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Unforced variations: Oct 2012

Filed under: — group @ 1 October 2012

This month’s open thread. Try to keep it at least vaguely focused on climate science…!


782 Responses to “Unforced variations: Oct 2012”

  1. 451
    Patrick 027 says:

    Re 443 Thomas Lee Elifritz – that’s also interesting. Both this stuff and Tom Murphy’s blog are interesting (lumens/W theoretical limits, how efficient is heating up water in a Microwave, in a water heater, etc.)

    I have some quantum mechanical questions – 1. what exactly is it that determines the probability of an energy transition such as an electron emitting or absorbing a photon (besides densities and occupancies of states and incident photons, etc.) – and how does refractive index affect this (it has to because the Planck function is proportional to n^2 – has to be in order to satisfy 2nd law of thermo…) – and does it make sense to use an k,E diagram when electrons are not actually propagating as plane waves – I mean, what is the wavevector when the waveform is not a plane wave; is k a function of space in atomic orbitals? How do plasmons work? What would the thermodynamics of a hot-carrier solar cell be? I’d like to find a blog that explains this kind of thing.

    —-

    But about what we need (breakthroughs) – we don’t may not need breakthroughs (or maybe we do depending on how you define ‘breakthrough’?); or maybe in a sense we do, but they could be of either the political/social or technological sort; the more the better, but just political/social could work okay (although that would work partly by boosting R&D to continue technological progress, but I’m not sure if that’s necessarily breakthroughs (it wouldn’t surprise me if someone got a zinc phosphide, CZTS, or pyrite solar cell to work economically at some point in the future, or used light-trapping to make c-Si cheaper and more efficient, or… – it would surprise me if it happenned tomorrow, but…). It’s OT so I won’t elaborate now but here’s links
    http://thinkprogress.org/climate/2008/04/30/202577/is-450-ppm-or-less-politically-possible-part-3-the-breakthrough-technology-illusion/
    (granted, that’s 450 ppm stabilization and I don’t remember if I read through it all or not)
    and

    http://www.skepticalscience.com/wind-carbon.html
    418 – 419 http://www.realclimate.org/index.php/archives/2012/08/unforced-varations-aug-2012/comment-page-9/#comment-244351 and

    453 http://www.realclimate.org/index.php/archives/2012/08/unforced-varations-aug-2012/comment-page-10/#comment-244742

    Well, breakthroughs in storage would be nice; however the necessity of … (don’t want to get into a debate about it now, just consider above and below):
    464 http://www.realclimate.org/index.php/archives/2012/08/unforced-varations-aug-2012/comment-page-10/#comment-244834 (note that there are some issues with that – not representative of seasonality of US electric usage, maybe also wind? – see 494-495, note some places have unusual wind seasonality
    http://rredc.nrel.gov/wind/pubs/atlas/maps.html
    http://www.nrel.gov/gis/solar.html
    – I found it helpful to copy and paste images into “Paintbrush” files and then view them as a slideshow to animate the annual cycle. Interesting stuff happens to solar in SW late summer – localized)…
    … you can get seasonality of energy usage here:
    http://www.eia.gov/totalenergy/data/monthly/index.cfm – you can get more years of monthly data from the cvm’s – I C&Ped each file to a worksheet in Excel, made other sheets to evaluate some things for each row and then combined them into a table using vlookup, etc.;
    also check out graphs here
    “Effects of aggregating electric load in the United States”
    http://www.stanford.edu/group/efmh/jacobson/Articles/I/CombiningRenew/CorcoranEnPol12.pdf
    also check out:
    “Projections of Levelized Cost Benifit of Grid-Scale Energy Storage Options”
    http://dotyenergy.com/PDFs/Doty-90377-Storage-ASME-ES10.pdf (somebody pointed this out in the Aug 2012 unforced thread but I can’t find the source comment)
    … 474 http://www.realclimate.org/index.php/archives/2012/08/unforced-varations-aug-2012/comment-page-10/#comment-244932
    471 http://www.realclimate.org/index.php/archives/2012/08/unforced-varations-aug-2012/comment-page-10/#comment-244897

    some background
    http://www.eia.gov/totalenergy/data/annual/?ref=bookshelf
    461 http://www.realclimate.org/index.php/archives/2012/08/unforced-varations-aug-2012/comment-page-10/#comment-244808 (hint: what about adding generators to the Welland Canal ?)
    – but see also (in case it matters) – 281: http://www.realclimate.org/index.php/archives/2012/09/unforced-variations-sep-2012/comment-page-6/#comment-249748 – and also, I assume the ‘net generation’ capacity is in AC output but note that sometimes PV may be given in DC; there’s a derate factor – see Tom Murphy’s blog (ironic); Secular Animist provided a link to SEIA… http://www.seia.org/research-resources/solar-industry-data – and there’s http://www.nrel.gov/docs/fy12osti/51847.pdf
    http://irecusa.org/wp-content/uploads/2011/06/IREC-Solar-Market-Trends-Report-June-2011-web.pdf
    … note all sector net generation from EIA doens’t include residential PV … see the appendices (Table F3, and check fine print).

    And then there’s (I have very little knowledge about this) http://energyfromthorium.com/ (not to be confused with that weird Th auroral battery conspiracy theory stuff)

    And dunite dust, biochar, etc.

    (Wow! I had no idea the list would look that long. Oops)

    ———–

    PS re Ric Merrit – I couldn’t figure out how to post a comment at Do the Math – maybe the problem was I was looking at older posts that were closed, but … any suggestions? (I was thinking about whether the shape of the water container would make a difference in microwave efficiency))

  2. 452
    Patrick 027 says:

    re my 446, 448, continued…

    So is the self-sustained feedback just a delayed feedback? Like if water vapor took decades instead of days to equilibrate with the climate – then as it increased, it would affect the climate, causing it to increase more, but with a determined destination that varies continuously with the forcing (and other feedbacks – note, if feedback is given as a ratio between sensitivity with it and sensitivity without it, then feedbacks don’t add linearly.)

    Or maybe it can be runaway, but it wasn’t called that because people associate runaway with H2O feedback and boiling the oceans?

    Runaway isn’t infinite. Going both into and out of a snowball state (theoretically?) involves runaway ice albedo feedback – it stops (starts) when the ‘iceline’ is at the equator; it starts (stops) when the ‘ice line’ reaches some latitude when the sensitivity goes to infinity (or when all the ice has been eliminated). There is a range where the equilibrium climate sensitivity is negative; the equilbrium is unstable. For H2O vapor feedback, there is a point where increasing temperature produces such an increase in H2O vapor that the OLR stays constant (as modelled thus far – clouds do what?) – obviously this must end when there is no more source of H2O vapor.

    to be cont…

    (but quickly: On the point of paleoclimatic evidence: if there is a threshold below (or above) which a feedback is not activitated, then climate variations staying below (or above) that threshold would not bear on the sensitivity with that feedback.)

