And so the debate begins; at least on this platform anyway, an endorsement to free speech, democracy, common sense and fresh, clean air. The Hockey Stick. As the crux of the man-made global warming agenda relies so heavily on the "Hockey Stick" evidence (MBH 98 report), it would surely seem wise to confirm it`s authenticity? I enclose a link of a video clip to such discussion: http://video.google.co.uk/videoplay?docid=4792388647776165925&ei=kDH9So-4OYaO-Aby4vTsCQ&q=global+warming+hockey+stick&hl=en# No matter how complex the computer model data, if the foundations are wrong, the building will undoubtedly fall..

Paragraphs 8 and 9 are very sensible, among a lot of twaddle and one untruth ("scientists involved in genuine research in this field have been refused platforms because they dare question the climate change orthodoxy" - not if their research is properly backed up buy evidence; after all, if anyone could actually prove that it's all wrong, most of us would be delighted) You're entitled to question orthodoxy - we should always do that - and it's always satisfying to see oneself as part of a persecuted minority of truth seekers. But please stop pretending that 'vested interests' are pushing the debate in one way, when it's the 'deniers' who have the vested big business interests behind them. Politicians have been persuaded by the evidence! (By which I mean, responsible, peer reviewed research, not the peddling of insubstantial or discredited red herrings.)

The main point of my comment to your previous article, edited out of the printed response, was that science is conducted in journals, so that people can check up on the claims and references that back up the interpretations being asserted. After your previous article, you were challenged several times provide the evidence to which you refer that casts doubt on anthropogenic climate change. You have not done so. Again you are casting unreferenced aspersions, with your claim that reputable scientists are being denied platforms to question climate orthodoxy, and that climate modeling is proving unreliable. Show your cards Amanda! Where is your evidence? Your making claims without backing them up is just being troublesome and contrary.

Let's deal with the issues one by one: 1) "...the science is far from settled" Sweeping statements like that are highly misleading. What journalists like Amanda don't understand is that science is never settled. However, just because someone like Einstein comes along, it doesn't render Newton's work useless. I would be happy to carefully go through each of Amanda's doubts offline and help her understand why the IPCC assessment says what it says and what the latest peer reviewed science is telling us. Suffice to say it is a one way street. 2) "...reliable forecasts of future climate are proving elusive." Again highly misleading. I would be happy to introduce Amanda to some of the people doing the modelling, then she can assess where the elusive aspects of the model lie. Again I can say that those aspects are not going to make the picture any rosier. 3) "It may well be that human CO2 activity is a significant factor in global warming, but there are also other reasons, like population growth and a huge number of other independent factors...." Here I think Amanda just simply gets confused. No serious scientists would deny population is an issue linked to climate change, but importantly the link exists because at the moment every extra person means using more energy and thus emitting more CO2. Other "independent factors" as Amanda calls them are included in most climate models and their influence accounted for as this is how system modelling works. 4) "the scientists involved in genuine research in this field have been refused platforms because they dare question the climate change orthodoxy." I am unaware of any serious scientist who has been "refused platforms" because of their views. Could Amanda provide an example? 5) "Is the best course of action putting a cap on emissions [...] or should we be adapting to climate change and using our energies and money in better preparing for the impact of events such as flooding and drought?" This question was answered comprehensively by the Stern Report and other similar economic reports which all said, roughly, that the costs of adaptation beyond 2 degrees increase are too much to bear, but because 2 degrees is close to inevitable, we need to spend big money on both mitigation and adaptation. 6) Use of the word "denier" is an attempt to remove the equally loaded term "sceptic" away from those who would stop action. There were were many sceptical tobacco companies who spent the better part of 50 years denying that their product was linked to addiction and death and actively undermining science and progress. All they needed to sell to policy makers was doubt in order to stop action. Have we as a society learnt nothing from this experience? Finally I come to the final point that it appears people of a certain age scarred into cynicism by their experience of political corruption and scientific scandal seem to feel they, having no prior knowledge of a field . There is truly a serious problem in society when the editor of a building design magazine claims to have better knowledge of the truth of a scientific issue (entirely unrelated to buildings) than the UK's chief scientist and literally thousands of specialists in the field. Here, perhaps, lies one of the greatest communication failures of the environmental movement. But in an attempt to turn this around, working on the one person can make a difference principle, I would like to put myself forward to help Amanda come to grips with the science around this issue and see if I can convince Amanda to listen to reason. Amanda, I am not an expert but please come and visit me and the expert scientists I work with. You need to help the building design professions get to grips with this issue and where the real debate stands on the nature of action and not get lost in the mire of an irrational debate.

