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Rob Honeycutt at 01:12 AM on 10 April 2014CO2 is not the only driver of climate
roosaw... Here's the RF chart from IPCC AR5 that has them broken out...
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John Hartz at 00:54 AM on 10 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
chriskoz:
Does your estimate of the length of time it would take to restore a rainforest in Indonesia take into account the full restoration of the peat foundation of the forest?
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roosaw at 23:34 PM on 9 April 2014CO2 is not the only driver of climate
In the rediative forcing graph it shows "well-mixed greenhouse gases". Is there a breakout of CO2, H2O, methane etc to show the relative importanct to the effect?
and a related question, when we burn a fuel we get CO2 and H2O in a 3:4 ratio (typical). Since H2O is a more potent green house gas why all the hupla on CO2 and not the incresed H2O?
Moderator Response:[TD] Water vapor's concentration in the atmosphere is limited by temperature. Putting more water vapor into the air than the air's temperature will support causes the excess water to drop out in about 10 days. Therefore water vapor is a feedback to temperature increase, not a forcing. See the rebuttal to the myth Water Vapor is the Most Powerful Greenhouse Gas.
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chriskoz at 23:31 PM on 9 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
Having watched this episode, I have to single out one inaccuracy/exaggeration: Ford's reporting on Indonesia's forests cleared for oil palms. The report states that once the trees are removed/burned, the carbon sequestered in them espaces to the atmosphere and is "lost forever".
That's incorrect. There might be other environmental issues with clearing the forests and the local environmental loss may be big. But in terms of global CO2 balance, the indonesian forest removal will be balanced by increased carbon intake by the biosphere. Further, even the restoration of said forests, although hard, is possible in a timeframe of few 10s to 100 years which is much less than "forever". And certainly, those who believe we can mitigate by drawing down CO2, point to planting forests and harvesting their wood then preserving it in form of furniture as the realistic way to achieve it.
By contrast, the main source of emmisions - fossils fuels dug from thte ground - contains carbon 100s My old - and that's indeed "forever". And there are no knwon methods of reduce its most oxydised form (CO2) all the way back to the form it came from (FF), nor any method to put it back to the ground.
So the FF emmsions are litteraly milion times more serious than land clearing. I claim that undoing the damage of FF (properly, without side effects like ocean acidification) is also about the same million times harder than undoing land clearing.
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Tom Curtis at 22:41 PM on 9 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
Klapper @53:
1) The data is not detrended, and nor has their been a lack of warming. Rather, the variation in SST in the NINO 3.4 region due to ENSO is very large relative to the warming due to global warming. The result is a large standard deviation of the values, and consequently the small trend due to global warming does not register as statistically significant. None-the-less, it is still there.
2) Re NINO 3.4 vs SOI, here is a direct comparison for the period over which we consistently have values for the SST in the NINO 3.4 region:
As a result of normalizing the values, it is easy to see that both are comparable as to ENSO values, and as to thirty year trends. It also allows a direct comparison of trends in units of standard deviations. Over the interval 1949-2012 inclusive (the period examined), the linear trend in NINO 3.4 is 30% larger than that for the SOI. That is consistent with a global warming trend being incorporated into the NINO 3.4 index (as it must be of necessity due to the nature of that index). Further, the consequences of including that trend are just as I predicted.
So, switching to NINO 3.4 does not significantly help your case; but it does have the disadvantage of incorporating a global warming signal in your ENSO index, thereby confusing the issue.
On a side note, from 1884 to 1949, blocks of up to six years data are missing from NINO 3.4. You may prefer NINO 3.4 for calculating the trend from 1916-1945, but that thirty year trend has ten years data missing from it, in two seperate blocks and is hardly reliable. This contrasts with the effectively complete record for the SOI.
3) Re volcanoes, the logic is very simple. Suppose you think models over state the temperature influence of volcanoes. From that supposition, it follows that the models will understate trends more relative to observations when it has a large number, or very large volcanoes in the last 15 years of the 30 year trend, and overstate them when the volcanoes are in the first 15 years of the 30 year trend. As the current thirty year trend has the influence of two large volcanoes in the first 15 years, that means if the models overstate volanic influence, then part of the discrepancy between models and observations is due to that problem rather than to the models running generally hot. It appears to me that you want to have your cake and eat it - it to state models overstate the influence of volcanoes, but also to interpret the full discrepancy between observed and modelled trends as due to models running hot.
For what it is worth, I am inclined to think that the models run slightly hot (about 15%), and that the models do overstate the cooling influence of volcanoes so that both factors are in play. However, regardless of what we think, you cannot assess how hot the models run in a period with trends significantly influenced by recent volcanism (such as the current period) without examining what effect the volcanoes have on the trend. You can, of course, take an average over periods when the volcanoes inflate model trends, and periods when they deflate the model trends to find the approximate average of how hot the models run with respect to the underlying trend, which brings us back to where we were eight days ago.
