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Why the continued interest?

Filed under: — rasmus @ 9 October 2009

I believe the idea that galactic cosmic rays (GCR) play a role for the present global warming is unlikely to fade soon, despite a growing number of scientific arguments that normally would falsify a hypothesis and lay it dead (see links here and here). Despite all the arguments against the role of GCR, there was a solicited talk about ‘cosmoclimatology’ at the European Meteorological Society’s (EMS) annual meeting in Toulouse. Henrik Svensmark is further invited by the Norwegian Academy of Science and Letters (NASL) to provide an introduction to their seminar on climate. So why is the GCR-hypothesis still perceived as an interesting explanation?

My impression from the solicited talk, is that the confidence in the GCR hypothesis now rests on two points that were made explicit in the presentation, and that we have not adequately addressed here. So, here they are:

Point I: When I asked Svensmark why he presented a curve describing low cloud-cover from the ISCCP – used for correlation study with GCR (link) – that differed from the curves presented at the ISCCP web site (link), he informed me that he used a corrected version that has been published. Nevertheless, the ‘correction’ of the curve is controversial, and the ISCCP team is clearly not convinced, despite the likelihood of instrumental degradation.

Good practice would then be to present all the curves that cannot be ruled out because of errors. When asked why he didn’t present the other cures too, he said that he only wanted to show the one curve. Not a very convincing answer, and not very reassuring.

Point II involves a ‘remarkable’ correlation, meant to demonstrate a link between high GCR flux and cold conditions. This analysis is based on a comparison between band-pass filtered ice-rafted debris from iceberg drifts (Bond, 2001) and Carbon-14 (a cosmogenic isotope) over the last 12,000 years (e.g. after the most recent ice age).

The relationship between temperature and drifting icebergs, however, is complicated and not so straight forward. Icebergs are formed when chunks of ice break off glaciers and icesheets – a process known as ‘calving’.

On the one hand, icesheets and glaciers grow when the accumulation of precipitation at below freezing temperatures (snow) exceeds the summertime melting. Very low temperatures, tend to be associated with low precipitation, however. One the other hand, iceberg calving does not require very low temperatures (as long as the ice is present), but is favoured by reduced friction at the base of ice caps, resulting in a faster flow towards the sea. Melt water can lubricate the ice sheets and hence affect the ice flow.

Once the icesheets have calved and produced icebergs, they will drift according to the winds and ocean currents. The most influential ocean currents for iceberg drift in the North Atlantic include the East Greenland Current EGC), which follows the east coast of Greenland and flows from northeast to southwest, the West Greenland current (WGC) into the Labrador Sea, and the Labrador current (LC), a coastal current following along the perimeter of the Labrador sea basin in an anti-clockwise fashion.

North Atlantic ocean current systems Many of the cores used to study the ice-rafted debris were from locations away from these currents. It is not clear whether anomalous cold conditions produced more southerly winds and ocean currents. However, many of the core locations are associated with a surface flow from the south in the present climate, so it is possible that the icebergs transported by the EGC, WGC, and LC end up in the North Atlantic current. One explanation is that the icebergs got caught in the warm currents from the south, and melted on their way north, but that does not necessary imply cold conditions in that region, as these warm ocean currents provide a heat transport and the melting of icebergs suggest higher temperatures.

Cold conditions favour the formation of sea-ice, which have very different characteristics to icebergs. Sea-ice forms when the sea surface freezes, and can affect the ocean circulation through their effect on salinity. However, sea-ice does not create debris of rocks and minerals, as the icebergs do when the bottom of the sliding icesheets scrape the rocks.

It is plausible that very cold conditions can produce thick sea-ice that will lock icebergs in place near their sources in the Labrador sea and along the east coast of Greenland, but seasonal variations in the sea-ice may also imply open water in the summer. Nevertheless, very cold conditions may not necessarily favour the production of icebergs, as freezing temperatures will prevent the formation of melt water acting as lubrication and the accumulation of ice is expected to be less due to lower precipitation.

