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« Cook's unreported finding | Main | What goes around... »
Friday
May172013

Today does climate sensitivity

BBC Radio's flagship Today programme covers climate sensitivity and features, among others, yours truly. I haven't heard it yet, but this is a holding post until I can find the audio.

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Reader Comments (65)

Well done Andrew - and well done the BBC and Today and Roger Harrabin for a for a balanced article. It was about 7.35 this morning. You came across well. They also interviewed Hoskins and Houghton who seemed out of touch and confused, saying warming hadnt slowed and/or that the heat had suddenly decided to all go into the oceans rather than the atmosphere this decade.

Later at about 8.25 they had Hansen on. He claimed 0.1C rise in the
last decade, and complained about "deniers".

May 17, 2013 at 8:40 AM | Registered CommenterPaul Matthews

On twitter, Ruth Dixon points out that according to Hansen's own data, the warming in the last decade was only about 0.01, not 0.1.

May 17, 2013 at 8:40 AM | Registered CommenterPaul Matthews

Considering this was the BBC and Harrabin, it was almost sceptical. Well done, anyway. Then they bvggered it up with the follow-up piece interviewing Hansen.

May 17, 2013 at 8:49 AM | Registered CommenterGrumpyDenier

Very well done indeed sir, the day the BBC turned.

May 17, 2013 at 8:56 AM | Unregistered CommenterLord Beaverbrook

Houghton's claim that global warming had recently slowed (in contrast to rising temperatures in the previous twenty years) because of heat absorption by the oceans was quite patronising. The sea's been there all my life, Houghton lives close to the sea, so why has the sea suddenly 'turned on' its influence in the last twenty years? Does he think we're all fools?

May 17, 2013 at 9:21 AM | Unregistered CommenterCapell

As regards climate sensitivity, it is impossible to determine a value for climate sensitivity until absolutely everything is known and understood about natural variation, what its constituent components are, and the upper and lower bounds of each and every one of its consituent components.

As regards natural variation, we know as fact that it can be at least equal to if not greater than any forcing caused by CO2. Evidence, the 1940s to 1970s cooling (during this period downward forcings of natural variation exceeeded any positive forcing due to CO2 such that notwithstanding an increase in CO2 emissions, temperatures cooled), and the post 1998 to date stasis (during this period downward forcings of natural variation equalled any positive forcing due to CO2 such that notwithstanding an increase in CO2 emissions, temperature anomaly did not change to a significant extent)..

The claim regarding ocean uptake requires a change in the so called basic physics of CO2 and if true it demonstrates that we do not understand the so called basic physics of CO2 GHE. During the 1970s to late 1990s warming the so called basic physics of CO2 was that it warmed the atmosphere. Now it is contended that the so called basic physics has changed such that CO2 no longer warms the atmosphere but instead now warms the oceans. We need to know what the process is, the physics involved and why and how this dramatic switch has occurred before any claims that the alleged missing heat is trapped in the oceans.

PS: I have not heard the interview. I would like to review a transcript.

May 17, 2013 at 9:31 AM | Unregistered Commenterrichard verney

Some parts of this programme were OK but why did Harrabin then fail to question the unfounded claims from the last contributer that extreme weather events had increased when there is clearly no proof, infact much data to suggest there has been no increase in extreme events.

It's time for the BBC to produce data to support these false claims, or to stop giving unchallenged air time to alarmists who make them.

To anyone who suggests flooding has increased through increased weather extremes is wrong. I am a developer and can attest to the fact that any increase in flooding events is due to the quite ridiculous number of houses that have been built on floodplains, together with the increase in hard run off areas associated with new developments causing flash floods in local waterways. This is still going on with the governments approval and should have been stopped long ago.

May 17, 2013 at 9:31 AM | Unregistered CommenterJohnB

I have to agree with Capell, unless the alarmists can produce evidence to show what transfer mechanism supports their claims that the heat has suddenly taken a dive to the 700 - 2000m ocean level as Trenberth has recently been claiming these claims should not go unchallenged on any media report. Houghton is clearly not one of the sharpest tacks in the box.