4) What your thoughts are do not matter. You have not provided evidence or reasoning to justify those thoughts. Indeed, your current position seems to be no different from that nine days ago when you though models ran 40-50% to hot based only on the most recent 30 year trend, and without regard to the influence of ENSO and volcanoes on that trend. Since then we have seen that:
1) Averaged accross many thirty year trends, models are on average 13-18% to hot;
2) ENSO has a substantial influence on thirty year trends, which is not reflected in the models;
3) Volcanism has a substantial influence on thirty year trends, which may differ between models and observations; and
4) If models overstate the cooling effect of volcanoes, then both ENSO and volcanic influences on the most recent thirty year trend tend to exagerate the discrepancy between models and observations - potentially by a large margin.
And you still show no willingness to revise down your estimate of how hot models run relative to observations!
Is there any point in continuing at this stage?
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Klapper at 18:56 PM on 9 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
@Tom Curtis #52:
There is no significant long term trend in the NINO3.4 data so either the data have been detrended by the originater or there is no warming in the east central Pacific over the last 100 years. Either way, it seems it's an OK metric to use as a proxy for ENSO. I do agree the pre-satellite era Nino3.4 data are suspect since they no doubt rely on Re-analysis to fill what are probably large holes in the data.
As for the disruption volcanoes pose to the CMIP5 vs SAT trend analysis, I'm having hard time discerning your logic. Do you think the CMIP5 models do a good or poor job of emulating the radiative forcing from large volcanoes? If you believe the former, then volcanoes can't be a significant reason for the CMIP5 to SAT 30 year trend error.
I can agree the recent 30 year trend in SAT has been suppressed by an ENSO bias, which the CMIP5 models don't emulate, but I'm surprised that you think volcanoes are also part of the discrepancy. In theory the models and empirical data are both influenced by these major volcanic events equally.
Summarizing my thoughts, the current discrepancy between model and empirical data 30 year trends is partially due to the models inability to emulate ENSO, and possibly some problems with the emulation of volcanic forcing, but most of the problem is that the models run too hot, that is they have some error in the feedbacks to GHG forcing, in addition to whatever problems they have with ENSO or volcanic aerosol forcing.
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Russell at 16:31 PM on 9 April 2014Recursive Fury: Facts and misrepresentations
The 'skeptics' have subscribed to, and serially rejected, so many alternative explanations of global warming that their rejection of the flat earth hypothesis ranks as a statistical outlier.
It is unfortunate that Frontier did not conduct enough legal diligence to realize the wannabe plaintiffs would be laughed out of court.
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Tom Curtis at 13:43 PM on 9 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
Klapper @51, IMO Nino 3.4 is clearly inferior to SOI as an ENSO index because it incorporates any global warming signal as a positive ENSO signal. That is, over time it will progressively inflate El Nino values and deflate La Nina values simply because the central Pacific SST are increasing in temperature due to global warming. If you are going to use a temperature based index, you should at least use the ratio of NINO 3.4 to the average of all tropical Pacific SST from + to - 15 degrees Latitude, and from the west coast of the Americas to the West tip of Sumatra so that any uniform warming across the Pacific is eliminated from the signal. Failure to do so renders any argument about the relative effect of ENSO and an underlying global warming trend futile in that you have incorporated the underlying trend in your ENSO signal. You will also have incorporated some part of the volcanic signal in your ENSO signal - again rendering discussion of relative influences futile.
I am not wedded to the SOI per se. An index based directly on the strength of the Walker circulation, or even better on relative Sea Levels in the Western and Eastern Pacific would also be good indices. However, we do not have accurate indices of those values extending back in time, wheras we do for the SOI.
Further, the volcanic trends are relevant to this discussion because:
a) It is quite possible that the model mean does not capture the actual temperature response to volcanoes; and certainly the observed temperature does not because there are confounding factors that cannot be eliminated (primarilly, but not exclusively, ENSO).
b) The large difference in thirty year trends between AR4 and AR5 are at least in part a simple consequence of the impact of volcanoes on the trend. As the impact of one of those volcanoes, and the one having the most influence on the trend for the last few years in the models, was scrubbed out by a concurrent El Nino in the observed record, any simplistic comparison between observed and model mean trends which does not factor in the effects of ENSO and volcanoes will come to mistaken conclusions.
c) Failure to recognize the impact of volcanism on the model mean trends will lead you to project any current inaccuracy into the future. However, that inaccuracy may be due to inadequate handling of volcanoes, but a correct determination of the underlying trend. In the later case, the underlying trend shown for the rest of the century will still be accurate.
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Klapper at 12:19 PM on 9 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
@Tom Curtis #50:
I use NINO3.4 as my proxy for ENSO, not inverted SOI. Certainly this is a better metric in the satellite era since the SSTs are a direct forcing as opposed to SOI which is indirect. The Nino3.4 trend is in fact close to zero for the period 1916 to 1946 (my spreadsheets do use 30 year trends, i.e. Jan. 1917 to Dec. 1946, not 31, but I use the years only for shorthand). Anyway, I don't think I've made a mistake; the period in question is ENSO neutral by the NINO3.4 metric.