  3. 453
    flxible says:

    Chris Dudley – there is nothing ambiguous about the units involved in UN estimates of food reserves, as stated in the article, the amount relates to expected consumption/demand in the coming [storage] year. Humanity has increasingly been consuming more than we produce, stockpiles are steadily dwindling. In a year when planted corn acreage increased hugely, production dropped. Given the state of the climate all here [well, except for 1 or 2] are concerned with, what is the likelihood those reserves will grow rather than dwindle, considering the fact that the global population continues to increase and we’re using our food to produce energy? As SA points out above, the “alarmist” prediction of agricultural collapse mid-century is probably optimistic.

  4. 454
    wili says:

    Patrick at 452: Thanks for posing the questions here that I was about to pose after your earlier post.

    I would love to hear a differentiation between runaway gw and self-sustained feedback (from you or anyone else on hand).

    I don’t get the impression that the former is used only of the Venus Syndrome thing. That’s not how Chu was using it, as far as I could tell.

    http://www.youtube.com/watch?v=oHqKxWvcBdg

  5. 455
    wili says:

    Now this from NOAA:

    http://www.noaanews.noaa.gov/stories2012/20121010_arcticwinds.html

    “Arctic summer wind shift could affect sea ice loss and U.S./European weather”

    “Changes in summer Arctic wind patterns contribute not only to an unprecedented loss of Arctic sea ice, but could also bring about shifts in North American and European weather, according to a new NOAA-led study published today in Geophysical Research Letters.

    A research team led by James Overland, Ph.D., of NOAA’s Pacific Marine Environmental Laboratory in Seattle, Wash., examined the wind patterns in the subarctic in the early summer between 2007 and 2012 as compared to the average for 1981 to 2010. They discovered that the previously normal west-to-east flowing upper-level winds have been replaced by a more north-south undulating, or wave-like pattern. This new wind pattern transports warmer air into the Arctic and pushes Arctic air farther south, and may influence the likelihood of persistent weather conditions in the mid-latitudes.

    “Our research reveals a change in the summer Arctic wind pattern over the past six years. This shift demonstrates a physical connection between reduced Arctic sea ice in the summer, loss of Greenland ice, and potentially, weather in North American and Europe,” said Overland, a NOAA research oceanographer. ”

    At neven’s blog, M. Owens is claiming that this influx of warm air into the Arctic is the main thing that explains the high rate of melt since 2007. Does that seem reasonable?

    http://neven1.typepad.com/blog/2012/10/record-dominoes-12-ct-sia-anomaly.html#comments

  6. 456
    Patrick 027 says:

    (but quickly: On the point of paleoclimatic evidence: if there is a threshold below (or above) which a feedback is not activitated, then climate variations staying below (or above) that threshold would not bear on the sensitivity with that feedback. … And if we could break a feedback into components, with some activated before others, then activation of some of that feedback won’t *simply and directly* bear on what the rest will do.

    So slow feedbacks will continue to feedback on themselves but possibly with less and less effect as equilibrium is approached.

    On the other hand, there are really many many tipping points and ranges of unstable climate, in a manner of speaking. There may be a cap for convection, but latent heating in a growing cumulus cloud (forced locally by … whatever) may eventually allow it to mushroom. Or it might not. There is a moment when a crack forms and then positive feedbacks grow it into a rupture – the ice calves (or the rock breaks); the bubble of CH4 rises and breaks the water’s surface. Etc. That’s weather, forming the texture of climate, and the particulars don’t matter so much on that scale, but hypothetically one could consider little tiny runaways which average out to a continuous slope in equilibrium climate in response to change in forcing when the resolution is not more than some fraction of a K, and then for practical purposes we see a finite sensitivity.

    So feedbacks can be slow or fast, lead to runaway (via total effect) or not; they can also lead to hysteresis or be immediately reversable.

    Hysteresis occurs on a small scale: magnetism; also, if a system’s pressure is changed or heat added or removed and some processes can’t keep up with thermodynamic equilibrium (disequilibrium states: untempered cocoa butter; also, cementite (Fe C mixture cooling, graphite formation themodynamically prefered but kinetically inhibited, so Fe3C forms instead), martensite (Fe3C formation inhibited, get supersaturated solution) – but for weather, see ‘Kohler curve'; also, supercooled cloud droplets – and similarly, phase changes can be/are delayed in subducting lithosphere (Karato, “The Dynamic Structure of the Deep Earth”; and of course, diamonds). When moist air rises and cools, latent heat is released. If condensed H2O is removed (precipitation), the air can’t follow the same p,T path (moist adiabat) in the opposite direction adiabatically.

    For climate, there’s hysteresis just from heat capacity. If we set that aside, hysteresis would occur with slow feedbacks. Setting both aside and just considering equilibrium climate, there can still be hysteresis. Consider that once the permafrost C is depleted, we couldn’t just take ‘our’ CO2 out of the system and have the other C go back where it came from – I would guess it would go in some different places, and different things would happen if we repeat the emissions. Going in and out of a snowball is a dramatic hysteresis; I think ice sheets may also exhibit hysteresis (threshold for glaciation not equal to threshold for deglaciation) though maybe I don’t understand that correctly. Ecological succession and biological evolution would also provide hysteresis (for example, I read of an idea that under some conditions, bogs will tend to take over forests; these bogs will have a higher albedo than forest when snow falls, thus potentially bringing an ice age…). Runaway H2O vapor feedback is generally reversable (setting aside CO2 feedbacks (although given sufficient time, I think that would be reversable), evolution…), but losing the H to space would lead to hysteresis.

    (Related point: it only just happens that the Earth is set up to have a positive CO2 feedback for orbitally-forced climate change; this could easily be different. It isn’t as systematic as H2O feedback. PS orbital forcing is rather small in the global annual average; it’s been my understanding that regional changes that cause growth or decay of ice sheets are what actually lead to significant global average warming/cooling; in that sense, the ice could be considered the forcing (with the additional ice that comes from global average changes being a feedback).)

