Has BBC Reached the Global Warming Tipping Point?

[Andre]

I missed it, but this is already from October, some time before climate gate.

What happened to global warming?

This headline may come as a bit of a surprise, so too might that fact that the warmest year recorded globally was not in 2008 or 2007, but in 1998.

But it is true. For the last 11 years we have not observed any increase in global temperatures.

And our climate models did not forecast it, even though man-made carbon dioxide, the gas thought to be responsible for warming our planet, has continued to rise...

I get infraction points whenever I say that, regardless in what form.

and the conclusion:

...One thing is for sure. It seems the debate about what is causing global warming is far from over. Indeed some would say it is hotting up.

Well you can read this kind of things anywhere, but as far as I know, it's the first time that the BBC left the 'partyline'. Tipping point?

 

[Ivan Seeking]

...In fact, the centre says they are just two of the whole host of known factors that influence global temperatures - all of which are accounted for by its models.

In addition, say Met Office scientists, temperatures have never increased in a straight line, and there will always be periods of slower warming, or even temporary cooling.

What is crucial, they say, is the long-term trend in global temperatures. And that, according to the Met office data, is clearly up...

But the groupthink skeptics and conspiracy theorists will go on. Of course the press loves headlines.

 

[mheslep]

Tipping point?

I'd say its a CYA point on their part. If we see another five years of flat or declining temperatures they'd be seen as ridiculously partisan looking back.

 

[Sorry!]

But the groupthink skeptics and conspiracy theorists will go on. Of course the press loves headlines.

I was just about to post that little tidbit but you beat me too it. We really need to stop tossing these 'groupthink' insults around. It seems kind of childish and doesn't address any problems it just pushes them to the side.

We have to recognize that groupthink can only be understood clearly AFTER the fact when all facts are known. We can't sit here saying 'blah blah is groupthinking' when we can't see the entire situation from an outside perspective yet. (I do not think we will be able to make a comment on 'groupthink' for many years from now.)

 

[sylas]

Well you can read this kind of things anywhere, but as far as I know, it's the first time that the BBC left the 'partyline'. Tipping point?

It certainly is well below the usual standard for the BBC; but not so surprising when you see who wrote it. Paul Hudson is not representative of the usually higher standards of BBC science reporting. It's not a "tipping" point, but an outlier point; a significant drop in standards.

I'm not kidding, by the way. The standard of this article is appalling; more like what you'd expect in the something like the Telegraph. Follow the regular BBC reporting and you can see no sign of a "tipping point". There are a couple of other oddities in this very strange article.

Cheers -- sylas

 

[lisab]

I was just about to post that little tidbit but you beat me too it. We really need to stop tossing these 'groupthink' insults around. It seems kind of childish and doesn't address any problems it just pushes them to the side.

We have to recognize that groupthink can only be understood clearly AFTER the fact when all facts are known. We can't sit here saying 'blah blah is groupthinking' when we can't see the entire situation from an outside perspective yet. (I do not think we will be able to make a comment on 'groupthink' for many years from now.)

I disagree. Look at some of the characteristics of groupthink:

1. Incomplete survey of alternatives
2. Incomplete survey of objectives
3. Failure to examine risks of preferred choice
4. Failure to reappraise initially rejected alternatives
5. Poor information search
6. Selective bias in processing information at hand
7. Failure to work out contingency plans (Janis, 1982)

(http://www.anthonyhempell.com/papers/groupthink/" )

If a group is aware of the phenomenon and is actively trying to avoid it, there are definite methods to do so.

 

[Sorry!]

I disagree. Look at some of the characteristics of groupthink:

1. Incomplete survey of alternatives
2. Incomplete survey of objectives
3. Failure to examine risks of preferred choice
4. Failure to reappraise initially rejected alternatives
5. Poor information search
6. Selective bias in processing information at hand
7. Failure to work out contingency plans (Janis, 1982)

(http://www.anthonyhempell.com/papers/groupthink/" )

If a group is aware of the phenomenon and is actively trying to avoid it, there are definite methods to do so.

Ok, I meant to say the term being used towards 'new sciences' such as climate science. The research is still being done and models are still being run. Constantly it's in flux, on BOTH sides. So to just accuse one side of 'groupthink' even though they are just doing their job and what they believe in is wrong. It can just as easily be applied to the opposing side, why? because this is a new science.

I don't exactly think I'm making sense right here and I'm trying to think of a better way to explain myself but it's hard. lol

 

[Andre]

This thread went astray quickly despite Sylas' attempt to keep it on track, however since "We really need to stop tossing these 'groupthink' insults around", maybe some remarks about it.

I don't think it's that easy. Groupthink is not about being right or wrong, it's just an element of social behavior, characterized by doing anything to enhance the bonds between members, and one of those is creating stereotypes, because the enemy of my enemy is my friend and I like to have friends, so we must make enemies, be it 'global warming' as a phenomenon or greedy 'deniers' who are obviously bribed by the oil companies. So if you find yourself doing that, you may wonder why. Also notice that Janis talks about victims of groupthink, not villains of groupthink. It is just so human.

