It? You mean the global temperature record? No it doesn’t. The only good data we have is from satellites and the first of those date from about 1974. So you can’t really do that clever little trick of claiming the world record is valid when it shows warming, but not valid when it shows the US was warmer in the 1930s.

The instrumental records go back to the mid 19th century and are reliable enough for the purposes of making this comparison. And no one is claiming that the record showing the US to be warmer in the 1930s is invalid. They just point out that the US is not the world, just a very small proportion of it.

The overwhelming, crushing, weight of evidence is that the MWP was global and it was significantly warmer. Dare I say there is a consensus for it? Wherever we look in the world we find evidence of it. There is no research, at least no real research, that says otherwise. Mann and his friends tried to write it out of the record but they have had to backtrack.

So we can’t say whether it was hotter before 1974 but we can say with absolute certainty that it was hotter 1000 years ago? Anyway, Mann and co have not had to backtrack and there is no credible reconstruction of past temperatures which shows the MWP as being warmer than now and several which say otherwise. There is most certainly a consensus amongst some people, just not those who actually study climate professionally or in the peer reviewed literature. Can you please provide a source for your assertion?

A model that does not consider solar forcing is useless even if the scientists writing it understood El Nino which they don’t.

The models do consider solar forcing so I’m not sure what they meant by that.

Which points out the criticism of climate models for producing monotonic warming. Using the same word even.

Pointing out there is criticism is not the same as saying the criticism is well founded. It goes on to say

However, even considering these criticisms, it is clear that the models can and do produce sustained multi-year periods of ‘‘cooling’’ embedded within the longer-term warming produced in the 21st century simulations.

Of course the projections made by the IPCC are not based on individual model runs, they are based on multiple runs, so you get a fairly smooth curve with a margin of error which allows for short periods of flat or negative growth. Of course if these periods go on too long they will fall outside the MOE of the models. But although the models are useful tools we shouldn’t overestimate their importance – we don’t need them to predict that it will get hotter if we continue pumping GHGs into the atmosphere.

What do you think you mean by saying that? How is a statistical analysis not an opinion?

What I mean is that we calculate the amount of date required to demonstrate a meaningful trend by way of statistical analysis, we don’t just say “ten years is a long time so the trend over this period must be meaningful”.

Indeed. Anyone can pick a time frame if they want a specific result. Which is why we need to wait for that longer term. Thirty years of (bad and misused) data is not enough. But what is also clear is that the evidence is not strong. The observed warming is within the error margin. The deviations are large. The case is just not strong.

Well the claim that the date is “bad and misused” has no substance, and the observed warming since the 1970s is not within the error margin. Regardless of whether it is due to CO2 emissions, it cannot be accounted for by the kind of natural fluctuations you get year by year.
Of course he does. What else would he say? Ten years ago was he saying that? Of course he wasn’t. The problem here is that if you quote Tamino we are not going to get anywhere because you may as well be consulting a crystal ball for all the credibility it brings.

What is your basis for questioning his credibility? Can you point to any errors in his calculations?

It is as clear as it is ever going to be that it was a global event. We find it on every continent on the planet where we can test. The Warmists are not disputing whether it all happened at the same time because that is safer ground for them – their case suffers if 1998 was not unusual. As it wasn’t.

No one is making any claims based on temperatures in 1998 – we know it was anomalous. Our claims are based on current temperatures, increases since the 1970s and, importantly, projected increases for this century and are not dependent on the existence or otherwise of the MWP.

As for solar variability, I have seen Warmists abuse people looking at the sun’s influence for about the last five years. They have tended to deny it. Good to see some people are willing to consider it.

A large amount of research has been done looking at whether current warming is due to solar influence and the overwhelming evidence is that it is not. No one has been abused for looking for this link – it is perfectly proper that people should do so. There has certainly been criticism of people who have produced papers of dubious merit (eg Svensmark) but that is usual in any branch of science.

A pity so few of the models bother to isn’t it?

As I said above the models do allow for solar forcing.

We assume that volcanic activity has a medium term impact by releasing CO2 and other gases. I am not so sure we are sure.

We assume volcanoes have an impact by releasing aerosols – we can be sure of this because the effects of large eruptions such as Pinatubo are easy to predict.

We need to do more research. We still don’t know what caused the MWP. We don’t know what made the 1930s so warm (in the US).

Of course we need to do more research – no one is claiming we know everything, we probably never will. But that doesn’t mean we don’t know a considerabble amount about teh way our climate works already.

