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aj1983 at 22:36 PM on 21 April 2010Climate's changed before
He probably just wants to "enlighten" us with a link to his own blog. Anyway, a large part of the discussion is about PETM and AGW (with the link to resilient earth). A lot of it sounds like, if we extrapolate our CO2 emissions it would take forever to reach PETM concentrations, and PETM wasn't even caused by CO2 alone, so PETM cannot be used as an indication for the effect of CO2, so AGW does not exist. All the individual statements above are probably correct, except the conclusion. Think about it, have we seen any projections from IPCC showing a 6 -9 C global temperature rise? No. Oh, BTW it can also be found on that website that models can not fully reproduce PETM even if we use the CO2 concentrations at PETM, so models are WRONG! (It is understood why, because GCMs currently use bandwidth parametrisation instead of line-by-line CO2 absorption schemes (because of limited computer power) and will thus deviate if brought very far from their original (~300 ppm) state. This probably introduces a large error when going to extremely large (2000 ppm) CO2 concentrations. This PETM event can (in "skeptical" reasoning) even be used to say "look, even if we get a 3 C global temperature, it is all natural! Because in the near past of the Earth's history it has been 9 C warmer, and humans were not yet around!" And, using this reasoning and the paleo record, all climate variation will always be natural... -
Bart Verheggen at 22:29 PM on 21 April 2010The significance of past climate change
The thing with this line of argument that your tackling is that it fails basic logic: Human activity of course didn't cause past climate changes, but that’s no evidence that it doesn’t now. Try that line of argument in a court of law against a arsonist, by saying that forest fires have always happened naturally; it won’t fly. Indeed, GHG had an important role to play in many past climate changes (even though their concentration changed without human involvement). Looking at the past actually strenghtens the evidence for a climatic effect of GHG. -
Spencer Weart at 22:28 PM on 21 April 2010The significance of past climate change
An excellent presentation of past climate change is available online: Richard Alley, "The Biggest Control Knob: Carbon Dioxide in Earth's Climate History" at the Fall AGU meeting, see http://www.agu.org/meetings/fm09/lectures/videos.php To be sure this is for a scientist audience but the main points can be adapted for others... admittedly not easy. And of course, bear in mind that people have a hard time grasping knowledge that conflicts with what they want to believe! -
nautilus_mr at 22:28 PM on 21 April 2010The significance of past climate change
I concur with #13. I think the first principle is explain what is causing warming now, then climate history comes in to a supporting role. -
Miriam O'Brien (Sou) at 22:21 PM on 21 April 2010The significance of past climate change
How about this: Rather than list all the possible primary drivers (forcings), start by describing a couple of periods when the climate changed in the past from different forcings. For example, Milankovitch and volcanoes as the initial forcing. For each of the two periods in turn, describe in simple terms what the earth was like before the change (eg ice free Antarctica) and what it was like afterwards (eg lots of ice everywhere). Describe the forcing that led to the change (and define the terms - engineers most probably use slightly different jargon from climate scientists). Then move to today and show the evidence that the climate is changing (temperature, ice, oceans, sea levels etc). And explain that the forcings that caused the prior changes you discussed are absent, and the only primary driver or initial forcing operating today is CO2 / greenhouse gases. Then show how greenhouse gases also acted as a positive feedback, amplifying the changes you discussed in the two first examples (warming or cooling). You can deal with the 'but couldn't it be due to ...' in the question time / discussion - keep your detailed slides on hand for when specific questions are asked. If there are particular points you want to elaborate on (eg role of water vapour/clouds which some often ask about), you can probably do this during the discussion by saying, 'someone often asks me xyz' and then whip out your extra slides :). (As a broad (over?) generalisation, engineers are often clever, but their thought processes tend to be linear rather than lateral. Simple works best. One step after another, with a bit of repetition and reiteration of key points along the way. No offense meant to engineers, it's just an observation from working with groups of engineers in a variety of contexts.) The following publication is rather good, and will no doubt be more useful than my off the top of the head idea: CRED guide -
CBDunkerson at 22:17 PM on 21 April 2010The significance of past climate change