Anyway, to judge if there is groupthink going around in the climate business, perhaps google foi2009.zip (the CRU 'hack' - or maybe the CRU wistle blow) and you will find a plethora of places where you can download this file. Then go to the email folder and open the file 0880476729.txt and read it carefully. I don't think that this has got the attention already in the blogosphere but I think it's one of the most important relevations, not in the last place for the staff here.

I'll quote two parts from this classic (1997) of Tom Wigley in response to a group of scientists, whom appealed for urgent action immediately:

To someone like me, who knows the science, it is apparent that you are presenting a personal view, not an informed, balanced scientific assessment. What is unfortunate is that this will not be apparent to the vast majority of scientists you have contacted. In issues like this, scientists have an added responsibility to keep their personal views separate from the science, and to make it clear to others when they diverge from the objectivity they (hopefully) adhere to in their scientific research. I think you have failed to do this...

... I fear that some will endorse your letter, in the mistaken belief that you are making a balanced and knowledgeable assessment of the science -- when, in fact, you are presenting a flawed view that neither accords with IPCC nor with the bulk of the scientific and economic literature on the subject.

That's the reason for my signature.

 

[Ivan Seeking]

Anyway, to judge if there is groupthink going around in the climate business, perhaps google foi2009.zip (the CRU 'hack' - or maybe the CRU wistle blow) and you will find a plethora of places where you can download this file. Then go to the email folder and open the file 0880476729.txt and read it carefully. I don't think that this has got the attention already in the blogosphere but I think it's one of the most important relevations, not in the last place for the staff here.

There you will see dicussions of data that was carefully considered by the IPCC, including the effort to match data points with trends, which makes this whole thread just more nonsense.

In spite of the fact that you have been corrected countless times, you insist on coming back time after time with the same old nonsense.

 

[mheslep]

There you will see dicussions of data that was carefully considered by the IPCC, including the effort to match data points with trends, which makes this whole thread just more nonsense. ...

Setting the wider discussion aside for moment, that http://www.tuxwerx.com/Climategate/mail/0880476729.txt" is the Tom Wigley letter strongly condemning the actions of "The Eleven". If any action could ever be condemned for unscientific consensus building, Wigley points one out in detail here.

 

[Evo]

It certainly is well below the usual standard for the BBC; but not so surprising when you see who wrote it. Paul Hudson is not representative of the usually higher standards of BBC science reporting.

Please post the well known acknowledged reports on Hudson that back this up. Stating a personal opinion as fact is a violation of our Guidelines. You can say, "it's just my opinion" and you can say why it's your opinion, but making accusations and demeaning remarks against people, dismissing them becuase they don't support your viewpoint is not the way to discuss issues here.

It's not a "tipping" point, but an outlier point; a significant drop in standards.

I'm not kidding, by the way. The standard of this article is appalling; more like what you'd expect in the something like the Telegraph. Follow the regular BBC reporting and you can see no sign of a "tipping point". There are a couple of other oddities in this very strange article.

Cheers -- sylas

Ok, "you" don't like the article because you disagree. Perhaps his article is full of blatant errors, then point them out.

When you make a post which only points out your dislike for a person and/or their views, you drag the level of discussion down. I see you doing this periodically and I know that you are capable of better posts.

 

[Andre]

Meanwhile, about the apparent errors in the article, we have to guess, but it's probably about whether or not the warming is stagnating.

So why not let the experts explain, http://www.tuxwerx.com/Climategate/mail/1255352257.txt for instance:

The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't.

So what was that about shooting the messenger and groupthink?

 

[sylas]

Meanwhile, about the apparent errors in the article, we have to guess, but it's probably about whether or not the warming is stagnating.

Yes, that is a part of it, but only a part.

So why not let the experts explain, http://www.tuxwerx.com/Climategate/mail/1255352257.txt for instance:

So what was that about shooting the messenger and groupthink?

I shall answer Evo's question in a bit more detail; but in the meantime, you appear to have misunderstood what Kevin Trenberth was saying. There's nothing there at all to back up Hudson's misunderstandings of trends.

Trenberth is complaining about the lack of adequate instruments to measure Earth's energy balance. If you read the actual email, you can see that he is talking about this paper:

• Trenberth, K (2009) http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/EnergyDiagnostics09final2.pdf , in Current Opinion in Environmental Sustainability, 1 pp 19–27.

The paper starts out as follows (with my emphasis in bold):

The global mean temperature in 2008 was the lowest since about 2000 (Figure 1). Given that there is continual heating of the planet, referred to as radiative forcing, by accelerating increases of carbon dioxide (Figure 1) and other greenhouses due to human activities, why is the temperature not continuing to go up? The stock answer is that natural variability plays a key role [1] and there was a major La Nina event early in 2008 that led to the month of January having the lowest anomaly in global temperature since 2000. While this is true, it is an incomplete explanation. In particular, what are the physical processes? From an energy standpoint, there should be an explanation that accounts for where the radiative forcing has gone. Was it compensated for temporarily by changes in clouds or aerosols, or other changes in atmospheric circulation that allowed more radiation to escape to space? Was it because a lot of heat went into melting Arctic sea ice or parts of Greenland and Antarctica, and other glaciers? Was it because the heat was buried in the ocean and sequestered, perhaps well below the surface? Was it because the La Nina led to a change in tropical ocean currents and rearranged the configuration of ocean heat? Perhaps all of these things are going on? But surely we have an adequate system to track whether this is the case or not, do we not?

