It’s worth going back every so often to see how projections made back in the day are shaping up. As we get to the end of another year, we can update all of the graphs of annual means with another single datapoint. Statistically this isn’t hugely important, but people seem interested, so why not?
For example, here is an update of the graph showing the annual mean anomalies from the IPCC AR4 models plotted against the surface temperature records from the HadCRUT3v and GISTEMP products (it really doesn’t matter which). Everything has been baselined to 1980-1999 (as in the 2007 IPCC report) and the envelope in grey encloses 95% of the model runs. The 2009 number is the Jan-Nov average.
As you can see, now that we have come out of the recent La Niña-induced slump, temperatures are back in the middle of the model estimates. If the current El Niño event continues into the spring, we can expect 2010 to be warmer still. But note, as always, that short term (15 years or less) trends are not usefully predictable as a function of the forcings. It’s worth pointing out as well, that the AR4 model simulations are an ‘ensemble of opportunity’ and vary substantially among themselves with the forcings imposed, the magnitude of the internal variability and of course, the sensitivity. Thus while they do span a large range of possible situations, the average of these simulations is not ‘truth’.
There is a claim doing the rounds that ‘no model’ can explain the recent variations in global mean temperature (George Will made the claim last month for instance). Of course, taken absolutely literally this must be true. No climate model simulation can match the exact timing of the internal variability in the climate years later. But something more is being implied, specifically, that no model produced any realisation of the internal variability that gave short term trends similar to what we’ve seen. And that is simply not true.
We can break it down a little more clearly. The trend in the annual mean HadCRUT3v data from 1998-2009 (assuming the year-to-date is a good estimate of the eventual value) is 0.06+/-0.14 ºC/dec (note this is positive!). If you want a negative (albeit non-significant) trend, then you could pick 2002-2009 in the GISTEMP record which is -0.04+/-0.23 ºC/dec. The range of trends in the model simulations for these two time periods are [-0.08,0.51] and [-0.14, 0.55], and in each case there are multiple model runs that have a lower trend than observed (5 simulations in both cases). Thus ‘a model’ did show a trend consistent with the current ‘pause’. However, that these models showed it, is just coincidence and one shouldn’t assume that these models are better than the others. Had the real world ‘pause’ happened at another time, different models would have had the closest match.
Another figure worth updating is the comparison of the ocean heat content (OHC) changes in the models compared to the latest data from NODC. Unfortunately, I don’t have the post-2003 model output handy, but the comparison between the 3-monthly data (to the end of Sep) and annual data versus the model output is still useful.
Update (May 2012): The graph has been corrected for a scaling error in the model output. Unfortunately, I don’t have a copy of the observational data exactly as it was at the time the original figure was made, and so the corrected version uses only the annual data from a slightly earlier point. The original figure is still available here.
(Note, that I’m not quite sure how this comparison should be baselined. The models are simply the difference from the control, while the observations are ‘as is’ from NOAA). I have linearly extended the ensemble mean model values for the post 2003 period (using a regression from 1993-2002) to get a rough sense of where those runs could have gone.
And finally, let’s revisit the oldest GCM projection of all, Hansen et al (1988). The Scenario B in that paper is running a little high compared with the actual forcings growth (by about 10%), and the old GISS model had a climate sensitivity that was a little higher (4.2ºC for a doubling of CO2) than the current best estimate (~3ºC).
The trends are probably most useful to think about, and for the period 1984 to 2009 (the 1984 date chosen because that is when these projections started), scenario B has a trend of 0.26+/-0.05 ºC/dec (95% uncertainties, no correction for auto-correlation). For the GISTEMP and HadCRUT3 data (assuming that the 2009 estimate is ok), the trends are 0.19+/-0.05 ºC/dec (note that the GISTEMP met-station index has 0.21+/-0.06 ºC/dec). Corrections for auto-correlation would make the uncertainties larger, but as it stands, the difference between the trends is just about significant.
Thus, it seems that the Hansen et al ‘B’ projection is likely running a little warm compared to the real world, but assuming (a little recklessly) that the 26 yr trend scales linearly with the sensitivity and the forcing, we could use this mismatch to estimate a sensitivity for the real world. That would give us 4.2/(0.26*0.9) * 0.19=~ 3.4 ºC. Of course, the error bars are quite large (I estimate about +/-1ºC due to uncertainty in the true underlying trends and the true forcings), but it’s interesting to note that the best estimate sensitivity deduced from this projection, is very close to what we think in any case. For reference, the trends in the AR4 models for the same period have a range 0.21+/-0.16 ºC/dec (95%). Note too, that the Hansen et al projection had very clear skill compared to a null hypothesis of no further warming.
The sharp-eyed among you might notice a couple of differences between the variance in the AR4 models in the first graph, and the Hansen et al model in the last. This is a real feature. The model used in the mid-1980s had a very simple representation of the ocean – it simply allowed the temperatures in the mixed layer to change based on the changing the fluxes at the surface. It did not contain any dynamic ocean variability – no El Niño events, no Atlantic multidecadal variability etc. and thus the variance from year to year was less than one would expect. Models today have dynamic ocean components and more ocean variability of various sorts, and I think that is clearly closer to reality than the 1980s vintage models, but the large variation in simulated variability still implies that there is some way to go.
So to conclude, despite the fact these are relatively crude metrics against which to judge the models, and there is a substantial degree of unforced variability, the matches to observations are still pretty good, and we are getting to the point where a better winnowing of models dependent on their skill may soon be possible. But more on that in the New Year.
Damien states: “it’s going to be very hard to argue that Fortran will run more efficiently than C?”
Uh two problems: the speed of compiled code depends on the capability of the compiler.