The main problem for these alarmists on OHC lies in the fact the the ARGO floats showing that the oceans have also virtually stopped warming since 2004.

May 17, 2013 at 9:42 AM | Unregistered CommenterJohnB

This was a very interesting interview sequence because our Establishment is apparently developing the view, at last, that Climate Alchemy does not cut the mustard. What we heard was justification of muddled science, Houghton and Hansen, by imaginary 'missing heat' in the oceans when there is no known physical explanation for this [check out the UNESCO Equation of State for the water data].

The problem is that Houghton made three bad mistakes in his physics: to claim the 2-stream approximation can work at an optical heterogeneity, that the Earth's surface radiates as a black body and the atmosphere is a grey body [it's semi transparent]. Hansen with Lacis also introduced Sagan's aerosol optical physics to clouds when that is wrong, due to an incorrect assumption Sagan made about earlier work. Hoskins is a follower. Hansen's first modelling paper also made a bad mistake in the assumptions about CO2 IR emission at ToA, later corrected but by then they were committed politically.

So, the ordure is hitting the fan: people at a high level are insisting the 3 H's explain themselves to justify the absurd measures demanded by this new Lysenkoism. In Germany, the call from part of Government is to start a pogrom against 'Deniers'

May 17, 2013 at 9:49 AM | Unregistered CommenterAlecM

Looks like the new spin is going to be that the climate sensitivity is lower, temperatures are going to rise less, but the effects of even a small rise in temperature are worse than previously thought, bolstered by bogus claims of extreme weather. That's the next thing for sceptics to concentrate on debunking.

It's better news than it has been, but there's still some way to go!

May 17, 2013 at 9:49 AM | Unregistered CommenterMichael Larkin

I have to agree with Capell, unless the alarmists can produce evidence to show what transfer mechanism supports their claims that the heat has suddenly taken a dive to the 700 - 2000m ocean level as Trenberth has recently been claiming these claims should not go unchallenged on any media report. Houghton is clearly not one of the sharpest tacks in the box.

The main problem for these alarmists on OHC lies in the fact the the ARGO floats showing that the oceans have also virtually stopped warming since 2004.

May 17, 2013 at 9:51 AM | Unregistered CommenterJohnB

If the deep sea warms up by 0.00004C per decade or whatever it might be, why should we care?

Even if this ocean warming story is true (which I very much doubt), the alarmist will have saved the existence of their God, but at the expense of failing the 'So What?' test.

May 17, 2013 at 9:52 AM | Registered CommenterLatimer Alder

Further to my comment at 09:31 hrs, perhaps I should have further pointed out.

As regards the first paragraph, the reason why as a condition precedent we need to know and understand everything about natural variation before we can begin to assess climate sensitivity, is because the temperature record (on all time periods, eg., annual, multi decadel etc) is noisy and variable and until we can identify which changes are due to natural variation, we are unable to seperate the signal of climate sensitivity from the noise of natural variation.

As regards the oceans, it is noteworthy that the annual variations can be large. So large that the variation from one year to another cannot possibly have been caused by slight changes in the concentration of CO2 in the atmosphere. That in itself suggests that other processes are involved which are driving temperature movements, alternative that our temperature measurements are not sufficiently representative of ocean temperature (it should not be overlooked that each and every year we collect temperature measurements from different locations so that we are never comparing exactly the same data set), or that our temperature measurements lack the accuracy and precision that we claim they possess,

Presently, due to our lack of knowledge and understanding, any assessment of climate sensitivity is hocus and nothing more than a guestimate. Any genuine scientist would call it out for what it is.

May 17, 2013 at 9:53 AM | Unregistered Commenterrichard verney

Well done, Bish. You did sound like the voice of reason (much like Lindzen does) which must annoy the hell out of the warmologists.

May 17, 2013 at 9:55 AM | Registered Commenterjamesp

Harrabin said on Twitter another programme will deal with the actual question, what to do about climate change.

May 17, 2013 at 9:57 AM | Registered Commenteromnologos

Further to: May 17, 2013 at 9:52 AM | Latimer Alder
////////////////////////////////

Latimer Alder raises a good point, but it goes back to the basic physics that I briefly touched on in my post of 09:31hrs.