Well, it seems that the answer is no, we do not. But we should! Given that global warming is unequivocally happening[2] and there has so far been a failure to outline, let alone implement, global plans to mitigate the warming, then adapting to the climate change is an imperative.​

That is, the travesty is simply the lack of measurement of critical aspects of energy balance. Things like being able to measure energy flux into the ocean -- particularly the deep ocean. Things like measuring albedo, or longwave emission from the top of the atmosphere. Trenberth is, of course, in no doubt that the short term drop in temperature in 2008 is a local short term effect. There's no question (for Trenberth, or indeed virtually all scientists working actively in this area) that there is a continuing ongoing warming effect, all the time. The issue is having adequate resources and instruments to measure how the energy is distributed within the complex climate system.

I think you probably disagree with Trenberth's actual opinions as he would express them himself. That is, of course, your prerogative. I'm just cautioning you against confused misreadings of the emails to support the notion that global warming has somehow stopped whenever your get a short term fall in temperature. You may think this; that's up to you. But Trenberth does not.

Cheers -- sylas

 

[seycyrus]

You guys might have missed it when i posted this tidbit from slashdot a couple of days ago.

http://science.slashdot.org/story/09...as-Manipulated

Science: Russians Claim More Climate Data Was Manipulated

"On Tuesday, the Moscow-based Institute of Economic Analysis (IEA) claimed that the Hadley Center for Climate Change had probably tampered with Russian-climate data. The IEA believes that Russian meteorological-station data did not substantiate the anthropogenic global-warming theory. Analysts say Russian meteorological stations cover most of the country’s territory, and that the Hadley Center had used data submitted by only 25% of such stations in its reports. Over 40% of Russian territory was not included in global-temperature calculations for some other reasons, rather than the lack of meteorological stations and observations. The data of stations located in areas not listed in the Hadley CRU survey often does not show any substantial warming in the late 20th century and the early 21st century."

 

[Andre]

Well everybody can observe what he said to his collegues more or less in confidence off the record

... we can't account for the lack of warming at the moment ...

has two elements:
1- he acknowlegdes that there is a lack of warming
2 - we can't account for it

But sure enough (from Sylas link)

Given that global warming is unequivocally happening..

Well, for some this may have some resemblance with newspeak from 1984.

Also that quote is referencing the 4th assesment report IPCC (which is not peer reviewed - given that the authors could ignore any peer comments that they chose to).

So the statement that global warming is happenings regardless whether it warms or not, appears to remove global warming from the scientific principles, it is not falsifiable.

 

[sylas]

So the statement that global warming is happenings regardless if it warms or not appears to remove global warming from the scientific principles, it is not falsifiable.

How quickly we back off from citing Trenberth as an expert... sigh.

The science is perfectly falsifiable in the usual scientific sense of the word. It is not falsifiable in the sense of anyone who doesn't like the conclusions should be able to show that they are false.

This isn't really complicated to understand. The fact is... there are natural variations. El Nino/La Nina is an obvious one. With an El Nino year you get higher global temperatures, and with a La Nina year you get lower ones. Trenberth is basically saying it is a travesty that they don't have the instruments to track exactly where energy flows and how in these short term variations.

One of the consequences of this kind of natural variation is that you can't expect to discover trend over a short period of time. It's not that hard to determine how long it takes to falsify the trend, given the measured natural variation we see going on. It turns out to be at least 15 years (2σ confidence). (In line with some recent posts on probability calculations... the proof is trivial and left as an exercise for the reader. Actually, this might be a good thread topic sometime.) You can get a trend with regression. Estimating the confidence limits on trend is a bit tricky as there is a significant amount of autocorrelation in the time series, but that's a statistical detail that can be addressed. The upshot is, you CAN falsify warming; but not with eleven years of data. That works both ways, you can't prove warming with eleven years of data either.

Now if you look at fifteen years you see warming. That means the trend over that time is real, in the sense of being statistically significant. If you look at eleven years you actually see warming as well -- despite with some folks seem to think -- but this is not statistically significant. It means that the underlying trend might have stopped or might have accelerated; but that the trend is obscured by short term variation. Eleven years is not enough to show a warming trend, or to show that warming has stopped, or even slowed down as it turns out!

But note that warming is not simply based on correlations and statistics! The physics of the increasing forcing is well established. As well as surface measurements, there are measurements of the heat flowing into the ocean... that too, is global warming; in fact it is a better guide than surface temperatures except only that we can't measure it as well. If we measure a statistically significant cooling trend, that would falsify the global warming hypothesis. There's nothing in principle preventing us from doing that... except the awkward detail that there IS NO cooling trend. Only short term up and down variations, pretty much as there have been all along the strong warming trend of the last 40 years.

Trying to read Trenberth as contradicting himself is just not paying enough attention to a legitimate expert or learning about the systems he describes. It is particularly naive to take stolen emails which were written for an audience of other experts who don't need this kind of trivial detailed hammered home at every point, as if they are disagreeing with what Trenberth says plainly in his published work. His email is arguing forcefully for the same thing as his paper.