In summary, the ‘remarkable’ correlation does not seem to support the hypothesis that high flux of GCR produces a very cold climate. The question is rather whether the ocean and atmospheric circulation were influenced by the level of solar activity and associated changes in the total solar irradiation (TSI) – without involving GCR. After all, GCR is affected by the level of solar activity through its influence of the inter-planetary magnetic field, and anti-correlated with the sunspots.

When taken in the context of the global warming, there are other problematic issues such as the lack of trend in GCR (here and here), stronger warming during nighttime than daytime, large unknowns regarding the physical mechanisms involved in the growth of ultra-small molecule clusters to much larger cloud condensation nuclei (here and here), and questionable data handling and statistical analysis (here). In addition, it is difficult to statistically distinguish between the apparent response to solar forcing in the observations and GCM which do not take GCRs into account (link to a recent paper by Gavin and myself), implying that GCRs are not needed to explain past global temperature trends.

So what makes the GCR-hypothesis so convincing that warrants a solicited talk at the EMS annual meeting and an invited presentation at the NASL? Is the support based on the attention in media, or does it have a scientific basis?

I want a response from the community still supporting the GCR hypothesis, explaining why they find it convincing after all these misgivings. The spirit of science is about discussing different ideas and challenge unconvincing points of view. So far, I feel that many of these issues have gone unheeded outside the climate research community. Perhaps an improved dialogue between various research communities can help resolving these issues – the counter-arguments and GCR hypothesis represent a paradox that should be sorted out if the science is to progress. Either the supporters of the GCR hypothesis should convincingly explain why these misgivings are unfounded or irrelevant, or the GCR hypothesis should be buried. However, I feel that there is a lack of dialogue and willingness to listen, so I think that progress is not likely to happen regarding a commonly accepted solution on the GCR hypothesis.

Update: According to a recent (October 16) news relsease from the International Ice Charting Working Group (IICWG), over 1,200 icebergs drifted into the trans-Atlantic shipping lanes in 2009, making the iceberg season in the North Atlantic the eleventh most severe since the tragic loss of the RMS Titanic in 1912.

P.S. So far in 2009, three articles have been published in the arXhive on GCR and clouds (here, here, here). It is possible that such articles are more accessible to communities other than climate research, and hence enhances the awareness about the controversy surrounding the GCR-hypothesis.

506 Responses to “Why the continued interest?”

  1. 251
    JCH says:

    “If you are referring to the mainstream scientists that did support the global cooling hypothesis, it would mean that they were wrong. …”

    But why were they wrong?

    Maybe I’m wrong about this, but the climate, independent of mankind’s interference, would be cooling and heading to an eventual ice age. Is that not correct?

  2. 252
    Mark says:

    “Maybe I’m wrong about this, but the climate, independent of mankind’s interference, would be cooling and heading to an eventual ice age. Is that not correct?”

    It wouldn’t be *warming*. Not any more than it did for thousands of years before 1750, anyway.

    The point is, man IS interfering. And despite any “interest” people have in GCR’s role in climate change, it won’t change the fact that we produce lots of CO2 and it will warm the planet.

    After all, these GCRs were bombarding the earth back in the Jurassic when higher CO2 and higher temperatures were around.

    If it didn’t kick in then (it had plenty of time to do so) and reverse the warming, bringing it to ~15C average why would it do so now?

  3. 253
    Jesse says:

    There is a bit in the index to the site that explains it — basically there was a slight cooling trend from 1940-70, driven largely by a some large eruptions as well as minimal sunspot activity.

    But the real problem was the popular press that got it all wrong and said that a glaciation was imminent. There were even a few bits of science fiction written that reflected that — I remember one story from Asimov’s back in the early 80s… anyway, the point is the ice age would be a long time coming in any event.

    There was also some idea floating around — and I gather it was garbled — that a fast warming would precipitate a cooling and glaciation because the water vapor would condense out as increased snow at the poles, setting us on another ice age rather quickly, but as far as I know that theory is dead.

    Anyone, tell me if I missed anything, please!

  4. 254
    rb says:

    Could someone tell me what the magnitude of the temperature difference is that’s associated with the difference between a solar maximum and a solar minimum?