I think part of the problem is that you are really conflating two different issues... which if separated might be phrased as; 1: 'Climate has changed in the past so how do we know humans are causing it now?' 2: 'How do we know that the climate change we are causing is going to be significant?' I think you can really handle the human causation question using CO2 alone (past correlations of CO2 and temperature, satellite and ground measurements confirming energy imbalance in CO2 absorption spectra, various proofs of increased CO2 levels being human caused, et cetera)... possibly following that up with explanation of why it ISN'T the Sun, cosmic rays, volcanoes, martian death rays, or whatever. All of which can be handled by showing lack of correlation - some match past changes, but none match the current. Once you have established CO2 as a major 'control knob' in determining temperatures then you can get into feedbacks amplifying that effect and what the historical record tells us about those. Basically, handle one issue at a time. Don't start talking about positive feedbacks before they've bought into CO2 increasing temperatures at all. -
nautilus_mr at 22:16 PM on 21 April 2010The significance of past climate change
re #6 and #9: I get that argument sometimes and my response is that it wouldn't matter if there was either a more rapid or larger warming at some point in the distant past - there weren't billions of people living near the sea then. "The Planet" is not endangered - it is a small percentage of the planet's flora and fauna, plus a big percentage of its human beings. Of course, it's like asking for anesthetic at the dentist and being told you shouldn't have it because the dentist's grandfather had to suffer more than you! -
Marcus at 22:15 PM on 21 April 2010The significance of past climate change
Thingadonta-how can you make such claims when global warming of +0.6 degrees has *already* occurred over the past 60 years, with nearly +0.5 degrees of that warming occurring in just the past 30 years?!?! The fact that virtually *every* natural climate change event in the past (with the exception of those caused by extremely massive natural disasters) has occurred at a rate of between 1/2 to 1/10th of the rate of recent change is simply further proof that nature is not the cause of the most recent climate change event. What humans are doing, by burning the accumulated & compressed CO2 storage of tens of millions of years of tree & plant life, is to effectively compress millions of years of geological activity into the space of just 250 years. To suggest that geo-engineering on this scale could *not* be the cause of rapid climate change simply shows how *weak* the contrarian argument actually is! -
nautilus_mr at 22:08 PM on 21 April 2010The significance of past climate change
It may seem a bit off-beat, but I personally think paleoclimate more often than not is about red-herrings. While a number of false arguments try to use paleoclimate to deny AGW, I must admit I have never been convinced that the paleoclimate record is terribly useful to the debate. Fundamentally, there is nothing it gives us that is not more clearly communicated by contemporary data. For example, the "Hockey Stick" shows that the contemporary rate of warming diverges enough from the last few thousand years to raise a smoking gun type of question, but the graph itself is not an explanation -only a way of flagging an anomaly. Even if the hockey stick was proven wrong, it wouldn't matter - because arguments about medieval warming, past CO2 levels, higher ancient temperatures etc. all miss the point: In the contemporary world, we can identify the rate of global warming, the mechanisms of warming and the predicted (and confirmed) effects. Until there is a better explanation for the colossal body of evidence of the last 100 years, the opponents of the AGW thesis will try and drag our attention into the distant past, where the ground under any given argument is weaker. -
John Russell at 21:54 PM on 21 April 2010The significance of past climate change
I would say that in my experience the key point to get across to sceptics is that during past climate changes there were no humans around to experience the effects. Consequently from today's human viewpoint past changes do not seem such a big deal. But the truth is they were huge. Although climate change of three, four degrees or more over tens of thousands of years would allow most plant and animal species to move, adapt or evolve to cope with that change; the more serious and/or sudden climate changes would cause huge extinction events. The problem, in explaining this, of course, is that such events seem no big deal to us today, looking back over millennia. So what, if large mammals -- which we're aware of only through scant fossil evidence -- once died, to be replaced by other equally unfamiliar species? On the other hand the current rapid Climate Change -- when humans are now one of our planet's larger animal species -- is a highly risky for both us and most of the other living species; though as an extinction event it will probably be no worse than many in the past. Arguably it's made worse by the unprecedented fact that humans are responsible for creating the problem this time. It would be interesting to conjecture (is it possible to know for sure?) the extinctions and changes to the nature of life on the planet as a result of past climate changes, and then extrapolate how the current climate change being instigated by humans could alter the nature of life on the planet today. Of course one of the problems in doing this is that global heating is only one of many serious issues now being caused by human influences on life's existence on our planet. Pollution; deforestation; industrial agriculture; fresh water diversion; resource depletion; over-population -- to name just some of the most obvious -- are all key components in the environmental timebomb we're creating. -
