area can be a hard task, orders of magnitude harder when presenting a full analysis of all the peer reviewed literature as well: I’m not sure that the IPCC process is up to it.
I’m not alone in that view. Call me IPCC-sceptic if you like.
Long may climate science flourish, in breadth and richness, and in particular improve its explanatory and predictive powers.
RE # 281
Tamino, those factual retorts are simple, complete and most useful. Your comments are a resource.
[[Also largely unrebutted is the films claim that solar/cosmic rays provide a better explanation for the evidence than GHG theories. ]]
This site has extensively rebutted both. Do a search on the site. In the meantime, here are some quick answers:
The Sun is Doing It. This is wrong because
1) The Solar constant hasn’t increased appreciably in 50 years (we’ve measured it from satellites). But global warming has taken off most noticeably in the last 30.
2) Increased sunlight should heat the stratosphere, which intercepts sunlight first and absorbs it in ozone. Instead, the stratosphere is cooling, a discovery predicted by climate modellers on the basis of greenhouse gas warming of the surface.
3) Increased sunlight should affect the equator most and the poles least, since higher latitudes have progressively less solar illumination (Lambert’s cosine law). Instead we see “polar amplification.” The poles are warming up quickest, another observation predicted by the modellers.
Galactic Cosmic Rays are Doing It. No, because
1) As with sunlight, the GCR level has no trend over the last fifty years.
2) GCR may well affect cloud formation, but the data simply isn’t good enough to say exactly how yet.
3) There are questions about the proxies used to estimate GCR intensity in the past. Until these are more reliable, the correlations Svensmark claims to have found are dubious.
William and Gavin wrote:
“The way they said this you would have thought that T and CO2 are anti-correlated; but if you overlay the full 400/800 kyr of ice core record, you can’t even see the lag because its so small.”
I know that was said only to illustrate that the two are not anti-correlated, but it reminded me of a skeptic who once said, “Let’s compare a 4 mm rise in the ocean levels next to the tiniest wave…”, as if that said anything about the scientific reality. This entire subject has to do with very small measurements and observed changes over some relatively long periods of time that carry some potentially huge (all sizes relative to a human perception scale) ramifications.
What is questioned is the a lag, and whether correlation has any bearing on causation as well, and whether the explanations offered, with their underlying assumptions, are correct. The questions won’t go away, so why not keep all charts in perspective at all times? Anything that stops the pendulum.
You also wrote:
“The correct interpretation of this is well known: that there is a T-CO2 feedback: see RC again for more.”
You say that “the correct interpretation” is well known, but then cite an article on your own site that attempts to explain the interpretation in layman’s terms. This is another example of begging the question with a circular reference. The article for the given link asserts that CO2 “could in fact” act as a feedback (the article was decidedly cautious in its initial wording, less so toward the end), but it was little more than a layman’s explanation, with plausible analogies for envisioning how this mechanism could work. Even then, I have some questions regarding its wording, to wit:
In cited article cited above, Professor Severinghaus claims that “…the other 4200 years of warming could in fact have been caused by CO2…” (his wording becomes more definitive toward the end). The article also states unequivocally that CO2 could not have caused the first 1/6 (the first 800 out of 5000 initial years) of interglacial warming.
Excerpts:
1) …ice core studies have shown that CO2 starts to rise about 800 years … after Antarctic temperature during glacial terminations.
2) …the lag shows … that CO2 did not cause the first 800 years of warming … CO2 could not have caused the first 1/6 of the warming.
There was at least some CO2 present at the onset of glacial termination. Would not the atmospheric CO2 extant at least be considered a minor, even negligible contributing factor, right from the onset of the first 800 years of interglacial termination?
In other words, how much CO2 must be present before it is considered an active feedback? A gnat hitting the windshield of a moving car still imparts energy, and has an effect, however indiscernible. Certainly CO2 could not have caused 100% of the initial warming, but was it not at least a contributing factor, however negligible? If so, why not state it this way? As it reads now, CO2 is sitting there like so much inactive, non-contributing dead weight for 800 years. What is there to suggest that whatever caused the first 800 years of warming (which Professor Severinghaus said could not have been CO2) could not also have been the primary forcing for the latter 4,200 years of warming as well?