If the so called basic physics of CO2 GHE is from now on to heat the oceansm, then any heating will be damped by the sheer volume and heat capacity of the ocean. IF it will heat the ocean at depth and remain there for a lebgthy period, then there is no CAGW. IF it will heat the ocean at depth but will later reemerge slowly from the depths of the ocean, then there is no CAGW.

However, there may of course be a switch in the process back to heating the atmosphere or the oceans giving up the accumulated energy and in which case CAGW could theoretically come back on the menu.

But all of this is conjecture, until we understand the so called basic physics and the reasons behind why CO2 can in one time period heat the atmosphere (but not the deper ocean) and then in another time period cannot heat the atmosphere but instead heat the deeper ocean.

Until the warmist expalin the basic physics behind this switch and how the deeper ocean is being heated and that heat is getting there without detection in the top 100 or 200 metres, the assertion that the missing heat from the CO2 GHE is now in (or going in) the oceans should be taken with a pinch of salt.

May 17, 2013 at 10:03 AM | Unregistered Commenterrichard verney

I did not think it was very even handed or good. The first clip from Bish was just a repeat of the cue to the piece and the other clip Harrabin arranged for Houghton and Hoskins to knock down. Harrabin let us know what he thinks and perpetuated the myth by letting Houghton and Hoskins talk about increase in weather extremes without challenging them. Then Harrabin goes on about the 'strange' UK weather saying that all this weather weirdness was coming along at the same time. Someone ought to give Harrabin a crash course in weather and statistics.

Also harrabin falsely sets up the argument that it was 'sceptics' vs the scientific community about the standstill for years. No it wasn't as the thorough GWPF report on the standstill showed the scientific community were talking about the standstill all the time and it was the media, especially Harrabin, who were ignoring it and painting it as a sceptic vs science position.

And, no disrespect to the Bish who did brilliantly, why did Harrabin not interview the GWPF who produced that brilliant report on the standstill?

Someone should have pointed out that the standstill in global temperatures INCLUDES the upper oceans as well, and that its not a question of explaining 'a decade or so' but 17 years!

May 17, 2013 at 10:09 AM | Unregistered Commenterexop

I have just listened to Hansen on the Today program. His first answer is wrong. He says the temp in the past decade has gone up 0.1 deg. According to his own data the rise is ZERO - statistically insignificant. Indeed, looking at the GWPF report I see Hansen has said that the 5-year running temperature average is DOWN.

So, if the temp rise is 0.1 deg how does Hansen explain that NOAA data (essentially the same data) shows a 0.1 deg FALL in the past decade.

http://www.thegwpf.org/2013-global-temperature-change/

Hansen is either out of touch of being deliberately misleading.

May 17, 2013 at 10:24 AM | Unregistered CommenterPBinn

The indication from the piece on the radio was that the heat has gone into the top two and a half metres of the ocean, mid and deep ocean not mentioned although those following will see the pea rolling in that direction.
If Harrabin is doing a follow up piece then you would expect, in the need for the BBC to fulfil it's charter for balanced reporting, that Andrew will get another call to add to the comments. (note to self... must practise holding breath)

May 17, 2013 at 10:25 AM | Unregistered CommenterLord Beaverbrook

From the Biased BBC site:

http://biasedbbc.org/blog/2013/05/17/mainstream-scientists-say-er-um-oh-i-dont-know-what-they-say/

May 17, 2013 at 10:39 AM | Unregistered CommenterOld Goat

Note once again that "weather is not climate", except when alarmists pray it in aid - heat-waves and "weird" weather.

Mr Harrabin - why do you allow alarmists their deus ex machine of "extreme weather" when this was debunked a couple of years ago by the IPCC itself through its SREX report? Or had you forgotten that? Extreme weather/weird weather is nothing more than a holding position until the much- and long-awaited resumption of warming that alarmists are praying for.

Why not ask the likes of Houghton and Hoskins (Harrabin, Houghton and Hoskins, very alliterative!) some HARD questions instead of just giving them a platform? Where is you basic journalistic curiosity? Or is a lack of curiosity front and centre in a BBC Person Specification (seems to be quite a lot of it about in that outfit)?