thingadonta at 21:50 PM on 21 April 2010The significance of past climate change
I agree with pretty much all of what you say above except for one major point-the issue of the time scales involved. The past geological record indicates that changes on a global scale are invariably very slow. We're talking tens of thousands, to hundreds of thousands and even millions of years in the vast majority of cases. For something like acidification of global oceans by volcanoes, and indeed the majority of mass extinction events (except in rare cases of eg bolide impacts), that is the sort of time frame the geological record indicates is invariably required. To take a few examples, the output of greenhouse and other gases by Siberian Traps volcanism at the end of the Permian occurred on a major scale over several hundred thousand to several million years, and that is how long it took to cause major climate changes such as (possibly) acidifying the oceans, the collapse of coral reef ecosystems, and mass extinction. It was not a ‘rapid process’ when compared to the scale of human lifetimes. The break-up of the Gondwana supercontinent is likely implicated in eg the Mid-End Triassic mass extinction-continents do not break up 'rapidly'. This occurred over millions of years - with possible stress-related tipping points etc, as rift-related volcanism increased over very long time periods. Many other examples from the geological record indicate much the same thing, (eg oceans don't ‘acidify’ within short human timescales when similar amounts of c02 have been added to the atmosphere in the sort of time scales involved as is currently the case). This is also the major reason people such as the gradualist Charles Darwin were so skeptical of the presence of 'mass extinction' events in the geological record in the first place, and also I suspect why the person on the street is with current climate change and the extreme predictions around it as well. It's like worrying about continental drift changing the climate within this century. This is one of the major skeptical arguments, that major global changes such as those predicted by the IPCC to occur within the next century by human emissions of greenhouse gases will NOT occur, not so much because the concepts and theory is wrong, but because the scale of time involved is far too short, and that the geological record provides very good support for this contention. Academics and other pro AGW advocates get the concepts largely right, but get the time scales involved largely wrong. -
LauraM at 21:48 PM on 21 April 2010The significance of past climate change
I think its important to mention the speed of climate change today vs the past. -
Marcus at 21:42 PM on 21 April 2010The significance of past climate change
Every time I hear the "Climate changed naturally in the past, so humans can't be responsible this time around" I always respond by saying "so does this mean that 'because many forest fires start naturally, humans are *never* responsible for forest fires?'" The comments are equally nonsensical, yet it never ceases to amaze me how often the Contrarians try & push this illogical position! -
theendisfar at 21:23 PM on 21 April 2010The significance of past climate change
John, In the past . . . What happened as Surface Temps rose, due to CO2 on occasion, with regards to the rates of convection and evaporation? Did they increase, decrease, or stay the same? If convection and evaporation rates increased as surface temps increased, did that cool the surface, heat the surface, or did the surface temps remain the same? ThanksResponse: See, this is the thing. In my presentation to the engineers, I did up this gorgeous little schematic of positive feedbacks, showing increased evaporation, more water vapor causing an increased greenhouse effect, more clouds, etc. Very colourful, I was very proud of it :-) But I think I went into so much detail describing the positive feedback processes and the derivation of climate sensitivity, I think everyone had forgotten the point of the explanation by the time I got to the end.
The basic point was to say that there are a number of feedbacks - both positive and negative. Finding the net feedback by adding up all the individual feedbacks is a complex job. But you can cut through all that in one fell swoop by looking at past change. By just comparing temperature change to changes in the energy balance, you determine the net feedback without having to know all the individual feedbacks.