We don’t know why 1998 was so warm if it was not natural.

Yes we do – it was the most powerful el Nino in a century. Just as we know 208 was relatively cool due to a combination of a la Nina and a significant solar minimum.

This is a sensible basis to destroy the world’s economy?

Aside from a few nutters no one wants to destroy the world’s economy and taking action to avoid GW does not have to do so.

From an analysis of more than a thousand treering, ice core, coral, sediment, and other assorted proxy records spanning the ocean and land regions of both hemispheres over the past 1500 years. The MWP was shown to be significantly colder than today in particular central Eurasia, northwestern North America, and the tropical Pacific and was therefore not a global event.

http://www.meteo.psu.edu/~mann/shared/articles/MannetalScience09.pdf

The analysis performed in “An observationally based energy balance for the Earth since 1950 (Murphy 2009)” clearly shows a continuing temperature rise:
http://www.skepticalscience.com/global-warming-stopped-in-1998.htm

The Sun’s recent influence has been a cooling one:
http://rspa.royalsocietypublishing.org/content/464/2094/1387.abstract

Monckton making his Communist plot claims..

“So at last the communists who piled out of the Berlin Wall and into the environmental movement and took over Greenpeace, so that my friends who founded it left within a year because they’d captured it, now the apotheosis is at hand. They are about to impose a communist world government on the world. You have a president who has very strong sympathies with that point of view….It is a privilege merely to stand on this soil of freedom while it is still free. But in the next few weeks, unless you stop it, your president will sign your freedom, your democracy, and your prosperity away forever.”

http://www.care2.com/causes/global-warming/blog/is-climate-change-a-communist-plot/

It? You mean the global temperature record? No it doesn’t. The only good data we have is from satellites and the first of those date from about 1974. So you can’t really do that clever little trick of claiming the world record is valid when it shows warming, but not valid when it shows the US was warmer in the 1930s.

The overwhelming, crushing, weight of evidence is that the MWP was global and it was significantly warmer. Dare I say there is a consensus for it? Wherever we look in the world we find evidence of it. There is no research, at least no real research, that says otherwise. Mann and his friends tried to write it out of the record but they have had to backtrack.

“They make projections of long term trends, they do not make specific predictions changes in temperature year by year or over just a few years.”

Sorry but they use Finite Difference Methods. These have to be run every month of every year. They may not provide useful specific predictions – depending on how you want to define those – but they provide estimates for every year going forward from wherever you start to whenever you end. It is the nature of the mathematics.

“See this peer-reviewed paper”

Which points out the criticism of climate models for producing monotonic warming. Using the same word even. They also point out the flaws in these models:

What does this say about the variability of the climate system? Climate models are often criticized for producing a more or less monotonic-type response to anthropogenic forcing in 21st century simulations. Part of this may be due to the lack of volcanic and solar forcing in the SRES scenarios of anthropogenic forcing increase for the 21st century and part could be due to the fact that largescale oscillatory climate features, such as the El Nin˜o-Southern Oscillation are not well simulated.

A model that does not consider solar forcing is useless even if the scientists writing it understood El Nino which they don’t.

“As I mentioned above, the period of time required to get a meaningful trend is a matter of statistcal analysis, not opinion.”

What do you think you mean by saying that? How is a statistical analysis not an opinion?

“See the link I posted above to Tamino’s site which explains this – he shows that using GISS temperature data as an example you need at least 15 years of data to get a statistically meaningful trend.”

Of course he does. What else would he say? Ten years ago was he saying that? Of course he wasn’t. The problem here is that if you quote Tamino we are not going to get anywhere because you may as well be consulting a crystal ball for all the credibility it brings.

“The site you linked to does demonstrate to an extent that if you choose shorter periods and are selective about your start and end dates you can indeed make very different interpretations, which is why it is important to look at what is hapening in the longer term.”

Indeed. Anyone can pick a time frame if they want a specific result. Which is why we need to wait for that longer term. Thirty years of (bad and misused) data is not enough. But what is also clear is that the evidence is not strong. The observed warming is within the error margin. The deviations are large. The case is just not strong.

“We do know natural factors which affect climate in the longer term, Dunc mentioned them above – solar and orbital variability and geological activity (including the release of CO2 and other GHGs). It is difficult to pin down a casue ofr the MWP because it is by no means clear that was a global phenomenon or that even in the NH it occurred everywhere at the same time.”