    RB

  5. 255
    Steve Fish says:

    Gavin in my ~#183, 14 October 2009 @ 9:37 PM:

    Thanks. I have seen this information multiple times. I just couldn’t believe that anyone would actually have the nerve to bring up the 70s cooling bit here. But along comes RodB! I strongly agree with Hank Roberts (~240, 15 October 2009 @ 12:16 PM).

    Steve

  6. 256

    #251 JCH

    They were wrong because we are warming. If there were no industrial GHG’s then we would still be around thermal equilibrium and moving slowly toward an ice age in about 20k yrs.

  7. 257

    #253 Jesse

    I think the lead theory is that it is a combination of natural variation and human influence. Industrial output of aerosols that reflected a lot of sunlight back out to space before it hit earth likely had a lot to do with it.

    http://www.realclimate.org/index.php/archives/2005/01/the-global-cooling-myth/

    http://www.ossfoundation.us/projects/environment/global-warming/myths/40s-to-70s-cooling-co2-rising

  8. 258

    #254 rb

    Maybe someone else knows the temp difference, but the forcing difference is about .2 W/m2

    http://www.ossfoundation.us/projects/environment/global-warming/forcing-levels

    Our current forcing is way out of whack at 1.6 W/m2 (mean including negative and positive industrial factors). Top end positive forcing above thermal equilibrium is estimated at 3.6W/m2 during solar minimum (would be 3.8 W/m2 during typical solar max).

    PS Feel free to use your real name here, if you don’t have a reason not too. As you can see most people do.

  9. 259
    Mark says:

    re 253, I think there was also the papers used “Glacial period onset overdue” because we were beyond the mean interglacial period by some tens of thousands of years. The paper said that this was not unusual because of the large variation in the lengths of interglacial periods.

    But newspapers saw a headline:

    Ice Age Overdue Say Scientists!

    And left out all that maths stuff. Making it rather like “NEWSFLASH: Sun going down! May Never Return, Say Pedants!”. And leaving out the logical arguments the pedant made: you can’t PROVE the sun will come up tomorrow. Because that’s boring.

  10. 260
    CM says:

    Mark (#206), re: magnitude of the effect,

    Just to be clear on this, I was not claiming either that there is a solar-GCR-cloud effect, nor that, if it exists, it has a discernible impact on climate, much less that it would somehow magically make CO2 unimportant.

    In the paper I referred to, Sl_oan and Wolfendale define the magnitude of the “effect” as the amplitude in the dip in the low cloud cover per unit change in sun spot number. For solar cycle 22 (1985-96) only, they get a good fit: If the correlation is real and is accounted for by the causal connection suggested by Svensmark, it suggests a very large fraction of low cloud cover is due to GCR ionization. However, the lack of latitude dependence, among other things, suggests that the correlation (if real) must be due to some solar-correlated effect other than ionization. — You’d better read it yourself, though, since I’m not a physicist and could easily get something wrong.

  11. 261
    TrueSceptic says:

    253 Jesse,

    That 40-70 cooling trend was really a sharp drop from the mid-40s to about 1950, followed by a flattish period until the late 70s (I know, climate is 30 years. ;) ) See here.

  12. 262
    colin Aldridge says:

    If we did then we would have a better fix on the amount of forcing that CO2 produces which is the big unproven factor in predicting the AGW impact”

    Mark Says
    We already know that CO2’s effect is between 2 and 4.5 C per doubling.

    Knowing all the other variables, we may be able to tell if 4.5C is less likely or if 2C is less likely.

    But in neither case will anything currently on display cause CO2 not to have a seriously deleterious effect on the climate and nothing means we would be wasting our time reducing CO2 production to as near nil as possible.

    Well Mark . We don’t KNOW that CO2 will 2C to 4.5C if we double CO2 Doubling, on its own on its own drivess between 0.8 and 1.2C increase according to the IPCC. The rest is due to forcing, mainly by higher water content in the atmosphere and it is this that is difficult to model/ test and prove. If doubling ONLY gave 0.8C then this would be a lot less than catastophic since we have already got 0.6 of warming today

  13. 263
    Mark says:

    “For solar cycle 22 (1985-96) only, they get a good fit:”

    This should be ringing bells in your head, CM.