Cheers -- sylas

 

[Andre]

I don't know, science is about analysis of observations and making predictions, regardless of how sound the hypothesis might seem.

So there was http://dir.salon.com/books/int/2001/10/23/weather/index.html

While doing research 12 or 13 years ago (note this is written 2001), I met Jim Hansen, the scientist who in 1988 predicted the greenhouse effect before Congress. I went over to the window with him and looked out on Broadway in New York City and said, "If what you're saying about the greenhouse effect is true, is anything going to look different down there in 20 years?" He looked for a while and was quiet and didn't say anything for a couple seconds. Then he said, "Well, there will be more traffic." I, of course, didn't think he heard the question right. Then he explained, "The West Side Highway [which runs along the Hudson River] will be under water. And there will be tape across the windows across the street because of high winds. And the same birds won't be there. The trees in the median strip will change." Then he said, "There will be more police cars." Why? "Well, you know what happens to crime when the heat goes up."...

...When did he say this will happen?

Within 20 or 30 years. And remember we had this conversation in 1988 or 1989.
...

Well at least he was right about the traffic.

 

[mheslep]

I've seen this take on Trenberth's email before, and don't want to let it pass again, so I'm jumping in here -

in the meantime, you appear to have misunderstood what Kevin Trenberth was saying. [...]

Trenberth is complaining about the lack of adequate instruments to measure Earth's energy balance. If you read the actual email, you can see that he is talking about this paper:The paper starts out as follows (with my emphasis in bold):
[Trenberth excerpt]

This is not my reading of Trenbert's email or paper. Your use of the terms 'instrument' and 'measure' implying the problem is a lack of a mechanical adroitness. No doubt Trenberth would like better instrumentation, as does every physical scientist, but he is allowing for a more a fundamental problem. The query "do we have an adequate system?" in the paper is not just a call for better sea gauges. It also allows there may be some gap in the understanding of the climate system. Some part of it may be unknown or misunderstood.

That is, the travesty is simply the lack of measurement of critical aspects of energy balance. Things like being able to measure energy flux into the ocean -- particularly the deep ocean. Things like measuring albedo, or longwave emission from the top of the atmosphere.

Simply? A failure to get the energy balance right is crucial to the predictions. A trillion words must have been set down in discussions of the global energy balance. There's nothing to be sanguine about here, just the opposite.

Trenberth is, of course, in no doubt that the short term drop in temperature in 2008 is a local short term effect.

This contradicts statements in the paper. Yes if heat was somehow absorbed an ocean sink or melting ice, examples he gives, then the recent lack of temperature rise would be temporary. However he also allows:

(Trenberth 2009)

Was it compensated for temporarily by changes in clouds or aerosols, or other changes in atmospheric circulation that allowed more radiation to escape to space?​

[highlights mine]

If the (excess) heat can escape to space now via some misunderstood mechanism it may (or may not) continue to do so.

[...] I'm just cautioning you against confused misreadings of the emails to support the notion that global warming has somehow stopped whenever your get a short term fall in temperature. You may think this; that's up to you. But Trenberth does not.

I've missed it if anyone in this thread attempted to say global warming stopped over the long term. The OP BBC piece phrase was "For the last 11 years we have not observed any increase", Andre used the term "stagnate", and Trenberth leaves it as an open question:
(Trenberth 2009) last paragraph:

A climate information system that firstly determines what
is taking place and then establishes why is better able to
provide a sound basis for predictions and which can
answer important questions such as ‘Has global warming
really slowed or not?’​

[highlights mine]

 

[Redbelly98]

The premise of the BBC article is faulted. 1998 was an outlier year, not representative of the late 1990's. To make claims about trends using a single outlier data point as the initial conditions is just bad science.

(From http://www.newscientist.com/article...er-1940-shows-co2-does-not-cause-warming.html )

 

[Evo]

Your graph does show 1998 as the hottest, which is what he claims. One abnormally hot year means nothing. We have only had a steady unbroken decrease in global temperatures since 2005, still not long enough to make any claims of a permanent reversal, but he doesn't claim that either. He only claims that we have not had a hotter year since 1998, which is correct, as your graph shows.

Do you find an actual error in anything he said?

 

[Redbelly98]

Do you find an actual error in anything he said?

Yes, the 3rd sentence in the article:

For the last 11 years we have not observed any increase in global temperatures.

This takes the abnormal year of 1998 as a valid starting point for the time period.

EDIT: just to clarify, the error here is in using an outlier data point to support what is being claimed, that we have not observed a global temperature increase in the last 11 years.

 

[sylas]

... One abnormally hot year means nothing. ...

Exactly. Which is why when an article starts out from an abnormally hot year you begin to suspect poor quality science writing. We can go further. Eleven years of data means local variation; and says almost nothing about whether warming has stopped, slowed, accelerated, stagnated, or anything else. We can quantify that mathematically.

To even start out by looking at eleven years and wonder what it says about warming is dubious. It will be still be dubious when temperatures pick up again (as they will, bet on it) and someone uses eleven years to say warming is accelerating.