May 17, 2013 at 10:40 AM | Unregistered CommenterAngusPangus

No real evidence to support CAGW. The BBC as usual, simply ignores this.

The clinging to a pretend small amount of recent warming shows how desparate they are. Oceans and extreme weather, neither of which has hard evidence to support, is the main theme now. I seem to recall from the audio something about the effect of the changing ocean chemistry and this not being discussed by skeptics????? That isn't true!

May 17, 2013 at 10:40 AM | Unregistered CommenterConfusedPhoton

His Grace's contribution aside, it came across as a preemptive PR strike that AR5 will be as big and bad as ever.

May 17, 2013 at 10:43 AM | Unregistered Commenternot banned yet

Harrabin was shouted at by Al Gore in October 2007. He has still not understood what is happening. Oh well.

May 17, 2013 at 10:44 AM | Registered Commenteromnologos

The heat will always be hiding somewhere that it cannot be detected or measured. That is a feature, not a bug, of climate "science".

May 17, 2013 at 10:51 AM | Unregistered Commenterrxc

Has anybody yet blamed the missing heat on Dark Energy? Seems like the safest place where to hide anything that need not been seen...

May 17, 2013 at 11:07 AM | Registered Commenteromnologos

I have high hopes that this mysterious heat that is lurking in the depths of the ocean will stay there ready to emerge in about a century or so to save us all (or should I say them all; I doubt I'll be around!) from the next ice age.
I have no reason to believe this but since reason doesn't seem to be a pre-requisite where climate is concerned I shall stick with this theory!

May 17, 2013 at 11:20 AM | Registered CommenterMike Jackson

I'm puzzled.

Don't discussions of 'climate sensitivity' automatically rule out the oft-repeated notion (well, Monckton and Corbyn have both stated this) that temperature changes drive CO2 levels rather than vice versa?

They can't both drive one another, or the Alarmist notion of runaways and tipping points would seem to come into play.

How does one square this circle?

May 17, 2013 at 11:29 AM | Unregistered CommenterRick Bradford

Mike Jackson

Good point.

Perhaps all this heat being banked for future generations is not 'sub prime', I see a valuable opportunity to enhance the prosperity of the great-great grandkids. Just off to run the hot water tap down the drain for an hour, wonder if we could get tax relief for inheritance investment?

May 17, 2013 at 11:34 AM | Unregistered CommenterLord Beaverbrook

Mike,

no need to worry about ice ages any more me old mucker. See my post on the Hansen thread - Jim "Cap'n Thermo" Hansen believes he has the power to easily prevent any more ice ages.

And I'm not even joking.

May 17, 2013 at 11:46 AM | Unregistered CommenterAngusPangus

@ omnologos 2013 at 11:07 AM

For god's sake, don't give them any more ideas.

May 17, 2013 at 12:07 PM | Unregistered CommenterLevelGaze

> Has anybody yet blamed the missing heat on Dark Energy?

Or the Heat Pixies?

:-)

May 17, 2013 at 12:27 PM | Unregistered CommenterNial

"They can't both drive one another, or the Alarmist notion of runaways and tipping points would seem to come into play. How does one square this circle?"

They both drive one another - it's what they call a feedback.

The solubility of CO2 in seawater depends on temperature. Massive amounts are released into the atmosphere near the equator and almost equally massive amounts are absorbed back into the oceans near the poles. A change in temperature affects the amounts released, but the magnitude of the effect is small - about 10% of the rise in CO2 can be explained by the observed rise in temperature.

It doesn't cause a runaway because the feedback factor, while positive, is less than 1. Suppose we add one unit of CO2 and the temperature goes up, which releases an additional 0.09 units of CO2 which pushes the temperature up by 0.09 times as much, which releases another 0.009 units of CO2, which pushes the temperature up another 0.009 times as much, and so on. The total of all these increments is 0.0999999.... which is another way of writing 0.1. So even after going round the loop infinitely many times, adding positive increments every time, we will still only get a finite 10% increase.
(I fudged the numbers slightly to keep it simple.)

