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Fun with correlations!

Filed under: — gavin @ 9 May 2007 - (Türkçe)

We are forever being bombarded with apparently incredible correlations of various solar indices and climate. A number of them came up in the excoriable TGGWS mockumentary last month where they were mysteriously ‘improved’ in a number of underhand ways. But even without those improvements (which variously involved changing the axes, drawing in non-existent data, taking out data that would contradict the point etc.), the as-published correlations were superficially quite impressive. Why then are we not impressed?

To give you an idea, I’m going to go through the motions of constructing a new theory of political change using techniques that have been pioneered by a small subset of solar-climate researchers (references will of course be given). And to make it even more relevant, I’m going to take as my starting point research that Richard Lindzen has highlighted on his office door for many years:



That’s right. Forget the economy or the war(s), the fortunes of the Republican party in the US Senate are instead tied closely to the sunspot cycle.

“Oh yes”, the sceptics might say “but that’s just a couple of cycles and doesn’t use up-to-date numbers. What happens after 1986?”

Well, that is a little problematic, however, the good early correlation is obviously still important (r=0.52! 1960-1986) and so we should be able to refer to it over and over again without noting that it breaks down subsequently (cf. Svensmark, 2007 referring to Marsh and Svensmark (2000)). But more importantly, it just demonstrates that the theory needs a little adjustment.

Let’s look at the second half of the record. Well, there’s another strong correlation for that period as well (r=-0.63, 1988-2006). Only this time the correlation is inverted, but that shouldn’t be surprising to anyone – solar-senator effects are complicated!

If we now put it all together, we can see that there is a reasonable match over the whole period…. well, except that break in the period 1984 and 1988 and, unfortunately, last year’s elections didn’t fit the pattern either. But 1984-1988 was Ronald Reagan’s second term and clearly no theory of Republican senators can ignore that. We therefore propose that the ‘Ronald Reagan second term phase shift’ combined with the change of sign of the Hale solar magnetic cycle in 1986, obviously changed the dynamics. This kind of phase shift is frequently seen in solar studies (cf. Landscheidt and many others), where it is rarely taken as a sign that two time series with decadal spectral power are in fact completely independent. Finally, it is permissible to leave off the more recent data points (cf. TGGWS) for “graphical convenience”. So after just a little work, we have managed to rescue the original theory to match a much longer amount of data:



Some readers may scoff and suggest that in the absence of any mechanism, these powerful correlations are numerological artifacts arrived at using post hoc fallacious reasoning that have no predictive capability. That might appear to be a valid argument. However the ultimate test will of course be experimental. On the basis of these intriguing results, we propose exposing Republican senators to varying levels of cosmic rays in a basement and monitoring their electability. Any refusal by the funding agencies or ethical review panels to support this would simply be confirmation that the political science establishment are scared of what this research would imply for their so-called “consensus”.

Convincing, eh?

The data for sunspots and senators can, I’m sure, be manipulated even more effectively than I’ve done here. I’ve made no use of various lags or filters (which can be altered as you go along cf. Friis-Christensen and Lassen (1991)), or of partial detrending (cf. Marsh and Svensmark (2003)), or of splicing of unconnected data sets (cf. Svensmark and Friis-Christensen 1997, Nir Shaviv). More ideas could be taken from “New evidence for the Theory of the Stork” (Höfer et al, 2004)”. A special RealClimate commendation for anyone who can do better!

356 Responses to “Fun with correlations!”

  1. 251
    PHE says:

    Re 233 (Timothy Chase). You seem to say “false”with such relish. In fact, I can meet the challenge quite easily:
    ‘You might look at reports of crop damage from the cold temperatures and late frosts. Fruit trees failing to ripen before the winter. Cold reduces the numbers of insects, leaving less food for the birds. Then there’s issues of timings: pollenators hatching or migrating at the wrong times for their crops. Then we could get into the excess of precipitation & winter snowpack, and the effects those are having on crops. Growing glaciers threatening downstream villages (a genuine fear in the 1700s). And the loss of revenue to the summer tourist industry. And on and on.’
    That was easy. The irony is that you will assume I lack concern for the environment. On the contrary, I wholeheartedly support its protection. I believe in energy efficiency, reducing airborne pollution, and protecting our countryside, rivers, etc. I left my car at home today and cycled to work. My concern is the use of pseudo-science by the media and campaigners. There is good science and scientists on both sides of the climate change debate. The regular nonsensical exagerations and claims we constantly hear from pro-AGW supporters (who I can only assume are not scientists) does a great diservice to their side of the argument. Cry wolf if you wish, but you will regret it once the general public lose interest, perhaps just when feel their support is needed most.

  2. 252
    Hank Roberts says:

    >Fermi paradox

    So far we have no evidence that any intelligent lifeform has survived the short period of time when the easily available fossil fuel gets used up, along with the easily accessible metal.

  3. 253
    Nick Gotts says:

    Re #245 Take a look at http://www.carbontradewatch.org/. I can’t vouch for everything on the site, but it’s a mine of information supporting your doubts. Certainly, scepticism about carbon offsets – and more broadly, carbon trading – is widespread among climate change campaigners. Even where offsets are genuine, it’s worth bearing in mind that it would always be better (at least from the point of view of combating AGW) to give the money to the offset scheme yourself, and not take the flight, or whatever the activity being offset is!

  4. 254
    Nick Gotts says:

    re #225 “I suggest you try this. Imagine the world is cooling by 1 degree per century (due to say manmade aerosol-induced global cooling). Then list all the bad things that could happen. You could easily achieve as long a list.”

    Up to a point – although the likely warming over the next century, if we do nothing to prevent it, is considerably more than 1 degree – if we could keep it to 1 degree, we’d almost certainly avoid really serious damage to human populations, and considerably moderate destruction of biodiversity. The point is that both human activities (notably agriculture and settlement patterns), and non-human species distributions, are adapted to current/recent climate conditions, and rapid change in any direction is going to cause serious problems. This is particularly the case as climate change will interact with other serious environmental problems such as overpopulation, soil erosion, regional fresh water shortages and pollution, deforestation, and problems with invasive species.

  5. 255
    Jim Eager says:

    Re 244 MDC: “My intent is not to justify not doing anything, or selfishness…”

    Sorry, but after reading your latest I’d say that’s precisely what you are doing, and that Tim, Nick and I had you pegged correctly.

    “I CAN see, however, that there are competing explanations for the perceived warming…”

    Such as? You’re clearly stuck between the second stage of denial (I’m not convinced that we have anything to do with it) and the third (in any case it’s too expensive and inconvenient to do anything about it).

    “That’s all I’m looking for: how much is okay and how much is too much?”

    How much rise in temperature will it take for you to get that this is a very real and very serious problem that needs to be addressed, the earlier the better?