    Remember, a broken watch is right twice a day, so if you find out that for 8:32 your watch is actually correct by your computer, this doesn’t mean you can forget about the stationary hands on the watch.

    Same idea with the graph picked and Rasmus is asking about: why that one? Was it selected for viewing because it happened to fit?

    “The science of discworld” has a good long section on this sort of selective reporting. I suggest you get a copy (good series of three, actually, not discworld books, but TP writes stuff every other chapter in a Discworld story).

    Listen to the little alarm bells.

  14. 264
    John Millett says:

    #150 “…zilch favoring GCR or any other natural explanation”

    Big call, Ray Ladbury. Model designers also ignored the natural alternating warming-cooling pattern in the instrumental temperature record. They made temperature change a function of a rising concentation of atmospheric CO2. That’s why the models look smart during warming periods and dopey during the current one.

    [Response: You are very confused as to how climate models work and what kind of output they produce. In fact they don’t input the observed temperature trends and do produce plenty of sort term cooling within any long term warming trend driven by the totality of forcings. -gavin]

  15. 265
    Patrick 027 says:

    CM, TrueSceptic, Mark – (on Eratosthenes) – okay.

    “colin Aldridge” –

    It is possible that any particular wiggle attributed to internal variability for lack of known cause might/could later be found to have an external cause. However, it is not generally a cop out to assume that variations with no known external forcing are manifestations of internal variability. WE KNOW internal variability is REAL. It is even simulated by the computer models.

    Also, CO2 forcing is not ‘the big unproven factor’; it is actually one of the best understood things about climate. In general, the unknowns are those things which take climate sensitivity away from where it is expected to be, or pin it and some regional effects down to a narrower range than we can right now.

    Mark –
    “Wasn’t it Aristarchus (some smart dude in greece, about 400BC) who considered that life came from the water, mud and slime and populated the land, descended from less complex creatures.”…”And who gets the credit? I can’t even remember the guy’s name off the top of my head.”

    And Democritis(sp?) came up with atoms. But what kind of evolution and what kind of atoms are we talking about? It’s interesting to find similiarities between modern scientific understanding and old philosophies and religions (Is there an element of quantum mechanics in Hinduism?)…

    Naindj –
    “because the actual monkeys evolved less than humans from the common ancestor.”

    Depends on what you mean by ‘less’. By certain traits, most likely – the amount of body hair has decreased more with humans – assuming the common ancestor was not merely half as hairy as today’s apes and monkeys, etc. Humans are bipedal, don’t have opposable toes, and many have a very different ecological niche (some of that being cultural evolution, though over time culture and genetics interact – adult lactose tolerance, for example). And there is the big one, intelligence (the biological part of that supports the cultural evolution). But could there be other traits that have changed less along the lineage that leads to us? If we quantify the amount of evolution by the amount of change in the DNA sequences, my guess is the difference in the amount of evolution might be less (some of that may owe to what I think are called silent mutations – when a mutation doesn’t affect the amino acid sequence) – of course, it needn’t be the same – a group of organisms that encounters a more different environment or starts to exploit a more different ecological niche might then evolve more. And mutation rates could vary, as well as generational spacing. And if one species lives at higher altitudes, it will experience a (inconsequential) different amount of time (General Relativity).

  16. 266
    Patrick 027 says:

    “we were beyond the mean interglacial period by some tens of thousands of years.”

    The mean interglacial period is negative? (Just kidding).

    Here’s what I’ve read about the next ice age:
    http://www.skepticalscience.com/news.php?p=2&t=71&&n=36#2768

  17. 267
    Patrick 027 says:

    “or starts to exploit a more different ecological niche”

    OR evolves to fit a niche which then shifts more than other niches filled by relatives.

  18. 268

    Naindj (various posts): what’s “intuitive” is conditioned by learning. Newton’s Laws are by no means intuitive, otherwise why did it take so long for them to appear? And no, it’s not just because no one had calculus before his time (please don’t tell me the theory of limits is intuitive: infinitesimals caused the otherwise very clued ancient Greek mathematicians serious problems: Zeno’s paradox, for example). The notion that gravitation is an inversed squared law is mathematically easy once you have the formula, but by no means intuitive (we experience gravity as something that makes things fall, not as something that attracts bodies over large distances and results in elliptical orbits); the notion that objects move indefinitely unless slowed by an external force is not at all intuitive.