So I skipped all those details in this blog post in the effort of a simpler argument. But going through the explanation too fast leaves people wanting more details. Where to draw the line? -
Glenn Tamblyn at 21:18 PM on 21 April 2010The significance of past climate change
VnceOZ Which bit of 'this' are you referring to? And why do you use a word like 'believe'? -
VinceOZ at 21:07 PM on 21 April 2010The significance of past climate change
You don't really believe this do you?Response: It's not a question of belief - this is the state of the science as explained in the peer-reviewed literature. I go into more detail with peer-reviewed references at Climate's changed before - this was an attempt at a simpler, easier-to-understand explanation. -
JulianRGP at 20:42 PM on 21 April 2010The significance of past climate change
I suspect that the argument has to proceed by easy steps. One step is to assert that it is not logical to exclude a new factor, without further examination. Before 1890, there were plenty of reasons for accidental deaths, but being involved in a motor car accident was not one of them - for obvious reasons. But we do not use that as an argument to say that car accidents should be ignored. In the case of CO2, it was not previously present in large quantities (unless you're going back before human history), but it now is and its projected increase in the time scale we're interested in will dominate other factors. -
Ari Jokimäki at 20:30 PM on 21 April 2010The significance of past climate change
Few comments on some issues I think should be explained if you want this to be as simple as possible: - The role of greenhouse gases in the past climate (or where they come to the atmosphere) might need an explanation. - You should explain what positive feedback means and the factors which are positive feedbacks. - The part about CO2 being an external forcing might call for additional explanation - I don't think it's readily clear for someone not familiar with the issue. -
Richard482 at 17:34 PM on 21 April 2010Tree-rings diverge from temperature after 1960
I think that this is the real reason for the decline in tree-ring data. An increasing amount of CO2 http://scienceblogs.com/pharyngula/2009/12/why_climatologists_used_the_tr.php -
Marcel Bökstedt at 15:34 PM on 21 April 2010Where is global warming going?
HumanityRules> How would you expect to detect the energy in transit? -
James Wight at 15:13 PM on 21 April 2010Where is global warming going?
I find the “missing heat” problem very interesting. I’m only a layperson, but I’m leaning towards the Arctic Ocean explanation. Since 2005, Arctic summer sea ice has declined dramatically. Less sea ice means that the ocean is able to absorb more heat. I’m guessing the Arctic Ocean on average is probably cooler than 4°C, so that might explain why the ocean hasn’t expanded more. If this explanation is correct, it would mean that ocean heat content measurements are biased for the same reason as HADCRUT global temperatures – inadequate coverage in the Arctic. -
HumanityRules at 14:18 PM on 21 April 2010Where is global warming going?
12.mspelto There's a couple of practical problems with the idea that the extra energy is hidden. While it could be anywhere in the ocean that we don't measure there remains the important question of how did it get there. Everything was accounted for pre 2003 so in that time period it wasn't heading for these unknown energy stores. After 2003 it must have started being sequestered but it wasn't detected transitting any of the regions we do measure to make it to these mysterious energy stores. We should take readings in those difficult regions not yet covered by the bouys but is there really any reason to believe we'll find the lost energy? -
HumanityRules at 14:04 PM on 21 April 2010Where is global warming going?
34.scaddenp The ocean doesn't just heat it also expands so there is a way of double checking the bouy data by using satellite data to measure sea level rise. For the present period (2003-2008) almost all the sea level rise is accounted for by melting land ice. That means very little thermal expansion, which means the energy is unlikely to be in the ocean. The bouy results are in agreement with the GRACE satellite data you don't just need to believe the bouy data. Secondly OHC was in line with expectations upto the mid 2000's before they began to diverge. So you have to believe that the data was fine and then became corrupted in some way. The reality is that the quality and coverage of the bouy ( and other ocean data) have only continued to improve a a time when we are meant to believe they have got worse. It's not just a matter of believing one or the other. -
HumanityRules at 13:11 PM on 21 April 2010Tracking the energy from global warming
Trenberth wasn't kidding when he says figure 1 is heavily smoothed and simplified. The other thing that confuses me is that it is meant to in some way relate to this figure.Now I realise this is in some way also a simplified graphic. But with no volcanic activity since 2000 to give those great spikes then a simple increasing nett radiative forcing and energy budget should be on the cards but it obviously isn't. There is obviously an extraordinary amount we don't know when it comes to the natural variation in radiative forcing and energy budget.
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scaddenp at 12:08 PM on 21 April 2010Where is global warming going?