Do you think FORmula TRANslation would be better targeted to compiling formulae in a computer than generic C?
Secondly, (and really related to the earlier), vector processors used to be written with fortran compilers. The IBM 3090 was a supercomputer ONLY if you used FORTRAN and turned on the vector processing. 30-100x faster.
Rob: “No, I mean just without an increase in CO2, all others stay the same.”
Yes, it would be flat (in the same way as the Midwest American Plains are flat).
“If you say “but raw materials don’t!”, wrong — raw materials require energy to extract from wherever they are hiding”
Wrong. Unless you’re talking of the very trivial.
I can grow potatoes.
I can farm a goat (milk is better than cows milk for humans adults and babies).
Power requirements: nil.
Matthew dissembles
“210, Martin Vermeer: We know too much, not too little.
If that were true, the models would be exact over all time scales.”
Incorrect. That would require we know everything, which isn’t the same as “too much”.
Remember: A little knowledge is a dangerous thing
So knowing a little is not knowing everything, but it’s worse than knowing nothing.
Just pointing out that you are (likely deliberately) messing up the meaning to get the desired conclusion.
Regarding the graph ” IPCC AR4 models plotted against the surface temperature records from the HadCRUT3v and GISTEMP products (it really doesn’t matter which). ”
If it really doesn’t matter which, then why not plot IPCC AR4 models vs UAH and RSS, which do cover the same time period and aren’t as subject to anthropogenic errors?
Regarding “the comparison of the ocean heat content (OHC) changes in the models compared to the latest data from NODC. Unfortunately, I don’t have the post-2003 model output handy”
Your comment Ignores the step at 2001 due, perhaps, to a major instrumentation change? This step can hardly be physical, as no such step is shown in the prior data. And 2003 is over half a decade past … why the reluctance to plot the models since, do you know if they are having difficulty matching the 2001 step change? The linear extrapolation to 2010 is pretty lame (starting point fallacy). A linear extrapolation starting in 1965 would be more appropriate and show the models in 2010 are out of line with the observations.
“… and this describes a completely different theory as to how the heating may occur. …” – TtTM
I think this is the source of his confusion. The article is a response to Fred Singer, who raised an objection to the existent notions of how GHGs warm the ocean. By my reading, the author was not proposing a completely different theory. He’s was merely trying to get the Singers of the world up to speed. I would think the models, since they predicted increased OHC and that has been confirmed by observations, already effectively included the physics the article explains.
#547 Hank Roberts
This is an important point.
To understand basically what is going on, focus on what is now virtually or reasonably certain. This gives one a good overall picture of the problem.
Once that is understood the uncertainties come into focus as to relevance to future potentials.
Science in a conservative endeavor by all reasoned accounts. In other words, I can reasonably expect that the uncertainties are worse, not better, than we would like to think based on current indicators.
Gavin:
“As you can see, now that we have come out of the recent La Niña-induced slump, temperatures are back in the middle of the model estimates. If the current El Niño event continues into the spring, we can expect 2010 to be warmer still.”
Apparently you consider “La Nina-induced slumps” as an aberration and El Nino induced rises as just getting back to normal. Why is that? Why not produce another ENSO corrected data set, and let’s see what has actually happened since 1998. If you don’t want to do it, then give the algorithm to me and I will do it. And I’ll let you know the results.
FurryCatHerder wrote: “When Al Gore cuts his electric consumption by 98.5%, then I think people will look at AGW more seriously.”
No, they won’t. Because the people who think that Al Gore’s electric consumption has anything to do with the scientific reality of anthropogenic global warming, are by definition incapable of looking at anything “seriously”.
If Al Gore reduced his electric consumption to zero and lived in a cave eating nuts and berries and wearing homespun hemp, Rush Limbaugh would just tell those folks that this was proof that Gore’s secret plan to get rich from wind turbines, while simultaneously destroying liberty and capitalism and imposing World Liberal Government with himself as dictator for life, was even more insidious than they had thought. And his listeners, being “skeptics”, would of course unquestioningly believe every word.
edrowland says: 3 January 2010 at 1:32 AM
“No, really. This is unbelievably shocking stuff…”
Once your shock has dissipated, what do you find in the way of actual problems with the output? And are all the models convergently wrong in their gross estimations? You say the code is so poorly readable, so how would the persons constructing the models produce that convergence?
“I don’t like the code”: Just another desperation argument, same as “all the data is bad” or “the tenure process is broken.” It’s a weak argument lacking necessary explanatory power against all the multiple indicators requiring to be accounted for in any successful effort to dismiss AGW.
Hank Roberts says: 3 January 2010 at 11:05 AM
Debunking —> “rebunking.” Wonderful!
Completely Fed Up: “Power requirements: nil”
wrong … aside from the fact that human food is a “raw material” for your personal energy requirements, even if you grow your taters and goats by human power alone using zero external inputs [the real raw materials], at the very least, someone consumed the energy to clear those carbon sequestering trees from your land, plus without the microbial energy expended in the soil extracting the plant nutrients needed you’ll have no edible tubers – in fact after a couple years of those microbes working away, your crops would have consumed all the nutriative energy available …. and at that level of agriculture how long would you last?
Comment by FurryCatHerder — 3 January 2010 @ 2:35 AM:
“In short, a “carbon tax” is a flat tax scheme, and as such is regressive. No one is really going to suggest that. A “carbon tax with quotas” — starting to make more sense, but that just gets us to tax brackets as we have them today. And instead of “loopholes”, you’d have the rich buying “offsets”.”
First, you could return the revenue form the carbon tax back to the public on a per capita basis while leaving the current income tax regime in place. If anything, this would make the tax system less regressive if you assume that people with low incomes use less energy than those with high incomes. Also, I don’t see why anyone should get tax credits for offsets, simply because they are so difficult to verify.