As for your ongoing comments about volcanoes; if you are saying they are some part of the reason for the discrepancy between CMIP5 and SAT, I can agree, but not the way you would like. Volcanoes are in fact modeled by CMIP5 so if you want to claim the models do a good job of modelling the volcanoes, then they are not part of this argument. Unlike ENSO, vulcanism affects both the models and the empirical data, supposedly equally, so they don't belong in this discussion. Either the major volcanoes are modeled well, meaning they are not part of the CMIP5/SAT discrepancy, or they are not modeled well in which case I would agree.
As for the 1969 to 1998 trend, the differences are modest compared to the current discrepancy which you accrue to ENSO error. Look at your own graph. The error just keeps getting bigger but the trend in NINO3.4 now is less in magnitude than 1998.
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citizenschallenge at 05:49 AM on 9 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
Thanks for posting this. I hope the video get's around.
FWIW: "Years of Living Dangerously - facing what's happening"
http://whatsupwiththatwatts.blogspot.com/2014/04/years-of-living-dangerously-facing.html
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Tom Curtis at 04:27 AM on 9 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
Klapper @46, sorry for the delayed response.
1) Here are the running thirty year trends on annual inverted SOI:
To determine the trend by start and end year, subtract 15 for the start year, and and 14 for the end year. Thus for the trend shown for 1931 in the graph, it has a start year of 1916 and an end year of 1945. You will notice that it has a 30 year trend of 0.213 per annum, a trend you mistakenly describe as "ENSO ... neutral". Rather than being ENSO neutral, it is the highest thirty year trend up to that date. It is just exceeded the following year, but not again exceeded till the trend of 1954-1983 (1969).
2) Here are the successive, inverted 360 month trends in stratospheric aerosol forcing as a proxy for the impact of volcanoes:
First, I apologize for the lack of dates. My spreadsheet did not want to put them in, and as I am only posting at the moment due to insomnia, I am disinclined to push the issue. The dates given on the graph are for the first initial month, and the last terminal month of the trends. It should be noted that actual volcanic response will be both slower, and more dispersed due to thermal inertia. The trends have been inverted so that positive trends on the graph will correlate with positive trends in temperature, all else being equal.
That brings us to the key point. You point to the strongly positive thirty year trend in ENSO from 1969-1998 as being a point where we would expect divergence between models and observed temperature trends. That period, however, coincides with a period with a significant negative trend in temperatures due to volcanism, as seen above. The actual negative trend for the Jan 1969-Dec 1998 is about half that at the trough indicated, but that strongest negative trend would have been delayed due to thermal inertia. Therefore it would have coincided very closely to the period you point to, suggesting that ENSO and volcanic influences are appreciably mutually cancelling effects in that period so that the observed temperature trend will be close to that due to the underlying forcing.
It should be noted that the volcanic influence becomes positive about terminal year 2002 and becomes strongly positive thereafter - an effect felt strongly in models, but cancelled by the strongly negative ENSO trend in observations.
3) Finally, here are the RCP4.5 vs Observed trends:
You will notice that in the year 1984 on the graph (initial year Jan 1969, terminal year Dec 1998), the observed trend is greater than the model trend. The precise values are: Modelled trend - 0.148 C/decade
Observed trend - 0.162 C/decade
This is despite the fact that on average observations run cooler than the models. In fact, the baseline trend for the period is about 0.2 C /decade for models, but 0.17 C/decade for observations, showing the modelled trend to have been reduced by approximately 25% due the the effects of volcanism (and a cooling sun), whereas the observed trend is scarcely reduced at all (due the the counteracting effect from ENSO).
You will also notice the clear pattern from the exaggerated model trend due to the effects of volcanism as discussed in my prior post.
To summarize, you presented two counter examples to my claims about the interactions of volcanism and ENSO in influencing the observed and modelled thirty year trends in Global Mean Surface Temperature. One of those counter examples is shown to be invalid because, whereas you describe it as ENSO neutral, it in fact shows a strong ENSO trend, and presumed ENSO influence on temperatures. The second counter example raises a valid point, ie, that we should expect the observed trend to be exagerated relative to modelled trend for the period 1969-1998. However, that fails as a counter example because the observed trend is exagerated relative to the modelled trend over that period, and even more so once we allow for the generally slightly (15%) lower observed relative to modelled trends. Detailed examination of the data, therefore, shows your "counter examples" to be in fact "supporting instances" - and shows the general validity of the account I have laid out here.