If the feedback factor is F (~0.09 in the example above) then the mathematicians say the end result of adding up all the infinitely many but ever-shrinking contributions will be 1/(1-F). If F is negative, it shrinks the answer. If F is zero it doesn't change it. If F is positive but less than 1, it magnifies it but doesn't run away. Only if F is 1 or more does it pose a problem.

May 17, 2013 at 12:28 PM | Unregistered CommenterNullius in Verba

There were lots of things wrong with this piece but I agree with jamesp that Andrew came across as the voice of reason. It was a considerable achievement in one sentence to trace the implications of lower sensitivity through to the rejection of expensive policies, in other words, to mention cost-benefit analysis. That this sounded so novel only underlines how shallow most BBC presentation is. But well done Harrabin for including Montford.

May 17, 2013 at 12:32 PM | Registered CommenterRichard Drake

Re: Richard Verney "As regards the oceans, it is noteworthy that the annual variations can be large. So large that the variation from one year to another cannot possibly have been caused by slight changes in the concentration of CO2 in the atmosphere."

Given the staggering difference in heat capacity between oceans and atmosphere, it surely becomes evident that ocean temperature changes largely influence the atmosphere and the reverse effect must be trivial?

May 17, 2013 at 12:35 PM | Registered Commenterthinkingscientist

I've just listened carefully to Harrabin's piece and I don't think it was balanced at all. Apart from the relatively short but very good comments from AM, the rest consisted of dire warnings about temperature rise, extreme weather and our grandchildren frying.

Harrabin has perfected the art of biased presenting where he explicitly mentions a few sceptical viewpoints then goes on to leave the listener in no doubt that warming is real and we ignore it at our peril.

It was more of the same old unsubstantiated alarmism and the fact that it hasn't warmed for at least 17 years seems to have got lost in the rhetoric.

May 17, 2013 at 12:38 PM | Unregistered CommenterSchrodinger's Cat

The BBC, certainly in Richard Black's time, took a big steer on climate change from RealClimate.

For an insight into the mind-set of a RealClimateer, have a look back to the Climatology's Nutcracker thread:

http://bishophill.squarespace.com/blog/2013/5/14/climatologys-nutcracker.html

where Jim Bouldin has put in a late appearance to stick up for his buddy Gavin (one for all and all for one, the SurrealClimateers!).

From the comfort of Californian academia, Mr Bouldin has declaimed that expensive energy hurting the poor is just "crocodile tears" which he doesn't believe "for a second". Hmm, I think if you asked a few poor and not so poor people in the UK, they might just disagree.

Perhaps Mr Harrabin can do a piece sometime on the impact of expensive energy prices on the poor? Or maybe his ivory tower is just as tall as Jim Bouldin's and he, too, thinks that it's just a made-up load of old rubbish?

May 17, 2013 at 12:43 PM | Unregistered CommenterAngusPangus

@Nullius in Verba

Thank you for taking the time to write that clear explanation.

May 17, 2013 at 12:50 PM | Unregistered CommenterRick Bradford

Early on (about a minute or so in), Houghton states that there remains a long-term trend of about 0.1 K/decade. [With which I agree, by the way.] The interviewer suggests that it was previously claimed to be 0.2 K/decade. Houghton responds, "We gave a range, I think, in 1990 of 0.1 to 0.3", which presumably refers to his AR1.

That didn't sound right to me, as I recalled a 0.3 K/decade projection under business-as-usual conditions for AR1. Figure 8 of the Policymakers Summary shows temperature curves labelled "low estimate", "best estimate" and "high estimate" corresponding to equilibrium climate sensitivity of 1.5, 2.5 and 4.5 K/doubling respectively. The 21st century slopes of the curves are 0.2, 0.3 and 0.5 K/decade resp. [Values are approximate, from the figure.]

The only temperature projection curves with a trend anywhere near 0.1 K/decade are those corresponding to various mitigation scenarios. The reduction in emissions postulated for those scenarios has not come to pass. So I think that Houghton was rather glib in dismissing over-estimation of warming trends.

