Jul 25, 2012 at 8:38 AM | geronimo

Geronimo - thankyou for your kind words! ;-)

As part of the "Fab Climate Scientist Four", I would like to clarify that climate science itself says nothing about what should be done about the projected changes in climate. Our jobs are to provide information to others to the best of our ability. I know that a small number of noisy climate scientists go further and espouse widely about what should be done, but that is something which I (and I think the other members of the 4) try to avoid.

The response to the projected changes should (rightly) be decided on the basis of engineering, economics, politics, morals etc. It is not the fault of climate scientists as to the response decided on by governments. Many here are understandably skeptical of some of the policies suggested by politicians, but this needs to be separated from the science itself. And, in a personal capacity I disagree with some of the policies myself.

Ed.

Richard Betts:

No, nobody asked us informally for the emails, the only requests were Martin's via FOI to both Met Office and Reading. We just thought that since both requests covered emails that were all part of the same email chain, which in itself may be of some passing interest to other BH readers, it would be good to just post the whole lot here.

Great decision Richard. And great decision to have a highly focused discussion, strongly edited, on Bishop Hill. On that I strongly agree with Eddy:

One of the reasons (imo) the CA is so influential is that the discussions stay on topic and are usually restrained. I think this style carries a lot of weight with the lurkers, however the debate turns out.

The needs of lurkers - 90% + of readers in most stats I've seen - is a key to the future of online media. And I fear the word has now stuck. In fact I've come to like the word - colourful and no longer pejorative in my ears.

w.r.t. Jul 25, 2012 at 11:14 AM | omnologos

Personal comment: Are you saying that all my e-mails related to my University address should be made publicly available. I do not agree with this at all. Would everyone on BH want their private and work related communications open to the world to see?

I do agree, however, that for every published study I am involved with, the data should be made available so long as that does not affect continuing research. For example, if I had a PhD student who publishes some of their data in Year 1, there should be no pressure to release raw data until after the PhD is completed so that he/she has the opportunity to publish all that is relevant from their data collection and research.

As part of the Fab Four, I cannot offer much w.r.t. instrumental prowess (maybe tin whistle?), but can sing a little.
:-)

Richard Betts Jul 25, 2012 at 10:55 AM

"Climate science is relevant to adaptation as well as mitigation policy. As you say, a significant reduction in global emissions would require other countries to do so, not just the UK. If the big emitters like China and the US decide not to reduce their emissions then we need to try to estimate as best we can what this may do to the climate, so that we can plan ahead (where appropriate) to live with these changes."

=======================

Seems that you have ascertained that CO2 will effect the climate enough that adaption and mitigation will be required?

Jul 25, 2012 at 12:04 PM | eyesonu

I don't think many here believe that CO2 has zero effect - that CO2 is a greenhouse gas and will warm the planet really is fundamental physics from the late 1800s. The big question is how large are the feedbacks which amplify (or not) the direct warming from CO2 and other greenhouse gases. So far, the evidence suggests that the feedbacks are net positive but there is uncertainty which we are trying to narrow.

However, the choice to adapt / mitigate is not a climate science choice. It is politics, economics etc. One possible choice is to do nothing and live with the consequences, whatever they may be. Another possibility is to drastically cut CO2 emissions tomorrow. Or perhaps to do something inbetween. But, these are NOT decisions that can be made by climate science or scientists. As Richard said, our job is to INFORM these decisions.

Ed.

Re: Jul 25, 2012 at 12:25 PM | Ed Hawkins

"However, the choice to adapt / mitigate is not a climate science choice. It is politics, economics etc. One possible choice is to do nothing and live with the consequences, whatever they may be. Another possibility is to drastically cut CO2 emissions tomorrow. Or perhaps to do something inbetween. But, these are NOT decisions that can be made by climate science or scientists. As Richard said, our job is to INFORM these decisions"

Ed,

Does that mean that the statement contained in the Met Office booklet

"Science - Driving Our Response to Climate Change"

http://www.metoffice.gov.uk/media/pdf/r/6/informing-mitigation.pdf

is a political statement rather than a scientific one?