It should be noted that I do not presume that ENSO plus the standard forcings (including volcanic and solar) are the only influences on GMST. They are not - but they are the dominant influences. So much so that accounting for them plus thermal inertia results in a predicted temperature that correlate with observed temperatures with an r squared greater than 0.92
(Note, you in fact quoted 31 year trends rather than 30 year trends. I have therefore used the nearest relevant 30 year trends in discussing your points.)
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One Planet Only Forever at 23:20 PM on 8 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Poster @ 11:
I'm not sure I follow the basis for your comment that I ignore the burning of fossil fuels in the internal combustion engine. My third point is the catchall of the unacceptability of any burning of fossil fuels. That activity is not just fundamentally unsustainable, putting at risk the future of any economy or society that relies on it, but it creates many harmful unsustainable results in addition to the excess CO2.
My fundamental position is that the only future for humanity is for all human activity to be 'restricted' to truly sustainable activity as part of a robust diverse web of life on this amazing planet.
So my view not only includes the need to curtail any burning of fossil fuels, it includes the need to ciurtail any consumption of non-renewable resources. The only acceptable use of a non-renewable resource should be no accumulating damage done getting the resource and converting it into a useful product and absolutely full recycling of the material...forever...
Humanity has several hundred million years to enjoy on this planet. They can't consume it along the way. The same applies to any thoughts of spreading life beyond this planet. If what we spread is the current attitude we spread a damaging disease, not sustainable life.
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Poster9662 at 17:35 PM on 8 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Comment@10. You,apparently, blithely ignore the burnign of fossil fules by the internal combustion engine. This aspect of the "West's" profligacy is rarely mentioned as too many in the "profligate West" rely on this to maintain their lifestyle, Rather than focus on "solar and wind" more Draconian actions on use of the ICE would be appropriate
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One Planet Only Forever at 13:03 PM on 8 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
A few points:
1. I am pretty sure that the scientific global average surface temperature increase of concern has been, and continues to be, 1.5 decgrees C. That is the temperature beyond which climate changes are likely to become less predictable combined with being more signficant. The 2 degree C limit is the result of global leaders in Copenhagen acknowledging that the failure of the most fortunate to significantly reduce the impacts of their lifestyles, including exporting larger amounts of their impacts to nations like China and India, has made it very unlikely that impacts can be limited to a 1.5 degree C increase.
2. The economic evaluations ignore one critical aspect. The people expecting to benefit most from failing to reduce the burning of fossil fuels is not the group that is expected to suffer the consequences of their irresponsible unsustainable and damaging activities.
3. The economic evaluations also typically ignore the fundamental unsustainability of burning fossil fuels. And they ignore far more unsustainable and damaging consequences than the results fo the excess CO2 that is produced.
4. Many economic evaluations actually discount the future costs, claiming a future cost is not as important as a current benefit. Though this is a valid way of evaluating alternative investment opportunities, it is a totally inappropriate way of evaluting the merits of current day activities. The only legitimate value of a current day activity is the benefit obtained into the future. By that measure it is clear that the current burning of fossil fuels is essentially a worthless activity.
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KR at 12:21 PM on 8 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
Matzdj - My apologies, I overlooked part of your question.
"How are these effects [ENSO, volcanic action, solar changes, etc] removed?"
The scale for the effects of these variations are derived from statistical models, namely by the use of multiple linear regression of the time signatures of those variations against the time signature of temperature. See Foster and Rahmstorf 2011 and Lean and Rind 2008 for details. And in anticipation of one of your potential questions, F&R 2011 in particular examined these variations against various lag times, which means that nonlinear responses of the climate to those forcings average out to zero in the long term - any mismatch between linear/nonlinear response cancels out.
There are other methods for these scale estimates which are in general agreement - see John Nielsen-Gammons estimates of ENSO effects, or any of the many papers on the climate effects of Pinatubo.
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KR at 12:03 PM on 8 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
Matzdj - Your first question was answered quite succinctly by Kevin C above; there are parameterizations for physics below model resolution, which are driven only by the match to observed behavior at those small scales - local physics only. There are, however, no statistically fitted parameters for global temperature response - that is an emergent result of the large scale physics, and certainly not (as you implied in your first post on this thread) a result of tuning the global model to provide a certain answer.
As to the second question, running a GCM takes quite a bit of time and effort, note the amount of computation - they are not something you want to (or can) run every afternoon, even if you have a supercomputer cluster just hanging around. The CMIP3 and CMIP5 model runs started with a specified set of forcings, including projections through the present, and were run on those common forcings for model comparison. If the set of forcings used in those sets of model runs were constantly changing, there would never be a time when all the various modellers were working from the same set of data, no way to compare models or to look at their spread.
But as to what happens when forcings don't match the projections of a few years ago, read the opening post and look at figure one.
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Matzdj10109 at 11:29 AM on 8 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
Thanks to all who responded to my questions above. I have two follow-ups:
1. I believe I am hearing that climate models have no constants in the models whose values are determined by fit to the actual data? is that true? I am very surprised because I have been led to believe that in some cases, for instance cloud formation, that we do not understand the physics well enough to precisely put them into the model ? Can you give me a reference to review one of these models that have no constants that need to be multiple-variable-regression-fit to actual data before they can be used for forecast?