In this instance, the choice of that curious number eleven is precisely targeted to start at an outlier point, which is at best foolish. It is feeding into the statistical confusions of people use poor quality pseudoscientific arguments to dismiss conventional science on the subject. This is a common confusion, and to foster it this way is not up to normal BBC standards.

The trend itself is generally given with linear regression. In fact 1998 was not the hottest year. It shows up as the hottest year in the HadCRUT3 dataset (plotted above) but that dataset omits regions with poor geographical coverage of weather stations... a reasonable approximation, but one that biases the trend downwards a little. Other datasets which include data from the rapidly warming Arctic indicate that 2005 is the hottest year; though in all datasets the difference is very small.

Paul must therefore be using HadCRUT3, which is fair enough for a BBC writer, as this is from the UK met office. The linear trend for the last eleven years does show a small increase -- even if you start in 1998! The regression gives 0.032 C/decade.

Of course, this rate of warming is below statistical significance... but it would STILL be below statistical significance even if the measured trend was greater than the long term mean! The fundamental problem is that eleven years is not enough for a statistically significant trend. The 95% confidence limits on trend, over that scale, is about 0.2 C/decade... which is greater than the strong warming trend seen over the last 30 years, of about 0.15 to 0.16. (This confidence estimate considers the autocorrelation of the time series; details might make a good post sometime. White noise based confidence limits will over estimate the confidence a bit.)

If you do the estimate with the GISS dataset, then you get a warming trend over 1998 through 2008 of 0.115 C/decade. This is warming, but it is still not statistically significant warming. The time period is just too short. You need at least 15 years to get reasonable significance to a warming trend. This also prevents skeptics from cherry picking their start point to get deliberately biased results, and it also shows up the warming unambiguously. 0.21 for GISS and 0.14 for HadCRUT3, with 95% confidence limits about 0.13. That's enough to show that the warming is real, but still not enough to say whether the rate is speeding up or slowing down. For that you need even longer time periods.

This is not a minor criticism. The headline of Paul's article is "What happened to global warming?"; suggesting that something has happened to global warming. There is, however, no good indication of any such thing. As far as we can tell from empirical measurements, global warming is continuing on as it has always done, with short terms variations as there have always been. It's possible, in principle, that warming may have stagnated; but there's no good statistical basis for this conclusion in the data. Statistically, it is still well within the confidence limits that warming has even accelerated, and is merely masked by the short term variations that Paul so badly misunderstands. This is not simply a matter of being an error or not. It is a case of poor quality and misleading science writing.

The normal standard for climate reporting in the BBC is better than this, and is usually provided by individuals like their Environment Analyst, Roger Harrabin, or regular reporters like Richard Black and others.

Cheers -- sylas

Since guidelines were mentioned, I'll just say for the public record. In good faith I do not believe I am violating the guidelines. I will, however, take that up with the mentors. I am always happy to answer questions about views I express in these posts. I will continue to aim to give friendly, substantive and robust engagement to the topics under discussion. I will continue to express my own views on the relevant merits of different sources. My evaluations are not merely based on prejudice or whether they happen to align with my views. I have never claimed to be infallible, or that my opinions must be taken as truth; they are, however, as true as I can honestly make them. That's why they are my opinions. I can explain my views if requested, but I do not think it is demeaning or unreasonable to note that Paul's article is well below the usual BBC standard. I don't mind if people disagree and I welcome friendly engagement with people who have different perspectives. I aim to be robust and challenging, but fair and friendly in the face of contrasting views. I usually have no problem remaining on good terms with people who disagree with me as long as they don't take offense themselves. But I don't consider myself a push over.​

 

[DrClapeyron]

What have tipping points accomplished other than pictures of icebergs and stranded animals as seen on nationaly syndicated magazines?

http://images.google.com/url?source=imgres&ct=tbn&q=http://www.treehugger.com/time-mag-gw-cover-001.jpg&usg=AFQjCNGwymG2joNeOTWfiwjOme6SwUtrrQ

Are things like this supposed to be inspirational or demoralizing?

 

[Andre]

The demoralizing part will come in another decade perhaps when it becomes ovbious to everybody that climate cannot be tamed by being good.

 

[Andre]

The premise of the BBC article is faulted. 1998 was an outlier year, not representative of the late 1990's. To make claims about trends using a single outlier data point as the initial conditions is just bad science.

So if we now think that El Nino is important for climate, why blame el nino for a single year? and why not talk about the La Nina's after 1998 that would affect the trends just as well. Right now we have a http://www.wmo.int/pages/prog/wcp/wcasp/enso_update_latest.html, does that change trends?

And can the current ENSO (El Nino Southerly Oscillation) activity be responsible for some of the recent warming? like http://www.agu.org/pubs/crossref/2009/2008JD011637.shtml

 

[sylas]

So if we now think that El Nino is important for climate, why blame el nino for a single year? and why not talk about the La Nina's after 1998 that would affect the trends just as well. Right now we have a http://www.wmo.int/pages/prog/wcp/wcasp/enso_update_latest.html, does that change trends?

Because El Nino and La Nina IS a short term factor. In the same way as the volcanic eruption of Pinatubo was responsible for the short term cooling spike seen in 1992/1993.