    Other point: for large climate changes, forcing for the same change isn’t the same in forward and reverse. Consider adding x amount of CO2 to the atmosphere. Now there’s more H2O vapor and the lapse rate and tropopause height are different, etc. Taking it away won’t have the same forcing because of that. However, the feedbacks will be different and, absent hysteresis, they difference will cancel the difference in forcing (my impression has been that this effect is small (enough not to bother with) for one or two doublings of CO2; however, I think it makes a sizable difference if one removes all CO2 and then adds it back).

    Also, for various purposes, some agents that are feedbacks may be treated as forcings. For example, in determining the total greenhouse effect, the effect of H2O can be calculated as a radiative forcing. And some shorter-term forcings can respond to climate over the longer term.

    Final point: I think in http://www.skepticalscience.com/hansen-and-sato-2012-climate-sensitivity.html , Earth system sensitivity was described with atmospheric CO2 as a forcing. But CO2 can be a feedback. Treating it as such and including it in total sensitivity, one would have to consider the forcing as specifically the anthropogenic emission (or other source that can be regarded as non-climate-induced with respect to some timescale – technically anthropogenic emissions are a feedback since humans have been shaped by climate, but see last paragraph) – in which case we already have seen a large negative feedback in oceanic+other CO2 uptake. It gets tricky now because the equilibrium climate sensitivity requires a timescale to be defined – barring large hysteresis, it isn’t so large going out many millions of years (weathering feedback); there will be a time scale of maximum sensitivity.

  7. 457
    Chris Dudley says:

    flxible (#453),

    It is just that the unit “days of consumption” already accounts for a larger population and that while back in 1970 37% of the population in the developing world were undernourished while now it is about 17% so our per capita consumption has risen. I was fasting for world hunger back in 1974 not because there was not enough food but because there was enough and people still starved. I was happy the grape boycott was over though.

    Grain stocks have been fairly steady since about 2002 and this seems to reflect increased meat consumption and diversion of food to fuel affecting the prior higher plateau. We ought to entertain the idea that the grain diverted to fuel production represents an emergency stock should there be an emergency.

    Still, I agree with Lester Brown that we should have larger stocks. At this point it is a matter of policy, not capacity.

  8. 458
    Ric Merritt says:

    Patrick 027 # 451: I have commented occasionally there, I guess on newer posts, so maybe the older ones are closed?

  9. 459
    no_name_thanks says:

    I’d be interested in reading something by your group about tornadoes, what has happened as a result of climate change, and what the trends look like for the future, what the current thinking is on them, uncertainties et cetera. My geography text says they’ve about doubled in frequency since 1990 and that the frequency of the higher intensity storms has also increased significantly. But NOAA’s website appears to say there hasn’t been a discernible trend. (Or did I totally miss something over at the NOAA site?) Thanks…

  10. 460
    SecularAnimist says:

    flxible wrote: “Odd how so many here go on about energy and CO2 when in fact our problem, as Tom ‘Do the Math’ really points out, is the unsustainable nature of human impact on the planets resources …”

    Well, first of all, “energy and CO2″ is closely related to the actual focus of this site — climate science, specifically the science of climate change resulting from global warming resulting from anthropogenic emissions of CO2, resulting in large part from our combustion of fossil fuels to provide energy. So it’s not at all “odd” that “energy and CO2″ would be a focal point of discussions here.

    Secondly, while there are indeed lots of other unsustainable human impacts on ecosystems and the Earth’s biosphere generally, the rapidly escalating effects of anthropogenic global warming threaten to overwhelm all of those other problems in the very near future, with devastating impacts not only for human civilization and the human species, but for all life on Earth, for a long, long time. If we don’t solve the global warming problem — in a hurry — then we are not going to solve any of the other problems.

    Lastly, if you want to talk about the foundations of the problem, I suggest you look closely at your own use of the word “resources” — because the root of “our problem” is the view that the world consists of two things: human beings, and “resources” for human use.

  11. 461
    Hank Roberts says:

    For “no_name_thanks”

    I copied your question above and pasted it into Google
    like this:

    From the first page of hits, I found an explanation of why there’s no simple answer to your question. You can read it here:

    http://www.wunderground.com/climate/extreme.asp

    “… Until a technology is developed that can reliably detect all tornadoes, there is no hope of determining how tornadoes might be changing …. According to Doswell (2007): ‘I see no near-term solution to the problem of detecting detailed spatial and temporal trends in the occurrence of tornadoes by using the observed data in its current form or in any form likely to evolve in the near future.’…”

  12. 462
    tamino says:

    I’ve tried to answer #459, but no matter what I do it’s flagged as spam. I can’t find anything in my comment which might trigger this. I think your spam filter has gone overboard.

    What’s the point of having the extraordinarily difficult recaptcha hurdle, when my comment ends up spam-trapped anyway?

  13. 463
    flxible says:

    If we don’t solve the global warming problem — in a hurry — then we are not going to solve any of the other problems.
    Until we “solve” the overpopulation problem there will be no solutions to any other problem, especially global warming, and including unsustainable overuse of every resource of the planet. Nine billion humans striving to the living standards of the “developed world” will not be generating less CO2 than 7 billion are now. I am well aware of the world view of entitlement, which is the primary reason that little to nothing can be achieved with current population levels. And with a lifetime in sustainable agriculture, I am more aware than most here what climate change portends for our future.

    RECAPTCHA says one-half aredsgo, I think probably 3/4

  14. 464
    Hank Roberts says:

    For Tamino, a workaround I’ve used:

    reposting a spamtrapped reply one paragraph at a time — sometimes one sentence at a time.

    (Often I find fewer words suffice, under this bloody-editorial-axe scrutiny by the spambot filter.)

    It ain’t elegant.

    Keeps the human-to-bot ratio here good, though, I expect.

  15. 465
    SecularAnimist says:

    Regarding tornadoes, the Des Moines Register reports (emphasis added):

    Iowa is on pace to see the quietest tornado season in nearly 50 years, thanks to the drought.

    State climatologist Harry Hillaker said this summer’s extreme dry conditions have helped keep tornadoes at bay. Iowa has recorded just 16 twisters this year.

    Hillaker said that total is the lowest since 1963. Iowa has seen an average of 47 tornadoes annually over the last 33 years. There were 49 reported during another drought year in 1988.

    Generally, the tornadoes that have hit Iowa this year were fairly weak.

    The extreme drought throughout the Plains and the rest of the country sapped the moisture required to trigger a tornado, said Roger Vachalek, a meteorologist with the National Weather Service in Johnston.

    “If you have no moisture, you’re not going to get thunderstorms,” Vachalek said. “And if you don’t have thunderstorms, you’re not going to have tornadoes.”

    No tornado has touched down in Iowa since May 24.