I know he annoys some people but George Monbiot's latest blog post seems very relevant to this discussion http://www.guardian.co.uk/environment/blog/2009/nov/13/climate-deniers-today-programme

The only 'other factor' you mention is population growth. Population growth is heating the planet? What, by body warmth? Too many radiators? This is why the science is settled - the opposition don't even understand their own arguments.

Will's response is measured and comprehensive. I hope Amanda takes Will up on his offer. Here is some info on studies done to try and ascertain degrees of 'consensus': http://www.skepticalscience.com/global-warming-scientific-consensus.htm. http://dvsun3.gkss.de/BERICHTE/GKSS_Berichte_2007/GKSS_2007_11.pdf

Thank you, Amanda, for referring to the tendency to want to penalise China and India, relatively marginal polluters, in this debate. Whether human-made global warming is true or not, the big danger comes from the developed world using the issue as a stick to beat developing countries. The developing world has already suffered hugely from the application of the west’s economic model. And that model was, of course (like human-made global warming) an unchallengeable orthodoxy until …

World population growth is the argument rich countries give to make poor countries responsible for global warming. However USA is still the world first CO2 emitter, closely followed by China, and UK the first European. Whereas countries like Nigeria have so low CO2 emissions despite their booming natality that they could be barely compared to average sized West cities.

Three cheers Amanda and shame on all the evil creeps who would shout you down. That man made global warming has been a sham all along is clear enough to anyone willing to explore the subject in any depth. It relied on a bunch of models (speculation turnned into numbers), the hockey stick graph, which has been comprehensively shown to be utter nonsense, and the ice core data, which, it is now conceded, shows the exact opposite of what the global warmers claimed. I have sought in vain to elicit from the key scientists promoting this theory, any other evidence that this tiny gas (CO2) is driving global temperatures. There is none. The real question is, given that this theory is, in scientific terms, a complete dud, why does it carry such enormous social and political weight? The truth is that the consensus around global warming is not scientific, but political. To see how, just read the earliest works of the big global warmers - people like Schneider and Tickell, when they were trying to convince us that global cooling was the problem. It was couched in exactly the same green terms as the global warming scare. The greens have always hankered after a climate crisis. The evidence is entirely secondary. Industry of course was the problem. These people are middle class anti-capitalists (of the sort to be found throughout our university system, the public sector, and 'creative' industries like architecture and TV). Their gripe against capitalism is not it has failed, but that it has succeeded. Too many people are consuming too much. The oiks are taking over the suburbs. Plumbers are paid more than professors and going on holidays to Egypt and spoiling everything. This green middle class anti-capitalism is snobby and elitist. But global warming does more than reflect their ugly hide-bound views. The scientific-administrative complex, as it used to be known, needs scares to justify funding. It adds fuel to the fire that this one fits perfectly with their jaundiced, reactionary, misanthropic world-view. The global warmers are so apoplectic when you dare to question the dogma because it offends their deeply held anti-industry, anti-capitalist prejudices, and, in the case of many scientists, because it undermines their very jobs. There is no evidence that GM technology is anything but beneficial, but the same people - architects, university professors and the like - will round on you for pointing it out. The only difference is, scientists get money for GM research, so there's no equivalent institutional bandwaggon. The global warming scare is a sorry, sorry business.

"These people are middle class anti-capitalists [...]. Their gripe against capitalism is not it has failed, but that it has succeeded." Succeeded?? I prefer read this than being blind.