    CO2-forced warming is no less intuitive than any of these things. Once you know that a greenhouse gas absorbs in the infra-red, it’s a small step to understand that this can have an effect not too dissimilar to that of a blanket (if by trapping radiation rather than by reduced conduction). The detailed science is hard, but that’s nothing special. All science of the real world is hard.

  19. 269
    catman306 says:

    A few people had already figured this out:

    Bush Admin Acknowledged Threat of Climate Change

    http://www.motherjones.com/mojo/2009/10/bush-admin-acknowledged-threat-climate-change

  20. 270

    On solar cycle: I see NASA has reported that we are at or near a 100-year sunspots minimum. Meanwhile temperatures remain stubbonly at or near 100-year record highs — and did so through the last La Niña, with the solar cycle firmly headed down.

    You want your answer as to why the GCR hypothesis is still attracting interest?

    The it’s all the sun and it’s all ENSO hypotheses are in tatters. The denial cult are nothing if not persistent.

    Meanwhile here in Queensland, Australia, the state government is spending tens of billions of dollars on a massive ramp up of coal export capacity. Could that be a sign that the industry sees the end is near, and wants to cash in while they can? After all, if coal really had a 200-year future as they want us to believe, what’s the rush to dig it up and sell it so fast? Unfortunately I am one of the poor mugs who’s paying for this idiocy through my taxes…

  21. 271
    david cook says:

    RE : 233 might it be argued that the effect could be the result of earths gravity bending the light rays/particles? (e=mc2)

  22. 272
    John Millett says:

    #143 “After all, you wouldn’t try to displace the conventional wisdom that the sun is the source of all our heat with a theory that it is actually The Interstellar Spaghetti Monster, would you?”

    Is that what the GCR is about? I don’t think so. However, it is what the AGW is about – the IPCC’s energy budget shows the surface receiving twice as much radiation energy from the cold atmosphere than from the hot sun.

  23. 273
    David B. Benson says:

    rb (254) — The reference to Tung & Cabin (2008) is many comments back by now. They determine an estimate for the variation in global temperature over an average solar cycle. The estimate is almost twice anybody else’s, so I don’t know how well accepted that work is (yet). Anyway, it is just another small pertubation on the long upward trend driven by excess global warming (so-called greenhouse) gases.

  24. 274
    John Millett says:

    #152 “…i.e. we don’t throw out our pre-exisiting knowledge and understanding of causality, and attempt to explain phenomena by “shoehorning” hypotheses for which there isn’t a significant evidence base.”

    Chris, along with the IPCC you didn’t include clouds in the list of variables about which we have good knowledge. My understanding is that GCR is about clouds and the CERN experiment is designed to test its evidence base.

  25. 275
    Fred Magyar says:

    And now a word from our sponsors…

    It seems the Saudis want some incentives to come to the table to discuss climate change in Copenhagen.

    It is better than anything the Onion could come up with.

    http://www.theatlanticwire.com/opinions/view/opinion/Saudi-Arabias-Money-for-No-Oil-Scheme-Dubbed-a-Real-Knee-Slapper-1297

  26. 276
    John Millett says:

    #148 and #153

    The passage from alternative to null hypothesis is the issue isn’t it? Both natural variation (A) and man (B) affect climate. To explicitly claim with 90% confidence that B is the cause of warming since the mid-70s is to implicitly claim with the same confidence that A isn’t. Can models that don’t understand clouds authoritatively support the claims?

  27. 277
    Marcus says:

    John Millet: “the IPCC’s energy budget shows the surface receiving twice as much radiation energy from the cold atmosphere than from the hot sun.”

    This is basic physics. You can make yourself a 1D climate model in Excel: Assume the surface receives 238 W/m2 from the sun. Calculate heat of earth using blackbody stefan-boltzmann. Have the surface radiate heat as T to the 4 time appropriate constant (also stefan-boltzmann). Calculate surface temperature: 254 K.