33 - this "missing heat" comes about because of the discrepancy between OHC (heat stored) and TOA measurements (difference between incoming energy and outgoing energy). Heat leaving is measured so unless there is error in measurement, you can discount that. What do you trust most? The satellite measurements of heat imbalance or the buoy network of ocean temperature measurements? There is clearly an issue to be sorted out here. Its not about models - its about the heat balance. -
actually thoughtful at 10:55 AM on 21 April 2010Where is global warming going?
Don't we have to give serious consideration to the idea that either 1) the heat is not there to be missing or 2) the heat is leaving the atmosphere? I would be satisfied to know that this "missing heat" comes from the 2000s "lack of warming" - this is tongue in cheek as everyone knows the world warmed - even during an el nino and the very low sunspot activity. So are we missing heat that IS there and it is just finding it? Or are we worried the models are wrong because they predict heat we can't find (so it could have never existed or left the envelope)? thanks. -
GFW at 09:44 AM on 21 April 2010Where is global warming going?
Taking dscheidt's idea and running with it. Let's suppose we're trying to imagine a biological sequestration of 0.5 W/m2 over the whole planet via phytoplankton. Let's ballpark that as 1W/m2 over the most productive 70% of the ocean (therefore ~50% of the planet). Skipping a bit of math ... and charitably assuming that dead phytoplankton is nearly as nutritious (i.e. energy-laden) as pure sugar ... that's around 40g of excess material every 24 hours, in every square meter. So a patch of ocean 1000km by 1000km would create 40 mega-tonnes excess every day, which would be about 1.5 giga-tonnes per year. Scaling up to 50% of the planet's surface, that would be 300 Gt/y. Bearing in mind that this is excess, on top of "normal" it doesn't fit with estimates of the *total* biological rain over the entire ocean. which is on the order of 1 Gt/y -
Donald Lewis at 09:36 AM on 21 April 2010Where is global warming going?
Here is my pass at the graph where area is proportional to magnitude. http://docs.google.com/present/view?id=d5sm6vp_50k3vzx2g3 -
Glenn Tamblyn at 09:04 AM on 21 April 2010Where is global warming going?
RSVP @25 The most recent figure I have seen are Murphy et al which go from 1950 to 3002 and give the total heat rise as around 1 *10^23 Joules. Thats around 3 Billion Hiroshima bombs. So thats what we are taking a percentage of. -
Riccardo at 08:35 AM on 21 April 2010Where is global warming going?
dscheidt, the NASA image shows that there's an inverse correlation between phytoplankton productivity and temperature. -
Berényi Péter at 07:36 AM on 21 April 2010Tracking the energy from global warming
#55 HumanityRules at 23:43 PM on 20 April, 2010 I also hunted down this presentation Thank you. It is useful. I have copied the 2000-2010 TOA radiation imbalance figure here. Also, I took NODC Global Ocean Heat Content for the same period, computed its derivative and made a figure.figure 1
figure 2 If all went well, the lower graph in figure 1 would be proportional to that of figure 2. It is clearly not, they are not even similar. Fluctuations in OHC as measured by floats are almost an order of magnitude larger than in net radiation imbalance at TOA as measured by satellites. Sometimes not even the sign comes out right.
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dscheidt at 06:53 AM on 21 April 2010Where is global warming going?
Riccardo @ 26, Thank you for the links. You are correct that phytoplankton productivity has not been increasing during the period for which there is data [1998-2008]. Over that period the observed sea surface temperature hasn't increased. Indeed, in the Behrenfeld paper that you cited shows that there is a strong corollation between sea surface tempurature and ocean productivity. In short, if I understand Behrenfeld correctly, globally phytoplankton is behaving as expected with respect to temperature. Since we know that phytoplankton growth is endothermic the elevated levels of phytoplankton shown by Behrenfeld (with respect to pre-1998 levels) must be absorbing more energy than pre-1998 levels. The question is whether the amount of the negative feedback is significant. Of course, if the feedback was linear then one would expect to see a consistant divergence between temperature and missing energy, which we are not seeing. I suspect that it is, as it always seems to be with AGW, a more complex process. I'm not at all sure that the phytoplankton feedback effect is significant. I suspect that it's not. But I wanted to pose the question. -
hu? at 06:44 AM on 21 April 2010Trenberth can't account for the lack of warming
Thank you for your response yocta, but your answer does not address my question. Where does Trenberth claim satellites indicate an energy imbalance? (not a sea level rise). There are two satellite data-sets discussed in the paper, CERES and GRACE. Which one does Trenberth refer to with this warming quote, in your opinion? -
Jacob Bock Axelsen at 06:25 AM on 21 April 2010Are we too stupid?