There's nothing new about this being seen as important for climate; it has consistently been a feature of the IPCC reports.

We do indeed have an El Nino forming at present; and if that continues -- and if we don't get a big eruption -- then there is a strong probability that 2010 will set a new record for the hottest measured global anomaly. It doesn't even need to be as strong as the 1998 El Nino event, given the boost from the long term trend.

The evidence at this point is that these events don't affect trends themselves; they are rather short term changes in the climate mode, not a cummulative effect that could give a trend. They are a significant source of short term variation.

And can the http://www.agu.org/pubs/crossref/2009/2008JD011637.shtml be responsible for some of the recent warming?

Some of the recent rise in temperature since 2008? Of course. But longer term warming? No. The short term changes in temperature are much stronger than the long term trend, and so it is entirely proper to recognize the role of such things for making one year warmer than another.

Cheers -- sylas

 

[Redbelly98]

So if we now think that El Nino is important for climate, why blame el nino for a single year? and why not talk about the La Nina's after 1998 that would affect the trends just as well. Right now we have a http://www.wmo.int/pages/prog/wcp/wcasp/enso_update_latest.html, does that change trends?

And can the current ENSO (El Nino Southerly Oscillation) activity be responsible for some of the recent warming? like http://www.agu.org/pubs/crossref/2009/2008JD011637.shtml

Andre, I was not blaming El Nino. I was objectively looking at a graph of the data. The 1998 data point is clearly no basis for making claims about trends.

My opinion:
This should be obvious to anybody who

1. has some minimal scientific training.​

AND

2. takes a look at the annual temperature graph.​

 

[Redbelly98]

The demoralizing part will come in another decade perhaps when it becomes ovbious to everybody that climate cannot be tamed by being good.

That is a pretty strong claim. Can you back it up please? If temperatures continue upward, one could always argue that we didn't do enough, or that it takes more than 10 years for our efforts to have an effect. To say that our efforts can do no good sounds, well, rather speculative.

 

[sylas]

I've seen this take on Trenberth's email before, and don't want to let it pass again, so I'm jumping in here -

This is not my reading of Trenbert's email or paper. Your use of the terms 'instrument' and 'measure' implying the problem is a lack of a mechanical adroitness. No doubt Trenberth would like better instrumentation, as does every physical scientist, but he is allowing for a more a fundamental problem. The query "do we have an adequate system?" in the paper is not just a call for better sea gauges. It also allows there may be some gap in the understanding of the climate system. Some part of it may be unknown or misunderstood.

It's not "mechanical adroitness"; just a lack of an adequate system for tracking energy flows.

If you are going to read the emails, don't just stop at the one email only. There's a lot of selection going on in the press and blogs right now which is actively contributing to distortions of what the scientists were actually saying; and singling out this one email is a case in point. In fact this email is part of a longish exchange of emails in a quite heated discussion, where Trenberth is challenged to explain himself, and where he does just that.

Better than the emails is the paper, where it is all spelled out in much more detail and in a form that is intended for wider readers, without making assumptions about colleagues Trenberth knows well.

The paper is explicitly a call for better tracking systems; not a set of questions about theory. He points out gaps in knowledge, of course; but they are not new gaps. They are questions of detail that have never been known, and which require adequate data on energy flows before answers can be given. The travesty is the lack of adequate systems to obtain that data -- especially given its evident importance. There are always questions, of course. The questions Trenberth wants to address are the questions of detail in energy flow, and the great imperative to address those questions is adequate data. Without that, they can't get the detail of short term and regional change.

It's worth bearing in mind that if you are at all a skeptic about anthropogenic global warming, then you will be reading opinions you do not share. Trenberth is no doubt whatsoever about warming. In his own words from his paper: "global warming is unequivocally happening".

Look at the title of his paper. It is "An imperative for climate change planning: tracking Earth’s global energy". That is, in order to plan for climate change, it is imperative to track Earth's global energy. He really is focusing on the importance of measurements, and obtaining data.

Look at the abstract. (My bolding.)

Planned adaptation to climate change requires information about what is happening and why. While a long-term trend is for global warming, short-term periods of cooling can occur and have physical causes associated with natural variability. However, such natural variability means that energy is rearranged or changed within the climate system, and should be traceable. An assessment is given of our ability to track changes in reservoirs and flows of energy within the climate system. Arguments are given that developing the ability to do this is important, as it affects interpretations of global and especially regional climate change, and prospects for the future.​

His focus is our ability to track changes. This information, this data, this measurement, is NEEDED in order to plan for adapting to climate change.

If you read any of this as needing data to be sure climate change is real, or to be sure that the planet really is warming, or to be sure that this is caused by anthropogenic effects, then you've not understood him at all. These are underlying basics that are thoroughly established to Trenberth's satisfaction; and indeed to the satisfaction of the vast majority of working climate scientists.

We can look at the alternative views of skeptics of AGW, of course, and we do it quite often. But that isn't the question here at all, when looking at Trenberth's concerns. It is entirely to do with tracking and measuring where Earth's energy goes, in detail, over short term variations and local regional changes.

Look at the top of page 20, right hand column. He starts out with the basic groundwork of what we do know.