2. I also am hearing that when you remove the effects of El Ninos, La Ninas, volcanic eruptions, etc. that what's left fits the observed data really well. How are these effects removed? How is the effect of a strong El Nino removed differently than the effect of a weak El Nino, or the effect of a big volcanic eruption versus the effect of small one?
If we understand how to remove these from the models at the correct intensity of effect, based only on physics, when they occur, then we should be able to put them into the model as zero effect when they are not occurring and then add their effect each time one does occur with the effect that was predetermined for that intensity of event.
These are major short term forcings. Why aren't they included in the models to incorporate their effect each time they occur?
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gws at 08:28 AM on 8 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
Note that the project comes with an educator resource linked through the main page, http://www.climateclassroom.org/. It is sparsely populated yet, but since movies generally make a good entry point for discussion, reinforcement, and motivation, it may become a useful resource, including for house (watching) parties.
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John Hartz at 07:34 AM on 8 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
The Tipping Points series cited by Jim Eager premiered on the U.S. Weather Channel in October of last year. An informative article about the series, Weather Channel series takes journey to Earth's tipping points, was posted on the Mother Nature Network website on Oct 10, 2013.
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Jim Eager at 06:58 AM on 8 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
Another good series is The Tipping Points,
currently showing on TVOntario
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John Hartz at 06:41 AM on 8 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
Another prominent U.S. female climate scientist is Heidi Cullen, who together with Joe Romm functioned as the science advisors to the production of Showtime's ‘Years of Living Dangerously’
Climate Central has posted a video of Cullen's appearnce on yesterday's NBC News Sunday show, Face the Nation. The post is Heidi Cullen Talks IPCC on Face the Nation. Cullen also discusses her role on the Showtime series.
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gws at 03:46 AM on 8 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
good post, giving context to the risk management nature of climate change
minor detail: IMHO, the text stating
"... the accelerating nature of climate damage costs with more warming would still mean that greater climate uncertainty translates into more climate damages."
should better be
"... the accelerating nature of expected climate damage costs with more warming would still mean that greater climate uncertainty translates into higher risks of climate damages."
since uncertainty does not directly translate to higher costs, by higher risks. The change keeps it more consistent with the remaining text, I think.
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Rob Honeycutt at 03:34 AM on 8 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
I watched it just this morning. All I can say is: Fantastic!!
I'm just floored by the important work that Katherine Hayhoe is doing. She's just amazing.
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Rob Honeycutt at 03:30 AM on 8 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Poster... Just to add a good visual for what KR is saying about asymmetry:
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vrooomie at 03:05 AM on 8 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Re: KR's mention of the 'long tail:' here's but one good explication of why this is a critical, but oft-overlooked aspect of what turns out to be a widespread and poor understanding of risk analysis.
http://earlywarn.blogspot.com/2010/05/explaining-long-tail-climate-risk.html
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vrooomie at 03:00 AM on 8 April 2014Watch Episode 1 of James Cameron's "Years of Living Dangerously"
I viewed this as soon as I saw a link to do so: it's *great* to see this level of attention paid to this critical and very real issue. Along with this, and NBC's program of last night, I expect a howl of protest from the denialati, which I will listen to with great relish. The louder the scientific community makes them howl, the loonier they will appear, and the sooner we can get down to the brass tacks of doing what we *all* need to do, to mitigate the oncoming damage.
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KR at 00:19 AM on 8 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Poster - This is tendency, for uncertainties to increase the cost risks, is exacerbated by the near lognormal distribution of sensitivity estimates. The high tail of sensitivity estimates is much longer than the low tail, meaning that for equal probability estimates the weighted high end will increase the total risk cost far more than the equal probability weighted low end will decrease total risk cost.
Add the asymmetric sensitivity estimate to the rise in risk cost due to larger uncertainty spreads, and the financial risk is considerably higher than if we had a highly constrained estimate of climate sensitivity. Uncertainty is not our friend.
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Kevin C at 23:28 PM on 7 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Poster:
The conclusion is based on how financial risk is calculated. If there are multiple possible outcoomes, you have to take into account the cost of all possible outcomes, weighted by the probability of each of those outcomes.
Increasing uncertainty increases the probability of both high and low cost outcomes. However the shape of the cost curve is such that the finacial risk, calculated using the above method, increases.
This is the standard approach used by insurers, investors and gamblers for decades or centuries, however the issue is clearly confusing to a lot of people.
