Fergus Brown

Quick question ; if glaciers are growing in some (very, very few) places, and shrinking in some other (very, very many) places, over an extended period of time, what do you think the trend globally is going to be?

Read chapter 4 or chapter 13 of the AR5. - I have read the latter. A 'inevitable' Greenland melt out is 'likely' to be locked in if temperature rises by 2 degrees. One study suggest the inevitable loss of the GIS might kick in for temperature increase of only one degree above pre-industrial. Possible it may not be so until temps are +4c. Timescale - thousand years or more. Solution? Radical mitigation reduces the rate of decline, permits the possibility of regrowth in the long term (post 2300, for example) to up to 80% of original levels. Contribution to sea level rise? 1-3 metres by 2300, up to 5 metres longer scale, theoretical maximum 7 metres. Sorry to be a stormcrow...

Is it important that glaciers are shrinking? It is if they are contributing to seal level rise -which they are. It is if they form glacial lakes which then collapse and inundate valleys, villages and crops. It is if your entire fresh water supply depends on glacial meltwater which is cut off or diverted as the glaciers retreat. It is if you are looking for evidence that the balance that once existed in the global climate system is in a perilous state. I'd say yes, generally speaking it is important.

There are six 'anonymous experts' quoted in the article alone, which is, of course, an editorial piece anyway. More seriously, this is an ongoing discussion on some of the science blogs. Interestingly, none of the discussion is about whether the IPCC conclusions might be an overestimate - it's all at the other end of the scale. And yes, Aslan Grinsted is a cracking name..

Hi Timini, Getting to the point of your post: That this is a negligible source of heating at the surface (or any number of points near the surface) is just as much of an educated guess. I had imagined that the Earth's energy budget incorporates 'background' heat, such as you describe. I am fairly certain that there is quite a lot of observation and analysis which accounts for this contribution. Therefore I can't agree that such a conclusion would be an 'educated guess'. Scientists are quite fussy about this kind of ambiguity on the whole. Can you post anything which shows the estimated heat at the global surface from Earth's own 'internal sun'? Hopefully, this will also show a level of uncertainty about the calculation. It could be described as a large known unknown. It could be described this way if it is true. Is it unknown? The IPCC does not figure it is worthy of a mention in the current climate analysis. Do you think that it is possible that there is a legitimate reason for this? Cheers.

Hi John, anyway this lot is for you to read most people have made there own minds up anyway so not sure why this thread was started I think it was started because someone thought it was worth discussing, with the difference that the presumption implicit in the discussion on the other thread was removed. a couple of points saying volcanoes cannot heat the planet is the same as saying co2 does not warm the planet as well Sorry, we are talking at cross purposes here - what do you mean when you say 'volcanoes heat the planet'? The impact of volcanism on climate has been studies for quite a long time and is taken very seriously. It is not ignored in the science. Making the statements you quote - are they of equal status? Surely, that is what we are trying to get to? also circualtion transport heat from the bottom of the oceans and not just heat from the surface Please note I mentioned this in a previous post. Are you suggesting that this is not factored in to the analysis done by scientists? also deep eruption do not always get noticed and you also do not always get earthquakes to foretell an eruption I agree. until the deep oceans have been properly mapped and discovered i will keep an open mind I am delighted that you are keeping an open mind, seriously. Can you point me to an explanation of the relationship between ocean temperatures and subsea volcanoes? anyway make your own minds up on this I think we are all trying to do this, all the time. Please don't stop pushing the point. A small side point; your post references are a bit long, which mean there is rather a lot to take in at once. I'd find it easier to focus on one or at most two pieces of material at a time. (won't speak for other people). For example, I'd appreciate it if you can find a paper on the earth-ocean heat exchange. Please don't post a part of a textbook, though - I think you can presume that your readers already understand how volcanoes work. I look forward to continuing this discussion in a positive and open-minded way.

Good point, Andy. It's the usual problem, though (see for example the skeptic thread recently); for every piece of evidence provided by careful methodology and assiduous examination, there is a website which presents its own version of 'evidence', very frequently sourced second-hand from another site, which got it from another site, which got it from (eventually) an organised, funded misinformationist source. It doesn't matter whether this 'evidence' is scientifically accurate, just so long as it looks scientific and is plausible, and supports a pre-existing opinion help by a reader - it will be believed, and assumed to have an equivalent value, at least, as the sum of all evidence which contradicts it. This is not necessarily the 'fault' of the reader though. There are few enough of us who are genuinely scientifically literate, and even fewer who have the skills to analyse, for example, the formulae used in presentations. If we are asked to choose between two things on face value, we tend to choose the one which suits our existing disposition. So the challenge for someone who wants to try to offer persuasive argument without alienating or being seen as hostile by a 'skeptical' other person (and this holds true for much of science, such as GM), is how to open the door to engagement and hold it open? How to create the conditions for a real dialogue which allows the other to both own their existing opinions and genuinely consider alternative opinions? It's a big ask...