    So, perhaps a midwest ravaged by AGW-driven, prolonged, extreme drought will at least be comforted by having fewer tornadoes.

  16. 466
    SecularAnimist says:

    flxible wrote: “Until we ‘solve’ the overpopulation problem there will be no solutions to any other problem, especially global warming, and including unsustainable overuse of every resource of the planet.”

    Please explain how to “solve the overpopulation problem” within five years.

    Because that’s about how much time we have to stop the increase in greenhouse gas emissions and begin steep reductions that will bring emissions to near zero within another ten years at most, if we are to have any hope of avoiding the most catastrophic consequences of global warming.

    Keep in mind that the overwhelming majority of greenhouse gases have been, and continue to be, emitted by the massive fossil fuel consumption of a tiny percentage of the Earth’s human population, most of them in countries with low rates of population growth — and that the overwhelming majority of human beings on the Earth, particularly those in countries with relatively high rates of population growth, generate only a small amount of greenhouse gases.

    Yes, population growth is a problem — it is a long term problem. If you want to solve it humanely — by reducing birth rates — it will take decades to do so. Meanwhile, the Earth’s current population can easily be supported — and comfortably so — with a fraction of humanity’s current “resource” consumption, and with zero fossil fuel use.

    Global warming is, in fact, a technological problem. And the only way we can possibly solve it in the short time remaining to do so is with a technological solution. That solution is to rapidly phase out fossil fuels and replace them with non-carbon sources of energy, use that energy with maximum efficiency, and use organic agriculture and reforestation to to draw down the already dangerous anthropogenic excess of atmospheric CO2.

  17. 467
    flxible says:

    SA – As much as I admire your views and contributions here, I’m sure you understand solutions to any of the myriad problems facing the planet will not be solved in 5 years, particularly with ‘zero fossil fuel use’, which would mean no more plastic food packaging, minimal, if any of the vital chemical compounds common to our “modern” lifestyle, and few of the medicines currently insuring our extended lifetimes and continuing population growth. Then there’s overcoming the inertia of the worlds financial systems. I’m sorry to say I believe your optimism toward our single species is misplaced. Technology has become the primary human curse on the planet, not the solution to anything. I’m starting to suspect AGW is the planets solution to the human cancer pillaging it.

    http://www.cbc.ca/news/business/story/2012/10/16/wto-ontario-green.html

    http://www.guardian.co.uk/environment/2012/oct/15/pacific-iron-fertilisation-geoengineering

    http://www.winnipegfreepress.com/arts-and-life/life/greenpage/research-suggests-disturbed-boreal-forest-more-diverse—-up-to-a-point-174406261.html

    “The critical issue really is how to mobilise the necessary financial, technical and human resources”

  18. 468
    Patrick 027 says:

    re my 456 “but losing the H to space would lead to hysteresis.
    – actually up to a point some H2O loss could be replenished by the mantle (there’s H2O there – it helps it flow! (Karato) (by being dissolved in rock, affects ability to deform) – see also: Kasting and Holm, “What determines the volume of the oceans?” http://www3.geosc.psu.edu/~jfk4/PersonalPage/Pdf/Earth_Planet._Sci._Lett._92.pdf
    (tons of interesting stuff here: http://www3.geosc.psu.edu/~jfk4/PersonalPage/Kasting.htm )

    and

    Consider that once the permafrost C is depleted, we couldn’t just take ‘our’ CO2 out of the system and have the other C go back where it came from – I would guess it would go in some different places, and different things would happen if we repeat the emissions. – well maybe a lot of it would stay in the atmosphere for a while and it’s the cooling path that couldn’t be retraced…

    (aside: for those thermodynamic disequilbrium states, hysteresis would be avoided if they remain – I mean, if you don’t then go to equilibrium at the same T,p and then try to reverse the process)

    ——–

    re my 451 re 443 Thomas Lee Elifritz cont.

    I do like to make things more complete:

    storage:

    my 459,
    my 534 http://www.realclimate.org/index.php/archives/2012/08/unforced-varations-aug-2012/comment-page-11/#comment-246805
    (see in particular the EIA storage link and the following paragraph with some off-the-wall suggestions (see comment 535 too).)
    (note there is some energy demand management that is is/has been already used to reduce the need for peak power supply; I don’t know offhand how much there is and what it would look like if this were simply reshifted to reduce the need for backup power supply, which would be like peaking and load-following plants now. EIA may have some info.. – see table 8.13 here http://www.eia.gov/totalenergy/data/annual/showtext.cfm?t=ptb0813)

    breakthroughs: Don’t forget cost of BOS (inverter, structural support, tracking if that’s used), installation.
    increases in conversion efficiencies would help some of that, but I wonder how much of that may come down to business practices (learning curves and economies of scale? – and maybe regulations to have (where it would make sense) new buildings built with building-integrated systems…)).

    see also http://www.solarserver.com/solar-magazine/solar-interviews/solar-interviews/bringing-down-bos-costs-an-interview-with-ideal-power-converters-vice-president-of-business-development-paul-bundschuh.html
    (background: http://en.wikipedia.org/wiki/Grid-tie_inverter , http://en.wikipedia.org/wiki/Photovoltaic_system ; costs- see somewhat down the page here http://www.seia.org/research-resources/solar-industry-data ; breakdowns of component costs are probably somewhere in the other links I gaver earlier )

    solar nonbreakthrough, just amazing progress:
    http://blogs.scientificamerican.com/guest-blog/2011/03/16/smaller-cheaper-faster-does-moores-law-apply-to-solar-cells/

    (there was a Scientific American blog entry on installation a while back.)

    Wind breakthrough ?:
    http://www.newscientist.com/article/dn19492-green-machine-wind-farms-make-like-a-fish.html
    (and also try searching for a ‘whale tail’ design (caution: my website security advisor stayed grey when I went here; preferably it should be green: http://darinselby.1hwy.com/whalestailwindenergyharvestr.html )

    But Tom Murphy’s blog has caused me to hope for efficiency breakthroughs (thermoelectric heat pumps/AC – how might those perform? On the flip side, TPV to convert residential furnaces to winter CHP plants… etc. Windows that only let in visible light summer, all solar (except UV) winter, etc…, except for whatever the luminescent concetrators take…)

    Okay, done.

    ———

    re 458 Ric Merritt – thanks.