embb A post ago you said that no one sees even the remotest chance for a trade war. Now it is "the lesser evil" and even real wars a possibility? Aren`t you a bit inconsistent? I claimed a tax and trade restrictions is not like a trade war. A trade war is the lesser evil as opposed to real war. I never denied the possibility of war. No inconsistency. I agree the type of fraud in the article does not affect the emissions. Still, a post ago you claimed there is no link between organized crime and emission trading... I doubted it. My bad. "Any asset market comprised of buying and selling non-physical, hard-to-measure goods is a con man’s dream."(...) Any game is a con man's dream. Strategies such as tit-for-tat amend that by stimulating cooperation through reciprocity. "An environment group slammed “false” carbon credit trading related to mainland China’s dams which allegedly *** undermines the Kyoto Protocol***, leading to a renewal of a carbon trading platform’s ban on the country’s hydroelectric power projects, reported South China Morning Post. " Apparently compliance can be checked in China. Contrary to what you persistently claim. If the US did not sign then most would agree that he did not become "bound by some tie" - as the act of signing means becoming bound to the agreement. So, there is no way for the US to defect on an agreement that was not signed. If USA signs it, they will come. If USA doesn't sign it, climate change will come. Cooperation or Defection. Take your pick. (...)are you suggesting the WTO fine the country that defects? Prison is of course meaningless in this context, so is tit for tat. I proved that taxes are always rigged to not be a dilemma. If there is no dilemma tit-for-tat will definitely beat all-defection. So US gets more money BY levelling the carbon tax on american companies and China gets a lot less by letting its companies become more competitive? In this case the 'prison time' can be substituted for 'trade restrictions'. You will see it makes sense. During the whole discussion I kept coming back to the point that the difference to the PD is that here we are not talking about individuals inside a state but about states with no organization above them. You keep coming back to explain trivial stuff about individuals. Unless you answer to my objections this is pretty much pointless. States, individuals - no matter. Tit-for-tat beats all-defection. No organization. No judge. No God. Just maths. they cooperated in Copenhagen? I missed that. Or maybe this wonderful change happened since December? If China, US and the rest of the world had signed a comprehensive deal to combat climate change it would have been wonderful? Absolutely. I was referring to the situation where a treaty to tax carbon emission was already in place. What is the point of even talking about game theory if you end up believing that the actors will not defect without any real analysis? I have never postulated that. It is the point of the post to analyse how to avoid defection. You must have missed that. Now, enough of what I know. What are your solutions to mitigate climate change? You must have something considering your clear stance. -
Riccardo at 06:17 AM on 21 April 2010Where is global warming going?
As mspelto pointed out there's the big unknown of the Arctic and the Antarctic oceans, we don't know much about what's happening down there. But I would say we do not know much about global ocean circulation either. For example, we know that convective mixing in the Labrador Sea stopped for a while and then resumed. Does anybody know why? Also, scientists are still debating on the behaviour of the North Atlantic thermohaline circulation or the fate of Anarctic Deep Water. These are huge amount of heat (energy, to make suibhne happy ;)). Although the overall picture is clear, the details are missing. Trenberth has shown he does not belive the ocean heat content measurements much (see the email exchange with Pielke Sr.). With him, I'd not be surprised if that heat is in part "hidden" somewhere there. -
mspelto at 05:58 AM on 21 April 2010Where is global warming going?
Albatross you are certainly correct that Trenberth has considered the polar areas. What to do to close that data gap is actually the focus of some new projects in the Arctic Ocean , and what Trenberth is trying to motivate us to do, better capture the energy balance of our globe. In the Antarctic the hidden area is under the ice shelves. or was in the case of Wordie Ice Shelf. -
Riccardo at 05:54 AM on 21 April 2010Where is global warming going?
dscheidt, phytoplankton productivity is not increasing. (See also here). -
RSVP at 05:00 AM on 21 April 2010Where is global warming going?