Volcanoes do have an effect on the climate - they have a cooling effect. This is so well established by experiment, observation and simple accounting, that arguing to the contrary is possible only if you choose to ignore all of the evidence. There are many things to say about the argument above, but keeping things simple; there are three recognised 'ocean levels' - upper, middle and lower. Recent measurements show the upper ocean is warming at a measurable rate. At the same time it is getting more acid. There is a known mechanism for both these - increased heat from above (the air) and increased CO2 absorbed into the water. The relationship between the increases in atmospheric CO2, oceanic CO2, atmospheric temperature and upper sea temperature can be established through calculation and accounting. There is a relation between top and bottom water (mixing), and there is circulation of water (the THC, broadly). The measurements of these processes indicate that the transfer of heat is going from the top to the bottom, rather than the other way around. Eventually, it will come back out again. There is no evidence that the amount of volcanic activity in terms of heat generated has changed in any way which can explain the concurrent change in GST. Lots of others, but this will do for now...

Well, lots of things come to mind, but first I thought it would be useful to deconstruct the 'sceptic' line. As there are several lines of attack, so there are variations and additions, but this as I understand it is the main line of reasoning: 1. Volcanoes are hot. Very hot. 2. There are volcanoes under the sea. 3. Heat transfers from hot to cold. 4. Therefore volcanoes are heating the sea. Add to this the 'science is worthless' meme: 5. Volcanoes are heating the sea. 6. We (including scientists) don't know how many volcanoes there are under the sea. 7. Therefore nobody knows how much the sea is being heated by volcanoes. Incorporate this into AGW: 8. Nobody knows how much volcanoes are heating the sea. 9. GWers are saying the sea is getting hotter. 10. We know that it isn't us. 11. Therefore It must be the volcanoes. Did I miss anything?

no worry I've got the message.

Hi John. Are you kidding? it's far too much for my brain to take. I have a strong opinion of the content of the website but in the name of peace will not express it. If you could find out a bit more about the credentials of the author it might help us understand the context of what has been presented. The two points I must make, at the risk of being shouted at, is that the site purports to provide a 'balanced' view of 'the debate' about 'natural vs anthropogenic' climate change. First: it isn't 'balanced', it's profoundly in the skeptic camp. Second, there really, honestly, truthfully isn't a 'debate' in Science. There is one amongst us (the Layperson), which is right and proper. You will have noted the significance of the Stevenson argument vs. Levitus. This is the hangover of a still ongoing piece of nonsense related to the so-called 'Leipzig Declaration'. Stevenson was one a very few scientists who joined the Pat Micheals camp back in the day. Admirable though he was as a person, in respect to the attribution of climate change, his arguments have been proven to be wrong. I am not now nor will ever claim that studying volcanoes and the impacts of subsea volcanism on ocean heat content is not important. Can you find us a paper, published in a scientific journal, which accounts for the change in OHC at 0-700 m by these volcanoes? Thanks.

http://whogoeswithfergus.blogspot.co.uk/2013/10/might-as-well-try-and-catch-wind.html Sorry, I need the blog traffic! Comment on Mora and Ostberg. Read the Ostberg.

Small point to note; the effects are 'small' and generally more useful (according to Slingo) on annual to decadal scales. Re your paper, J - good find - more interesting from the weather pov in addition to climate, since it deals with initial conditions, which are so critical to forecasting. A good source for open access science is the EGU/Copernicus programme. I use it all the time.

Here is something for anyone who struggles with the argument about the reliability/value/etc of computer models: http://www.theguardian.com/science/2013/oct/09/nobel-prize-simulating-chemical-reactions Apparently, complex computer models can do quite useful things, and some scientists can do good work with them. I'd also observe that, generally, earth system models are orders of magnitude more complex..

Excuse my obtuseness. Assuming you are referring to Mollgawks' chart, which of the forcings (apart from Solar) are you counting as 'natural' ? To my eye, all the other cited forcings are anthropogenic ?? BTW: good post on the other thread. respect

Spent some time looking at the available material. Questions: What is 'long-term'? What do you mean by 'melt out'? These matter because some of the material points to, for example, a total irreversible loss of the GIS over millennia if mean surface temperature over Greenland is anything betweeon 1-2c above pre-industrial levels. Or are we looking at decades rather than centuries? And what proportion of the GIS would have to be 'lost' for it to count as 'melt out'?

Thank you. I note the 'standard' estimated forcing from 2xCO2 alone is equivalent to ~1.2 c. [Climate Sensitivity including forcings from same is ~3c.] How does the 1.2c of the 'standard' estimates compare with Mollgawks calculation? On the irradiance ranges, I'm afraid you'll have to explain a bit more... perhaps give an example?