For example such statements as -

• If emissions continue to rise, temperatures could rise by 4 °C1 by the end of the century

• Early and rapid reductions in carbon emissions will give a good chance of keeping temperature rises below 2 °C

• Increases of 4 °C would have major implications, such as decreasing agricultural yields for all major cereal crops in all growing regions

• 4 °C of warming globally will mean an average of 5.5 °C over land and considerably more in some areas, particularly at middle and high latitudes

"Man-made greenhouse gas emissions have been the main driver of the climate change we have seen over the past 40 years."

"Crucially, however, if emissions are reduced early and rapidly the extent of climate change will be mitigated. On the other hand, if greenhouse gas emissions continue unabated, or increase, the implications of global warming grow more severe and pose ever greater risks to life on Earth.
Research has shown that it is the cumulative effect of greenhouse gases which is crucial in determining the extent of future climate change. Early and rapid reductions in greenhouse gas emissions can produce significantly lower cumulative levels and reduce the temperature rise projected to occur in the 21st century and beyond. Delaying cuts in emissions means even more rapid reductions would be needed later to achieve the same cumulative emissionsand temperature target. These more rapid reductions may not be technically feasible or affordable. "

"There is a high probability that business as usual scenarios would push warming to 4 °C this century, and in the worst case this could come as early as 2060"

"Many impacts of climate change are progressive as temperatures increase, for example increased flooding and drought. However, higher temperatures are more likely to pass dangerous thresholds in the climate system. These tipping points include irreversible loss of the Greenland ice sheet, which would lead to similarly irreversible sea-level rise. There are also potentially dangerous feedbacks, such as the possible release of huge quantities of greenhouse gases from marine hydrates and permafrost. The bigger the increase in global temperatures, the more exposed we become to the risk of passing irreversible thresholds and causing dangerous climate feedbacks."

"The bigger the increase in global temperature, the more exposed we become to the risk of passing irreversible thresholds and causing dangerous climate feedbacks."

Or can you confirm that they do accurately summarise the science.

Jul 25, 2012 at 1:01 PM | Breath of Fresh Air

In principal, I agree with you.
However, in light of the recent “contentious” Nature Climate Change paper I was co-author on with Jan Esper
(http://www.geo1.uni-mainz.de/Dateien/Esper_2012_NatureCC.pdf)
should someone, for example, be allowed to ask for ALL e-mails related to this particularly study? These would go back to 2006 when we undertook the original living tree fieldwork in Finland and Sweden?

Hi Marion,
I don't work for the Met Office, and haven't read that document. But none of those statements you listed are decisions about what to do in response to the climate projections - they are scientific statements of our understanding designed to INFORM decisions. A policymaker could look at the science and decide to do nothing or something.
Ed.

Jul 25, 2012 at 12:57 PM | matthu

There are many feedbacks, some positive and some negative, but the evidence suggests that the feedbacks are net positive. There has been a temperature increase since 1850 which is explained by the many different radiative forcings (not just CO2) and a net positive feedback. Ice core data suggests that the climate undergoes large changes for relatively minor changes in the Earth's orbit, suggesting there must be a net positive feedback. Having a net zero feedback then requires other explanations for past climate changes.

cheers,
Ed.

So Richard / Ed,

"Early and rapid reductions in carbon emissions will give a good chance of keeping temperature rises below 2 °C"

&

""The bigger the increase in global temperature, the more exposed we become to the risk of passing irreversible thresholds and causing dangerous climate feedbacks."

Is this what you both understand from the science?

It seems to me there is little uncertainty in these statements nor do they give any indication of the extent natural processes impact temperatures but that they are effectively telling us to reduce our carbon emissions.

"DocMartyn

We don't tune the models to make them agree with observed warming! That would invalidate their use in attribution - and also would be too expensive, as it takes months of supercomputing time to run a GCM for a century, so it's simply not practical to keep running the model, comparing with observed warming, changing the model and then running it again.