    Now, add one slab of atmosphere: assume some percent of surface emits directly to space. 1 – that percent is absorbed by your slab. Have the slab radiate (stefan-boltzmann), but half up, half down. The surface receives the sun’s heat, plus heat from the atmosphere (which originally came from the sun, via the surface). This is a circular equation, but Excel can handle that these days. If the percent directly transmitted is 25, then the surface heats up to 286, because it is receiving 381 W/m2 from the atmosphere. You can add more slabs and the answer doesn’t change much if you do it right…

    Really, in order to keep the surface at 33 degrees C above the blackbody temperature, there has to be 2 times the sun’s radiation coming from the atmosphere. Remember, the sun is a tiny bit of the sky, very far away. The atmosphere is wrapped around the earth, very close. That’s why we don’t die every night when the sun goes down…

  28. 278
    TrueSceptic says:

    271 John Millet,

    Those figures would be interesting. Perhaps you could supply them?

  29. 279
    Ray Ladbury says:

    John Millett says, “the IPCC’s energy budget shows the surface receiving twice as much radiation energy from the cold atmosphere than from the hot sun.”

    WRONG!! Greenhouse forcing is less than 5% of solar forcing. Do you bother to even find a reference or do you just make this [edit] up?

  30. 280
    Hank Roberts says:

    Better question — John Millet, someone misinformed you; can you tell us where you got the information, and why you believed it enough to repeat it here under your own name? It’s sometimes very useful to find out where these ideas arise. I did search for a while and could not find anything.

  31. 281
    MarkB says:

    Re: #33

    “But already the examinations say “it’s wrong””

    Just to clarify, I wasn’t necessarily arguing against the hypothesized effects of cosmic rays on global mean temperature. I think that’s been done pretty well here and elsewhere. That fact that global mean temperature is around record levels now could just mean the cooling effect of GCRs (along with reduced TSI) is strong offset by other influences (i.e. human-induced greenhouse gases). The observation of global mean temperature alone isn’t enough to refute it.

  32. 282
    Rod B says:

    Did all you guys just do a 180 and are now fully on board and agree with the global cooling hypothesis of the 70s? Were you once a moonshiner?? ;-)

  33. 283
    Rod B says:

    well, some of you guys…

  34. 284
    Rod B says:

    Ray, don’t pull the trigger so fast. Marcus described the relative energy budget simply but well in #275. From the standard T&K diagrams, the atmospheric back radiation absorbed by the surface is roughly twice the solar energy absorbed by the surface. Granted this is simplified and could be misleading; but it is not “WRONG.”

  35. 285
    Patrick 027 says:

    Ray Ladbury – John Millet obviously didn’t get the physics and also remembered the wrong values, but I don’t think you’re refering to what he was refering.

    (John – see Marcus)

    The backradiation from the atmosphere to the Earth is not twice what the surface+atmosphere absorb from the sun; it is just a little bit more than what the surface+atmosphere absorb from the sun; but that is beside the point of the physics; with a strong enough greenhouse effect it easily could be twice as much.

    (Figures from
    Kiehl and Trenberth:
    http://www.atmo.arizona.edu/students/courselinks/spring04/atmo451b/pdf/RadiationBudget.pdf
    see also update:
    http://chriscolose.wordpress.com/2008/12/10/an-update-to-kiehl-and-trenberth-1997/
    Note that this is an approximation. Note also that innaccuracies larger than a few W/m2 do not render useless studies of the effects of a 1 W/m2 forcing or feedback – a good first guess is that the errors would tend to be proportional to the values; proportionalities might vary but perhaps in a predictable way … anyway: (and here I am also using the approximation that all solar radiation and zero terrestial radiation is in the SW range of wavelengths, which is a good approximation.)

    Total greenhouse effect at the top of the atmosphere is around 155 W/m2. This is the amount of LW radiation emitted from the surface (390 W/m2) minus the total LW emitted to space (235 W/m2).

    Total solar forcing at the top of the atmosphere is 235 W/m2. This is the downward SW (solar) radiation (342 W/m2) minus the upward SW radiation at that point (107 W/m2), equal to the absorbed SW below that point (235 W/m2).