It is clear, or reasonably clear, that the industrial revolution, changes in landscape due to farming practice ( deforestation, water use ) and massive increase in the use of fossil fuels are all heavily impactful on the environmental conditions on this planet. You could not sensibly argue differently. Amanda rightly points to population growth as the most serious issue, if you genuinely want to reduce human influence on the planet stop having babies, the problem will be solved in 80 years. It may also be possible to consider humanities recent flourish as the parting stages of an organic anomaly, global systems will adjust to our presence and this brief 70,000 year window of relative easy living will close leaving the planet clear to enjoy whichever new species rises to best exploit the prevailing conditions. It may therefore be better to rush out and buy a few air tickets and commission a few coal powered power stations to hasten our demise and prepare the ground for something altogether more sensible to occur.

Is anyone here actually a climate scientist? If not, then we simply don't have the knowledge or the skills to truly debate climate change. In any case, science relies on falsification, not debate. The science should be separate from the policies, from how we deal with climate change. They are very much open to debate, but let's not drag the science into the politics, that helps no one.

Martin Durkin wrote: ". It relied on a bunch of models (speculation turnned into numbers)..."

It is simply not true to say that the models are "speculation". The models encapsulate sound physical processes and the models are tested rigorously against historical data. The models successfully predicted, amongst other things, "Cooling of the stratosphere; Warming of the lower, mid, and upper troposphere; Warming of ocean surface waters (Cane 1997); Trends in ocean heat content (Hansen 2005); An energy imbalance between incoming sunlight and outgoing infrared radiation (Hansen 2005); Amplification of warming trends in the Arctic region (NASA observations)" (to quote skepticalscience.com)

Martin continues "...the hockey stick graph, which has been comprehensively shown to be utter nonsense"

Again, simply not supported by the evidence available in the peer reviewed journals! True, there have been controversies over the "hockey stick" graph. But the issue has been researched extensively since the original publication of the "hockey stick" graph. The conclusion of the "Committee on Surface Temperature Reconstructions for the Past 2,000 Years" (assembled by the National Research Council's Board on Atmospheric Sciences and Climate, 2006) can be summarised as "It can be said with a high level of confidence that global mean surface temperature was higher during the last few decades of the 20th century than during any comparable period during the preceding four centuries. This statement is justified by the consistency of the evidence from a wide variety of geographically diverse proxies.". i.e. the main conclusion of the hockey stick graph is valid and has been reinforced with subsequent data. It most certainly has not been shown to be "utter nonsense"

Martin continues "...and the ice core data, which, it is now conceded, shows the exact opposite of what the global warmers claimed."

Please provide references. I presume you're talking about the "lag" between temperature increase and CO2 increase in the ice core data. This has been explained many times before. For example, see this post: http://www.skepticalscience.com/co2-lags-temperature.htm to quote from it "CO2 causes temperature rise AND warming causes CO2 outgassing from oceans. This feedback system is confirmed by the CO2 record - in the past, the amplifying effect of CO2 feedback enabled warming to spread across the globe and take the planet out of the ice age."

By the way, for those who don't know, Martin Durkin produced the Channel 4 documentary "The Great Global Warming Swindle". http://en.wikipedia.org/wiki/The_Great_Global_Warming_Swindle

There is so much scientific evidence that conditions have been warmer and colder in the past. When ever the alarmists are presented with evidence they squeal "it's not been peer reviewed" Well the Hockey Stick graph was peer reviewed and showed to be a statistical nonsenese see Wegman et al. It will, without doubt, have come to your Lordship's knowledge that a considerable change of climate, inexplicable at present to us, must have taken place in the Circumpolar Regions, by which the severity of the cold that has for centuries past enclosed the seas in the high northern latitudes in an impenetrable barrier of ice, has been during the last two years greatly abated. This affords ample proof that new sources of warmth have been opened, and give us leave to hope that the Arctic Seas may at this time be more accessible than they have been for centuries past, and that discoveries may now be made in them, not only interesting to the advancement of science, but also to the future intercourse of mankind and the commerce of distant nations." President of the Royal Society, London, to the Admiralty, 20th November, 1817, Minutes of Council, Volume 8. pp.149-153, Royal Society, London. 20th November, 1817.(from) http://www.john-daly.com/polar/arctic.htm They call us deniers:- Fact 1 The Holocaust happened Fact 2 Groupthink in Germany played a large part. Fact3 We wont get fooled again