    How much of a rise in sea level will it take? How much ice loss? How much crop failure?

    You need to ask yourself these questions.

  6. 256
    Philippe Chantreau says:

    I have a couple of comments on your post, PHE. If you’re so concerned about the use of pseudo-science in the media and elsewhere, you should be up in arms against the innumerable misrepresentations, erroneous assertions, misleading statements and dishonest picking of data that this site spends so much time addressing. All these have done so much disservice to their side of the argument in my view that I consider their side of the argument completely moot.

    It is an opinion that I have formed over 2 years of attentive and abundant reading about the subject (both sides).

    Although I concede that some “green” organizations are annoying with the language they use, they are still closer to reality than the denialists trumpeting that CO2 is good because it is “plant food.”
    Yes, they actually do say that, and worse.

    “There is good science and scientists on both sides of the climate change debate.” Please define exactly what these sides are. If they are the same that I see, there are a few credentialed scientists (very few) defending positions on which there is very little research on one side and an almost unanymous scientific community with an enormous body of research on the other side. It does not help that the few aforementioned scientists spend most of their time advocating instead of doing research, or that they receive funding from entities with immense financial stakes in the BAU scenarios.

    If you know of different sides, in which scientists and data are more evenly distributed, I would like to know about it too.

  7. 257
    John Mashey says:

    Re: #251 PHE

    Consider a simple X scale of professed belief:
    0: AGW is a hoax (denialist)
    0+ .. 1- : probability of AGW, opinion based on evidence (rational skeptics), and usually as people learn more they move higher.
    1: AGW is the end of the world, and fund my environmental organization (Alarmist)

    0 normally gets that way for economic, ideological, or political reasons, i.e., if one works for fossil fuel organizations, automatically disbelieves anything the UN or Al Gore says,then one will stay at 0 regardless of any accumulating evidence.

    1 sometimes gets that way for ideological reasons (be nice to the Earth), and sometimes generates alarmism for funding. My “favorite” was a book that decried the future disappearance of penguins in the Arctic, which was irritating enough to drop my view to .2 for a little while years ago.

    If one uses a 3D visualization (X = above, Y = relevant scientific knowledge, Z = certainty level), the relevant clusters of people become obvious, as do the evolving paths of opinions over time. For instance, someone who stays at 0 or 1 in the face of changing evidence is different from somebody who can change their minds. Knowledgable people at .9+, having had numerous run-ins with those at 0, sometimes get short-tempered with somebody at .2, if they ask enough questions that sound like those of 0.

    The problem (PHE? is this your issue?), is that if someone is exposed to much of 1 (before building a strong knowledge of evidence), distaste can quickly drive them down to the .1-.2 range. I’d guess most real climate scientists have moved to .9+, over the last few decades. Those at 0 do their best, sometimes successfully, to conflate those at 1 with world-class scientists at .9+:

    i.e., try Google: james hansen alarmist … gets 50K hits

    [gavin schmidt alarmist only gets 960 … need to work harder :-)]

    [Response: I’m still young(ish). There’s time…. -gavin]

  8. 258
    James says:

    Re #244: [I plan on ‘not doing anything’ for exactly as long as it makes economic sense to do so.]

    Suppose we look at that from a different angle, and ask if you would do things which do make economic sense, even though they might have a positive effect on climate? From your next paragraph (about driving your SUV) the answer would seem to be no, since unless you’re one of the rare people who e.g. live at the end of a rough dirt road, you’d very likely save money by driving a smaller, more fuel-efficient vehicle.

    So I have to wonder about your reasoning. On the one hand you’re attacking people for wanting to spend money mitigating CO2, yet you’re seemingly willing to do the same thing in reverse, and waste money on things that contribute excess CO2. Why?

    There are a great many things that could be done at zero cost (or even at a profit/benefit) to partially mitigate CO2. Even if one is sceptical about the accuracy of CO2-related climate change forecasts, what exactly is the objection to doing these, simply as a precaution?

  9. 259
    Arvella Oliver says:

    MDC (244)– Your comments remind me of my neighbor, who defended her purchase of a Chevy Tahoe thusly: “We’re tall people. We need big cars.” Now, I love this woman dearly; she is my best friend, and she was a stand-in mom to my children while I was going through chemo. But my first thought was, WTF?!

    You defend your 4Runner by saying that you have a lot of “stuff” to haul around. I’m always flabbergasted by this “stuff” rationalization. I mean, if my family of four can fit ourselves and the “stuff” we need for a week-long trip into our Prius, and then drive more than 500 miles on ONE TANK of gas, I honestly wonder just what kind of “stuff” other people feel compelled to tote around with them.

    I think many of us just can’t tell the difference between what we *want* and what we *need*. We say we *need* this and we *need* that. Makes me think of a great movie where one guy looks at the other guy and says: “You keep using that word. I don’t think it means what you think it means.”

    For example: I’d really love to have a Jaguar. A blue convertible Jaguar. With leather seats and satellite radio. But I don’t *need* it; I *need* to save money for my kids’ college fund. Driving a Jaguar won’t make me thinner or sexier…Hm. I think you’ve pushed a few of my buttons too.

    We’re not being asked to make enormous sacrifices. We’re not being asked to patrol Baghdad. We’re not being asked to wade into the surf at Normandy. We’re not even being asked to give up meat on Fridays (though we’d probably be healthier if we did). All that’s required is that we be a bit less self-centered, a bit less self-indulgent. If we can’t manage that, then humanity doesn’t stand a snowball’s chance in hell.

    Okay. Deep breath. I’m finished now. It’s been a bad day.

  10. 260
    The Wonderer says:

    I am not an economist, but I did have to take an economics class once. I do enjoy saving money by driving a small fuel efficient car, using public transportation or riding my bike when feasible, owning a small, well insulated home, and using CFLs. I also occasionally feel good that I’m doing something good for the environment. But absent coherent government policies that will unmask the true cost of energy, I often worry that my frugality is just helping to keep energy prices down and encouraging others to use more. By the way, I recycle my junk mail. I don’t have a good explanation of why.

  11. 261
    Matt says:

    Timothy writes: “Carbon offsets may work, but it will have to be well-documented, probably by independent parties. ”

    The fact that I can completely offset a year of Hummer driving from TerraPass.com for $80 should tell you all you need to know about carbon offsets. Keep in mind that’s an extra $80 after I’ve spent $2500 on fuel for the year.

    Either offsetting carbon is so cheap because it’s so easy to do and all this is much ado about nothing, TerraPass is lying or Hummers aren’t evil. Hmmm.