If we’re talking about the “eliminate income tax and replace it with carbon tax” proposal, I don’t think it’s reasonable to assume that carbon tax could fully replace income tax revenue and be set at the appropriate level to meet emissions targets at the same time. If you do the math for the US with 300 million people and emitting 20 tonnes CO2 per capita, in order to generate $1 to 1.5 trillion a year to replace just personal income tax revenue, you’d need a tax rate of $170 to $250 per tonne CO2 (or $600 to $900 per tonne C). From what I’ve seen, even the studies which suggest relatively high C prices (e.g. Ackerman and Finlayson, Climate Policy, 2006, 6, 509-526) don’t reach this kind of a price until the 22nd century. So you’d have to think such a tax rate would reduce consumption by quite a bit, which means the rate would have to be even higher to replace personal income tax revenue.
Completely Fed Up: #553
“Yes, it would be flat (in the same way as the Midwest American Plains are flat).”
Then it would be wrong; since climate has almost never been flat – even when there was little or no change in CO2.
Tilo misses the point by miles (by ducking):
““Yes, it would be flat (in the same way as the Midwest American Plains are flat).”
Then it would be wrong””
Nope, the climate would be flat in the same way as the Midwest American Plains are flat.
Ever stood in them, Tilo?
Not really flat. You can hide a lot of infantry in that flat country. Same with the Ural plains. Great land for an ambush, despite being “flat”.
Heck, even a perfectly flat lake isn’t flat if it extends far enough.
The earth curves. The moon pulls.
“flxible says:
3 January 2010 at 1:25 PM
Completely Fed Up: “Power requirements: nil”
wrong ”
Right, not wrong.
Unless you go to that insane place where the answer to “What powers a boat, a train and a human?” is “The Sun!” then link wind power to the sun, fossil fuels to trapped sun and food to the sun.
No power required.
Tilo, Ever been to the Midwest American Plains?
Mathew: the payback time for nuclear power is much shorter than the payback time for solar.
BPL: What parallel universe did you say you came from?
In this one a solar installation can be complete in a couple of years and a nuke takes 7-10 years, and the solar installation can start generating electricity as soon as part of it is up, while the nuke has to wait until the whole thing is finished.
Tilo Reber, #558
Here you can find a series with volcanic forcing and ENSO removed (“GISS adjusted”, fourth graph in the page.) The result is… interesting :-)
http://tamino.wordpress.com/2009/12/31/exogenous-factors/
I note that fixable DID go the “The Sun powers all these things” route.
Tell me, how does nitrogen fixers produce CO2?
Mind you, you’re deliberately dissembling: the problem isn’t energy, it’s burning fossil fuels for energy.
CatHerder,
Al Gore owns a large mansion, which he uses as an office for a number of his enterprises, and which houses his secret service detail as well as his family. Despite that, he has insulated the place thoroughly, installed solar panels, and buys wind power. What more do you want?
But assume Gore were a profligate hypocrite. If Albert Einstein was cruel to his wife, as recent documents indicate, does that mean that relativity is wrong? If Samuel F.X.B. Morse was a racist political crazy, does that mean the telegraph doesn’t work? If William Shockley babbles about race and IQ, does that mean his work on transistors was valueless?
In short, do you know what an ad hominem argument is?
Tilo Reber@558 asks “Why not produce another ENSO corrected data set, and let’s see what has actually happened since 1998.”
Be careful what you ask for:
http://tamino.wordpress.com/2009/12/31/exogenous-factors/
Result from Tamino: “The interesting thing is that, using the adjusted data, the warmest year on record is 2009!”
Dave Salt,
Your latest post (#517) helps. Unlike a number of pseudo-skeptics coming by here, you are focusing on an important point: cloud feedbacks being uncertain, poorly constrained by observations, and of potentially huge significance. You also read and learn from materials pointed your way, so perhaps you are one of the few genuine global warming *skeptics* to grace these pages.
My layman’s understanding is that your conclusions (1) and (2) are basically sound. I don’t think anyone here would disagree with you that cloud feedbacks (among others) are not “settled science”. On the other hand, you may be missing some perspective on the independent evidence for a climate sensitivity of around 3 degrees C. And you have not backed up your conclusion (3) with any examples. I think it’s wrong if you are talking e. g. about the IPCC Summary for Policy-Makers. I thought PeteB (#537) made these points well.
When you complain about lack of any testing against “real-world evidence”, I wonder why you are dismissing all that is said e.g. in ch. 8 of the IPCC report (which you have read) about how the models are tested against observations of various cloud properties and found wanting — which is why their cloud-feedback projections remain uncertain.
‘Uncertain’ rather than ‘falsified’ — is that what bothers you? From what you wrote earlier (#246) I gather that by ‘prediction’ you mean something that enables falsifying a theory, and your gold standard of such a prediction is the tropical troposphere ‘hot spot’. So let me ask: What do you think the hot spot means, what is it that you think will be falsified if the hot spot fails to turn up? This is not a digression — I want to understand what ‘predictions’ you want, and I think you may have been misled about this one.
Tilo, you’ve misunderstood 553– you can’t have ever walked across any significant part of the Great Plains. He’s saying the model output without the change in CO2 would be “flat” resembling the last 10,000 years of climate, I think, plenty of wiggles in that.
You know the uncertainty goes up over longer time spans. I hope you’re not just intentionally misunderstanding the conversation there. The question was about the actual current models being discussed and what they do if CO2 is left at a fixed level. We’d see something like the Holocene, eh?