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Poster9662 at 22:38 PM on 7 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Reading the summary from the University of Bristol I am puzzled by this comment " Scientists have shown that as uncertainty in the temperature increase expected with a doubling of carbon dioxide from pre-industrial levels rises, so do the economic damages of increased climate change. Greater uncertainty also increases the likelihood of exceeding ‘safe’ temperature limits and the probability of failing to reach mitigation targets" Why is the uncertainty focussed only on increases in temperature (and on sea level rises)? Surely if the uncertainty in rises is increasing, isn't the uncertainty of stabiity or even falls in temperatures (and falls in sea levels) also increasing. Why does greater uncertainty also not increase the likelihood of not exceeding "safe trmperatures'? Why is ths aspect not considered worth a mention?
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localis at 17:19 PM on 7 April 20142014 SkS Weekly Digest #14
At least future earthlings (if there are many) will find a wonderful record of how accurately we measured our own destruction while doing nothing to stop it.
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johnsnz at 15:56 PM on 7 April 20142014 SkS Weekly Digest #14
Because the human psych is alien and that intellegence-wise we are barely at the cave mouth, its only natural that way deep down we will get off this planet - perhaps to return home?
In a mad rush theres always stumbling, no and wrong decisions. Lets relax, just embrace GW and over population as prompts to capitalise on our technological prowess to make it all happen.
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barry1487 at 15:25 PM on 7 April 20142014 SkS Weekly Digest #14
Checked, they are the final drafts, yet to be edited.
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One Planet Only Forever at 14:47 PM on 7 April 2014Earth has a fever, but the heat is sloshing into the oceans
Bob Laidlaw @ 15,
There are indeed many statistical methods to try to figure out what has been happening in the later part of a set of data points in an extensive series of data with values widely, and occasionally rapidly, fluctuating due to significant random influnces.
However, such evaluations can be challenged, and require reworking, as soon as the next randomly influenced value is added. That does not occur with a simplistic evaluation like a 30 year roilling average. Even wildly aberrant values such as the 0.5 C degrees changes of one month to the next or the 0.35 C chnages form one year to the next in the GISTEMP data set are smoothed by beig averaged with the opposite aberations within the larger set of averaged values.
Also, as I clarified, accounting for the random significant influencing factors would allow a more reasonable evaluation.
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One Planet Only Forever at 14:31 PM on 7 April 2014Earth has a fever, but the heat is sloshing into the oceans
Klapper @14,
As I mentioned, what I mean by a rolling average is that I calculate a new 30 year average for every new month of data. And the 30 year rolling average can also show 'rates of change'. More importantly, temporary eroneous fluctuations cannot give credence to unjustifiable misleading claims based on evalautions of temepratures since moments like the last major temporary induced extreme in the global average surface temperature data.
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barry1487 at 12:40 PM on 7 April 20142014 SkS Weekly Digest #14
The Daily Fail has once again posted a pack of lies.
The article claims that conclusions have been changed from the "original" WGII report, but what they actually do is quote sentences on one of a variety of opinions in the body of the report (Chapter 9 on migration, Chapter 12 on conflict), and present them as conclusions.
IPCC have responded to the article.
http://www.ipcc.ch/pdf/press/140406_statement_mail_online_statement.pdf
The references to the underlying report cited by the Mail on Sunday in contrast to the Summary for Policymakers also give a completely misleading and distorted impression of the report through selective quotation. For instance the reference to “environmental migrants” is a sentence describing just one paper assessed in a chapter that cites over 500 papers – one of five chapters on which the statement in the Summary for Policymakers is based. A quoted sentence on the lack of a strong connection between warming and armed conflict is again taken from the description of just one paper in a chapter that assesses over 600 papers. A simple keyword search shows many references to publications and statements in the report showing the opposite conclusion, and supporting the statement in the Summary that “Climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence...”.
For instance, the Mail quotes this sentence as being the "original" conclusion.
While alarmist predictions of massive flows of refugees are not supported by past experiences of responses to droughts and extreme weather events, predictions for future migration flows are tentative at best.
But that is a verbatim quote from the abstract of one paper mentioned in Chapter 9 [Tacoli (2009)], and in no way a concluion.
(Don't know if these are final. Seem to be)
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Klapper at 12:00 PM on 7 April 2014Climate Models Show Remarkable Agreement with Recent Surface Warming
@Tom Curtis #45:
" ..looking at the effect of adding just eight years data on thirty year trends is little better than focusing on eight year trends..."
I don't agree. There has been a rapid divergence over the last 8 years between the CMIP5 projections and empirical data 30 year linear trends. You've given some reasons, namely the timing of ENSO and volcanos, but in both you are assuming both are just noise confounding the true warming signal.
In the case of ENSO I don't agree that it is just noise. But for the sake of argument let's assume ENSO is just noise. Let us also assume the models also respond correctly to volcanos, so the error between the model and SAT trend cannot be attributed to volcanic espisodes. Again, I don't agree, I think the models overcool during volcanic episodes, but for the sake of argument...
So then let us then run a rolling 30 year trend on ENSO to find the coherence between model and empirical warming trends. Since the models don't replicate ENSO, the coherence should be good in periods when the ENSO trend is neutral and not so good when the ENSO trend is either positive or negative, right?