  12. 262
    Matt says:

    James writes: [You’ve touched on an important point, but missed one as well. Turn the question around, and think about why I, like many people, choose not to smoke or eat (large amounts of) nachos. It’s not because I’m into self-denial, or that I’m trying to minimize potential risks 20 years down the road: it’s because not doing so improves the quality of my life right now. That I may also see long-term gains is, as with helping folks in Africa, just a nice fringe benefit.]

    And I can tell you that I’d buy health insurance before I’d buy cable TV and cellphones and a second car. But most of the country disagrees with me on that. My point was that a huge portion of the population can’t even plan for the basics. Don’t count on them sacrificing anything for the future. My second point was that when you consider the certainty of global warming (very, very high), the impact to GDP (less certainty) and the cost to mitigate (less certainty), then those that are skilled in the art of betting one way or the other on these types of things have looked at the evidence and have decided to wait it out for now. That might change, but that’s the fact right now.

    [Why? I choose to drive a Honda Insight instead of an SUV: what am I sacrificing by doing so? The privilege of paying several tens of thousands more to purchase the vehicle, then yet more every time I fill the tank? I use CFLs instead of incandescents: what do I sacrifice? ]

    You are right James, you haven’t sacrificed a thing. You are MUCH closer to the SUV driver than the farmer in India. Now, if you tell me you don’t have a car and spend an extra 2 hours a day riding public transportion and you bike your kids to soccer games, you are completely off the grid and you grow your own food, then you’ve got my ear. And in that case I think you’ll agree that you have sacrificed a lot at that point. CFL will save 5-7% of your electricity per year, yet most families are adding electronics to the home at 5+% per year. What your counterpart pedals in China makes your Insight look outright glutonous. Do you know when your counterpart in India goes to bed? When the car battery that he charged all day via a small solar cell finally is exhausted.

    This rational of a percent here and a percent there is just utterly bogus when the world energy consumtpion is growing by 5% per year. To solve global warming, those in the west need to get their carbon footprint to 10% what it is today, because your counterpart in China is enjoying things he’s never had before, and is about to explode his footprint by 10X. And there are 10X more of him.

    Note when I say that you need to get your footprint to 10% what it is today, realize that 75% of your footprint isn’t even under your control. Household consumption in the US is around 11000 KWH, yet annual per-capita consumption for a family of four is 48,000 KWH. Your house could go to zero KWH and you still have Home Depot running the parking lot lights all night on your behalf. You still have The Mirage hotel in Las Vegas running massive water features all day on your behalf. And on and on.

    Folks REALLY don’t understand how painful it is to get CO2 waaaay down when you have a large portion of the world (rightfully) tasting for the first time how wonderful cheap power can be.

    The one way to avoid the hurt is nuclear power combined with electric cars. That gets us 90% of the way there and the engineering is well understood. I’d pay a massive gas tax to see that go into a superfund XPrize type of arrangement.

  13. 263
    Matt says:

    [We’re not being asked to make enormous sacrifices. We’re not being asked to patrol Baghdad. We’re not being asked to wade into the surf at Normandy. We’re not even being asked to give up meat on Fridays (though we’d probably be healthier if we did). All that’s required is that we be a bit less self-centered, a bit less self-indulgent. If we can’t manage that, then humanity doesn’t stand a snowball’s chance in hell.]

    Sorry, but you are so very wrong.

    We all know that Kyoto required us to hit 1990 levels of CO2 output, and we also know Kyoto wasn’t a solution, but it was a bandaid that bought us just 6 years of relief in terms of warming. So since 1990 levels weren’t sufficient, let’s instead try to solve the problem and hit 1975 levels. In 1975, CO2 output was about 4.8B tons. In 1990 it was about 6B tons, and in 2000 it was 6.5B tons.

    Now, let’s assume that everyone in the world gets to produce CO2 equally. Afterall, it’s not fair to deny a developing nation things we enjoy.

    So that is 4.8B tons per year, shared among 6.5B people. That is 0.74 tons (1500 pounds) per person per year. If we can do that, then we hit 1975 levels and will likely solve the problem for good.

    The problem is, however, is that those in the west are producing between 13 and 33 tons per capita per year.

    So if we really want to address this, we all need to figure out how to get our carbon footprint to 1/10 or 1/20 what it is today.

    If you limit your Prius driving to 4000 miles per year (1408 pounds of CO2), then you get a few hundred hours of a single CFL bulb. No heat. No AC. No computer. No TV. Nothing else. At that point, you will be using “your fair share”

    This is a very, very serious problem that require drastic action. CFL and hybrids don’t even begin to cut it. And it’s a shame that many people believe that is all that is needed.

  14. 264
    Matt says:

    One item I’d appreciate a pointer or two for study is how do folks detect subtle temperature trends (shifts in mean) when the sigma of our temperature is so high?

    For example (http://www.wrh.noaa.gov/tfx/pdfs/NORMALS.pdf) shows that Great Falls max temp over the last 30 years for Aug has a mean of about 83 degrees, and a std dev around 9 degrees.

    If I use Excel to generate 5 trials of 1000 Aug 1 temperatures (say year 1000 to year 2000), then across those five trials I see the mean vary by about 0.9’F even though the mean going into the RNG with normal disti was 83’F.

    What this says is that even if our mean was declining we could easily still see several years of warming. With a sigma this large, you really need about 10,000 temp samples to see the mean across 5 trials converge to within a few %.

    Thanks in advance for any article pointers.

  15. 265
    Hank Roberts says:

    Hey, there’s bogosity any place you look.

    Check the clever ‘Ethanol Myths” page here:
    http://e85.whipnet.net/ethanol.faq/topten.myths.html

    Down near the bottom, they’ve tucked in this ‘myth’ which I suspect they made up:
    Ethanol Production is 100% efficient.

    And this explanation:
    “Producing Ethanol requires a vast amount of energy and multiple resources. The process reportedly contains 65 percent less usable energy than is consumed in the process of making it.”

    And that’s from the website _encouraging_ the stuff.

    Their further explanation is that, eventually, they’ll be making the stuff out of cellulose and that might actually be energy-efficient, and in the meantime, well, hey, it’s, er, yellow. And you can get a tax credit for vehicles burning it.

  16. 266
    Timothy Chase says:

    Re: Alarmist, Hansen

    I have tended to think that even though there are positive feedback mechanisms which we are just beginning to learn about or which are just now getting started, we should go with the conservative models of climate change and let the more dire predictions wait until the models improve and the evidence accumulates. However, the more I read, the more I begin to wonder. Still, the IPCC needed to go with the more conservative projections simply in order to get different science organizations and more importantly, different governments to sign on. But honestly, the material I am seeing makes me nervous on a number of fronts.