    In general, a radiative forcing or feedback at a given vertical level is the amount downward minus the amount upward, thus representing a net gain in energy over time below that level. The vertical variation of such a net radiative flux is equal to a radiative heating or cooling rate of a layer.

    One approximation in particular: that the surface is a perfect blackbody. This is not quite true – I think it has an emissivity in the LW band around 95 % (or maybe a bit more?). Note however, while this means that emitted surface radiation will be less than 390 W/m2 (at ~ 288 K), there will also be some reflection of backradiation upward from the surface. If the LW albedo (the term albedo is often used in the context of SW – please don’t confuse this with LW albedo) of the surface were 5 % (for example), than the emitted radiation would be 19.5 W/m2 less than 390 W/m2, or 370.5 W/m2, but the total upward radiation from the surface would be closer to 390 W/m2 – though the albedo could depend on wavelength and angle and the downward radiation from the atmosphere is not generally isotropic, so the same LW albedo might not apply.

    I could say more but I’m stopping for now.

  36. 286
    sidd says:

    Marcus is correct. Back radiation from the atmosphere is large.

  37. 287
  38. 288
    Paul Thiers says:

    I wonder if any of the experts on this site can give me any information about Peter Taylor, author of the book “Chill.” Taylor is a policy analyist who used to work for Greenpeace. I see him refered to regularly as an “environmentalist and scientist.” I’m not that interested in the environmentalist part. But I would like to know his training and pubs record. I ahve not been able to find a CV.

    Thanks,

  39. 289
    dhogaza says:

    RodB:

    Did all you guys just do a 180 and are now fully on board and agree with the global cooling hypothesis of the 70s? Were you once a moonshiner?? ;-)

    No, we agree what was said then, when honestly presented, with all the various caveats (primarily “we don’t know how much warming increased CO2 will trigger”) and “we’re talking about 10s of thousands of years in the future (for the Milankovich guys).

    How about you? Are you willing to turn a 180 and admit that you’ve presented strawmen?

    RodB – you’ve been here for years, with people trying to educatue you for years, and you continue to present the denialist talking points as though you’re incapable of learning.

    What’s your excuse? Is it medical? Can you tell us the diagnosis?

    Or is it too much exposure to Ayn Rand or Robert Heinlein?

  40. 290
  41. 291

    John Millet (276),

    you wrote:
    “The passage from alternative to null hypothesis is the issue isn’t it? Both natural variation (A) and man (B) affect climate. To explicitly claim with 90% confidence that B is the cause of warming since the mid-70s is to implicitly claim with the same confidence that A isn’t. Can models that don’t understand clouds authoritatively support the claims?”

    It’s one issue that you got backwards. And I guess the incomplete understanding of the system (eg clouds, aerosols) is a major reason for our confidence in a strong human influence being 90% rather than 99%.

    However, the longer the warming trend continues and natural forcings exhibit no trend, the stronger the confidence will get that natural forcings can not explain the warming, no matter how little we know about the microphysics of clouds.

  42. 292
    CM says:

    Mark (#263), I’m trying to have an on-topic discussion in a thread that’s filling up with monkeys for some reason, so could you please cut me some slack and take as read that I understand the problem of the disappearing correlation? I thought I had already made that pretty clear when I raised this question (#201), and I cited Sl_oan & Wolfendale’s findings to you (#260) emphasizing their caveat “if it is real”.

    By taking the sun-cloud correlation on face value, even though it could well be spurious, S&W appeared to neatly falsify Svensmark’s GCR hypothesis by deriving an empirical consequence from it (latitude dependency) and testing it on the same period and phenomena for which Svensmark found a link.

    What I’d like to know whether scientists think (a) this is one sound objection against the GCR hypothesis, or (b) it’s considered beside the point because the correlation is cherry-picked junk anyway, or (c) it could be relevant, but the physics might be challenged.

  43. 293
    Mark says:

    “Can models that don’t understand clouds authoritatively support the claims?”

    Yes.

    If they model clouds sufficiently well to explain past climate as the cloud emerges as the property, yes.

    They do.

    We can’t model each human’s consumption but army stores still model the needs of an army well enough to ensure supply lines are adequate.