In some periods where the ENSO trend is basically neutral, like 1936 to 1966, and 1976 to 2006, the CMIP5 trend agrees with the SAT 30 year trend. However, in other periods where the ENSO 30 year is neutral (1916 to 1946), there is significant divergence, indicating the models are in error for some reason, either incorrect treatment of aerosols, incorrect aerosol data, or possibly incorrect treatment of GHG forcing.
Likewise, in some periods where there are strong trends in ENSO, the models have good coherence with SAT, which is puzzling, since in theory they don't "know" about ENSO. Take the 1968 to 1998 period for example, there is a strong positive trend in ENSO, which should mean the models underestimate the warming. In fact in this period the models are in good agreement with the 30year SAT trend.
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johnthepainter at 11:24 AM on 7 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
The idea is familiar. In fact, I just sent a letter to my congressman in response to his response to an earlier one I sent him. He indicated that the cause of global warming was still in doubt and called (twice) for more study. I argued that we know enough to be aware that the risk is high, and the need to act is urgent. I quoted this excerpt from William Nordhaus's devastating analysis of the letter that sixteen scientists (if you include some engineers and an astronaut/senator in the count) published in the Wall Street Journal in 2012, in which they cited Nordhaus to buttress their position that it was best to do nothing about global warming. He rejected the position they attributed to him and, on the idea of uncertainty as a basis for doing nothing, he wrote,
"One might argue that there are many uncertainties here, and we should wait until the uncertainties are resolved. Yes, there are many uncertainties. That does not imply that action should be delayed. Indeed, my experience in studying this subject for many years is that we have discovered more puzzles and greater uncertainties as researchers dig deeper into the field. . . . Policies implemented today serve as a hedge against unsuspected future dangers that suddenly emerge to threaten our economies or environment. So, if anything, the uncertainties would point to a more rather than less forceful policy—and one starting sooner rather than later—to slow climate change."
Richard Alley made the same point in a lecture, saying, "The less you trust me, the more worried you should be."
The new research is a welcome addition to buttress this argument. -
Bob Loblaw at 11:05 AM on 7 April 2014Earth has a fever, but the heat is sloshing into the oceans
With regard to moving energy or heat from the surface into the deep oceans without warming the middle depths:
Energy transfer by convection or mass transfer has some rather subtle features that may come as a bit of a surprise if someone is stuck in a mind-set of conduction/diffusion thermal transfer.
Let's take the analogy of three rooms with connecting doors. The three rooms have temperatures of +20C, 0C, and -20C. Each room also has a large box, full of air equilibrated to room temperature.
- I pick up the box in the +20C room, walk through the middle room to the -20C room, while at the same time another person picks up the -20C box and walks through the middle room to the +20C room.
- at the end, the +20C room is now colder. It has a box of -20C air, which will (over time) equlibrate with the room, slightly cooling the rest of the room.
- the same happens at the -20C room: it has a box of +20C air which will warm the -20C air slightly as it equilibrates.
Note that there has been no net transfer of mass - each room at the end has lost a box and gained a box of air.
There has been a transfer of energy from the +20C room to the -20C room.
And most important of all: the room in the middle has not changed its temperature (energy content).
The same can heppen in the ocean: warm water from the surface to the deep ocean, offsetting water mass moving from the cold depths to the surface, No net mass transfer, but an energy transfer, and the middle layers just watch in fascination.
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Bob Loblaw at 10:52 AM on 7 April 2014Earth has a fever, but the heat is sloshing into the oceans
Rolling averages? Not perhaps the best way of smoothing things, particualrly if you are interested in what is happenng at the ends of the time series.
Tamino has a good three-part series on the subject, from earlier this year:
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John Hartz at 10:21 AM on 7 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Poster::Your comment is off-topic and therefore was deleted.
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Klapper at 10:14 AM on 7 April 2014Earth has a fever, but the heat is sloshing into the oceans
@One Planet Only Forever #2:
"I personally prefer to use a simple spread sheet to follow the rolling 30 year average of the GISTEMP Land-Sea monthly average (a new 30 year average for every new month)"
Aren't we more interested in changes in the warming rate? Why not do your analysis on a rolling linear trend of the last 30 years, instead of a rolling average?
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One Planet Only Forever at 07:40 AM on 7 April 2014Video: Climate science crash course by Dana Nuccitelli with Citizens Climate Lobby
I agree it is great to see examples of faith-based and politically-fiscally conservative individuals who acknowledge the need to change the system to undo the motivation for the unacceptable types of development that the system has been creating.
The need to change the system so that people who try to benefit from unsustainable or damaging activities and attitudes cannot succeed is easily understood by people with a wide variety of value sets. About the only groups that fight against the required change are people who want to benefit from unsustainable and damaging activities as long as they can get away with. And that group has many masks, but they commonly hide behind the Conservative Movement, which is only a sub-set of faith-based and fiscal-conservative people hoping to be confused with, and get support from, the larger population of faith-based people and fiscal conservatives.