  19. 469
    Patrick 027 says:

    re my last comment: clarification: Aug 2012 535 responds to 534 ‘energy storage’ via demand side management via desalinating/cleaning water and storing it in an aquifer when energy is available; also apply to sequestration efforts, fuel production, others…

  20. 470
    Chris Dudley says:

    flxible (#467),

    Just another numbers correction. SA said 15 years to near zero emissions, not 5. Hansen et al. (2008) actually said coal phase out by 2030, which does not take us quite to near zero emissions but it does need to start soon which is what SA was getting at with the 5 year figure; getting started. Near zero emissions come around 2100 for Hansen et al. with some moves towards drawn down from the atmosphere using forestry and some more active methods to compensate for that extended emission period.

    http://pubs.giss.nasa.gov/abs/ha00410c.html

  21. 471
  22. 472
    flxible says:

    Chris Dudley – Read for comprehension please, not confirmation.
    SA said “Please explain how to “solve the overpopulation problem” within five years. Because that’s about how much time we have to stop the increase in greenhouse gas emissions ……. Meanwhile, the Earth’s current population can easily be supported — and comfortably so — with a fraction of humanity’s current “resource” consumption, and with zero fossil fuel use.

    Neither Hansen nor you can predict when coal use is likely to end, nor state what will “come around 2100″ – as much as I respect Dr Hansen, I’d be as inclined to listen to Nostradamus for predictions of our situation 90 years hence. As SA hopes, zero emissions could happen within 15 years – it could happen next week – it’s unlikely to happen until existing known reserves are exhausted.

  23. 473
    Hank Roberts says:

    Azimuth continues to be educational — a little math and good illustrations, a good bit of history.

  24. 474
    Jim Larsen says:

    466 SecularA said, “five years. Because that’s about how much time we have to stop the increase in greenhouse gas emissions and begin steep reductions that will bring emissions to near zero within another ten years at most, if we are to have any hope of avoiding the most catastrophic consequences of global warming.”

    Amazing certainty. Fortunately, I couldn’t find anything which gives your claim the slightest credence. Look at the IPCC 4 graphs. Note B1. It gives rising emissions for the next ~40 years, gets back to current emissions in ~2080, and declines from there. Far, far, far higher emissions than you suggest are the absolute maximum to prevent humanity’s extinction (that is the most catastrophic, right?), yet they only get ~2C warming by 2100, which the scientific consensus says is fairly safe. Quibbles: Overshoot VS a bit lower emissions VS very minor geoengineering.

    In any case, gliding down over 50 years prevents sending all our fossil power plants and stoves and furnaces and cars and trucks and trains and ships and airplanes and fertilizer and everything else to the trash compactor (that would hurt BAD) and appears to be a very conservative path according to the science.

    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-10-26.html

    “Today’s global emissions rate for carbon dioxide is 30 billion tons per year. For the world to emit in 2061 no more than 30 billion tons of carbon dioxide is as difficult a task as I could endorse today”

    http://www.climatecentral.org/blogs/wedges-reaffirmed/P2

    “We know that our continued emissions of CO2 is increasing our levels of environmental risk, but it’s really hard to quantify exactly how much risk we’re facing.”

    http://dge.stanford.edu/labs/caldeiralab/Caldeira_Videotranscripts/Caldeira_Climate_Experiment.html

    So, could you explain your comment further? Perhaps I’m misinterpreting or missing something. Thanks.

  25. 475
    SecularAnimist says:

    flxible wrote: “… ‘zero fossil fuel use’, which would mean no more plastic food packaging, minimal, if any of the vital chemical compounds common to our ‘modern’ lifestyle, and few of the medicines currently insuring our extended lifetimes and continuing population growth …”

    First, you are conflating the use of relatively small amounts of petrochemicals in materials such as plastic, with the combustion of massive amounts of fossil fuels in the open atmosphere which results in the emission of gigatons of carbon — which is what I am referring to with “zero fossil fuel use”.

    Second, we already know how to replace petrochemicals in many of those applications — e.g. plastic — with biodegradable materials derived from plants. In fact, you can buy stuff made from plant-derived, biodegradable plastics on store shelves today.

    Third, we can do without a lot of those things a lot more easily than we can do without productive agricultural land, forests, and oceans that support life — all of which are at imminent risk of destruction from CO2 emissions.

    Fourth, as for “medicines currently insuring our extended lifetimes”, most of the increase in human life expectancy in modern times has resulted from improvements in sanitation and nutrition, not “medicines” (and indeed, the misuse of “medicines”, particularly antibiotics, threatens to undermine some of those gains). Moreover, many medicines are in fact derived from compounds found in plants, not from petrochemicals.

  26. 476
    SecularAnimist says:

    flxible wrote: “… I’m sure you understand solutions to any of the myriad problems facing the planet will not be solved in 5 years …”

    I said nothing about solving “myriad problems facing the planet” in five years. I said we need to stop the increase in greenhouse gas emissions and begin steep reductions within five years.

    Consider the following, from the International Energy Agency’s World Energy Outlook 2011 (PDF) published last November:

    We cannot afford to delay further action to tackle climate change if the long-term target of limiting the global average temperature increase to 2°C, as analysed in the 450 Scenario, is to be achieved at reasonable cost. In the New Policies Scenario, the world is on a trajectory that results in a level of emissions consistent with a long-term average temperature increase of more than 3.5°C. Without these new policies, we are on an even more dangerous track, for a temperature increase of 6°C or more.

    Four-fifths of the total energy-related CO2 emissions permissible by 2035 in the 450 Scenario are already “locked-in” by our existing capital stock (power plants, buildings, factories, etc.). If stringent new action is not forthcoming by 2017, the energy-related infrastructure then in place will generate all the CO2 emissions allowed in the 450 Scenario up to 2035, leaving no room for additional power plants, factories and other nfrastructure unless they are zero-carbon, which would be extremely costly. Delaying action is a false economy: for every $1 of investment avoided in the power sector before 2020 an additional $4.3 would need to be spent after 2020 to compensate for the increased emissions.

    Keep in mind that the IEA’s “450 Scenario” is intended to limit warming to 2°C — even though we can plainly see that the warming that has already occurred is sufficient to cause far worse effects than scientists imagined possible only a few years ago, and we have every reason to believe that 2°C will be truly catastrophic.

    Which is why — I’m trying to stay “at least vaguely focused on climate science” now — what we most urgently need from climate scientists now is an emphasis on the IMPACTS of the GHG increases that have already occurred, and the emissions that are now already locked in given that we cannot possibly literally end all GHG emissions “today”.

    Because unfortunately, most policy makers, and those in the general public who are informed about the problem, are still behaving as though we have decades in which to gradually reduce emissions if we want to limit warming to 2°C, and that doing so is sufficient to prevent severe impacts. They need to understand that the situation is much worse, and much more urgent than that.