Citation: Barletta, V. R., Sørensen, L. S., and Forsberg, R.: Scatter of mass changes estimates at basin scale for Greenland and Antarctica, The Cryosphere, 7, 1411-1432, doi:10.5194/tc-7-1411-2013, 2013. link here:http://www.the-cryosphere.net/7/1411/2013/tc-7-1411-2013.pdf The summary conclusion: For the whole GRACE period (2003–2011) our trend estimate for Greenland is −234 ± 20 Gt yr−1 and −83 ± 36 Gt yr−1 for Antarctica (−111 ± 15 Gt yr−1 in the western part). We also find a clear (with respect to our errors) increase of mass loss in the last four years.

Hi S, As I read it, the blogger has decided to map temperature vs CO2 on a log curve rather than a line - is this correct? My question is; why? what is the correct relation between temp (GST) and CO2? Climate sensitivity has become a larger discussion point recently, so it's important that we understand what CS is and what the right way of calculating it is.

Hi John, This directly addresses Casey: http://www.agu.org/pubs/pdf/2011EO240001.pdf Note the final sections and the concluding paragraph in particular. One of them must be wrong, surely. Honestly, I can't see the correlation in the two maps. It seems to show that around some parts of the plate edges there are negative anomalies and around other positive ones. How do I get a correlation? good night

This is for those of us who have an active interest in the subject and like to think we are open-minded ('pro' or 'anti' or whatever). This came up on the interblognetosphere today; http://www.skepticalscience.com/earths-climate-system.html I read it and found it helpful. It ties together lots of stuff and explains it in a way I can understand. I have a couple of open questions: 1. Is this a reasonable summary of the earth's climate system? 2. Are there any elements of it which you think are unfair, inaccurate or misleading? 3. If the answer to (2) is Yes, which one of these elements do you challenge? Suggestions - It's a long-ish bit of writing but it really helps if you can, even if it takes a day or two, actually read it. Also, try to stick to one criticism at a time. If anyone bothers to reply and if there is more than one challenge, we can decide between us where we want to start.

I have a suggestion... well, more of an idea half-thought through, tbh.

Hi John, Not sure if this helps or hinders, but here is the summary of climate forcing observations and assessments: I know what you mean about the levels of confidence thing - it just makes it confusing. It's one of the ways that scientists talk about stuff which is different to ordinary people and seems to say 'we think this but we aren't sure', which could easily sound like 'this may or may not be true', but it doesn't really mean that. Take the chart above: it gives a list of climate forcings, positive and negative, attributes values to them, and on the left puts them in two sections: Anthropogenic and Non-Anthropogenic. Let's say that you insist that all values are presented at the highest possible confidence level (let's say 95% ?); what changes would that make to the chart? Take a look at the overall picture (anthro vs non-anthro forcings); what does the chart suggest is the principle cause? To me, given that this is just a summary of loads of work by loads of people over a long time, using physics which has been tested, retested, challenged, validated and effectively proven, it looks reasonable to summarise the evidence as 'AGW is real'. I am happy, though, to consider evidence to the contrary, for example which shows that there is a reasonable level of doubt, because of ... well, anything. I make assumptions along with everyone else, but I try not to make the assumption that I am right and someone else is wrong. Because I am only mediocre at reading science, there are some things which I have to take on faith. There - I said it.

TBH I'm struggling a bit here. So much of what is exchanged in the threads is framed in adversarial terms - you're either for or against, pro or anti, alarmist or denialist. Yet at the same time many of us contributing to the dialogue are pointing out our own particular views are not 'standardised'. I think all of us have to look at ourselves and ask if we are being fair to each other? So often, we make assumptions about what others' meanings or intentions are, and simultaneously take exception when others do the same to us. This is not the way to agreement or even progress towards agreement on anything. The needle is stuck, as so many have pointed out. So: can we jog the track on a bit (for some younger people: this uses a metaphor based on the days of Vinyl...)? Is it possible to find a way where agreement can be reached, or are we condemned to an eternal recurrence of all that has gone before? Communities and Forums are potentially useful tools - they allow us to focus on numerous threads of discussion and at the same time to go into detail on specifics. But this doesn't work if we (yes, me too) bring our baggage of assumptions and pre-judgments with us. so, as a staring point: Is it important to understand the World we live in and our interaction with? Yes or no? No qualification required. Is the World really made up of 'people like us' and 'people not like us' - or are people (and here, that means this community) simply more complex than that? Finally (for now); is there anyone out there who honestly wants to learn/understand/explore a specific topic that can be isolated and discussed (for example, John's interest in the role of Volcanism in the Global Heat Budget) amongst free-thinking people who respect each others' thoughts even if they disagree with them?

Hi Tamara, In response to your assertion that the feedback assumptions are uncertain, here is a link to chapter 10 of the AR5 : http://www.climatechange2013.org/images/uploads/WGIAR5_WGI-12Doc2b_FinalDraft_Chapter10.pdf It is quite a lot to read, so it's probably forgiveable to focus on the summary. On the basis of the evidence presented there, which of the feedback assumptions do you think we should look more closely at? I agree that it is important to be open minded, so I am not asking you to agree that I am right, but giving you the opportunity to show me that I am wrong to think that humans are responsible for at least half of the observed warming, as asserted by the IPCC in summary of the evidence of scientific research.