The present-day climate is changing mainly in response to human-induced changes in the composition of the atmosphere as increases in greenhouse gases promote warming, while changes in aerosols can increase or diminish this warming regionally depending on the nature of the aerosols and their interactions with clouds. The current radiative imbalance at the TOA has increased from a very small imbalance only 40 years ago when carbon dioxide increases and radiative forcing were less than half of those today. The excess in heat does several things. ...​

The warming, and the main cause of warming, is taken for granted. Sure, in principle, everything in science is open to question. But for working climate scientists, and Trenberth in particular, these are no longer the important unknowns. The unknowns are the modulating effects of aerosols and cloud -- which are smaller than the greenhouse warming but still significant and much less well known and hence a proper focus for investigation. He goes on to describe four effects of the known excess heat: only one of which is the increasing surface temperature.

But to get the detail of those effects, they must be measured, and on page 23 he comes back to his recurring complaint:

We cannot track energy in absolute terms because the accuracy of several measurements is simply not good enough.​

Trenberth is, of course, in no doubt that the short term drop in temperature in 2008 is a local short term effect.

This contradicts statements in the paper. Yes if heat was somehow absorbed an ocean sink or melting ice, examples he gives, then the recent lack of temperature rise would be temporary. However he also allows:

(Trenberth 2009)

Was it compensated for temporarily by changes in clouds or aerosols, or other changes in atmospheric circulation that allowed more radiation to escape to space?​

[highlights mine]

If the (excess) heat can escape to space now via some misunderstood mechanism it may (or may not) continue to do so.

This is not a contradiction at all; you've misunderstood him completely. Immediately prior to this he said:

The stock answer is that natural variability plays a key role [1] and there was a major La Nina event early in 2008 that led to the month of January having the lowest anomaly in global temperature since 2000. While this is true, it is an incomplete explanation. In particular, what are the physical processes?​

He GIVES you the stock explanation. It really is short term natural variability for a cooler 2008. This is not in any credible doubt; and what is lacking is detail. We know the La Nina was involved; the question is... how does it do it, physically? Where does the energy go?

We KNOW the energy is there. The greenhouse forcing didn't suddenly stop, and there was no less sunlight. So all that energy was still coming in. HOW did that La Nina event lead to lowered temperatures? There are several credible possibilities.

The inference you have made is as follows: "If the (excess) heat can escape to space now via some misunderstood mechanism it may (or may not) continue to do so." That's not Trenberth's inference, or mine either. Trenberth is quite sure about the La Nina association, and recognizes that it definitely will not all just keep going on. It will go away at the next El Nino (which is now, as it turns out, and so we are hotting up again of course, just like we always do with El Nino).

The question Trenberth is asking is simply this: during these La Nina events, what is the actual energy flow that gives this short term cooling? It's not about some strange "misunderstood" mechanism. It's rather that we don't have the tracking systems in place to tell which mechanisms are the ones involved.

I've missed it if anyone in this thread attempted to say global warming stopped over the long term. The OP BBC piece phrase was "For the last 11 years we have not observed any increase", Andre used the term "stagnate", and Trenberth leaves it as an open question:
(Trenberth 2009) last paragraph:

A climate information system that firstly determines what
is taking place and then establishes why is better able to
provide a sound basis for predictions and which can
answer important questions such as ‘Has global warming
really slowed or not?’​

[highlights mine]

Trenberth is right. Andre, and Hudson, are wrong; or at least misleading.

We simply do not have the statistical data to say that global warming has "stagnated" or "slowed". As I showed in a previous post, this is a straight statistical question. We know the process involves both long term trend plus short term variations. And the trend may not be constant. So how can we tell whether it has really slowed or not? Most people seem to think you tell by just looking at trends with the data.

They are wrong. Statistically, the natural variation is too great to let you determine what the trend is doing from a short period of measurement, like eleven years. Heck, in all seriousness, the data is actually consistent with the global warming trend having accelerated!

That's what Trenberth is saying. Statistically you cannot tell what warming is doing by looking at eleven years of global anomalies. The skeptics take it for granted that global warming has "slowed" or "stagnated" or something else; which is incorrect. A short trend line does not let you infer that.

Trenberth notes that the only way you can possibly tell this is by actually understanding the natural variation, rather than simply treating it as a random process of some kind... which is what you do to estimate confidence limits on the trend calculations. So Trenberth is saying that it is imperative to get the tracking systems in place that actually let us measure where the energy is going. That's the key to understanding what is going on, because the trend is masked over the short term by natural variations.

Cheers -- sylas

 

[Andre]

That is a pretty strong claim. Can you back it up please? If temperatures continue upward, one could always argue that we didn't do enough, or that it takes more than 10 years for our efforts to have an effect. To say that our efforts can do no good sounds, well, rather speculative.

No it is not. The essence is the predominance of negative feedback, which precludes the "amplification" of the basic Planck reaction of some 1.1 - 1.2 degrees per doubling CO2 as per Lindzen and Choi 2009 and diverse publications of http://www.aai.ee/~olavi/

 

[Andre]

Andre, I was not blaming El Nino. I was objectively looking at a graph of the data. The 1998 data point is clearly no basis for making claims about trends.