  27. 477
    Chris Dudley says:

    What a difference a week makes. Yesterday marked the end of 100 days of consecutive daily records for daily lowest Arctic sea ice extent. Sea ice extent has tracked below 2007 for 100 days, but yesterday it came back above the 2007 daily record. And, the recovery rate over the last week has been at 87% of the fastest 7 day recovery rate in the prior 10 years. Off to the races.

    http://www.ijis.iarc.uaf.edu/en/home/seaice_extent_prev.htm

  28. 478
    Chris Dudley says:

    flxible (#472),

    You have misunderstood. I was just correcting your misquoting of SA. S/He’s done so his/herself in #475.

    I think also that you don’t understand the Hansen et al. targets paper. Those are not predictions, they are targets, as is made clear even in the title.

  29. 479
    Chris Dudley says:

    In #477 that should have been 69 consecutive days of daily records. Added an extra month in there by mistake.

  30. 480
    Bernd Herd says:

    #474 Jim Larsen: “Look at the IPCC 4 graphs. Note B1.”

    Note that these IPCC graphs take 0°C reference as the 1980-2000 average, while the hopfully secure 2 °C aim is referenced against “the natural, preanthropogenic climate”, making a difference of about 0.7°C,

    http://www.realclimate.org/index.php/archives/2009/07/two-degrees/

    So B1 is already 0.7°C over the limit in 2100 and would likely get even higher afterwards.

  31. 481
    flxible says:

    SA – As a master composter involved in food waste composting for a long time I’m aware of the “biodegradable” polymers and the problems involved, including using yet more of the worlds food supply to replace petro products. As for the amount of petroleum for non-fuel production, I believe 15-20% is not “relatively minor” with respect to the industry bottom line, resulting in things like OxoBiodegradeable plastics.

    “Moreover, many medicines are in fact derived from compounds found in plants, not from petrochemicals.”

    The original derivation may be from plant compounds, but industry immediately translates the chemistry to a synthetic form that provides a profitable pat-ent. See ASA for example, originally derived from willow and/or meadosweet, which products may still be found in ‘natural food’ stores, but not in ASA, sold by the ton to patients everywhere.

    I’m very much “on your side” wrt climate, probably quite matching or exceeding your lifestyle in regards to contributing to solutions. My point remains, overpopulation is the primary root of virtually every problem we face, and here at RC, like most everywhere it remains unaddressed.

    As for Chris Dudley’s “targets”, and yours, and Hansens, I firmly believe they are hand waving with the current population, even with the slowly declining rate of increase in the developed world – time is not on our side.

  32. 482
    Hank Roberts says:

    For Jim Larsen, from Eco-Equity (linked in the right sidebar on RC pages):

    “… If you haven’t read the whole of McKibben’s Terrifying New Math, read it now. Here’s the link again. When you’re ready to loop back and think more about the carbon bubble in particular, see From “peak oil” to “unburnable carbon”, which I wrote last year when Carbon Tracker’s Carbon Bubble report was released. And by the way, it too is mercifully short….”

    Yes, there’s a good bit of arithmetic on the pages the Eco-Equity — but it’s readable and has a lot more thought behind it than the opinions common in blog comments. It’s a critical look at McKibben’s widely recommended piece.

  33. 483
    Susan Anderson says:

    New Revkin stresses the need for research (though slightly buried). Might be worth a look:
    http://dotearth.blogs.nytimes.com/2012/10/17/obama-and-romney-oil-and-science/#more-46562

    Sad that our history shows Carter had it right and gets almost no credit for it.

  34. 484
    Susan Anderson says:

    Terrific Antarctic movement animation (please don’t extrapolate, caveats at site). I got interested because of recent new Thwaites tongue break.
    “Antarctic Ice Floes: A Complete Picture”
    http://www.nasa.gov/multimedia/videogallery/index.html?media_id=106877491

  35. 485
    SecularAnimist says:

    flxible wrote: “… overpopulation is the primary root of virtually every problem we face …”

    Again, I am not talking about “virtually every problem”. I am talking about greenhouse gas emissions from burning fossil fuels.

    Most of the greenhouse gas problem results from a tiny percentage of the Earth’s population burning massive amounts of fossil fuels. If the four or five percent of the Earth’s population who live in the rich countries of North America, Europe and Japan ended all their fossil fuel consumption tomorrow, it would have more of an impact on AGW than if the poorest 50 percent did so.

    And again, our rapidly dwindling window of opportunity to address the greenhouse gas problem is now measured in YEARS, not DECADES. There is no way to humanely reduce population growth, leading to an actual decrease in population, leading to an actual decrease in anthropogenic GHG emissions, in that time frame.

  36. 486
    Hank Roberts says:

    Revkin’s pointer to “PESWiki” tells me they need a fact checker working on his column. If you want attractive fantasies, you’ll find them at the PESWiki site. Look at ‘litroenergy’ coverage there over the past some years, apparently people can get money from investors who don’t understand physics with nothing more than a superficially convincing line of talk.

  37. 487
  38. 488
    Jim Larsen says:

    480 Bernd, thanks for the clarification. Personally, I gag when I see B1. IMO it’s insanely high. I keep pondering about the tiny push of orbital cycles and the resulting ice ages as compared to the wicked hard shove our emissions are giving the planet. Wili brought up permafrost. There’s lots and lots of variables, and we know they sum up to making a mountain out of a molehill. What do you get when you start with a mountain?

    482 Hank, thanks for the link. Good stuff. The third number, reserves, is obviously fantasy, not in that they aren’t there, but in that they can’t be developed sanely. Thus, looking for more reserves is a waste of money, and most of the value represented by current reserves is fake money. We can write it off now or later, but it will be written off. Also, it leaves out the truly important number, which is already-been-built-or-drilled carbon-based assets. REAL money. Unless we brake hard, not on emissions, but on the creation of carbon-based assets, then we’ll end up in a situation where SecularA’s solution, trash-compacting much of our civilization, will become necessary. Even if we do brake hard, which would result in a 50 year glide to near zero, we might need some minor geoengineering (might? look at arctic sea ice!), and even then way bad things such as too much ocean acidification might happen.

    No new wells.

  39. 489
    SecularAnimist says:

    Susan Anderson wrote: “Sad that our history shows Carter had it right and gets almost no credit for it.”

    Carter?

    In 1952, the Paley Commission, appointed by President Truman, reported that “Efforts made to date to harness solar energy economically are infinitesimal. It’s time for aggressive research in the whole field of solar energy — an effort in which the U.S. could make an immense contribution to the welfare of the whole world.”