It is as clear as it is ever going to be that it was a global event. We find it on every continent on the planet where we can test. The Warmists are not disputing whether it all happened at the same time because that is safer ground for them – their case suffers if 1998 was not unusual. As it wasn’t.

As for solar variability, I have seen Warmists abuse people looking at the sun’s influence for about the last five years. They have tended to deny it. Good to see some people are willing to consider it. A pity so few of the models bother to isn’t it? We assume that volcanic activity has a medium term impact by releasing CO2 and other gases. I am not so sure we are sure. We need to do more research. We still don’t know what caused the MWP. We don’t know what made the 1930s so warm (in the US). We don’t know why 1998 was so warm if it was not natural. This is a sensible basis to destroy the world’s economy?

Really? If he made it, probably. But I have yet to hear him make that claim.

“With your references to warmists you haven’t a clue about where the level of debate is. Not even the sceptical scientists dispute that it is warming. 0 points. I suggest you do some reading:”

Not even I dispute there has been some warming. You might try reading me first.

First of all, it is the nature of scientists to use cautious language of this kind. We know the likely consequences of gobal warming but of course it is impossible to quantify them exactly. That does not mean that the possibility of such things can be treated lightly or that the consequences will not be serious.
We have adapted to changes in temperatures in the past, but we are likely to see changes of a magnitude never experienced by humans before, and in past times there were many fewer of us and our way of life was very different to the way it is now. It may not be as easy to adapt as in the past. There are millions of people without proper access to clean water as it is, do you think that will get better as the planet gets hotter?
Of course there have been floods and droughts in the past. Any many people have died as a result and there are likely to be more of them in future.

*Possible* consequences – believe it or not sea levels have never been stable – the sahara desert was once a sea bed – and termpretures have risen and fallen before. We adapted.

*Could* have a serious impact – and then lists flooding and droughts, both natural phenomena which have been documented as far back as the bible

Its about as lame as it gets – so what ??

Not demonising, just pointing out some rather obvious facts. Isn’t it strange that the Right show so much snorting fury at the spectre of ‘PC gone maaaad’ when it suits them, but the minute they are faced with their own shortcomings in brutal terms , there is a need for the twee euphemisms?

So what is the PC term for people who ignore science and make up lies, just so the can carry on their own destructive lifestyles?

Ethically challenged?
Differently moral?
Scientifically excluded?
Reality disenfranchised?
People of greed?
Differently personal responsible?
Consequently challenged?

What about selfish greedy bastards? Has a nice ring to it, and explains their sad plight correctly.

Hope that helps.

Well that is not quite true. This decade is the consistently hottest since world wide records were first kept. That is, since the 1970s. The 1970s were cool. That is not a surprise. But we know that even the 1990s were not hotter than the 1930s in the United States. We also know the Mediaeval Warm period was hotter still. Having the hottest out of three decades means little.

BTW, the original comment was not me, so I agree with your first sentence, but it goes back a lot further than the 1970s. We do indeed know that a couple of years during the 1930s were hotter in the US but the US covers only 2% of the earth’s surface and there will always be more variation in smaller geographical areas than globally. But we don’t by any means know that the MWP was hotter globally, in fact the research seems to indicate otherwise.

The models did predict monotonic warming in the absence of a Pinatubo-style event. We have not had one. But we have not continued to warm. The models did not predict this. We are not entirely sure of why it is either. Which shows how little we understand the system we are supposed to be studying.

The models most certainly did not and do not predict monotonic warming – do you have a source that says they do? They make projections of long term trends, they do not make specific predictions changes in temperature year by year or over just a few years. See this peer-reviewed paper

http://thingsbreak.files.wordpress.com/2009/09/is-the-climate-warming-or-cooling.pdf

Here we show that periods of no trend or even cooling of the globally averaged surface air temperature are found in the last 34 years of the observed record, and in climate model simulations of the 20th and 21st century forced with increasing greenhouse gases.

Of course [a decade] is long enough. But then we only have three decades of data to go on so by this reasoning we don’t have enough data to know anything.

As I mentioned above, the period of time required to get a meaningful trend is a matter of statistcal analysis, not opinion. See the link I posted above to Tamino’s site which explains this – he shows that using GISS temperature data as an example you need at least 15 years of data to get a statistically meaningful trend. The site you linked to does demonstrate to an extent that if you choose shorter periods and are selective about your start and end dates you can indeed make very different interpretations, which is why it is important to look at what is hapening in the longer term.