Richard Betts"

Dear Richard, I have a background in biology and so I would like to use a biological metaphor, that I believe will be instructive.
One can compare your large climate simulation programs to a living organism. Each of the mathematical constants contained within the sub-routines is analogous to a gene. It may be for a particular constant you are able to estimate its value (A), based on analysis of a physical process, as to be 1+/- 0.05.
Within a particular program you have a large number of these constants, which can be considered to be a unique set of genes.
You then host you organism/simulation in an ecological niche, where you set the initial conditions and throw in changes in [CO2] and episodic events.
At the end of your runs you compare the output of you simulation with your preferred outcome; hind-casting.
Here you are acting as an evolutionary selection pressure; Should you find that the value of constant A at 0.95, you get a far better match to the desired temperature record, you will give the next generation of simulants a gene A with a value of 0.95, and all the candidate simulations that had a value of 1.05 will become extinct.
I suggest that you and colleagues have be behaved like Shepard's with wolves. Through generational interation you have been breeding Sheepdogs; 'good' dogs breed and 'bad' dogs don't.
Each time you run your simulants in you designed niche AND then select, you are performing evolution in action.
You may believe that the model evolution is entirely rational, and that you ascribing particular values to constants (within a reasonable physical range) does not constitute tuning, however, if one thinks of the process in terms of evolution, then your comparison of output with the past climatic record counts as an evolutionary bottleneck.
Might I suggest you look at Dawkins generation of biomorphs in his book 'The Blind Watchmaker'. The Dawkins program has only 15 genes and yet can generate a huge variation of shapes:-

http://evolbiol.ru/dawkins_watchmaker/images/fig06.jpg

Rob Wilson Jul 25, 2012 at 1:30 PM

====================
Your paper was published on the public dime. It may influence the decisions of policy makers on an international level. Systematic errors have been observed in the processes involved in other papers in this field.

Why would it not be relevant to review full context of the influencing factors in the creation of this paper?

Sorry, missed this one off - I didn't think the Met Office science was in a position to make a statement such as this

"Man-made greenhouse gas emissions have been the main driver of the climate change we have seen over the past 40 years."

DocMartyn: An interesting thing about the blogs is that they attract a wide range of expertise. I'm interested in ways in which approaches used in other disciplines can be applied fruitfully to the study of the climate. This really takes time and patience on both sides though. I attended a meeting recently (http://www.earthtemp.net/) which brought together people working on different aspects of surface temperatures. That seems like it should be a fairly like-minded group, but it was clear that there are already pretty hefty barriers to communication between people working on say land surface temperatures from satellites and land surface air temperatures from met stations.

More informally, the different questions people ask can help to see the scientific problems I'm facing from a different angle. I find it takes a bit of mental discipline to reflect on why a person has asked a particular question and try and understand what scientific reasoning underlies that to help answer the question in a way that doesn't appear to the other person as if I'm ducking the point, misunderstanding, being obtuse etc... Not saying I always achieve that (or often even) but sometimes things sink in slowly and re-emerge later.

In response to the GISS thing, models aren't tuned to global temperature changes in that way. To add to what Richard said, the jitters between different updates of the GISS global average are smaller than the estimated uncertainties in those estimates, so it would be a misguided thing to try to tune to the details from that point of view too.

Jul 25, 2012 at 10:41 AM | Ed Hawkins

I agree with you Ed and the rest of the Fab Four, if you read my words carefully you'll see I don't know what your personal positions are, so won't say. I know you all believe that CO2 is dangerous and will cause some problems, but you don't have the solutions. The top of the Met Office, to me at least, is riven with green activists. People like Peter Stott who told us that the current summer of cold peeing down rain is what global warming would look like, while over the other side of the atlantic NOAA scientists are telling us that the droughts are what global warming will look like. In fact we've been told that freezing winters are what global warming will look like, and for me the least believable of all is that tropical cyclones will increase in intensity.

Here's what it looks like from the outside looking in. People in the climate science community (not all, or even the majority) but I will list a small number of names to give you a feel. Hansen, Trenberth ( who famously gave the impression he was an expert on hurricanes), Mann, Viner, Stott, Gleick are making outrageous and untrue statements to frighten the public into taking action on climate change to reduce CO2 output. Our own government's policy is going to cost £18bn/annum, and we don't have a proper engineering plan for our future energy needs. You don't have to be very bright to see a reduction in CO2 output to satisfy the information we're getting from the scientists will be disastrous in terms of the cost of energy, and ultimately futile because we don't emit enough CO2 to make the slightest bit of difference, so the advice we're getting from the scientific community is akin to telling a pilot whose plane has lost all power that it will crash unless he starts the engines. Reducing CO2 is not an option it will simply bring forward different disasters for the human race so telling us it's the only solution, as the Met Office and IPCC does is wilful ignorance.

Only 'maybe'.....

But thanks, Richard, it's nice to get a concession or two :-)