Also, Professor Severinghaus wrote, “From model estimates, CO2 (along with other greenhouse gases CH4 and N2O) causes about half of the full glacial-to-interglacial warming.”
If he had included sunlight and water vapor (the granddaddy of them all) he would have hit the trifecta. Since excess CO2 is the main focus of blame, why lump it in with other GHG in the article? What was the reason for that? Why not just give an estimate (based on model estimates or otherwise) that breaks out CO2’s estimated contribution to warmings?
Can anyone comment on my suggestion in 274, the explanations of the lag given are the weakest part of your case. By conceding that CO2 did not start the warming and that it perhaps only slowed down the cooling you could end this topic.
Here’s another critique of the movie by John Houghton (head of the IPCC from 1988 – 2002):
http://www.jri.org.uk/index.php?option=com_content&task=view&id=137&Itemid=83
Re#288, Stephen, you’re missing a basic point – even at the height of the glacial period, CO2 played a significant role in warming the planet, as compared to say, the temperature on the Moon (-273C on the dark side).
You say: “As it reads now, CO2 is sitting there like so much inactive, non-contributing dead weight for 800 years. What is there to suggest that whatever caused the first 800 years of warming (which Professor Severinghaus said could not have been CO2) could not also have been the primary forcing for the latter 4,200 years of warming as well?”
Well, that’s because the effect of the Milankovitch cycles (eccentricity, precession, and axial tilt) are fairly minimal, and are related to the seasonal timing and location of solar inputs, not on changes in the total solar energy recieved at Earth’s surface.
For example, see Simulating the amplification of orbital forcing by ocean feedbacks in the last glaciation, Khodri et al Nature 2001:
According to Milankovitch theory, the lower summer insolation at high latitudes about 115,000 years ago allowed winter snow to persist throughout summer, leading to ice-sheet build-up and glaciation. But attempts to simulate the last glaciation using global atmospheric models have failed to produce this outcome when forced by insolation changes only. These results point towards the importance of feedback effects-for example, through changes in vegetation or the ocean circulation-for the amplification of solar forcing. Here we present a fully coupled ocean-atmosphere model of the last glaciation that produces a build-up of perennial snow cover at known locations of ice sheets during this period. We show that ocean feedbacks lead to a cooling of the high northern latitudes, along with an increase in atmospheric moisture transport from the Equator to the poles. These changes agree with available geological data and, together, they lead to an increased delivery of snow to high northern latitudes. The mechanism we present explains the onset of glaciation-which would be amplified by changes in vegetation-in response to weak orbital forcing.
As far as why to include the full component of greenhouse gases, that’s because the question is: how do changes in the atmospheric composition affect the planet’s surface temperature? In this case the correlation between temperature and atmospheric composition has a clear mechanism that relates the two: the absorption and re-radiation of infrared energy by greenhouse gases.
There are many, many processes that show such feedback effects – consider striking a match (a small amount of friction leads to a large amount of heat being produced), starting an avalanche with a small rock, etc.
Angus, do you think that the professional climatologists, palaeoclimatologists and atmospheric physicists hereabouts have never heard of Milankovich and the causes of ice ages?
What! No, they haven’t!
Well, glory be! You appear to be correct then (in a funny, distorted kind of way), “that CO2 did not start the warming and that it perhaps only slowed down the cooling” … oh, and added to the warming.
All comments in response to my posts above are most appreciated. Thank you for helping to better inform me.
I guess it all boils down to:
1. CO2 has risen from 280-380ppm during the last 150 years. For the previous 650,000 years atmospheric CO2 has held steady at between 180 and 280ppm.
2. Average global surface temperature has risen 0.8C during the last 150 years.
(I’m here ignoring whether or not solar and/or cosmic forcing accounts for much, if any, of the said temperature increase. The concensus – at least here on this blog – is that they do not.)
As such – and admittedly stating the obvious to you folks here but at the same time clarifying things in my own lay-person’s mind – the REAL issue here then IS: Just how much of the observed increase in temperature is due to anthropogenic CO2 output??