Here, for Tilo:
http://2.bp.blogspot.com/_3c5RQ0PubuY/St_ySuiyKqI/AAAAAAAAHXI/aOrgYMsUwTU/s400/entire+track.jpg (map route, including crossing the Great Plains)
http://1.bp.blogspot.com/_3c5RQ0PubuY/St_yFYlWYaI/AAAAAAAAHXA/AEk6nGxLW5Q/s400/entire+profile.jpg (profile; note the resemblance to the Holocene)
> rebunked, rebunking
From a “team effort” (heh) based on an original word by Rob Dekker
http://www.google.com/search?q=site%3Arealclimate.org+rebunking
Secular Anamist: #559
“Rush Limbaugh would just tell those folks that this was proof that Gore’s secret plan to get rich from wind turbines,”. . . “And his listeners, being “skeptics”, would of course unquestioningly believe every word.”
Can you identify a single person who claims to be a skeptic because of Rush Limbaugh? Or is that just a stereotype you like to use because if fits the warped notions that you love to delude yourself with.
I love this discussion. I have been reading it from the binning, got tired around post #139, which is the thread I was watching the most.
The problem with the issue is, I think, is not whether or not global warming proponents or skeptics are right. I am a skeptic, but I must say, I might be wrong. I am also an “environmtalist”, in the sense that I join efforts to protect the soil and the air from on-going distrous damage. So, I am really, really tempted to jump on the band-wagon, since I can imagine all sorts of side benefits to reducing CO2 emmissions for the environment.
The problem I see it is the scale of action that is being proposed by global warming proponents.
In order for me to intellectually jump on the bandwagon of the scale of actions recommended, something frankly only someone who pays a lot of taxes can appreciate the difficulty of, I would have to have near certainty on 4 or 5 things, since the overall certainty is the combination of those things. Those things are:
1. Global Warming is “happening” in the sense that is being suggested.
I could give this maybe a 90%. Everyone is being too rude to one another for me to fully trust them. Sadly, the East Anglia emails show those guys to be just the sort people I wouldn’t personally trust with something important.
2. Global Warming is happening quickly, inexorably, and with catastrophic effect, such that the current generation needs to do something big. I’m pretty iffy on this one. Maybe 50%.
When models have to go back so far to show the trends, and 10 years of recent data that challenge the model is too “short-term” to draw a firm conclusion on the model’s accuracy (I think Gavin said the data show that the model “could be right”), I’m not feeling a real urgency on this one. Granted, if it takes 100 years to do something, and there are only 90 left, then we are late. I understand that. Not convinced.
3. Man is causing global warming to a significant degree, such that if we stopped doing whatever is that is causing it, it would stop or signifcantly slow. I am at about 40% on this.
I’ve been reading here, including the helpful links, for about 4 hours now (after many more than that over the years of course), and I am amazed at how badly the media reports the real case for global warming, and how reluctant the GW proponents are to discuss them. This link is fantastic: http://www.skepticalscience.com/How-do-we-know-CO2-is-causing-warming.html . And yet . . . the CO2/water-vapor link is being discussed like a salesman discusses a creaky ball-bearing, rather than like a teacher or scientist would. It seems the “amplification” affect needs quite a bit more study. It is a big weak link, let’s discuss it.
4. CO2 emmissions are the overriding means by which man is causing global warming. I am at about 10% on this one.
I am just not convinced of this by anything I have read. I see that there is SOME effect, but it could be extremely tiny based on what I have read. The CFC paper from Waterloo, as credible on the surface as anything else I have read today, seems so slow to make it into discussions. What gives?
5. Stopping CO2 emmissions will fix the problem. I am 95% on this on.
The problem is, there are so many other good environmental benefits to using less fossil fuel, it is tempting to try and fit this whole discussion into that box. This issue presupposed all the previous issues are truw of course.
6. We are near a tipping point, such that at any moment, we may pass a point of no return. I am at maybe 1% or 2% on this one.
If someone wants to point me to THAT link, I would love to see it. I might be more inclined to join the asteroid deflection crowd based on the probablities there.
The net is, I am at about 45% that one day we should do SOMETHING; at about 18% that it is necessary in my lifetime; at 1.8% that we ought to do what is being prescribed; and .018% that we ought to do it NOW.
I note that FedUp went to that “insane place” where vegetables and animals are raised without recourse to the use of fossil fuels for energy – for clearing the land, for fertilizers, for making the tools to do the farming, for getting the crops to the consumer, for building the storage facilities …. of course the sun powers all things, especially growing food, which has nothing to do with the original posters statement that energy extraction requires energy – your assertion of energy-less potato culture is the trivialization
the “problem” actually isn’t even using fossil fuels for energy, it’s overuse driven by overpopulation
Brennan, you’ve missed this: human activity matches past asteroids in impact.
Early draft of a paper now paywalled, I think; you can find more like this:
http://www.agci.org/dB/PDFs/03S2_KCaldeira_OceanPh.pdf
“… unabated CO2 emissions over the next several hundred years may produce changes in ocean pH greater in magnitude than any experienced in the past 300 myr, with the possible exception of rare catastrophic events in Earth history 7,11
——–
7. Caldeira, K. & Rampino, M. R. Aftermath of the end-Cretaceous mass extinction – possible biogeochemical stabilization of the carbon cycle and climate. Paleoceanography 8, 515–525 (1993).
11. Beerling, D. J. & Berner, R. A. Biogeochemical constraints on the Triassic-Jurassic boundary carbon cycle event. Global Biogeochem. Cycles 16, 101–113 (2002).
So as you’re worried about the consequences of an asteroid impact, and understand what they were — read up.
http://scholar.google.com/scholar?hl=en&q=ocean+pH+change
Yes, for some reason people are more upset about what some outside force does than what we do to ourselves — how many people die on highways every year from drunk drivers? how many die from terrorist attacks? Which worries us enough to make fundamental changes in how we live?