    The Paley Commission estimated that solar energy could ultimately provide more energy than nuclear power, and that the US could have 13 million solar-heated homes and offices by 1975 (a year before Carter was elected).

    Note that this report was written two years before Bell Labs demonstrated the first silicon photovoltaic cells, so the Paley Commission was only referring to the potential of solar water and space heating.

  40. 490
    Norman says:

    Tamino at his blog “Open Mind” directed me to this thread to ask a question here that I have been asking on “Open Mind”.

    Tamino did a calculation on how much more energy the Earth would receive because of the dwindling snow and ice in the Arctic during the summer melt season. The Arctic albedo goes down drastically when the ice melts. His calcualation spread over the Earth was that the energy gained was 0.45 watts/meter.

    If the Earth receives this much more energy during the summer, my question was what does the lack of insulating effect that snow and ice provide in the winter do to that balance? Will less ice and snow in the Arctic during winter increase, decrease or be about the same radiation loss as years with thick multiyear ice?

  41. 491

    Some really interesting recent weather events in the High Arctic have shown me the reality of a warmer polar region, snow flakes do not melt in an ocean -1.5 C cold, and ice does not form when its -6 C outside. Snowfall covers the ocean looking like ice, but a closer look is even more fascinating. http://eh2r.blogspot.ca/

  42. 492
    Tony Weddle says:

    Joe Romm posted this year’s update (I hadn’t realised he did this every year) on climate impacts. It is horrific. Is he cherry picking or does his (long) summary of the science reflect what researchers are finding? The November edition of Scientific American also contained a similar type of story, though not as dire as Romm’s summary (at least not yet). Which story more accurately reflects scientific concern about what we’re doing to our only habitat?

  43. 493
    Chris Dudley says:

    Norman (#490),

    This simplified picture might help: Suppose we had no seasons or even day and night but the sunlight came in evenly over the Earth. We’ll have two knobs. We can change the concentration of greenhouse gases and we can change the amount of sunlight that is reflected to space (not absorbed at the surface). If we turn the first knob, increase the concentration of greenhouse gases, the temperature at the top of the atmosphere has to say the same because the energy being radiated to space in the infrared has not changed. It hasn’t changed because the energy absorbed at the surface has not changed. But, the altitude at which that radiation is emitted has to increase because there is more greenhouse gas opacity up there. The surface gets warmer because the thermal lapse rate, a structural element of the atmosphere*, is suspended from a higher altitude and thus intercepts the surface at a higher temperature.

    If we turn the second knob, reduce the amount of sunlight reflected to space, then there is more energy to get rid of and the temperature at the top of the atmosphere has to increase to get rid of it. In that case, the thermal lapse rate starts at a higher temperature at the top of the atmosphere but at the same altitude it always started from. When it intercepts the surface, it is also at a higher temperature, but because it started that way not because it had farther to go.

    In this simple picture, the properties of the surface are only important in the optical not the infrared. The emissivity of the surface in the infrared is unimportant because it behaves as though it were in a blackbody cavity in equilibrium with the lowest layers of the atmosphere. In practice almost everything has high emissivity in the infrared, ice, soil, water, and heat transfer between the surface and the atmosphere happen more through air circulation than radiatively.

    There is the background for your question.

    With that background, we can give a simple answer. The thermal properties of the surface are unimportant, everything depends on how much sunlight is reflected.

    Now things are not that simple. We know that there is a direct infrared radiative connection between the surface and space, particularly in dry cloudless conditions. And desert nights can get so cold because the thermal conductivity of sand is low and so the surface can cool quickly without releasing a whole summer of stored heat in one night. In the Arctic, while the infrared emissivity of soil, ice and water are about the same, there could be substantial differences in how summer stored heat comes out in the winter depending on how these surface elements change. But, I think that is likely to affect weather patterns much more than the radiative balance at the top of the atmosphere. And that may be the most interesting aspect of your question.

    *The thermal lapse rate holds up half the sky. Multiplied by the decreasing density with altitude (the other half), there is always just enough pressure for the lower layers of the atmosphere to hold up the upper layers and so on up leading to lower and lower pressure with altitude as there is less and less mass above each layer (hydrostatic equilibrium).

  44. 494
    Susan Anderson says:

    Thanks Secular Animist. You are right. The disappearance of brain matter about climate change is tracking with the increase in consequences. I was going from the energy research graphic Andy Revkin brings out from time to time in the cited article, which clearly demonstrates the “fail” on research funding over time:
    http://www.youtube.com/watch?v=MkXXDG2is5U
    “America’s Bipartisan Slumber Party on Energy Research”
    I’m having a little trouble finding the original; this is mentioned:
    http://www.aaas.org/spp/rd/fy2013/SeqBrief.shtml

  45. 495
    Jim Larsen says:

    494 Susan A, unfortunately the graph isn’t useful to me, as I missed “color-to-label” day in school. Blue is ? Yellow is ?

  46. 496
    SecularAnimist says:

    Susan Anderson wrote: “The disappearance of brain matter about climate change is tracking with the increase in consequences.”

    With regard to “roads not taken”, it is … well, interesting … to contemplate this document from the presidential library of Richard Nixon (PDF), a memo from Nixon advisor Daniel P. Moynihan to John Ehrlichman, written in September 1969:

    As with so many of the more interesting environmental questions, we really don’t have a very satisfactory measurement of the carbon dioxide problem. On the other hand, this very clearly is a problem, and, perhaps most particularly, is one that can seize the imagination of persons normally indifferent to projects of apocalyptic change.

    The process is a simple one. Carbon dioxide in the atmosphere has the effect of a pane of glass in a greenhouse. The CO2 content is normally in a stable cycle, but recently man has begun to introduce instability through the burning of fossil fuels. At the turn of the century several persons raised the question whether this would change the temperature of the atmosphere. Over the years the hypothesis has been refined, and more evidence has come along to support it. It is now pretty clearly agreed that the CO2 content will rise 25% by 2000. This could increase the average temperature near the earth’s surface by 7 degrees Fahrenheit. This in turn could raise the level of the sea by 10 feet. Good bye New York. Goodbye Washington, for that matter. We have no data on Seattle.

    It is entirely possible that there will be countervailing effects. For example, an increase of dust in the atmosphere would tend to lower temperatures, and might offset the CO2 effect. Similarly, it is possible to conceive fairly mammoth man-made efforts to countervail the CO2. (E.g., stop burning fossil fuels.)