    PS

    When you do a search for “james hansen alarmist,” you get a great deal of webpages. However, you should probably check the actual content of those pages to see what they are saying. The “most relevant” (judging from the fact that they rise to the top) are those which are responding to attacks on Hansen’s credibility, not attacking his credibility. The first which actually attacks him is six down – and it isn’t actually attacking him but a record of a speech by Senator Inhofe.

    I guess this says a little more than the mere number of webpages that come up, but then again, it probably says a great deal more to you if you are a real fan of Senator Inhofe…

  17. 267
    Nick Gotts says:

    “If I’m to be held to some sort of moral standard (as implied in #239), then I can only assume that Mr. Gotts has stopped ALL production of CO2 in his life (I’ll accept exhaled breath) or can demonstrate in concrete terms that he is 100% balanced not in carbon credits but in actual CO2 absorbing activities balancing out all his production.”

    I don’t claim anything of the kind; I don’t always do what I know I should. It’s ridiculous to claim there’s no reason to do anything until someone can tell you exactly how much is too much. For almost everyone in rich countries, it’s abundantly clear that we need to cause less GHG emissions than we’re doing now. It’s also clear that to deal with this problem we need both government legislation and individual action.

  18. 268
    The Wonderer says:

    Re 265 Hank, In the articles I’ve read on ethanol production, I’ve never seen an apples-to-apples comparison which includes details on the amount of energy required to produce a gallon of gasoline at the pump. I presume it’s not insignificant, although due to sheer volume, I don’t doubt assertions that it’s currently cheaper. Any thoughts?

  19. 269
    tamino says:

    #264: (Matt)

    For example (http://www.wrh.noaa.gov/tfx/pdfs/NORMALS.pdf) shows that Great Falls max temp over the last 30 years for Aug has a mean of about 83 degrees, and a std dev around 9 degrees.

    If I use Excel to generate 5 trials of 1000 Aug 1 temperatures (say year 1000 to year 2000), then across those five trials I see the mean vary by about 0.9’F even though the mean going into the RNG with normal disti was 83’F.

    The standard deviation they’re talking about is for the temperature in a single location on a single day. Monthly averages will have considerably less deviation; accessing data for Great Falls from GHCN, I compute the August monthly average has a standard deviation of right around 3 deg.F (1.67 deg.C). The annual average temperature anomaly has even less standard deviation — for Great Falls it’s 1.8 deg.F (1.0 deg.C).

    And that’s just Great Falls! The standard deviation in the annual average temperature for the planet is about 0.3 deg.F (0.15 deg.C). That’s 30 times smaller than the 9 deg.F you used in your RNG.

  20. 270
    MDC says:

    Thanks for all the comments. I’ll try to keep this a little more on track and address the issues I think are important (because I really DON’T think MY compliance/acceptance/denial is what’s important here).

    For all: My 4Runner/Prius issue… my exact needs (and your unawareness of them) are EXACTLY the point. Broad policies not driven by specific, quantitative measures are going to be poor fits for half of the bell curve of personal transportation needs, and will be resisted by that half. Perhaps it makes more sense for me to spend the money to transport a subset of my household back and forth across the country twice a year by rail instead of in the back of my 25MPG highway SUV, or perhaps it makes sense for me to sacrifice bringing some things, or perhaps it makes sense to use rail, or perhaps just buy the things I need on each end. Where is the information for me to make that informed decision? Witnessing the effeciencies of the government in housing, welfare, and tax collection, I am hesitant to believe that satisfying decisions will be made by a policy letter. Doubling of CO2 means something, the IPCC says, but that does not help in day-to-day decisions.

    As for my selfishness: Instead of merely calling me selfish or in denial, accept that I am a reasonably well-educated, mid-40s American that is not invested in the oil industry that has done a little poking around and am unconvinced of the imminent danger here. I’ve got questions, like Matt in #264, about the number of significant digits in play here. I am emotionally put off by the arrogance (any hypocrisy) of Al Gore’s presentation, so seek harder numbers than pictures of swimming polar bears. I’ve been to NASAs website after googling for satellite-derived temperature trends and oddly don’t find a smoking gun (granting that the most recent posts are 1997 and 2000… why IS that?). I’m the target audience, and answers of “just do something” leave me unconvinced. Sure there’s game theory in play here, Pascal’s Wager and all that, too. We’ve all seen the reports that indicate that money and focus is better spent on non-weather-related disaster preparation, so what raises GW to the top of the priority stack?

    Again: there is nothing wrong with living cleaner. I’d just rather not do it because of trumped up alarmism. Heck, according to the Peak Oil folks, this will be a self-correcting problem anyway.

  21. 271
    Hank Roberts says:

    >nuclear power combined with electric cars
    Fifty years ago, 1957 — William Ford alongside a 3/8 scale Nucleon model: http://www.damninteresting.net/content/ford_nucleon_model.jpg

    By contrast, an older idea still makes sense today:

    “… the new Doble steamer … Model E zipped from zero to seventy-five miles per hour in a jaw-dropping ten seconds…. free of noticeable vibration, and the steam piston engine was turning at a leisurely 900 RPM. The model E …. achieved about fifteen miles per gallon of kerosene with negligible emissions….. Many of the Model E Dobles which have survived are still in good working condition, some having been driven over half a million miles with only normal maintenance. Astonishingly, an unmodified Doble Model E runs clean enough to pass the strict emissions laws in California today.”
    http://www.damninteresting.com/?p=669

  22. 272
    MDC says:

    P.S. And I recognize that I’ve drifted (vigorously) off the “causation/correlation” angle of the article. There are probably better threads for this discussion… but since the lead article was about sketchy assumptions reduced to the absurd, this may be just the place.

  23. 273
    Nick Gotts says:

    Re #263 “This is a very, very serious problem that require drastic action. CFL and hybrids don’t even begin to cut it. And it’s a shame that many people believe that is all that is needed.”

    Matt, you’re right about that. Where I think you’re wrong is in thinking that means individual action to reduce wasteful energy consumption is pointless. Governments (particularly elected ones) are more likely to take serious action on an issue if they see evidence that significant sections of the public are concerned about it. Even if the actions taken have trivial direct benefits, even if they are actually not directly beneficial at all – like many offsets – they are evidence of concern, both to governments and corporations (once they become statistically measureable), and to others in your own social circle, who may be prompted to do something along similar lines themselves. To use an example remote from AGW, during the last couple of years different parts of the UK have been introducing bans on smoking in enclosed public places – this process will be completed in a month or so when England joins the rest of the UK. This would have been unthinkable 20 years ago, and in introducing bans, UK governments have had to take on important vested interests. But in that time, it has become socially less and less acceptable to light a cigarette without asking permission, first in someone else’s house, then in shared spaces like offices and restaurants – and those asked have become more and more willing to refuse permission. Similar processes have made it much less socially acceptable to drive after drinking alcohol (here, legislation followed the initial shift in public opinion, but has also reinforced it). Thus any evidence that you are concerned about greenhouse gas emissions may influence those you interact with (although of course, it’s possible to put people’s backs up by proselytising) – and this is perhaps most likely to be effective if it clearly involves some sacrifice, but one within most people’s ability to make – so there is a good chance they will think “I could do that”. Of course you can still say, truly enough, that the chances of anything you do making a crucial difference even by such indirect routes is minute. Fortunately, most people value the good opinion of others, and many like to feel that they are acting in accordance with their principles, or in such a way that if everyone else acted similarly, the results would be good. (If this were not so, at least so far as the opinion of others is concerned, I suspect human societies would be unworkable.) I suspect, on reflection, that this is true of you – otherwise, why would you bother visiting this site to argue about it? (OK, maybe you enjoy arguing, but why this particular argument?)