Look at the extreme rapid change in the oceans, the foundation of the food chain, where most of the food and oxygen are produced by plankton. If it were an asteroid impact, would you work to stop it from happening?
Knowing we’re doing it to ourselves, will you work to stop it?
If some enemy were doing to the planet what we’re doing, we’d be at war.
Brennan says: 3 January 2010 at 7:07 PM
Taking at face value what you say about your commitment to caring for the environment and your belief in the value of reducing fossil fuel usage, why do you even -care- whether you need to “jump on the bandwagon”? I suspect maybe something to do with fear of financial loss, given your remark about taxation.
Mysterious.
Alfio #568
“Here you can find a series with volcanic forcing and ENSO removed”
Thanks Alfio. But there are two problems. First, I don’t use GISS. I consider it an outlier. But I will take UAH, RSS or HadCrut3. Second, I want to plot it myself and put a trend line through it. I don’t need a hundred year chart to show the last 12 years. It only obscures what I’m trying to find out. Last year Gavin produced an ENSO corrected set of HadCrut3 data. I plotted the data against the regular adjusted HadCrut3 data here:
http://1.bp.blogspot.com/__VkzVMn3cHA/SHLOM1k5XJI/AAAAAAAAADE/u7AlyoBk0EU/s1600-h/ENSO+Adjusted+HadCrut3v+Data.bmp
As you can see, both trend lines are close to flat. I would like to see what the same ENSO adjusted trend line looks like with the 2009 El Nino year added. I expect that the HadCrut3 adjusted line will now be slightly up instead of slightly down. But I would expect that the ENSO adjusted line would be very similar. Meaning that 90% of the IPCC expected warming of .22C would still not be there. It would be nice if Gavin produced the same data, but updated. On the other hand, it might be even better if I had the algorithm and could update it myself whenever I want. Obviously I can’t be certain what the results will be. But I would like to know.
Ray: #571
“The interesting thing is that, using the adjusted data, the warmest year on record is 2009!”
Fine by me Ray, if it comes from satellite data or a HadCrut3 data. My interest is in the slope of the line and how close to the .2C per decade IPCC prediction it is.
“If you just look at the changes since 2000 say, the spread is wider but there is no obvious discrepancy either (you can draw in the 2009 values if you like). – gavin]”
Done – http://www.imagenerd.com/uploads/ipccgistemp-a47CE.jpg – with an OLS trend from 1998 drawn in, and which is only slightly less than the trend from 1995, statistically significant per http://tamino.wordpress.com/2009/12/15/how-long/
“A new international task-force set-up, charged with the responsibility of establising an officially recognised database for ‘Global temeprature’ to support all future policy planning.”
“There are however other measures that have less noise – stratospheric temperatures, or Arctic sea ice – the signals are stronger there. – gavin]”
Hoe about http://www.woodfortrees.org/plot/nsidc-seaice-n/from:2006.6/trend/plot/nsidc-seaice-n/from:2002.6/trend/plot/nsidc-seaice-n/from:2000.6/trend/plot/nsidc-seaice-n/from:1998.6/trend/plot/nsidc-seaice-n/from:1990.6/trend for “trends” upon which to base policy, with the understanding that as long as the ice is decreasing, it’s too hot, and policy to reduce GHG’s (carbon tax rates, whatever) must be set proportional to the decline. And when the Arctic Ice gets below half its historic levels. the rate of decline will level off(since negative values of area/extent are physically impossible), so we will have to start using another metric such as glacier volume, or Greenland Ice sheet mass loss. The advantage of using these metrics is that we already have historic data, so we don’t have to delay action for another data set to be implemented. and they are relatively low variability.
“…without the microbial energy expended in the soil extracting the plant nutrients needed you’ll have no edible tubers – in fact after a couple years of those microbes working away, your crops would have consumed all the nutriative energy available…”
The energy is continually being renewed by sunlight, stored using water and CO2. Fixed Nitrogen also only requires sunlight and air to be regenerated. The P, K, and mineral micronutrients can be badly redistributed by human activities (landfilling, “disposal” of sewage in streams, rivers, and ultimately the ocean), but it’s not really thrown away. see http://nssdc.gsfc.nasa.gov/image/planetary/earth/apollo17_earth.jpg “Probably the most requested picture of the Earth, this picture was taken by the Apollo 17 astronauts…”
#577 Brennen
I invite you to contact me directly. I would be happy to give you a call and discuss these points. It is a lot easier to examine through interactive discussion on these points that to write out all the contexts.
You are reading, so your knowledge and understanding will improve.
http://www.ossfoundation.us/contact-info
It’s all about context. For example, you say that you are 95% confident that stopping Co2 emissions will fix the problem but only 10% on mans Co2 emissions are a problem. These things need context to be better understood.
For some light reading try these:
1. http://www.ossfoundation.us/projects/environment/global-warming/natural-cycle
2. http://www.ossfoundation.us/projects/environment/global-warming/forcing-levels
3. http://www.ossfoundation.us/projects/environment/global-warming/human-caused
4. http://www.ossfoundation.us/projects/environment/global-warming/greenhouse-gases
5. http://www.ossfoundation.us/projects/environment/global-warming/security
http://www.ossfoundation.us/projects/environment/global-warming/summary-docs/leading-edge/2009-may-leading-edge
6. http://www.ossfoundation.us/projects/environment/global-warming/feedbacks
Regarding : “That’s basically what the article is doing, except it’s putting far more attention on the “applied to the ocean” part than you apparently expected and taking it more or less for granted that the reader already understands the “downward longwave radiation to eventually become some X W/m^2 term” part.”