    In any event, I would think this is a subject that the Administration ought to get involved with. It is a natural for NATO. Perhaps the first order of business is to begin a worldwide monitoring system. At present, I believe only the United States is doing any serious monitoring, and we have only one or two stations.

    Hugh Heffner knows a great deal about this, as does also the estimable Bob White, head of the U.S. Weather Bureau. (Teddy White’s brother.)

    The Environmental Pollution Panel of the President’s Science Advisory Committee reported at length on the subject in 1965. I attach their conclusions.

    It is remarkable to compare this brief summary of the scientific understanding of global warming — and of its projected impacts — with James Hansen’s famous Congressional testimony, some 20 years later.

    Note the reference to the possible “countervailing effects” of particulates — and the recognition that global warming could become a national security issue (“a natural for NATO”), and of the need to “stop burning fossil fuels”.

  47. 497
    Bernd Herd says:

    #480 Jim Larsen: “Personally, I gag when I see B1. IMO it’s insanely high.”

    As far as I understand, the world is rather more on the A1 path than on the B1 path. However the IPCC SRES scenarios (B1, A1…) are intentionally ignoring the possibility of mitigation. I think at some time sooner or later people will start actions to reduce emissions, so B1, A1 etc. will not come “true”. They are only valid up to the point where people actually decide to do something. Afterwards the actions are more important than the scenarios.

    #434 Ric Merritt on Tom Murphys blog: Interesting stuff. I’ve got a 9,8 kW peak PV on my roof connected to the grid and there is one interesting difference to Tom Murphy results: I’m in Germany, further in the north than Tom Murphy. His approach could not work here at all. While I get around 40kWh/day in summer, I get less than 10kWh/day in winter. So while the PV produces 10000 kWh/Year, most of it is transfered to the grid but I still have to buy 2500 kWh/Year from the grid. The days in winter are just too short here, there wouldn’t be much electricity here in winter to fill the batteries. I even had times with 0,0kWh/Day when we had snow on the PV cells. So Tom Murpyhs results with his simple PV system are so promising because he is farther in the south, having more sun time in winter and about twice the average energy per kW Peak that we do here. You can easily put the power for one night into batteries, but not for a week.

    Nevertheless I find PV is great. It’s just that for now you still have to have nearly the same power in conventional power plants available that you had before adding PV, to step in for the times where PV power is insufficient. So you’ll replace 40 GW of coal with probably 30 GW of PV, 30 GW of wind and yet still need 30 GW of coal or gas, that is most of the time off-line.

    Some References:

    http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/PV-Norddeutschland-2008-Monatsdarstellung.svg/790px-PV-Norddeutschland-2008-Monatsdarstellung.svg.png

    Germany has a transparency system where we can see how much renewable energy is currently available on the grid. Might be interesting to you as well:
    http://www.transparency.eex.com/de/

    #67, “We’ll spew funds towards biofuels and electrons, but nobody knows which will be the better investment”

    Concerning battery-powered cars: I don’t think it makes sense to build battery-powered cars as long as our clean electricity is not even sufficient to run our already electrified trains from clean electricity sources. Trains here mostly run with electricity created by burning coal. This has the effect that a Prius+ with 7 persons in it emits about 1/4 of CO2 per person than an electric train.

  48. 498
    J Bowers says:

    Re. 487 Craig Nazor

    It gets more interesting: Canadian government ‘knew of plans to dump iron into the Pacific’

  49. 499
    Chris Korda says:

    Gavin @323:

    You need to take into account … the thermal inertia of the oceans which slows the response in temperature.

    The IPCC AR5 Representative Concentration Pathway (RCP) scenarios include forcing, concentrations, and emissions data, but unlike the equivalent AR4 scenarios, temperature data is omitted. This shortcoming motivated an attempt to derive RCP temperatures from RCP CO2 concentrations, using a simplified thermal inertia model called a Climate Response Function (CRF), described in the 2011 NASA/GISS paper Earth’s energy imbalance and implications by Hansen et al. Given an instantaneous forcing, a CRF models the distribution of the resulting temperature change over time. Specifically, the CRF predicts what percentage of a given instantaneous forcing will be manifested as temperature change in each of the subsequent 2,000 years. Hansen et al. present three CRFs: Slow, Intermediate, and Fast. Slow approximates the consensus of current climate models, intermediate is what they consider more likely, and fast is their upper bound. Mathematically, a CRF is a four-segment polyline in log space. The three variants are encapsulated in the following table, which gives the percentage for the final year of each line segment, for each CRF.

    CRFn ___Final Year___
    Name 001 010 100 2000
    ==== === === === ====
    Slow 15% 45% 60% 100%
    Med. 15% 55% 75% 100%
    Fast 15% 65% 90% 100%

    The first step is interpolating the CRFs, in order to obtain a percentage for each year of the model’s time span. Here are the results, plotted on a linear scale, and more usefully, on a log scale. The latter plot appears to match Hansen et al.’s Figure 5.

    The second step is to apply the interpolated CRFs to RCP CO2 concentrations, yielding RCP temperature data. For each combination of RCP and CRF, an array of yearly temperature buckets is created and initialized to zero. Each year’s concentration delta is sliced into 2,000 shares of decreasing size, as dictated by the CRF, and these shares are added to the appropriate buckets, which form a 2,000-year moving window. The results are presented as two groups of temperature series. The first group has one plot per RCP, and shows how that RCP is affected by each CRF: RCP3-PD, RCP4.5, RCP4.5-SCP, RCP6, RCP6-SCP, and RCP8.5. The second group has one plot per CRF, and shows that CRF’s effect on each of the RCPs: Slow, Intermediate, Fast, and Instantaneous (included for completeness only). All of these plots are also available as a single PDF file.

    It should now be possibly to more realistically answer the question originally posed @203. Assuming the IEO2011 Reference case of “1 trillion metric tons of additional cumulative energy-related carbon dioxide emissions between 2009 and 2035″, and given that this case equates to following RCP8.5 until 2035 as previously demonstrated @408, what increase in average global surface temperature relative to pre-industrial would result by 2035? Depending on CRF choice, the answers are 1.3ºC (slow), 1.54ºC (intermediate), or 1.77ºC (fast). For details, please refer to the comments in the platform-independent C code, which can be viewed here. A zip file containing the VC++ project and all input and output data is here. Thanks to Chris Dudley for recommending the Hansen paper.

  50. 500
    Chris Korda says:

    Correction: “previously demonstrated” in the last paragraph should have referred to @289. Also “possibly” should be “possible”, sorry!


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