  24. 274
    Dan says:

    re: 270. “We’ve all seen the reports that indicate that money and focus is better spent on non-weather-related disaster preparation, so what raises GW to the top of the priority stack?”

    It might have something to do with the 90% liklihood/certainty as discuss in the IPCC reports (based on science, not political commentaries). It is all readily available for learning and understanding. The issue is the unequivocal, peer-reviewed science, not what any politician says about it. What Gore presented happens to be quite accurate science, with a few caveats as discussed on this site in detail. We need more politicians who are able to understand the science as he does. And present it to people as well as he did/does in a way that is easy for laymen to comprehend.

    The uncertainties in global warming are far, far fewer than many scientific “certainties” that are accepted by the mainstream. Probably the only reasons there are those who question it are: 1. they have not read the science (which is quite clear and basic physics) and 2. they are reading the “disinformation” published in grey literature from “polluted”, non-scientific, non-peer reviewed sources (or from those who are not the least involved in climate science research: op-ed writers, economists, science-fiction writers, some geologists, engineers, etc.). It is not difficult to separate the two and discard the trash from the later. It is astonishing and quite sad that certain laymen with little background in the science beleive they know more about the subject than literally thousands of climate science researchers across the world. Every major atmospheric science society across the globe agrees about the issue of global warming. To give equal weight to disingenuous comments (which have been thoroughly discredited by scientists) from non-experts is simply inexcusable, head-in-the-sand logic. And a sad reflection on the state of critical thinking and science education as well, I suppose.

  25. 275
    Arvella Oliver says:

    Matt (263) You’re right; this is very serious, and I didn’t mean to imply that a few lightbulbs and a car can solve the problem. I should’ve said that we should *as a beginning* be a little less self-indulgent. We have to ease people into this (and I know, we don’t have much time for that). My point, badly expressed, was that we have to find a place to start.

    MDC (270) Thanks for the explanation of ‘stuff’. I appreciate it. There will always be people who need a bigger automobile for work, or health reasons, or because they’ve got six kids, but I think they’re a minority. And I agree that it would be hard to figure out the most efficient way to move your stuff around. BTW, thanks for not driving a Hummer. Cheers!

  26. 276
    Philippe Chantreau says:

    Matt does have a point as to the seriousness of the problem. In fact, it may even be more serious than he says.

    The real problem is that it is simply impossible for all 6 B people on this planet to share equally even the middle class western lifestyle. We would need several Earths for that. Energy is one of the most visible components of the problem, but there are many others. There is no plan whatsoever to address this. In my opinion, it is the biggest market failure ever and the threat that it represents has no equivalent in human history.

    I’m not sure that energy will be the most difficult issue in the overall problem. Has anyone seriously looked at what can be achieved by combining, on a global scale, solar, wind, geothermal, biomass hydro, tidal, wave and nuclear with optimized transmission and distribution? Nuclear offers options whose efficiency and waste generation are far better than what is widely used today. We need to stop talking about all these possibilities and make them become realities. With a barrel sutained above $70 and coal not being much of a long term option because of climate, it has to be possible. Whatever cost is there is simply the cost of a decent life for all in this world. We will not have it if we don’t want to shoulder the cost.

  27. 277
    John Mashey says:

    re: 266, alarmist, Hansen

    “However, you should probably check the actual content of those pages to see what they are saying. The “most relevant” (judging from the fact that they rise to the top) are those which are responding to attacks on Hansen’s credibility, not attacking his credibility. The first which actually attacks him is six down – and it isn’t actually attacking him but a record of a speech by Senator Inhofe.”

    I checked, of course, but I guess I should have better articulated the point better. It may be that I know more than I ought to about PR/marketing campaigns :-), which are *not* anything like scientific arguments, even when they try to masquerade as such.

    If one is doing a PR/lobbying campaign intended to create confusion, in the general public, one wants to throw mud and hope that it sticks a little, as widely as possible. You may have heard the phrase “No publicity is bad publicity.” [Not really true, but sometimes it works.]

    Hence, if one can force someone into saying “James Hansen is not an alarmist”, at least some of the readers will wonder: why are they being defensive? Or maybe, in a blog, people will argue with that, possibly leaving confusion in the minds of the unwary. Or, since people have lots of other issues to think about, maybe a vague impression lingers.

    If you look at the first hit from Google [A Few Things Ill Considered], the first part is a (good) discussion by Coby, followed by 17 comments, which include 4 different posts (by Anonymous) that include:

    “alarmist rhetoric spouted by Dr. Hansen”
    “Alarmist is exactly what I meant”
    “What I object to is alarmist rhetoric”
    “public information is skewed in favor of alarmist news”
    [Others argue the other side of course]

    [This kind of thing makes me long for the good old days of USENET, when most people posted under real names… Long ago, it became clear that on on-line bulletin boards, it is *always* easier to create confusion and obfuscation than clarity, even without anonymous posters.]

    The second one is from DeSMogBlog: that page just says:
    NZ Climate Neanderthals Blast Network for Airing Hansen’s “Alarmist” Views
    The skeptical New Zealand Climate Science Coalition is pressuring TV New Zealand to “balance” the “alarmist” climate forecasts by NASA chief climate scientist James Hansen — whom they call “a supporter of global warming.”

    That’s certainly reporting an attack, and Ross Gelbspan’s view of the Neanderthals is clear …
    but “No publicity is bad publicity.”

    The Inhofe speech certainly attacks Hansen, and of course it’s Inhofe, right there with Joe Barton (I guess Oklahoma legislators don’t recall the Dust Bowl) …
    but it is on an official US Senate website.

    Viewed as a marketing/political campaign, I’d say the denier/denialist/contrarian side (whatever it should be called, which is a problems) has done a good job of selling a political-style anti-brand term “alarmist”, using the term consistently and getting it to rub off on serious scientists. That side would be happy about every hit…. even if most of the pages were doing their best to refute it. That side would be happy that “Google: Richard Lindzen skeptic” gets more hits than denier, denialist, or contrarian…
    since “skeptic” has better connotations. Sigh … and sorry for dragging RC off into politics/marketing.