May 17, 2013 at 1:14 PM | Registered CommenterHaroldW

Schrodinger's Cat: If you add James Hansen to John Houghton and Brian Hoskins then I fully agree that the BBC's Today programme on sensitivity was highly imbalanced. But Andrew came across very well and ordinary people will have spotted that. That would not have happened a few years ago and it's surely because even in the Beeb people are realising that the temperature standstill and the latest findings on sensitivity, from real world data, are a problem.

Looking more widely Barack Obama's tweet in support of John Cook is an even clearer signal to me that the whole alarmist cause is motoring on empty. It's only a matter of time. Not to say it isn't going to be a bit messy getting all the toothpaste back in tube.

May 17, 2013 at 1:16 PM | Registered CommenterRichard Drake

Strange that in a piece which dealt with how the experts were slow in acknowledging that global warming has stalled, Mr Harrabin did not raise the Met Office's recent explanation for the "pause" and their associated, verifiable, prediction:

Is Global Warming All Over: 28 April 2008?

http://www.metoffice.gov.uk/news/releases/archive/2008/global-warming-speculation

In that article, the Met Office patiently explain that the apparent pause in warming is down to La Nina, you see, which has been masking the underlying warming. Also, they got it all sorted out in the models as well, because 10 year forecasts by the Met Office do capture "this levelling of global temperatures in the middle of the decade".

The Met Office go on to say:

"These same forecasts also predict we will experience continued and increased warming into the next decade, with half the years between 2009 and 2014 being warmer than the current warmest on record, 1998."

This wasn't just a puff piece of Met Office PR. It was backed by a peer reviewed piece in Science, here:

http://www.sciencemag.org/content/317/5839/796.full [requires free registration]

Well, we can see how that worked out now, can't we?

So, here we have "the Consensus" as late as 2008, denying there was any pause in the warming. They offer a firm reason for the pause - La Nina. They make a firm prediction for the future - warming will soon resume and half the years from 2009 - 2014 will be warmer than 1998.

Wrong. Wrong. Wrong. Wrong.

Here we are 5 years later. Still no warming. Still more deus ex machine explanations from "the Consensus". More epicycles. More reassurances that it will still warm as expected (or even if it doesn't then the weather will be, like, weird, man!).

Where is the holding to account by the BBC? Why are two establishment scientists given a platform by the BBC to say that, whatever an unqualified blogger says, climate change is still going to be terrible? Surely the BBC's role here is hold the feet of the establishment to the fire on this? They've made predictions time and again that were wrong and wronger. Does anybody even remember that, only 5 years ago, Met Office scientists said that warming was just being masked by La Nina and it would soon restart? Does it not even matter that this was completely wrong? Does it not matter that our catastrophic energy policy is based on this failed "science"? Does it not matter that, as a result, we're deliberately screwing everyone with expensive energy and hobbling our economy at a time when we can least afford it?

What the hell is the BBC doing, not just letting the establishment get away with this, but actively supporting them in this charade? THAT'S NOT WHAT THE BBC IS SUPPOSED TO BE FOR.

May 17, 2013 at 1:17 PM | Unregistered CommenterAngusPangus

The BBC must be moving some of its pension fund out of renewables.

May 17, 2013 at 2:15 PM | Unregistered CommenterSteve Jones

AngusPangus,

Bravo! Well said, that man.

May 17, 2013 at 3:00 PM | Unregistered CommenterJames Evans

Seconded.

May 17, 2013 at 3:16 PM | Registered CommenterRichard Drake

Speaking personally, the BBC have to be congratulated on what I think was a noble effort at fairness in what is undoubtedly a difficult subject to cover in a fair and impartial way given the relative imbalance of resources of the two sides. However, we still have the problem that even if the BBC are showing a desire to be fair now, the past coverage has not been impartial with the result that occasional viewers/listeners will continue to be influenced in their views by past broadcasts from the BBC for some time.

There are some issues I don't think it covered well. E.g. the question of whether we act now or wait to act later. I would like to see updates on the many suggested effects such as the 50-60m sea level rise. But perhaps most important is attitude because if the BBC continue as they have, then impartiality will follow. And to be fair, what we have seen it is no mean feat given the size and complexity of dealing with this in an organisation like the BBC.