But there is potentially a world of difference between a heating component added to the ocean and then mixed down versus heat that never got out in the first place. Especially when it comes to implimentations in a model.
Regarding : That paper published 20 years ago, and I don’t think it means what you think it does.
Well I think it stated “Northern Atlantic” so had a limitation on the area the skin temperature is on average lower than the ocean bulk temperature, but other than that what do you think it means?
Brennan@577. Let’s look at the evidence wrt your criteria:
1. Global Warming is “happening” in the sense that is being suggested
OK, if you don’t like HADCRUT, the is GISTEMP (terrestrial), and UAH and RSS (Satellite), all of which show about the same trend as HADCRUT. In addition, we have a lot of other data (trillions of tons of ice lost, earlier springs, later first frosts…) that also support the notion of a warming world. There is zero evidence that suggests a cooling or constant temperature world.
2. Global Warming is happening quickly, inexorably, and with catastrophic effect, such that the current generation needs to do something big. I’m pretty iffy on this one. Maybe 50%.
The pace of warming over the past 30 years is the fastest pace in any comparable period over the period for which we have reconstructed temperatures. We also know (from ice core data) that the effects of CO2 persist for centuries, and that it can take decades for temperatures to stabilize even after CO2 stabilizes. At the current rate of growth we will easily reach 450 ppmv within 20 years. This equates to between 2 and 3 degrees of warming, where we could start seeing very significant effects due to climate change. Read this paper:
http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf
3. Man is causing global warming to a significant degree, such that if we stopped doing whatever is that is causing it, it would stop or signifcantly slow. I am at about 40% on this.
The current warming carries the signature of a greenhouse mechanism–including such aspects as simultaneous tropospheric warming and stratospheric cooling, polar amplification. What is more, we know with 100% certainty that CO2 is an important greenhouse gas. The fact that increased CO2 would cause warming was predicted in 1896. So the fact that we are causing warming is not a surprise–it’s what we expect from the physics.
4. CO2 emmissions are the overriding means by which man is causing global warming. I am at about 10% on this one.
See above. Also, Lu’s CFC chemistry is interesting, but his climatology is utter crap. Look at Uncle Eli’s sight among others for a critique.
http://rabett.blogspot.com/2009/12/if-you-got-hammer.html
5. Stopping CO2 emmissions will fix the problem. I am 95% on this on.
No. Stopping CO2 emissions will sotp making things worse.
6. We are near a tipping point, such that at any moment, we may pass a point of no return. I am at maybe 1% or 2% on this one.
Consider what this means. When the biosphere and oceans and melting permafrost become a carbon source rather than a carbon sink, then there is probably nothing at all we can do to bring things back. We are on the rollercoaster, and the only planet we know that is hospitable to life will have just become a 4th grade science experiment.
Look at the evidence, Brennan. Look at all of it. This is important.
JCH says: …I would think the models, since they predicted increased OHC and that has been confirmed by observations, already effectively included the physics the article explains.
And I would think that because there is no followup paper that quantifies the effect (that I’ve found anyway) there can be no way the models can include the physics because its not formalised.
The fact the models have confirmed the historical observations comes more from their finely tuned assumptions that the observed ocean heating that isn’t accounted for by “anything else” is accounted for by anthropogenic effects.
Pity it all goes wrong when the oceans do something unexpected…like start to cool. Then the predicted global temperatures begin to go pear shaped when compared to reality as well.
Ken W @ 550:
Wait, I didn’t say that AGW is or isn’t real. I’m very on the record here as saying that I don’t think it matters, because the problem that WILL affect us far sooner — dwindling fossil fuels — has the same solution as AGW.
Do I personally believe in man-made global warming? Sure. I also believe that the giant ball of fire in the sky has more of an impact than most of the scientists here will accept simply because they’ve not found something other than “Hey, SC24 is a fizzle, and the temperature isn’t going up, but Tamino says that’s okay, too!” So I’m skeptical on the ratio of “solar influence” to “CO2”. But I’m 100% in agreement that if we burn every bit of carbon fuel we can get our fat fingers on, we’re in for hot weather and no energy to do much about it, to say nothing about changing the face of the planet not for the best.
But that’s besides the point. The point is that ACTIONS speak far louder than words. And based on that Snopes article, Al Gore still uses more power in a month than I use in a year. Based on that, I stand by what I said — Al Gore does not believe in global warming. It makes him some money, maybe helps if he wants to run for president again some day, but believe in it? No.
Can you identify a single person who claims to be a skeptic because of Rush Limbaugh? Or is that just a stereotype you like to use because if fits the warped notions that you love to delude yourself with.
Tilo Reber — 3 January 2010 @ 5:55 PM
http://www.nationalcenter.org/2008_06_01_BlogArchive.html
‘I believe Rush Limbaugh is America’s #1 asset on global warming education. He takes the time to understand the science and the economics, and has the talent to explain it understandably and entertainingly. I shudder to think we’re we’d be without Rush.”
Hank #573
“Tilo, you’ve misunderstood 553– you can’t have ever walked across any significant part of the Great Plains.”
Hi Hank. I live in Colorado – a few miles down the road from Trennberth and Pielke. I’ve been to Iowa, North Dakota, Nebraska, Kansas and Oklahoma. And I prefer cycling to walking. I took the first part of his statement literally. “Yes, it would be flat”. I assumed that he just added the second part for color. But you do bring up an interesting point when you say:
Hank: #574
“profile; note the resemblance to the Holocene”
So are you saying that a model with no CO2 forcing could produce the same kinds of effects that we had in the Holocene, particularly the period 6 to 8 thousand years ago, including a century or more long warming period that produced temperatures higher than today? And what elements of natural variation would the models be modelling when they did that? It reminds me of this statement by Briffa:
“… and I contend that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate.”