Anna said " Is anyone here a climate scientist if not then we simply do not have the knowledge or skills to truly debate climate changes" End of part post Anna could have said "is anyone here a priest we simply do not have the knowledge or skills to truly debate religion? or Anna could have said "is anyone here a politician we simply do not have the skills to truly debate politics. The appeal to higher authority is all the alarmists have, for to be sure they do not have any scientific evidence, the past demonstrates the hypotheis of man made global warming to be false. The alarmists don't seem to get it, there is no boy and there is no wolf therefore we have nothing to fear. What we should be scared of are proposals to throw into the atmosphere material to reduce the Global temperature. The people who propose this nonsense do not appear to be aware that a credible hypothesis on the cause of ice ages are cool summers snow ice linger for longer causing lower temperatures due reflection of the solar rays and the process repeats itself. Finally when Anna talks about climate scientists what she should understand is that their methods are almost completely statistical and because they are not trained statisticians well the results are clear to see Global Alarmism.

My response to Will is as follows

1. Sweeping statements like that are highly misleading. What journalists like Amanda don't understand is that science is never settled.

Why are ABs "sweeping statements" misleading, when the climate change debate has been flooded with the same? The oft-repeated mantra that in Britain, global warming will result in "hotter, drier summers and warmer, wetter winters". This is a very simplistic transposition of the key features (i.e. sub-'O' level geography) of the Mediterranean climate, northwards into the temperate maritime we currently experience.

It is absolutely true that science is never settled which is exactly why the questioning of some of the extravagant and simplistic claims of the politico-media juggernaut must be challenged.

However, just because someone like Einstein comes along, it doesn't render Newton 's work useless. I would be happy to carefully go through each of Amanda's doubts offline and help her understand why the IPCC assessment says what it says and what the latest peer reviewed science is telling us. Suffice to say it is a one way street.

The one way street is patently untrue! There are a number of variations in model predictions, as there are in the contention that CO2 and other greenhouse gasses are the main drivers. The cause and effect relationship that high CO2 concentrations drive climate change in a particular, i.e. warming direction, is open to doubt from the historical record, where the converse appears to hold.

2) "...reliable forecasts of future climate are proving elusive." Again highly misleading. I would be happy to introduce Amanda to some of the people doing the modelling, then she can assess where the elusive aspects of the model lie. Again I can say that those aspects are not going to make the picture any rosier.

There is a difference between predictions and forecasting. The outputs from models are largely predictions of generalised climate conditions, and are presented as changes in indicators, e.g. mean temperatures, numbers of days with rain, frequency of winds. These are quite "bland" statistics, and not very suitable for working in the context of design. The "climate generators" included in UKCP09 are a move n the right direction, but from what I understand are still rather limited. In short your statement is quite OK.

3) "It may well be that human CO2 activity is a significant factor in global warming, but there are also other reasons, like population growth and a huge number of other independent factors...." Here I think Amanda just simply gets confused. No serious scientists would deny population is an issue linked to climate change, but importantly the link exists because at the moment every extra person means using more energy and thus emitting more CO2. Other "independent factors" as Amanda calls them are included in most climate models and their influence accounted for as this is how system modelling works.

I think your statements may have been mis-interpreted. Were you perhaps trying to comment on the contention that climate change is the greatest danger threatening the world? The point about the CO2 focus is that it has been taken up as a single issue, i.e. cut down CO2 emissions, and the world is saved. This diverts attention from many and much more practical means of adaptation and resilience.

There are numerous other factors in the way climate behaves. As Ian Stangeways, an expert in meteorological observation, states in his text book "Precipitation" (Cambridge University Press, 2007): "Trends and means are not the whole story, however. Variability and extremes are also important.."