One way I think the BBC could improve its coverage is to introduce the concept of "natural climate variation" because this is a very important difference between the two sides. Although I will say that however well informed, this is my own opinion.

For the sceptic, many of whom are engineers who are used to this concept, "natural variation" is a simple way to say "there is an awful lot we do not understand that could cause the climate to vary". So, e.g. when we see a similar trend from 1910 to 1940 as from 1970 to 2000 if the former is "natural variation", then it is quite possible to explain all the latter as "natural variation", although obviously we would expect about a third to be due to the rise in CO2.

So, by saying there is a lot we do not know about why the climate varied in the past, leads us to be conservative in our predicted estimates for the future because if we do not fully understand the past, we cannot fully understand the future. But even if we do not fully understand some aspects of the climate, we do know that we expect a similar scale natural changes seen in the past to have a similar scale of effect on the climate in the future.

So if CO2 directly caused about 0.2 (from memory) of change, there is up to 0.6C of variation that is unexplained. So based on the size of these unknowns (up to 0.6C/century in the 20th century) we can expect a similar scale of change for similarly unknown reasons in the future, both up and down. As such, depending on the level of feedbacks, perhaps the majority of climate change will not be captured by the climate models.

In contrast the scientific community approaches the issue based on the view that all the nuances of climate can be encapsulated in one model and that models should not leave anything out. In other words it is assumed that everything can be known and so the models should fit all the data. But this is not possible without large feedback effects and so they are forced to include large feedback effects which implicitly forces them to believe they must exist. So, using their approach and discounted the possibility that there is climate change which is not captured by their models leads them to scale up of the CO2 effect by these hypothetical feedback mechanisms in order to make the models fit the observed temperature change from 1970-2000. The result is to artificially increase the projected trend leading to the overestimation of the effect of CO2 we have seen.

So the treatment of "natural variation" is quite critical to understanding how the two sides derive very different understandings of the climate.

May 17, 2013 at 4:10 PM | Unregistered CommenterMike Haseler

Mike.

Noble effort. Difficult subject to cover.

This is Roger Harrabin's job. We should expect more than a 'noble effort.' He's supposed to be a professional and spend all his time on this stuff with a handsome salary and all the resources he needs. He can go anywhere in the world, speak to anyone, but what he gave us was a 'noble effort!'

May 17, 2013 at 4:19 PM | Unregistered CommenterPbinn

Harrabin's scientific analysis of AGW, and other environmental issues, is conducted with the depth and rigour to be expected of a graduate in English. Are other areas in BBC news covered by journalists totally unqualified in the subject?

May 17, 2013 at 4:21 PM | Unregistered CommenterSteve Jones

You came across very well Andrew, and it is exciting to hear a (mildly) skeptical tone on the BBC! I wonder if they recorded more from you, and edited it later - I know you could have said a lot more.

Did you get any interesting discussions with Roger Harrabin?

May 17, 2013 at 5:10 PM | Unregistered CommenterDavid Bailey

@ AngusPangus 1:17

Thanks for your link to the Met Office's prediction of 29 April 2008.

However, their page was Updated 18 April 2011, I wonder what was changed after 3 years???

May 17, 2013 at 5:16 PM | Unregistered CommenterJoe Public

Pbinn, to be fair to Roger Harrabin he is a reporter and his job is to report news that is given to him - with due diligence and fairness. It isn't normally the job of a reporter like Roger to do climate research or generate the kind of material that most organisations give to the news media and is the mainstay of our news.

OK, a few of us have been making a sterling effort (and we can all name the blogs as well as this one), but as chairman of the Scottish Climate and Energy Forum I tried to generate that media-ready material and it simply was not possible within the resources I had available. We were competing with institutes with millions of pounds of budget, dozens of staff, the full authority of prestigious names ... and what did we have except plucky determination? So, even when we tried to generate material I understand why the BBC found it difficult to use.

However, there are other issues which are similarly problematic. Of the top of my head, natural childbirth could be seen as "professional doctor" versus amateur. So getting this balance right is not unique to this area and is something that should have been done better.

May 17, 2013 at 5:26 PM | Registered CommenterMikeHaseler

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