So are you saying that the models are modeling the variability that Briffa is talking about? And what is that variability if it is not CO2 and it is not Milankovich?
Being a first time poster here, I’ll say thanks and congrats to realclimate and all its contributors.
#577 Brennan says: “I am at about 45% that one day we should do SOMETHING; at about 18% that it is necessary in my lifetime; at 1.8% that we ought to do what is being prescribed; and .018% that we ought to do it NOW.”
May I suggest you keep reading. From reading I have become even more aware of how the climate is sensitive and of its immense complexity.
Out of curiosity I wonder if you have considered how you reached your views on other matters which are not nearly as complex. For example, do you support:
1 the wearing of seatbelts in cars and/or crash helmets with bikes
2 action to limit CFC emissions to help restore the ozone layer
3 programs to discourage smoking cigarettes.
If so, why? Was it mainly because you understood and accepted the science, or because of weight of public opinion, or because it seemed intuitive or that governments made laws about them or other reason? Conversely, if not, why not?
I suspect that now that 190 (more or less) governments from all political persuasions and types of rule have accepted the risk of global warming, more people will come to accept it as well. It is very rare for so many dissimilar nations to cooperate in this fashion and most heartening.
Although I strongly doubt there will be a universal satisfactory agreement on a common means of tackling the problem (at least in the short term), this may turn out to be less important than the already achieved agreement that there is an urgent problem.
Tilo @ 576:
The amount of influence Rush Limbaugh has should not be underestimated. While I can’t NAME a person, I do know quite a few people who quote Rush Limbaugh and are full-blown denialists.
The worst thing about Limbaugh and the environment is that he’s a flat out liar on the key points, and he knows it. His mantra is that Mankind is too puny to damage the planet (though lately he’s appealing to G-d being too smart to create a planet we could destroy — he’s really hammering on the G-d thing these days). And yet he’s known of, seen, talked about, etc. places that we have done a very thorough job of trashing.
But it gets him ratings and makes him money. So …
Tilo, #576:
I know half a dozen people whose understanding of global warming is based on what they hear on “conservative media”.
They were at my house on Christmas day discussing what a hoax global warming is along with other ‘conservative’ topics. They’re all family – I know what their information sources are.
Given that ‘conservative media’ would include Rush, Glenn, Sean, Neal, Laura, Fox News in general, and a few more, and that they all use the same playbook, I suppose it’s hard to blame Rush all by himself. But that’s not really what you were asking, is it?
538, FurryCatHerder:
“In short, a “carbon tax” is a flat tax scheme, and as such is regressive.”
That doesn’t make it wrong.
The whole point of a carbon tax is to somehow price in negative externalities, which, by definition, are real costs that are currently not borne either by the producers or the consumers:
http://en.wikipedia.org/wiki/Externalities
This distorts the market because it will lead to greater production/consumption of products with greater externalities rather than products with lower overall costs.
In the case of fossil fuels, a carbon tax seems like the most straightforward way to price in those externalities and allow the free market to operate correctly.
I would argue that the price placed on the carbon should be, in the first instance, based on the best scientific estimate of the true cost of that carbon without regard for any policy goals. This would basically remove the distortion that currently exists, and would naturally increase or decrease in response to changes in the climate’s status (i.e. the true cost of the carbon would go up as the earth warmed, while it could potentially drop down to zero if we ever managed to get CO2 concentrations low enough — in fact, in the face of an imminent ice-age at some point in the future, the true cost could even be negative and the carbon tax turned into a carbon subsidy!).
Note that I am not proposing a formula for carbon price based on the earth’s temperature or anything silly like that — it would have to be based on the best estimate of the true cost of emitting that carbon at that point in time.
Yes, it would be a “regressive tax”, but then the price of a litre of milk is also “regressive” in that sense, and in the above scenario, all we’re trying to do is make the price of the product accurate.
You’ll note that I deliberately left out policy considerations in the above carbon price calculation. By that I mean questions like “We want to advance the nuclear/solar/wind power industry, what carbon price do we need to impose to make them competitive with coal?”. Those policy considerations — which would re-introduce distortions into the market to advance some goal — are a separate issue that governments could think about adding on top of the “correct” carbon tax, and elections could be fought on that basis if they wish. But those issues can’t be discussed clearly until carbon is priced “correctly” and all distortions in the current system are removed. An implication of this is that the base carbon tax rate itself should be determined independently of the government of the day, similar to the way reserve banks determine interest rates in response to measures of inflation, and, ideally, the same base rate would be used worldwide (since the cost shouldn’t really depend on location). Countries should be free to impose tax “corrections” on imports from countries that have set their tax rate below the international standard; this would encourage recalcitrant countries to impose the correct tax themselves so that at least they get to keep the money rather than the country they are exporting to.
NB: I am under no illusions about how hard it would be to price carbon “correctly”. Some externalities would be really hard to account for — for example, how much of the cost of things like the Gulf Wars should be added to the cost of the carbon in oil? No doubt it is non-zero, but getting a single number that everyone agrees on would be impossible. Likewise, it is almost impossible to estimate the future possible financial impact of emitting one tonne of CO2 right now given the uncertainties not only in climate forecasting but also in how we will respond in future. Nevertheless, I think we need to try, and make the best guess we can at each point in time, with some inertia in the price to avoid changing the market too much from year-to-year and making investment decisions completely impossible. Heck, calculating the correct carbon price could be the remit of the IPCC as part of its reporting process[*], with that price fixed until the next IPCC report.