  28. 278
    Hank Roberts says:

    > This kind of thing makes me long for the good old days of USENET

    Oh, yes. And don’t forget the killfile. Being able to simply not see those who were trolling was an enormous help when keeping a conversation going that led somewhere interesting and stayed fun and informative.

  29. 279

    [[I’m all in favor of budgeting more money for research… just not for policies designed to ‘fix’ a problem that we can’t define.]]

    By that logic, FDR shouldn’t have done anything about Hitler. After all, Hitler could have done anything. Unless he knew ahead of time how many lives would be lost per dollar of military expenditures, he wasn’t justified in spending anything on military appropriations.

  30. 280

    [[To loop this back around to the thread topic: correlation/causation issues and snarkiness do not convince me that my driving my SUV negatively impacts the global climate (local pollution levels, maybe). I do not equate CO2 with littering in any meaningful sense of the word and I question the comparison between between the two.]]

    All you’re saying here is that you don’t know much about atmosphere physics. That can be fixed by doing a little studying.

  31. 281

    [[There is good science and scientists on both sides of the climate change debate. ]]

    There isn’t any “debate,” except in the minds of people like you who have bought into the denial propaganda. As for the scientists, 99% of the climatologists believe global warming is real, we’re doing it, and it’s a serious threat. That’s good enough for me.

  32. 282

    [[I’ve been to NASAs website after googling for satellite-derived temperature trends and oddly don’t find a smoking gun (granting that the most recent posts are 1997 and 2000… why IS that?).]]

    A smoking gun? You don’t think global warming is even happening? Do you believe in evolution? Relativity? Gravity?

  33. 283
    PHE says:

    Re 281 (BPL). No debate. All the experts agree. I’m a monkey and I love cheese.

  34. 284
    MDC says:

    Sigh… #280-282 (Levenson): [self-delete]diatribe

    1) Is climate science as predictable, testable, falsifiable and repeatable as the theory of gravity? Relativity? If this is the case, then you are right, I’d be a fool to even question AGW. I just wonder if I’d have gotten the answer correct in high school had I said “acceleration due to gravity, in a vacuum, on Earth is 32 ft/sec/sec… +/- 8ft/s/s… so the ball dropped from a height will fall between 12 and 20 feet in the first second” or “the speed of light in a vacuum is 299,792,458m/s… +/- 100,000m/s. So… E=mc(ish)^2.” I don’t THINK Gavin is saying that…

    2) In your appeal to the authority of climatologists, can you point me to the source data for the 99% figure? I’m not sure if it’s significant or not, but I’d be darned curious to know how that number is derived, and what it’s margin of error is.

    Bottom line: There wouldn’t be a need for this site if, in fact, there was no room for further discussion, or if everybody should just study their physics and climatology a little more. Again, I’m not a dumb guy (or so I keep telling myself) and I have no vested interest in self-destructive behavior. Why am I unconvinced by “just do something” and “there are no further questions to ask?” Perhaps a better question would be why are you satisfied. I trust that it’s more than just the 99% figure. The base article on this thread was to lampoon those who can see causation in any set of corollation, providing it’s sufficiently massaged and looked at through squeenky eyes. Fair enough.

  35. 285
    Hank Roberts says:

    > climate science
    > gravity
    > relativity

    All required serious computer work to get beyond the simple basic idea.
    See the AIP History, first link under ‘Science’ in right column.

    Read a bit; right now you’re asking questions answered fifty years ago.
    That’s part of why people aren’t rushing to retype the answers for you.

  36. 286
    Philippe Chantreau says:

    Re 284: in my opinion, the need for this site was made dire by the insane proportions of the denialist propaganda, more than the debate. Like for evolution, there are many points in climatology that are a matter of debate. Like for evolution, the basic idea is not a matter of debate.

  37. 287
    Dick Veldkamp says:

    Re: #284 MDC (Levenson)

    1) Can climate science be compared to relativity etc? Depends how you look at it. Have predictions been shown to be accurate with 20 decimals accuracy or so? No. But are predictions good enough to be convincing? Yes. Can we predict and falsify? Yes again, for example check out the current thread on Hansen’s predictions. Is the theory of AGW based solidly in physics? Another yes.

    I think that the theory of AGW may well compared to many fields of engineering: building bridges, making airplanes fly, construct cars. In all this fields calculations typically are within 10-20% of reality. Not perfect, but certainly good enough not be afraid to travel by air. And much, much better than gut feelings.

    To restate the obvious, there is no discussion about the basics, like:
    – AGW is happening
    – It’s caused by CO2 emitted by us
    – Temperature is going up by 2 deg or so this century.
    As far as the need for immediate action is concerned, the debate is over. We know the enough for that, period.

    2) It’s not really an appeal to authority, it’s trust in the scientific process. For (something similar to) the 99% figure, check out Oreskes: http://www.sciencemag.org/cgi/content/full/306/5702/1686

    “99% of scientists agree with AGW” is shorthand for “there is now such an incredible amount of peer reviewed interlocking evidence that no person in his right mind, having looked at the evidence in depth, could possibly disagree with AGW theory any longer.”

    Which of course does not mean that we shouldn’t continue improving models and working on outstanding issues.

  38. 288
    James says:

    Re 262: [You are right James, you haven’t sacrificed a thing.]

    Which was my point: the issue under discussion was the need for the US (and, lest I be accused of being provincial, the rest of the “first world”) to make sacrifices in order to reduce CO2 emissions from their current levels. I cited those examples (and could add many others if I were into recreational typing) as evidence that considerable reductions could in fact be made, and not just without sacrifice, but to the net benefit of the people who made them.

    The fact that I haven’t yet reduced my CO2 footprint to that of an Indian peasant is a straw man. The reduction process, as others have pointed out, has to be incremental. Most people aren’t interested in sacrifice: if I demonstrate that I can reduce my CO2 without sacrifice, I may persuade others to do so as well. That creates an attitude shift, and a market for more energy-efficient goods. Manufacturers may discover efficiency as a selling point (convincing those who are swayed by advertising), thus shifting attitudes further. And maybe someday Home Depot and the like will decide that turning off their parking lot lights after they close at night is a good idea.

  39. 289
    MDC says:

    #287 (and some others): Thank you for the comments and links. The Science Magazine article was certainly a much better explanation of the ‘99%’ than others (and FAR superior than merely an appeal to the IPCC). Speaking as a helicopter pilot, I certainly hope that the engineering and aerodynamics tolerence that went into my helicopter is better than 10-20% ;^)… but I get your drift.