I don’t think that is what [Trenberth] was referring to. Actually. I think he was referring to the basic fact that the climate did not do what the models said they would. And none of them could explain why.

Actually we don’t know that. I mean it is a safe assumption, but we cannot and do not know what causes long-term climate change. Something does. But it is as yet beyond us to say what it is. Just ask someone to explain the Mediaeval Warm Period. The best guess is still an Act of God. We might one day be able to work out why but we are not within a lifetime or two of research to doing it yet.

We do know natural factors which affect climate in the longer term, Dunc mentioned them above – solar and orbital variability and geological activity (including the release of CO2 and other GHGs). It is difficult to pin down a casue ofr the MWP because it is by no means clear that was a global phenomenon or that even in the NH it occurred everywhere at the same time.

“the really strange thing about Monkton is that the more you look at his World Government claims, the more sense there is too them”

Monckton’s argument that global warming is a communist plot involving almost all the scientific community requires a little evidence don’t you think?

It seems like a strange view to be supporting on here.

With your references to warmists you haven’t a clue about where the level of debate is. Not even the sceptical scientists dispute that it is warming.

0 points. I suggest you do some reading:

http://www.skepticalscience.com/argument.php

No I wouldn’t. They are hawking their credibility in the streets and will live to regret it. Science does not work this way.

“To be said in such an, err, forthright a manner, if all of our scientists didn’t, at the very least think that prevention was better than cure?”

Sorry but what forthright manner? As I said they are not certain. Read what they say – possible consequences, could have an impact.

And the question of prevention depends on many things. The risks have to be weighed against the costs. The cost of an 80% CO2 cut is massive. It means an effective de-industrialisation and a return to an early modern agricultural society. Sort of what Morgenthau wanted to do to Germany. This cost is very certain. The risk of there being a problem is small. The costs of that problem so far appears to be rather manageable even if it does occur. So only a fool would support the CO2 cut.

“Sure, there is a possibility that they are all wrong. But I am not at all keen on a libertarian gamble, much as they aren’t.”

I am not keen on what is being offered as a solution either. I am old enough to remember Cambodia and the Killing Fields. I have no desire to see it happen again. You show me a cheaper solution and I will support it. But the slight risk of some minor inconvenience – which is all a 2 C rise is – against the utter and deadly certainty of what is being offered as a solution is a fool’s gamble.

“Seems to me that an existential threat ought to be treated, as such, rather than as a political game. Politicians know damn all about anything.”

Sorry but what scientist posting from Planet Earth thinks this is an existential threat? Again notice the utter discontinuity between what the science says and what the Green hysterics are claiming.

When are we ever going to get an edit facility around here?

You’d hardly expect statements like this from the Royal Society:

International scientific consensus agrees that increasing levels of man-made greenhouse gases are leading to global climate change. Possible consequences of climate change include rising temperatures, changing sea levels, and impacts on global weather. These changes could have serious impacts on the world’s organisms and on the lives of millions of people, especially those living in areas vulnerable to extreme natural conditions such as flooding and drought.

http://royalsociety.org/Climate-Change/

To be said in such an, err, forthright a manner, if all of our scientists didn’t, at the very least think that prevention was better than cure?

Sure, there is a possibility that they are all wrong. But I am not at all keen on a libertarian gamble, much as they aren’t.

Are you?

Gamble your life, or your kids future on a hunch?

I have here a revolver, only one chamber of which is loaded.

Go on, spin it…..

Would you be mad enough to risk it, no matter how mant chambers the gun had? maybe if it had a thousand chambers? Or a million? Don’t bother pointing the gun to your head, point it to your balls instead. For that is the timescale, not you, but your childrens children. Well, perhaps in your case, not….

Seems to me that an existential threat ought to be treated, as such, rather than as a political game. Politicians know damn all about anything.

What “highly resourced denial machine”? The Warmists have been getting billions of pounds since the 1980s. They have had the goodwill of the majority of liberals and the institutions they control. They have had an unimpeded run at the media. On the other hand, the Skeptics have been a small number of academics and others who have been reduced to covering this issue from blogs.

There isn’t even a Skeptical equivalent of Real Climate.