4) "the scientists involved in genuine research in this field have been refused platforms because they dare question the climate change orthodoxy." I am unaware of any serious scientist who has been "refused platforms" because of their views. Could Amanda provide an example?

Within scientific circles, I am sure there are reasonable (and reasoned) debates going on. The worrying thing is that the findings which challenge the politically inspired orthodoxy are at best given little exposure, or at worst held up to ridicule. For instance, in the Trends report, part of the UKCP09 outputs, it is clearly stated that:
"frequency of drought episodes.show no clear trend over the period 1776-2006",
and,
"because of natural high variability and short observational data sets, unambiguous trends are unlikely to emerge.. for several decades."

These sorts of qualification are never publicised.

5) "Is the best course of action putting a cap on emissions [...] or should we be adapting to climate change and using our energies and money in better preparing for the impact of events such as flooding and drought?" This question was answered comprehensively by the Stern Report and other similar economic reports which all said, roughly, that the costs of adaptation beyond 2 degrees increase are too much to bear, but because 2 degrees is close to inevitable, we need to spend big money on both mitigation and adaptation.

It is obviously beneficial for all sorts of reasons to cap emissions, but it is dangerous to see them as a panacea to "control" climate. The combination of emissions control and mitigation and adaptation doesnt get the same level of promotion. We must remember that Stearn is an economist, not a climatologist, and his brief started with the assumption that the climate model projections were a given.

6) Use of the word "denier" is an attempt to remove the equally loaded term "sceptic" away from those who would stop action. There were many sceptical tobacco companies who spent the better part of 50 years denying that their product was linked to addiction and death and actively undermining science and progress. All they needed to sell to policy makers was doubt in order to stop action. Have we as a society learnt nothing from this experience?

I dont think the principal aim of deniers and sceptics is to stop action. My (and a number of professional colleagues) view is that action needs to be tempered and focussed through logic and good science, not driven by political fashion.

7. Finally I come to the final point that it appears people of a certain age scarred into cynicism by their experience of political corruption and scientific scandal seem to feel they, having no prior knowledge of a field . There is truly a serious problem in society when the editor of a building design magazine claims to have better knowledge of the truth of a scientific issue (entirely unrelated to buildings) than the UK's chief scientist and literally thousands of specialists in the field. Here, perhaps, lies one of the greatest communication failures of the environmental movement. But in an attempt to turn this around, working on the one person can make a difference principle, I would like to put myself forward to help Amanda come to grips with the science around this issue and see if I can convince Amanda to listen to reason. Amanda, I am not an expert but please come and visit me and the expert scientists I work with. You need to help the building design professions get to grips with this issue and where the real debate stands on the nature of action and not get lost in the mire of an irrational debate.

This final paragraph is a bit rambling, but the offer "to convince Amanda to listen to reason", sounds like the re-education methods employed by totalitarian states!

James wrote: The cause and effect relationship that high CO2 concentrations drive climate change in a particular, i.e. warming direction, is open to doubt from the historical record, where the converse appears to hold.

It is true that the historical ice core data demonstrates that when the world exists an ice age, the world starts to warm before CO2 levels rise. Warming caused by changes in the earth's orbit causes the oceans to release CO2 and this CO2 then amplifies the warming (the increase in insolation (incoming sunlight) is not sufficient to explain the extent of the warming on its own. This is a well established principal. It in no way falsifies the theory that anthropogenic CO2 can warm the world. Observing that object A can drive object B tells us nothing about whether object B can also drive object A. Please see this link for more info: http://www.skepticalscience.com/co2-lags-temperature.htm

Dear Jack, You say 'models are tested against historical data'. OK here we go. How many of these models predicted 10 years ago that global temperatures would go down? Yet, over the past decade, that's precisely what has happened. On the absurd Hockey Stick see the damning Wegman Report and of course MacIntyre's brilliant expose. On references for the Ice Core Data, just look at every ice core research paper ever published. You can find them at 'CO2 Science' together with an excellent analysis. The models are quite clearly ridiculous and your silly agw hypothesis is contradicted everywhere by observed real data. Yet you people cling onto this theory with the same passion I used to see in the eyes of Stalinists defending the Soviet Union.