    I guess the last paragraph of that article captures my thoughts well:

    Many details about climate interactions are not well understood, and there are ample grounds for continued research to provide a better basis for understanding climate dynamics. The question of what to do about climate change is also still open. But there is a scientific consensus on the reality of anthropogenic climate change. Climate scientists have repeatedly tried to make this clear. It is time for the rest of us to listen.

    The real question is the “what do we do about it” and I find efforts like the Kyoto protocol to be unacceptable for a number of reasons that have nothing to do with the underlying science.

    In your list of ‘givens’ (GHG, AGW, 2 deg rise this century), I’m only uncomfortable with the lack of an explicit “based on the mechanisms we are aware of and modelling right now” for the temperature rise. To quote a former Secretary of Defense, which while it sounds funny, strikes me as particularly applicable to a system of systems like climate science.

    because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don’t know we don’t know.

    Unless I miss my guess, climate scientists (well, 99% anyway) don’t disagree with this statement, no matter how awkwardly worded.

  40. 290
    Dick Veldkamp says:

    Re: 289 MDC

    I think that your proposed addition “based on the mechanisms we are aware of and modelling right now” reinforces my statement “there will be 2 deg or so temperature rise this century”, rather than weakening it. To me this means: “Models that incorporate all our best knowledge of physics, warn us that there’s going to be trouble. We’d better take it seriously.” (Also remember that things might turn out WORSE than predicted by the models.)

    For a nice view of the spread in predictions (for the UK), see http://www.bbc.co.uk/sn/climateexperiment/theresult/abouttheresults.shtml

    PS As a helicopter pilot, don’t worry (not about aerodynamic models anyway). While the uncertainty in aerodynamic model calculations is considerable, engineers counter that by testing and using appropriate safety factors.

  41. 291
    Matt says:

    Dick Veldkamp writes [ think that the theory of AGW may well compared to many fields of engineering: building bridges, making airplanes fly, construct cars. In all this fields calculations typically are within 10-20% of reality. Not perfect, but certainly good enough not be afraid to travel by air. And much, much better than gut feelings.

    To restate the obvious, there is no discussion about the basics, like:
    – AGW is happening
    – It’s caused by CO2 emitted by us
    – Temperature is going up by 2 deg or so this century.
    As far as the need for immediate action is concerned, the debate is over. We know the enough for that, period.]

    Look inside the IPCC reports and you’ll see there is still a ton of debate, and you don’t have to peel back the onion very far to find it. Earth is warming. Check. Manmade CO2 is the culprit. Check. As we double CO2, the earth with rise by…….wait…not a lot of agreement….X to 1.5X, X to 2.8X, etc, depending on the scenario. Modeling for different scenarios is a smart thing, but in each scenario there is a massive range that results from a range of models. Presumably each model is taking the same input. But the guy building model M obviously believes that something works differently than the guy building model N. Otherwise, given the same input they would show the same output. Does the guy that built model M believe his model is wrong? Or does he believe model N is un-enlightened? They can’t both be right given the same input. If there is a 2X difference between two analysis given the same input, then there is a fair bit of disagreement/debate in the underlying mechanisms.

    An electrical engineer can purchase tools from any number of vendors, and the results will agree withing a few 10’ths of a percent. And if I care to accurately input parameters related to my real physical circuit, the model and reality with agree within a few 10th’s of a percent. If I don’t, it’ll still agree within a percent or two. This is because the models are well understood. I don’t think we can state that about climate models.

    Now, the usual response is “Yeah, but you don’t get how complicated this stuff is! This is ground breaking stuff!” Well, very true, but we need to be careful about placing too much trust in things that aren’t well understood.

    A typical climate model contains a million lines of code (http://physicsweb.org/articles/world/20/2/3/1). Using normal industry figures, you’d expect there to be 10,000 bugs in this software. A company like Sun or Microsoft or IBM would have a test team of 200-300 engineers testing this software, a team of 200-300 engineers writing, evolving and maintaining this software.

    And keep in mind, at Microsoft, Sun or IBM you usually have sofware ENGINEERS working on large software projects. I’d venture a guess that most folks working on climate models are scientists first, and software enthusiasts second or third or fourth. You can bet code quality suffers given the emphasis.

    What happened to the guy who wrote the model that said the temperature wouldn’t change if CO2 doubled? How many people inspected his million lines of code and found the mistakes? Or did folks just decide his answer was an outlier and toss it out?

    One thing we all really need to admit here is that we’ve seen some really sloppy science with some pretty big errors slip through peer review. If a group of scientist can’t even manage to reproduce each others basic maths during peer review, what on earth gives you confidence that the models are getting the scrutiny they deserve? And if a computer model is really as complicated as the link above indicates, how are we certain that complexity is being managed with the proper resources?

    So! Be very suspicious of the models. Lack of agreement among the models means lack of understanding and a reliance on intuition. Combine that with a software process that that is a small fraction of what Microsoft would apply to even your photo sorting software, and consider that there isn’t a ton of data available to validate these complex pieces of software, and you really are looking at something quite primitive.

  42. 292

    [[1) Is climate science as predictable, testable, falsifiable and repeatable as the theory of gravity?]]

    On some things, yes, it is. And, by the way, the theory of gravity runs into serious snags in a lot of situations, not just in the incompatibility between relativistic and quantum theories of it, but in a lot of celestial mechanics problems.

    Is the human cause of the present global warming as well established as the theory of relativity? No, probably not. Is it well enough established that it can be taken for granted by educated people? Yes, it is.

  43. 293
    Ray Ladbury says:

    Matt, Your argument is specious, because for the most part, given the same scenario, the models agree, and if anything, the models are conservative, since they do not reflect positive feedbacks that we now know are in the cycle. Whether a model says the globe will warm by 2.6 degrees or 2.8 degrees is for the most part in the noise. Either eventuality means drastic changes in climate.
    You do not dispute that climate change is occurring. You do not dispute that humans are the cause. It seems that your only question is how much warming there will be. You seem to draw comfort from a sense that we might be unable to predict the amount of warming we will see. If you don’t mind my saying, that is a wierd attitude. The inability to predict risk RAISES risk rather than lowering it. If the climate models cannot predict climate, then why is a rise of 3.5 or even 5 degrees less likely than a 2 degree rise? I work in a field where we mitigate risks. If we have a risk that cannot be defined, then that risk is immediately red-flagged and we expend resources trying to define it while simultaneously trying to mitigate it. That is an expensive process. Likewise, if we cannot limit the risk due to climate change, then how do we limit the level of effort we direct at mitigating it? Climate models are your friend, Matt. They help you anticipate the extent of the threat and its probable effects. Without them you are flying blind.
    You seem to view uncertainty as an excuse for doing nothing–despite the fact that we are certain that the climate is changing and that WE are doing it. That is not a viable or responsible viewpoint. We have a threat. We know its cause. We know its impact will be in the trillions of dollars on the global economy–minimum! A level of effort commensurate with that risk is the minimum required. Now all we need is an upper limit. Any ideas how we can define that without models?