[*] You can tell I’m not afraid of the bizarre “world government” scaremongering that some people seem to think is relevant to this discussion, especially given the obvious inability for countries to put aside their own self-interest as evidenced by the Copenhagen outcome. I’m also not afraid of governments using carbon as an excuse to raise taxes — in my experience governments the world over have been able to raise and lower taxes as required for as long as civilisation has existed without needing any help from climate “scares”. Nevertheless, making the carbon tax revenue neutral (i.e. by returning all revenue collected in some way) would help increase the palatability of it for some. (In reality, governments always acquire the money they need for their spending programs one way or another — and taxing is better than borrowing in the longer term — so it’s all swings and roundabouts anyway, regardless of whether the carbon tax is officially revenue neutral or not.)
“6. We are near a tipping point, such that at any moment, we may pass a point of no return. I am at maybe 1% or 2% on this one.”
Brennan — 3 January 2010 @ 7:07 PM
http://eprints.soton.ac.uk/64607/01/2009gl039191%2Baux.pdf
“More than 250 plumes of gas bubbles have been discovered emanating from the seabed of the West Spitsbergen continental margin… If this process becomes widespread along Arctic continental margins, tens of Teragrams of methane per year could be released into the ocean.”
http://www.nature.com/climate/2009/0904/pdf/climate.pdf
“The Siberian Shelf alone harbours an estimated 1,400 billion tonnes of methane in gas hydrates, about twice as much carbon as is contained in all the trees, grasses and flowers on the planet. If just one per cent of this escaped into the atmosphere within a few decades, it would be enough to cause abrupt climate change, says Shakhova. “When hydrates are destabilized, gas is released under very high pressure,” she says. “So emissions could be massive and nongradual.” Shakhova and her colleague Igor Semiletov of the University of Alaska, Fairbanks, believe the plumes they’ve observed confirm previous reports that the permafrost cap is beginning to destabilize, allowing methane to escape from the frozen hydrates below. “Subsea permafrost is like a rock,” explains Semiletov. “It works like a lid to prevent escape of any gas. We believe that the subsea permafrost is failing to seal the ancient carbon pool.”
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/20080726.jpg
Note the hole and the thin area in the arctic ice North/NE of the New Siberian Islands; I believe this is being caused by methane fountains (like those described in the first reference above) from the seabed bringing up warmer, saltier plumes of water which have melted the ice from beneath.
“If someone wants to point me to THAT link, I would love to see it.” Be careful what you wish for.
Ray Ladbury could this paper be relevant to TRY’s question??
thanks jl
http://www.eumetsat.eu/HOME/Main/AboutEUMETSAT/Publications/ConferenceandWorkshopProceedings/2007/groups/cps/documents/document/pdf_conf_p50_s9_01_harries_v.pdf
For Tilo:
“… there’s another class of skeptics who get their climate science from talk radio. They don’t really understand any of the science …”
http://www.npr.org/templates/story/story.php?storyId=121139996
Tilo Reber, you’re full of it. I have personally run into “skeptics” who believe Limbaugh’s “volcanoes put out more CO2 than people” idiocy many times. Happened in person and on blogs, including John Cook’s Skeptical Science. Why do they believe it? Because Rush says so, as moronic as it may be. There is plenty of these people, everywhere. It’s not a stereotype and makes up a sizeable portion, if not the bulk, of the “skeptics” in the general population. And they don’t even know about McIntyre’s existence (not that they loose much, really).
570, Barton Paul Levenson: But assume Gore were a profligate hypocrite. If Albert Einstein was cruel to his wife, as recent documents indicate, does that mean that relativity is wrong? If Samuel F.X.B. Morse was a racist political crazy, does that mean the telegraph doesn’t work? If William Shockley babbles about race and IQ, does that mean his work on transistors was valueless?
Fair enough, but ad hominem arguiments are used against “denialists” as well.
567, Barton Paul Levenson: In this one a solar installation can be complete in a couple of years and a nuke takes 7-10 years, and the solar installation can start generating electricity as soon as part of it is up, while the nuke has to wait until the whole thing is finished.
Nuclear power plants pay back the energy that is invested in making them much faster than PV panels do. However, the difference is diminishing (comparing the current generation of PV panels to the kind of PWRs that America uses.)
Brennan, (#577, currently) reactions to your points:
1) The “climategate” emails involve a tiny fraction of the climatologists actively working on the question today. You may not like the picture painted, but that doesn’t change the data.
2) “Quickly, inexorably, and with catastrophic effect” is a pretty high bar. Why does it need to be BOTH quick and inexorable to merit action? (And technically, aren’t we all hoping like hell it isn’t really “inexorable?”)
The catastrophic effect part certainly seems well-supported, if also admittedly rife with uncertainties. Generally, I think you’re not asking the right questions here.
3) Keep reading. There’s lots on this.
4) Paleo work seems to constrain climate sensitivity to CO2 usefully. The human problem with CO2 is of course that combustion is just so darned convenient. But CFCs should certainly be seriously looked at as well.
5) Don’t see how you can be 95% on this one if you’re 10% on number 4. The two propositions are more nearly equivalent than independent.
6) I think you’re backwards on this one. The greater the uncertainty, the more motivation we should logically have to err on the side of caution, and (in the words of another RC post) “hit the brakes hard” on our CO2 emissions.
And you don’t need this worry to justify action anyway–any two of the criteria you give in point #2 ought, in my view, to suffice. (Eg., a quickly-approaching catastrophe sans “tipping points.”)
Your “net:” curious numbers, to say the least. . . they seem highly arbitrary, to this reader at any rate. Sorry you’re so unconvinced, but I have to say that your reasoning seems much more consistent on an emotional than a logical basis. Ie., you don’t like the “prescribed action” very much, despite your protestations to the contrary in point 5 and elsewhere.