Comments 1 to 20:

1. Joe Blog at 13:18 PM on 8 October, 2010
   Im a lil confused by this i have to admit...Well the metabolic rate in warmblooded animals should increase with cold...not warmth, it takes more energy to maintain our core temperatures... Cold blooded is the opposite o course, ill have to have a read o the paper;-)
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2. Joe Blog at 13:21 PM on 8 October, 2010
   Ahhh, it is about cold blooded species.
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3. Stephen Baines at 13:51 PM on 8 October, 2010
   Interesting. Hey John. I sometimes use a paper from PNAS by Deutsch et al 2007 in class in my physiology lectures as a good example of how to apply physiological principles (in this case temperature vs performance curves) to ecological problems. That paper also finds that tropical insects, and perhaps tropical cold-blooded species generally, are likely to be more susceptible to increasing temperature than temperate species, even though the temperature change is likely to be greater at high latitudes. The reason in that case has to do with adaptation to climate variability. They show that tropical species are operating much closer to their optimum and maximal temperatures, presumably because low seasonal variability in temperature in the tropics allows them to be more finely tuned, metabolically speaking, to their environment without too much risk of experiencing lethal temperatures. Temperature species, on the other hand, operate well below their thermal optima and maxima, presumably to avoid the possibility of experiencing lethal temps. The much lower margin for error in tropical species causes their population growth to be negatively affected by predicted temperatures, while higher latitude species actually experience an increase in population growth initially in response to warming.
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4. Stephen Baines at 13:53 PM on 8 October, 2010
   BTW that's Deutsch 2008. I'm bad with dates...Must be my age.
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5. KR at 14:57 PM on 8 October, 2010
   Not terribly surprising, actually. Tropical species are adapted to much more consistent conditions than temperate or arctic species.
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6. chris1204 at 17:38 PM on 8 October, 2010
   No doubt, as the tropics expand into temperate zones, some ectotherm populations may manage to migrate to new ecological niches. On the other hand, much will depend on the extent to which potential new habitats are physically accessible, the capacity of other plant and animal species forming part of their food chain to migrate with them, the extent of competition from species already present in new locations, and the extent of general habitat degradation. Clearly, a fascinating new variable in an array of challenges for our stewardship of the planet.
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   Response: If I'd been more organised (and less forgetful), I would've referenced a recent blog post on observed local extinctions of lizards over the last 35 years.
   