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r.pauli at 03:01 AM on 7 April 2014The climate change uncertainty monster – more uncertainty means more urgency to tackle global warming
Gravity rules.
The airplane has run out of fuel and is going down. The crew is looking for the best place to land, we may find a soft field or we may crash hard. We are uncertain of the exact location.
Uncertainty does not mean that it won't happen.
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TonyW at 18:33 PM on 6 April 2014Toward Improved Discussions of Methane & Climate
Sorry, I see that saileshrao has posted a link to the Beckwith reponse, but I didn't see a response here.
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TonyW at 18:26 PM on 6 April 2014Toward Improved Discussions of Methane & Climate
Paul Beckwith "published" a response in the Arctic-News blogspot, on Friday August 9th. I'm not really inclined to link to that site, but the suffix of the link is /2013/08/toward-genuinely-improved-discussions-of-methane-and-climate.htmlHas Chris Colose read that piece and, if so, responded anywhere? -
Rob Honeycutt at 04:25 AM on 6 April 2014Earth has a fever, but the heat is sloshing into the oceans
Topal... "Overall, there is no change in the heat content, it's just redistribution and mixing of existing heat."
Your question was not in regards to changes in heat content. You asked about mixing and how heat gets distributed to lower layers.
If you're actually interested in ocean-atmosphere coupling here's a really great page that explains all the mechanisms in plain language.
http://eesc.columbia.edu/courses/ees/climate/lectures/o_atm.html
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Rob Honeycutt at 04:22 AM on 6 April 2014Earth has a fever, but the heat is sloshing into the oceans
Topal @6... Previously you asked the question, "What is the mechanism that pumps heat down without mixing it with the layers on the way down? What is the driver or this pump?"
The diagram I showed you @7 explains how it's not a matter of "mixing with the layers on the way down." It's a matter of shifting the thermocline, and the "driver" or "pump" the mechanism is surface winds.
If you understood this in the first place, I'm not clear on why you asked such a question.
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howardlee at 02:08 AM on 6 April 2014Alarming new study makes today’s climate change more comparable to Earth’s worst mass extinction
Tom - Ii think the climate sensitivity question goes to the heart of the issue. We have on the one hand sensitivities based mainly on modeling and the instrumental record that are 1.5-4.5°C (2.7-8.1°F) (IPCC AR5).
On the other hand, looking at the geological record, it suggests that actual Earth System Sensitivity is double that. For transient sensitivity - relevant to the year 2100 - we have to bridge the gap between what we are doing now to that long term sensitivity. Zeebe does this in this paper: "even if the fast-feedback sensitivity is no more than 3 K per
CO2 doubling, there will likely be additional long-term warming from slow climate feedbacks"Even though The AR5 study included the paleoclimate sensitivity in this paper i worry that by heavily weighting the study with benign glacial-interglacial changes which happen within the slow feeback timeframe, we may have generated an overly benign estimate of climate sensitivity. The carbon-belch scenario - with atmospheric emissions overwhelming the surface ocean and fast feebacks before deep oceans come into play would - intuitively - suggest a much higher sensitivity. That's why study of LIP-generated climate change could be crucial for understanding what's in store for us, more so than glacial-interglacial changes.
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One Planet Only Forever at 02:03 AM on 6 April 2014Earth has a fever, but the heat is sloshing into the oceans
A clarification of my comment @2.
Evaluation of global average surface temperature for time periods that are not long enough to average in the broad range of the significant influences like ENSO (phase and strength) and volcanic dust (amount, nature of the particles, and height and distribution in the atmosphere), can be performed by reasonably accounting for those influences.
The challenge is getting people who want to believe otherwise to stop choosing to focus on information in a way that suits their interest. Some people may never overcome their struggle to better understand what is going on because they won't give up their strong personal desire to get the most possible personal benefit any way they can get away with.
For the sake of the future of humanity (and all other life on this amazing planet), these people need to be disappointed by policy and actions regardless of the impression of popularity and profitability that can be created for the unacceptable unsustainable actions and attitudes they refuse to change their mind about. (That is delving into the politics, but I mention it because I consider it to be the best understanding of what is going on, which is an assessment of the available observations, which is what science is all about).
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sidd at 15:21 PM on 5 April 2014Earth has a fever, but the heat is sloshing into the oceans
there is actually a nice dichotomy to be explored herea)isotherm heaveb)water mass changethe first has a short time constant, on the order of montthe second perhaps decadesthis is explored in a fascinating paper by Purkey and Johnson dealing with the southern hemisphere DOI: 10.1175/JCLI-D-12-00834.1also i note that my previous comment is now a)redundant, since the comment previous to it has been removedb)self-referentialheeheeheesidd
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