  44. 294
    James says:

    Re: [Is climate science as predictable, testable, falsifiable and repeatable as the theory of gravity?]

    We might reflect a bit on the theory of gravity, and the usefulness of computer models. We have a very simple, elegant theory of gravity: just one simple equation, so we ought to be able to plug in the relevant numbers and figure out the answers exactly, once and for all. And that works just fine, as long as you only have two bodies in your system. Go to three or more, and (except for a few special cases) you can’t solve the equation.

    In fact, if you want to do anything useful with gravity, like planning a course for your interplanetary space probe, you have to use one of those inaccurate, presumably bug-ridden computer models instead. Yet somehow this seems to work in practice: NASA & ESA can send a probe off to Saturn, bouncing it off two or three other planets en route, then send it caroming through a system of dozen or more (I’ve lost track) moons, and still plan in advance what their cameras are going to be taking pictures of.

    The difference between numerical models and software such as Microsoft’s (leaving out my personal feelings about Windoze) is that the models connect fairly directly to nature, while MS has to deal with arbitrary things such as user preferences and hardware designs. It’s thus much easier to test models, as long as you can find simple cases with known physics. A gravity simulator can be tested against the cases that can be solved exactly: doesn’t handle the simple Earth-Moon system, for instance, you know it’s wrong, while MS’s photo-sorting software presumably depends on users deciding whether it does what they want it to.

  45. 295
    Ben Alexander says:

    Where can I find raw solar, carbon emission, and temperature data so that I can construct my own correlations?

  46. 296
  47. 297
  48. 298
    PHE says:

    Re 292 (BPL) “Educated people” don’t take things for granted. They take the effort to understand the science themselves.

  49. 299
    Matt says:

    Ray writes: (note I’ve changed the order in which he made his points) [Your argument is specious, because for the most part, given the same scenario, the models agree, and if anything, the models are conservative, since they do not reflect positive feedbacks that we now know are in the cycle. Whether a model says the globe will warm by 2.6 degrees or 2.8 degrees is for the most part in the noise. Either eventuality means drastic changes in climate.]

    Where do you get your figure of 2.6 to 2.8 C? The ranges I’ve seen are much broader.

    Regarding the models being conservative, I’m not sure how you can say this. The models of the 90s missed significant components of cooling, such as particles and clouds. How do we know there aren’t other cooling mechanisms that will come into play (or warming mechanisms that will fail to have as large an impact)? Some of these early (poor) assumptions had a pretty dramatic impact on sensitivity (3X).

    And yet, even though we continue to learn of all these omissions from previous models that are significant, we still have been facing the same predictions of what the increases will be. For the last 25 years, the estimates have ranged from about 2 C to about 4.5 C. How can this be? Personally, seeing a sensitivity range remaining relatively static for all those years in spite of increased understanding and discovered critical omissions points more to a confirmation bias than a rigorous derivation.

    [You seem to view uncertainty as an excuse for doing nothing–despite the fact that we are certain that the climate is changing and that WE are doing it.]
    Ray, please re-read my previous posts on whether or not we should act. If I were President of the US Iâ��d argue we should be building from our present 100 nuclear plants delivering 20% of our power to 400 plants delivering 80+% of our power, with the remaining ~10% coming from subsidized alternate energy (we’ll likely always have 5% of transportation that needs petroleum). I’d also argue that the US should be invest 10’s of billions a year to develop a next-generation lower-cost battery for electric cars that surpasses Li-Ion significantly in cost and safety, and marginally in gravimetric and volumetric efficiency. Iâ��d put a 15 year time horizon on all this, and fund cell development with a $0.10/gal tax on the 400M gallons of gas the US consumes per day. Thatâ��s $14.6B/year in pure R&D directed at batteries (the #1 problem in all this), and I’d adjust it upwards in a moment’s notice if I thought it’d help. In 10 years, hopefully we could state the US had zero reliance on foreign energy, which is my real motivation. The CO2 reduction is a massive bonus.

    [You seem to draw comfort from a sense that we might be unable to predict the amount of warming we will see. If you don’t mind my saying, that is a wierd attitude. The inability to predict risk RAISES risk rather than lowering it.]
    Comfort? No. Technically, the risk is the same whether or not I can predict it – My ability to manage the risk gets more difficult if I don’t understand the risk.

    Skepticism? Yes. And the fact that these models are built with a staffing structure that is a fraction of what Sun or Microsoft would devote to a comparable problem should cause everyone to think twice. Remember, statistically there are 10,000 bugs in a 1M lines of code climate models. That assumes you have a few hundred testers working to validate the code.

    If there is one issue you want to dig in with me on a response, I think this avenue would be the most fruitful:

    Assume all models do a reasonable job with historical data and 5 years into the future. Now, if model maker A believes it’s important to assign a feedback weighting of 0.5 to a certain mechanism, and model maker B believes it’s important to assign a feedback weighting of 0.51 to the same mechanism, and model maker A’s model spits out a 2 degree sensitivity, and model maker B spits out a 4.5 degree sensitivity, then you must admit that the difference was due to differences in intuition.

    But what if someone believed the feedback mechanism should be 0.49 and his model delivered a cooling sensitivity? Is his intuition flawed? Whose intuition is correct?

    [If the climate models cannot predict climate, then why is a rise of 3.5 or even 5 degrees less likely than a 2 degree rise?]

    Bingo! At that point you are relying on someone’s intuition. Which is my point.

    [We have a threat. We know its cause. We know its impact will be in the trillions of dollars on the global economy–minimum! A level of effort commensurate with that risk is the minimum required. Now all we need is an upper limit. Any ideas how we can define that without models?]

    This indeed gets back to my first post on this thread. Why do folks want to mitigate this? A summary of answers included: we’ll starve if we don’t, save lives in Africa, save our own lives, save our coastal cities. All good reasons. My next question was “at what cost?” The range of figures from economists are even more varied than the scientists.

  50. 300
    Philippe Chantreau says:

    Re # 291: “we need to be careful about placing too much trust in things that aren’t well understood.”

    That is oversimplification, and another variation on the we-don’t-know-enough-to-act tired argument. Open a physician drug reference book and you’ll be suprised to see how many of these drugs’ actions are presented with the sentence “mechanism of action not fully understood” or sometimes the more blunt “mechanism of action unknown.” You’ll be glad to use one of them if you need and you won’t care about the mechanism of action.

    The current state of the working knowledge of climate is better than for many of the physiological processes on which we tinker with merry abandon through medicine.