7. chris1204 at 23:32 PM on 8 October, 2010
   John, I recall the lizard post rather well. I responded somewhat frivolously at the time. I thought this time I'd look into the business a little bit more closely and went behind a couple of pay-walls - a seriously worrying manifestation of skepticalcience addiction. The article you cited essentially models the metabolic theory of ecology, which suggests that larger species may have higher metabolic rates and that metabolic rates increase with temperature. Ectotherms which lack the capacity to regulate temperature would be especially vulnerable to increased temperatures for the very reasons you cited. The Wikipedia reference I've given above contains the same equations for metabolic rate as a function of temperature as Dillon et al. Entering 'temperature and metabolic rate' into Google yields over 800,000 hits. Most of the references dealt with hibernation but this article by Marshall & McQuaid (2010) was the first I came across dealing with temperature increases and metabolic rate: Warming reduces metabolic rate in marine snails: adaptation to fluctuating high temperatures challenges the metabolic theory of ecology The title is self-explanatory. Interestingly, the authors also note in their introductory remarks: 'Departures from the model's prediction of acute metabolic responses to temperature (the slope) have been shown for insects and arachnids...' The importance of this study lies in its demonstration of decreased metabolic rates via heart rate and oxygen consumption in aestivating (estivating) snails at temperatures between 30 and 40 degrees C. Aestivation comprises the 'summer sleep' or torpor experienced by a range of organisms to protect against heat stress and seems to be a widespread phenomenon in organism inhabiting marginal zones. In short, the behaviour of real organisms may differ in significant respects from what one would expect from the metabolic theory of ecology, which derives from Kleiber’s law, itself based on the posited physical and geometrical principles underpinning animal circulatory systems. Of course, the mere fact that I've come up with one paper identifying one organism (with references to the behaviour of some other organisms) whose behaviour does not accord with the metabolic theory of ecology doesn't automatically invalidate the concerns raised by Dillon et al. Dillon very properly cautions: '...plenty of real ectotherms have some ability to moderate their temperatures through behavior, such as darting under rocks to escape the sun. These measures have limits though, especially for small creatures, and actual biology — not just temperature — needs investigating. “You can’t assume that the temperature patterns tell you what the effects on biology will be,” he says.' The Marshall & McQuaid paper nevertheless suggests that the picture may indeed be very much more complicated at least for some organisms and ecosystems. However, the mere fact that these systems are so beautifully complex is reason enough to be wary of complacency about potential climate impacts.
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8. Bob Lacatena at 00:21 AM on 10 October, 2010
   One thing I've noticed here in New England this year is a dramatic increase in bugs, particularly spiders. They're absolutely everywhere. I can't believe how many inconvenient places I'm finding not one but five spider webs, how big the spiders are, and how many types I'm seeing that I've never noticed before. The frogs and toads are also far more numerous, and more importantly, far, far larger. For a long time the frogs have been vanishing, along with the wetlands (due to over development), but this year I'm finding toads all over the yard, each of them twice as big as anything I normally see. This is accompanied by more plant growth. Despite a serious drought, weeds, shrubs and plants are have spread to encroach on the yard like never before. All of this is relative to my experience of the past twenty years. It's never happened before in that time. Is it just an anomaly, or is it related to the focus of this article? The next few years will be interesting to watch.
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9. chris1204 at 15:35 PM on 10 October, 2010
   Echoing Sphaerica, I've been carefully watching Sydney's deciduous plants - specifically frangipani and jacarandas. It may be just a subjective impression but they seemed to retain their leaves longer and while the frangipani lost all their leaves, many jacarandas seemed to retain leaf cover through winter. I know the jacarandas bloom earlier further north - I remember distinctly from an early October visit to Brisbane just twenty two years ago to be surprised to see the whole city in bloom. The visit and its timing were memorable for the fact that I passed my psychiatry exams in Brisbane and my son was born a few days earlier :-). Admittedly, I haven't made a conscious effort to watch the timing of the shedding and flowering before this year (but I've been inspired to do so by some of the posts on this blog). The difficulty of course lies in the fact that we tend to look out for anomalies when we worry that something may be going amiss. At any rate, I found evidence of earlier seasonal flowering in some settings here and delayed flowering in other settings here both attributed to warmer springtime conditions. Interesting times indeed.
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10. johnd at 15:51 PM on 10 October, 2010
    chriscanaris at 15:35 PM, taking you mean 1988, of all the memorable events of that October, which would you attribute to the declining El-Nino and which to the emerging La-Nina. ;-)
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11. chris1204 at 17:55 PM on 10 October, 2010
    johnd, I wouldn't have a clue if it was an El Nino or La Nina - I was so climate illiterate then! Possibly the fact that my son was born means it must have been an El Nino while my next child was a daughter so you might just be right about the transition from an EL Nino to an El Nina. However, the hotel I'd checked into was called the Gateway which I thought was deeply symbolic - I passed :-) while my colleague who checked into a hotel called The Terminus failed :-(. All very pregnant with meaning :-)
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12. johnd at 18:05 PM on 10 October, 2010
    chris, all :-) :-)
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13. Doug Bostrom at 18:35 PM on 10 October, 2010
    Probably safe to say Chris' immediately local population statistics were not influenced by global warming, more a case of natural variability. :-)
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14. chris1204 at 00:04 AM on 12 October, 2010
    Funnily enough, Doug, I read today it was Sydney’s coldest winter in thirteen years and Sydney’s coldest September in five years. Additionally, we we had our coldest day in thirty years last June. But 2010 seems to be tied as the warmest year on record worldwide.
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15. adelady at 01:43 AM on 12 October, 2010
    Praise be. But what really concerns everyone is just how infrequent the record cold temps are compared to the frequency of the hot record temps. I really do not want to see what might happen if there were no record cold temperatures showing up anywhere in the world. Or is that comment related to the view of warming being like transposing music? I see so many people saying that if it's warming why can't I look forward to things being milder where I am (UK or US). It's not supposed to be like transposing a piece of music up a third from C to E. It's more like a couple of toddlers joining you at the piano and banging discordant keys anywhere and everywhere.
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16. michael sweet at 02:00 AM on 12 October, 2010
    Chris: From your link to coldest winter in 13 years: "This winter was still warmer than the long-term average." When we claim winters warmer than average are now cold that tells us what the trend is. From coolest September in five years: "The city had an average maximum temperature of 21 degrees, making it the coldest September in terms of daytime temperatures in three years. This is despite being warmer than the long-term norm of 20." Have the last five Septembers been the hottest five on record? If we limit our records to a single year it will always be the coldest year.
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17. KR at 03:00 AM on 12 October, 2010
    Of some interest to this thread is the related Flowers blooming earlier now than any time in last 250 years discussion. I suspect that some of the more successful tropical species will be the ones that migrate pole-ward, as invasive species in the temperate zones.
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18. chris1204 at 12:23 PM on 12 October, 2010
    adelady @ 15 & Michael Sweet @ 16: all very valid points :-)
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19. Daniel Bailey at 12:27 PM on 12 October, 2010
    Re: adelady (15)

    "I really do not want to see what might happen if there were no record cold temperatures showing up anywhere in the world."

    Probably the most insightful comment I've read today (and there were many). Thank you. The Yooper
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20. Byron Smith at 10:08 AM on 14 October, 2010
    so too does it's need for food Typo: it's --> its
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