A car without shocks gives a bad ride and on a subjective level can seem horrendous, but the amount of energy related to these extra vibrations is very small. Similarly, the big blue circle representes a percentage, whereas its the absolute value that matters. -
Marcel Bökstedt at 04:33 AM on 21 April 2010Tracking the energy from global warming
John> Thanks for comment! And above all, thanks for this great site! I believe that you are right in that we should only consider change in energy imbalance, not the imbalance it self. The sign (positive or negative) of the second time derivative of the energy. A second derivative is clearly a priory something which is hard to measure. This also means that in figure 1, the relative height of the blue and the the black curve is arbitrary. We could as well shift the (entire) black curve downwards by a fixed amount to give a better fit. I'm not sure that Trenberth states as clearly as you do that the satellite data show that there is an increasing energy imbalance, but maybe I just haven't found where he does so. HumanityRules> From reading your links, I get the impression that the satellite data have not really arrived yet. At present there is a huge year to year variability and also a huge uncertainty, and in addition to that there is a suggestion that there might be systematic errors (instrument drift). On the other hand these measurements will eventually arrive, and become very important once they do. It seems to me that the black line in figure 1 is pretty close to a smoothing AND upwards shift of the green line in Figure 2.26 from the "presentation" you mention. As usual, I could be wrong about all this. -
Albatross at 04:02 AM on 21 April 2010Where is global warming going?
mspelto @12, You beat me to it. I was pondering the same thought after reading John's articles. The period of divergence does seem to coincide with the time when the Arctic has experienced a significant loss of sea ice (2005, 2007, 2008 and 2009 were all very low). So perhaps some of the "missing" energy has been sequestered into those portions of the Arctic Ocean which have been largely ice free during the "warm" season since 2005? As mspelto pointed out, there are no Argo floats or other instrument platforms up there to measure the OHC. Not sure about the Antarctic though, sea ice cover has not changed much, although if the Southern Oceans did have a role in this puzzle it would not surprise me. Anyhow, I don't want to presume to know more than Drs. Trenberth and Fasullo; they have probably already considered mspelto's idea in addition to many other possibilities.... -
dscheidt at 03:19 AM on 21 April 2010Where is global warming going?
Let me know if this makes sense. Consider the following: 1) Excess heat is radiated predominately into the oceans. 2) Algae growth increases due to increased heat. 3) Algae growth is an endothermic process therefore the increased growth absorbs a portion of the excess heat[ref Barinov et al, "Respiration energetics of marine algae for total heat production and some features of photosynthesis", Thermochimica Acta, Vol. 309, Is. 1-2, 1998] 4) Increased algae growth "consumes" both energy and C02, sequestering both on the sea floor eventually (either directly or indirectly) Could this account, at least in part, for the missing energy? -
Riccardo at 03:02 AM on 21 April 2010Where is global warming going?
suibhne, it's not very constructive to think that Trenberth doesn't know physics, besides being absurd. You are probably missing what Joule demonstrated more than a century centurie ago and the first law of thermodynamics. It's taught at the high school level, no need for a higher degree. Think twice before beliving that you know more than reputable scientists. -
chris at 02:53 AM on 21 April 2010Where is global warming going?
suibhne at 02:16 AM on 21 April, 2010 I don't think so. Your point might be worth considering if everyone has a Physics background or has taken a first year university introductory thermodynamics class! Trenberth's concept is pretty straightforward and easily understandable by the layman. If there is a radiative imbalance we expect an accumulation of thermal energy in the system. Why not call it "heat", since everyone can understand that? Once we've grasped the simple idea, then we can develop it towards more rigorous directions (the expected accumulation of Joules in the ocean under a radiative imbalance of so many W/m^2, and so on). I suspect Trenberth knows full well what he's doing - he's trying to communicate simple concepts in an easily understandable manner. -
Andy Skuce at 02:51 AM on 21 April 2010Where is global warming going?