My opinion:
This should be obvious to anybody who

1. has some minimal scientific training.​

AND

2. takes a look at the annual temperature graph.​

Again, once more, maybe the essence is that Trenberth acknowledges no warming:

... we can't account for the lack of warming at the moment ...

would that depend on any starting year?

 

[sylas]

Again, once more, maybe the essence is that Trenberth acknowledges no warming:



would that depend on any starting year?

Of course it would. Reading the actual context of that quote makes it abundantly clear that Trenberth is specifically talking about accounting for where energy flows during the short term variations which dominate climate over the short term. The context also shows that Trenberth is in no doubt whatsoever that this is about short term variation on top of an unambiguous warming trend.

More detail in [post=2499641]msg #29[/post]. A comparison of my msg #29 with Andre's use of a half-a-sentence and no context demonstrates just how badly you can misrepresent someone when you cherry pick phrases and ignore meanings. Sheesh.

The short term variations are on the way up again, by the way. If there's a new record warm year soon, will that mean global warming has accelerated? Let me answer for you: NO IT WON'T. You cannot figure out the actual trend by looking at individual years or individual decades. It's statistically not possible. That is precisely why Trenberth is calling so strongly for a measuring system that will enable scientists -- ALL scientists -- to have data about where energy flows as temperature fluctuates up and down from year to year.

Just using a global temperature trend tells you almost nothing about trend unless you look at at least 15 years of data, and more than that if you want to know if trend is increasing or decreasing. But if we have data that enables us to track precisely physically where energy goes, then we have the basis for understanding these short term variations, and separating them out from trend on shorter time scales.

Cheers -- sylas

 

[sylas]

No it is not. The essence is the predominance of negative feedback, which precludes the "amplification" of the basic Planck reaction of some 1.1 - 1.2 degrees per doubling CO2 as per Lindzen and Choi 2009 and diverse publications of http://www.aai.ee/~olavi/

As opposed to the predominance of positive feedback, which means the lower bound of sensitivity for doubling CO2 is well above 1.2 degrees as per http://www.agu.org/pubs/crossref/2006/2005GL025259.shtml, Wigley et al. (2005), Schneider von Deimling et al. (2006), http://www.sciencemag.org/cgi/content/abstract/310/5749/841, http://geotest.tamu.edu/userfiles/216/dessler09.pdf , Forster et al. (2006), http://www.iop.org/EJ/article/1748-9326/3/1/014001/erl8_1_014001.pdf?request-id=7ffdbae3-8892-4567-8067-33a2055ffc40, http://www.sciencemag.org/cgi/content/abstract/325/5939/460 , Gregory et al. (2002), Bony et al. (2006), http://www.agu.org/pubs/crossref/2008/2008GL035333.shtml, and Minschwaner et al. (2006).

And by the way. Just to anticipate a repeat of not-so-subtle hints by some other contributors (not Andre, I hasten to add!) that anyone claiming to know too much is merely googling; this was not obtained by google. These are all papers already on my own computer, which I have obtained and checked out for myself well before writing this, and some of which I have discussed already in various threads. Had I used google I would expect to find a lot more, even if I limited myself to stuff published in the last 12 months. As long as we are going to drop papers into threads without discussion as a some kind of authority argument, this helps indicate what that technique would really show.

This is becoming a science based discussion, rather than political discussion. I think it would be more appropriate, given the focus of PF on actually learning about the science, not to merely dump references as some way of closing off discussion or overwhelming it; but to actually discuss the content of particular methods for inferring feedback (there are many different independent methods giving support to the same conclusion represented in the above papers) in a more focused science thread, with one or two papers as a backup for more detail.

Cheers -- sylas

 

[mheslep]

...Statistically, the natural variation is too great to let you determine what the trend is doing from a short period of measurement, like eleven years.

Yep, then why make this following statement?

...Heck, in all seriousness, the data is actually consistent with the global warming trend having accelerated!...

On your summary of Trenberth's paper I almost entirely disagree. We'll have to leave it there.

 

[sylas]

...Statistically, the natural variation is too great to let you determine what the trend is doing from a short period of measurement, like eleven years.

Yep, then why make this following statement?

...Heck, in all seriousness, the data is actually consistent with the global warming trend having accelerated!...

Because the second statement helps explain the first, to show just how large the confidence limits are.

You can quantify this mathematically, and I gave the numbers back in [post=2498365]msg #22[/post]. Here it is for you again, with all numbers in degrees per decade.

• Regression trend since 1998 with HadCRUT3: 0.032
• Regression trend since 1998 with GISS: 0.115
• 95% confidence limits given autocorrelation: 0.2

So as you can see, even using the dataset with the least amount of warming, the trend is still apparently somewhere between -0.17 and 0.23

The thirty year trend is enough to nail down the values better, as the confidence limits are about 0.05, and the values (since 1979) are 0.15 (HadCRUT) and 0.16 (GISS). That gives you a trend of somewhere from 0.10 to 0.22 degrees per decade, 95% confidence, with the trend since 1998 being anything from complete reversal to a significant acceleration. OK?

And if you think that sounds implausible... try figuring the 11 year trend from 1999 to 2009 inclusive. Use both datasets, to get the two estimates.

Cheers -- sylas