    Why do you think you have to be 100% right to not be 100% wrong?

    We also know from measurements that the climate is sensitive to CO2 doubling in a range that the models with their “faulty” clouds agree with.

    This independent corroboration shows that clouds are sufficiently explained to explain climate.

    So why do you think you have to be 100% right to not be 100% wrong?

  44. 294
    Mark says:

    Millet asks of the FSM : Is that what the GCR is about?

    It seems to be.

    All the papers raise more questions than they answer.

    “Why do you use that graph when other graphs explain the observations”
    “Why is there a 7 day delay”
    “What is the magnitude of the change”
    etc

  45. 295
    Mark says:

    Patrick asks: “And Democritis(sp?) came up with atoms. But what kind of evolution and what kind of atoms are we talking about?”

    What kind of atoms were we talking about 100 years ago?

    Dalton’s plum pudding atom or Bohrs mini-solar system? Or later ones like the humming string model or the even later one of smeared possibility clouds?

    And evolution? Well, Aristarchus (if that was him) thought we grew from simpler creatures that moved from the slime and the water to colonise the land. In what way (apart from the “speciation driven by natural selection”) is this different from the current evolution theory?

    If we evolved from simpler organisms, so did everything else.

    Ergo some time in the past, we evolved from the same creature the monkey did.

  46. 296
    Mark says:

    “We don’t KNOW that CO2 will 2C to 4.5C if we double CO2 Doubling, on its own on its own drivess between 0.8 and 1.2C increase according to the IPCC.”

    Oh dear, colin.

    We know that if we increase CO2 we will increase water vapour. We know we will increase cloud. We know ice will melt and the albedo of the earth change.

    We know that when we increase CO2 lots of other things will change.

    We know from measurements that doubling CO2 increases temperatures by 2-4.5 C.

    We know from models that add all these effects in that doubling CO2 increases temperatures by 2-5 C.

    You’re just proving that the models are very much more skillful than you think. Just doubling CO2 and if that (as the denialists want to insist is true when they demand monotonic increases of temperature with monotonic increases of CO2) CO2 were the only driver, we’d get 1C per doubling.

    So what is included in the models, despite you and Millar’s attempts to cast doubt on them by not being 100% correct is correct enough to model the overall temperature change of the system with all the feedbacks it has.

  47. 297

    John Millett:

    the IPCC’s energy budget shows the surface receiving twice as much radiation energy from the cold atmosphere than from the hot sun.

    That’s about right.

    http://BartonPaulLevenson.com/JJandJ.html

  48. 298

    Columbus believed the Earth was 1/3 smaller than Eratosthenes’s estimate, not 1/3 the size. His estimate was a diameter of 5,800 miles and a circumference of 18,000 miles (versus the actual 8,000 and 25,000), because of an argument involving the Earth’s shadow on the moon.

    What disturbs me much more is that his chief lieutenant beat a native woman with a belt to force her to have sex with him, and that Columbus did nothing about it, and generally let his men abuse the hell out of the Arawaks/Taino.

    He died thinking he had found a western route to India, even after four trips. He was a confirmed pseudoscientist as well as being a tyrannical jerk.

  49. 299
    Mark says:

    PS Colin, I don’t understand where this is coming from AT ALL: “If doubling ONLY gave 0.8C then this would be a lot less than catastophic since we have already got 0.6 of warming today”

    That doesn’t follow. The 0.6C is from CO2 and all other feedbacks (that add up to 2-4.5C per doubling), not just CO2 (that makes 0.8 C per doubling in your assumption).

  50. 300
    Ray Ladbury says:

    Rod B., You utterly ignored what I said about the ’70s global cooling meme. It is what I have said all along, and the same goes for Dhogaza and Hank Roberts and the others.

    Facts: Aerosol-induced cooling was a concern to some climate scientists in the ’70s, mainly because they underestimated CO2 sensitivity. This was NOT a consensus view, but it was not beyond the pale either. In fact, aerosols did curtail warming from 1944-1980. Now why is that so hard to understand and why do we have to explain it to you over and over again every 6 months. You know, there are starting to be treatmens for dementia. Have you tried Soduku?