Delingpole is noticeable for being a late convert to the cause and the really strange thing about Monkton is that the more you look at his World Government claims, the more sense there is too them. But let me ask you – do you think this mindless abuse is furthering the debate? Do you think it is helpful? And if you do, don’t you think that is a sign of why your side is losing this debate?

Do you also think your post is in line with this site’s community standards?

I can’t agree that it is the primary cause for an increase in scepticism. I am sure that the medias coverage of the CRU emails and IPCC mistakes are the primary causes. Tabloids and even the BBC on Andrew Neil’s blog have been lapping up the propoganda from the highly resourced denial machine. The nutjob conspiracy theories of Monckton have been regurgitated not just by the loathsome Delingpole but more widely across the news channels.

They have used all the tactics at their disposal including calls for false balancing.
http://www.globalissues.org/article/710/global-warming-spin-and-media#MediaFalseBalancingAllowedExtremeViewstobeTreatedSameasScientificConsensus

Jim Hogan explains what is going on well here:
http://www.desmogblog.com/slamming-the-climate-skeptic-scam

So it is. But those claims are false. Most such institutions make the general probabilistic claim I mentioned – it is likely we are doing something and it is likely that it will be a problem – rather than the definite claim we see here.

“Science, if it is to predict the future, rather than do what it has always done, describe our present, has to operate on a consensus. I’d have thought that was obvious.”

Umm, nonsense. Science has always made predictions about the future and there is no real reason at all for it to operate on a consensus whatever it does. Science makes progress by one man being right and everyone else being wrong. Lord Kelvin represented the consensus when he said Physics had explained everything but a few minor lose ends. Einstein didn’t when he showed that view to be absurd.

It is claimed that every National Scientific Institute says otherwise, I seem to recall….

Science, if it is to predict the future, rather than do what it has always done, describe our present, has to operate on a consensus. I’d have thought that was obvious.

Because none of this is true. There is not a consensus on AGW and especially not on Catastrophic AGW. What there is something like a consensus on is that it is likely that mankind is having an impact on the climate and it is also likely that this will have unfortunate consequences. Notice the caveats. Not that it matters as science is not a consentual enterprise.

Nor are your delusions about Skeptics anything other than delusions.

Well that is not quite true. This decade is the consistently hottest since world wide records were first kept. That is, since the 1970s. The 1970s were cool. That is not a surprise. But we know that even the 1990s were not hotter than the 1930s in the United States. We also know the Mediaeval Warm period was hotter still. Having the hottest out of three decades means little.

“Temperatures over the last decade do not contradict the models – they are well within the margin of error of all of them.”

Which is a problem in and of itself as the margin of error is so large and the observed warming so small in comparison that there is no real reason to think we even have a problem. But you are confusing two separate issues. The models did predict monotonic warming in the absence of a Pinatubo-style event. We have not had one. But we have not continued to warm. The models did not predict this. We are not entirely sure of why it is either. Which shows how little we understand the system we are supposed to be studying.

“But then a decade is an entirely arbitrary period and, importantly, too short a period to tell us anything meaningful about how our climate is changing.”

Of course it is long enough. But then we only have three decades of data to go on so by this reasoning we don’t have enough data to know anything. It is true that if you pick you start and end points carefully enough you can show almost anything. As here:

http://masterresource.org/?p=5240

“For example, my understanding is that in the absence of any other factors global surface temperatures will naturally vary slightly from year to year and we cannot currently account for these variations (this is what Trenberth was referring to in his “travesty” email).”

I don’t think that is what he was referring to. Actually. I think he was referring to the basic fact that the climate did not do what the models said they would. And none of them could explain why.

“But in the longer term climate does not change for no reason – it is not enough to cite “natural variation” as the cause of the warming we have seen since the late 70’s, or other changes in climate before then. It may well be “natural” in the sense that its is not man made but that doesn’t not mean we cannot isolate a specific cause or causes.”

Actually we don’t know that. I mean it is a safe assumption, but we cannot and do not know what causes long-term climate change. Something does. But it is as yet beyond us to say what it is. Just ask someone to explain the Mediaeval Warm Period. The best guess is still an Act of God. We might one day be able to work out why but we are not within a lifetime or two of research to doing it yet.

Conversely it seems to me that you are guilty of not at least trying…

It very much sounds like you think the climate scientists are the goodies and the denialists are the badies.

There’s nothing like demonizing the opposition, eh? Especially when accusing them of doing the same.

And so it goes: Round and round and round and …………..

The Milankovitch cycle doesn’t explain where we are today.