Oops, sorry about that premature submission. I find the graphic to be a little misleading. The circles seem to be scaled so that their diameters are proportional to the percentages, whereas the implication from a graphic of this type is that it's the areas that are proportional. The area of the "ocean" circle (from my rough measurements) is about 750 times the area of the "atmosphere" circle. The point that the oceans are massive sinks of heat compared to the air, land or ice is still entirely valid, it's just exaggerated in that figure.Response: You're completely correct - it should be areas, not diameters. Should've thought of that (smacks forehead). Am updating the graphic accordingly. -
hank at 02:47 AM on 21 April 2010Where is global warming going?
> suibhne Look it up; you're wrong about language physicists use: http://scholar.google.com/scholar?q=climate+heat+storage+missing First year physics? where are you reading this stuff? -
suibhne at 02:16 AM on 21 April 2010Where is global warming going?
Anyone with a Physics background will wince at phrases like "heat storage" and "missing heat". A lecturer may have just finished taking a first year university Physics through an introductory thermodynamics class. Where it would be explained that for instance it would be wrong to say that the higher temperature reservoir contained "a lot of heat". The correct description would instead use "internal energy". Heat it would be explained is reserved for the process by which energy is transferred from a body at a higher temperature to a body at a lower temperature. Its disappointing that leading NCAR scientist Kevin Trenbertht uses phrases like “missing” heat." and “The heat will come back to haunt us sooner or later,” Perhaps he doesn't know any better! -
Chris G at 01:51 AM on 21 April 2010Where is global warming going?
Re #15, Yes, the polar regions are still cold relative to everywhere else. I don't find that surprising. But, I'm wondering if you are totally disregarding GISS data. http://data.giss.nasa.gov/gistemp/graphs/ -
Berényi Péter at 01:38 AM on 21 April 2010Where is global warming going?
#12 mspelto at 00:46 AM on 21 April, 2010 The arctic in particular has had high air temperatures Come on. The "Arctic" has only one active GHCN station in Canada. It is Eureka, Nunavut (79.98 N, 85.93 W). This year the average March temperature there was -32.2 °C. It is higher indeed than the multi-year average of -37 °C, but still damn cold. And all the excess heat comes from a brief hot spell at the end of the month when temperatures reached an unbelievable high of -9 °C (between 7 AM and 4 PM, 29th March). -
Chris G at 01:36 AM on 21 April 2010Where is global warming going?
Re 12 MsPelto, While the distribution of buoys may not be very uniform, I don't think that can be eyeballed from that map. The map, like most flat maps, suffers the distortion of projecting a globe onto a flat surface. Nice article. I was trying to imagine the relative sizes of the various possible heat sinks, and it was very fuzzy to me, then click, there it is. -
embb at 01:22 AM on 21 April 2010Are we too stupid?
Jacob:For two agents the 'tax-payment-game' is trivial and looks something like this: i) Mutual defection and temptation is the initial saved tax payment, tax, plus the high probability of a fine, fine=tax, and N years in prison: pay-off = tax - fine - N*income << 0. Okay, let us make this concrete. We are talking about carbon tax in the Us and China say. temptation is to lie about the carbon enmission and to not tax the local companies for energy consumption, thus acquiring a competitive advantage on the world market. Fine - are you suggesting the WTO fine the country that defects? Prison is of coursemeabningless in this context, so is tit for tat. Naturally, on top of this comes the future cost of indirect reciprocity from your surroundings that disapprove of parasitic freeloaders. However, you benefit from the public goods financed by the tax. You mean the world public opinion? ii) Mutual cooperation and being cheated is 0 plus the public goods financed by the tax. Your average payoff when cooperating is larger than 0, and your average payoff when defecting is much less than 0. No dilemma. So US gets more money BY levelling the carbon tax on american companies and China gets a lot less by letting its companies become more competitive? I really dont see how this should work, can you explain? During the whole discussion I kept coming back to the point that the difference to the PD is that here we are not talking about individuals inside a state but about states with no organization above them. You keep coming back to explain trivial stuff about individuals. Unless you answer to my objections this is pretty much pointless. Jacob:China, inspite of being a communistic dictatorship, has already understood the pay-off from international trade and domestic entrepreneurship. Oooh, so they cooperarted in Kopenhagen? I missed that. Or maybe this wonderful change happened since December? What is the point of even talking about game theory if you end up believeing that the actors will not defect without any real analysis? If you disagree, then by all means, try to disprove it.
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