Nice initial article. I came here from ClimateAudit. Unfortunately the comments are light brown on white and about 8 point. Completely unreadable.

Will wrote " Suffice to say it is a one way street." No it isn't a one way street. But you don't have to take my word for it, or the word of any blogger who may - or may not - under stand climate science. How about the 700 scientists who signed a petition in the US: http://www.epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=10fe77b0-802a-23ad-4df1-fc38ed4f85e3 The 160 members of the American Physical Society who wanted to amend the Society's statement on Global Warming: http://bx.businessweek.com/lockheed-martin/physicists-send-letter-to-senate--cite-160-scientists-protest/5055833238436719000-5408b770a6621a0558b98ae6de1acc0c/ The over 60 scientists who wrote to the German chancellor http://www.eike-klima-energie.eu/news-anzeige/klimawandel-offener-brief-an-kanzlerin-merkel-temperaturmessungen-ab-1701-widerlegen-anthropogen-verursachte-temperaturschwankungen/ Or look at the Heidelberg Appeal (4000 signatories including over 70 Nobel proze winners): http://www.americanpolicy.org/un/theheidelberg.htm Or you could read through the following list of 450 peer-reviwed, published-in-the-scientific-literature articles: http://www.populartechnology.net/2009/10/peer-reviewed-papers-supporting.html I could go on, but that'll do to start with.

asmilwho – there are plenty of lists of the type you reference on climate change misinformation websites. With a little scrutiny (dare I say, skepticism) such lists can be rapidly whittled down. Would the list of 700 scientists you refer to be the one that contains numerous non-scientists, and even tv Gardener Alan Titchmarsh? The recently produced list of 450 peer-reviewed papers is bulked up with 82 papers from Energy and Environment. Energy and Environment is little more than a vanity publisher for climate change denialists, The Institute for Scientific Information doesn’t include E&E in their journal citation reports, and Scopus classifies E&E as a trade journal. The list is also bulked up with papers on the Medieval Warm Period, the Little Ice Age, and the CO2 lag at the end of glacial periods as if studies these studies are incompatible with MMCC, when they are not (Martin Durkin please take note). Roger Pielke jnr has just asked that 21 papers by him and his father be pulled from the list - http://rogerpielkejr.blogspot.com/2009/11/better-recheck-that-list.html. When a genuine skeptic scientist asks to be removed from that list you have to question its veracity.

"the science is settled" ius a statement made by Al Gore et al. I would like to refer readers to Richard Feynman's address (Cargo Cult Science) to graduating students at UCLA. This is available on the Net by googling the title. Feynman was a Nobel prize winner and spent his life driven by his curiosity and his obsession with the process of science and knowledge.

In the light of the leak, on or about 19 November, of much evidence from the CRU at University of East Anglia, would all those commenters in favour of the theory of AGW please review their statements, and revise them if necessary?

Yokel - nope. CO2 is still a greenhouse gas, is still accumulating in the atmosphere because of human activities, and the climate is still changing. Stealing computer files in an attempt to find evidence of a conspiracy shows many so-called sceptics for what they genuinely are – mere Conspiracy Theorists. Provided the stolen material is read in its proper context there is very little for deniers to work with, but they will no doubt do their best to make mountains out of molehills and divert people’s attention from the wider body of science. In light of the completely unprecedented weather the folk of Cumbria have experience recently, would you like to take a more cautious and circumspect attitude?

So if a anti AGW comentator points out that the earth hasn't warmed for the last ten years, they are told by the pro AGW that this is not proof of a halt in AGW and you can't just cherry pick a small piece of data to deny AGW you have to take in the whole view of temperatures since records began, but if a pro AGW points to a single alarmist event, as in the recent floods, this is positive proof of AGW? Cake and eat it springs to mind...