That’s got to be a really tough one to answer with any certainty. SURELY the climate has ALWAYS been liable to temperature swings a couple of degrees one way or the other on a century and milennium basis.
For example and from:
http://www.nationalcenter.org/NPA194.html
[lengthy excerpt eliminated. readers can go to this link if they like. But lets not pretend this is honest information; this is an industry-funded disinformation site]
Mike
Re: #289 (Angus)
I think everybody who knows (including the moderators) agrees that CO2 did not start the warming. But I doubt that will end this topic. Skeptics have perceived a weakness, and they’re going to milk it for all they think it’s worth.
I disagree that it’s the weakest part of the case. It’s not really much of the case, for one thing. For another thing, the only ones I’m aware of who ever seriously claimed that CO2 was the sole cause of warming during deglaciations are the skeptics — who set it up as a straw man argument. But it is (a small) part of the case, because without greenhouse-gas amplification we can’t explain the large warming during deglaciation.
Re: #292 (P. Lewis)
I see no reason to be anything less than grateful to Angus. As far as I can see, he has made no denialist statements, hasn’t spread any misinformation, and he has correctly identified what is at least perceived as the weak link in the chain of reasoning. We should be paying close attention.
I have looked for comments regarding the experiment last Year in which Prof Henrik Svensmark successfully generated cloud condensation nuclei by bombarding a replica atmosphere with ionising radiation. Why does it appear that this is being ignored by everyone?
> Why does it appear that this is being ignored by everyone?
Because you don’t look? Use Google? Type it into the search box at the top of each page.
Re 270:
A nice hypothesis but there is no evidence for it. Indeed, the posting admits that it would only hold if “all other things were the same”. But in a complex system such as climate all other things will not be the same. Like all GW propoganda, posting 270 cliams the hypothesis of man-made global warming is proof of itself!
There is no evidence for man-made global warming and making a mantra of the hypothesis of man-made global warming cannot change that.
Also, the carbon-14 change is far too great for it to be explained by the anthropogenic emission. Science is about interpretation of evidence: it is not the distortion of facts to suite the purpose of advocacy (be it of global warming or anything else).
And why is it acceptable to put personal insults of me on this web site but my rebuttals are censored?
Richard
Re #295 Because you haven’t bothered to look. Try searching for “Svensmark” on this site.
Re #289: [Can anyone comment on my suggestion in 274, the explanations of the lag given are the weakest part of your case. By conceding that CO2 did not start the warming and that it perhaps only slowed down the cooling you could end this topic.]
Explanations of the lag aren’t the weakest part of the case: they aren’t part of the case at all. The case for AGW doesn’t depend on records of past climate changes; it comes from the known behavior of CO2, and the indisputable (except by blithering idiots) fact that humans have put a lot of it in the atmosphere over the last century or so.
At its most basic, AGW theory is no more complicated than saying you’ll be warmer if you put a sweater on, and that doesn’t depend on what your granny told you, does it?
Saying so certainly wouldn’t be a concession: it’s been part of what we might call the standard AGW model all along.
I don’t think it would end the topic: I know I’ve given my own explanation (over-simplified and non-expert as it may be) several times in the last few days; others have tried to explain it as well. If it’s not getting through, either we all lack the ability to explain it clearly enough, or the readers aren’t interested in trying to understand.
Re: #293 (Mike Forster)
The best numerical estimates I’ve seen of the magnitude of the various contributions to global warming are the “forcings” data from NASA/GISS. You can download the data here. The colums are:
W-M_GHGs = well-mixed greenhouse gases
O3 = ozone
StratH2O = stratospheric water vapor
Solar = solar variation
LandUse = land-use changes
SnowAlb = snow albedo
StratAer = stratospheric aerosols
BC = black carbon
ReflAer = reflective aerosols
AIE = aerosol indirect effect
All forcings are given in watts per square meter, and the zero point is taken as the value in 1880. Positive values imply warming relative to 1880 values, negative value imply cooling.
That’s just plain incorrect, but it’s one of the most common lies told by denialists. Take a look at the many temperature reconstructions and it’s plain to see that “a couple of degrees” is way outside the norm.