Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  2143  2144  2145  2146  2147  2148  2149  2150  2151  2152  2153  2154  2155  2156  2157  2158  Next

Comments 107501 to 107550:

  1. Climate Cherry Pickers: Falling sea levels in 2010
    #75 was a case of hitting submit before typing. Please delete. From Peltier 2009, Closure of the budget of global sea level rise over the GRACE era: the importance and magnitudes of the required corrections for global glacial isostatic adjustment The net rate of sea level rise is therefore predicted to be: 2.54 mm/year +/- 0.52 mm/year or 2.32 mm/year +/- 0.31 mm/year Clearly both of these estimates are consistent with the net rate of global sea level rise of 2.5 mm/year that has been measured by the altimetric satellites over the GRACE era.
  2. The value of coherence in science
    Eric, it partially depends on what the definition of 'catastrophic' is. For arguments sake, let’s accept the basic idea of your MEC (thanks Doug) premise – so that more storms and heat waves mean less sea level rise; that still doesn’t mean that both won’t be catastrophic. For example, let’s assume we can expect weather extremes like those seen this year every X years and Y meters of sea level rise by 2100 – even if changing X to 2X means Y goes to Y/2 doesn’t mean that both X and Y won’t be catastrophic. Were the floods in Pakistan and the heat wave in Russia catastrophic? I think the people effected would say ‘yes’, and the people of Bangladesh would probably say that even ½ a meter of sea level rise would be catastrophic.
  3. A detailed look at climate sensitivity
    @Karamanski: "Even though warming may continuing the rate of global temperature increase is steady and is not accelerating." CBDunkerson's graph seems to suggest otherwise. Instead of restating your original argument, you should respond to that counter-argument. "For example, thermal inertia might be much larger and slower than expected." It seems we would have observed this already. Do you have any scientific article that suggest this may be happening?
  4. Climate Cherry Pickers: Falling sea levels in 2010
    By the way, BP, thanks for damping somewhat a reverberating misconception concerning how heat reaches the abyss. Understanding heat transport in the ocean is impossible without at least a glancing look at thermohaline circulation. Regarding geothermal flux, it helps to keep the numbers in context: Another neglected energy source is the geothermal heat flux through the sea floor. This trickle of heat, which is due to the slow cooling of the solid earth, is estimated to have a typical value of 50 mW m−2 (1 mW = 10−3 Watts) on abyssal plains and up to 200 mW m−2 on mid-ocean ridges [Sclater et al., 1980; Kadko and Baross, 1995; Stein et al., 1995; Murton et al., 1999]. Even these peak values are small compared to typical values of air-sea heat fluxes, which are of order 100 W m−2. Impact of Geothermal Heating on the Global Ocean Circulation (full text, pdf)
  5. The value of coherence in science
    @Eric: let's assume, for the sake of argument, that you are right, and such MECs exists (I'll be eagerly awaiting your detailed explanation of this as well). What you don't seem to understand is that having multiple possible outcomes is not being incoherent, as these are future probabilities, not statements on past events. Saying "there is no warming," then claiming "the warming is natural" is being incoherent, because it describes things that have allegedly already happened, but which are contradictory.
  6. Global warming is accelerating the global water cycle
    Johnd @22, "Note that it is E as measured by pan evaporation that is charted. I think that pan evaporation should exceed rainfall is something that should be self evident." Actually, it is not self evident that pan evaporation should exceed P. Pan evaporation is not the same as ET, in fact it is is more of a measure of the potential evaporation or atmospheric demand-- a theoretical measure which is very rarely achieved. So, again, it is best to use actual ET. Making the rather dangerous concession that pan evaporation can be used as a proxy for ET, we see (as you note), that in semi-arid areas (which large swaths of Australia are), P-E << 0. In contrast, in more moist climates, such as over extreme southeastern Australia, P-E ~ 0 or P-E > 0. See this paper for a more thorough discussion. Some researcher use the difference (or ratio) to identify semi-arid areas, for example. Or to distinguish between drought (P-E < 0) and pluvials (P-E > 0). See here for an example.
  7. It's the sun
    @Ken: ""In fact, there is a continuous range of TSI values, any one of which can be balanced by a corresponding OLR value, leading to some particular stable temperature." Question: And can you guess what that particular temperature of interest is? " There is no such fixed temperature, it's a relative value. This theoretical equilibrium temperature would be determined by the sum of all forcings. Again, you're looking for an absolute reference point that doesn't exist.
  8. The value of coherence in science
    Eric - There are whole ranges of negatives associated with global warming, particularly at the rates we're seeing. Assuming that there are MEC's (mutually exclusive catastrophes, excellent acronym) is a False Dichotomy; an oversimplification of the consequences.
  9. It's the sun
    @Ken - I completely agree with archiesteel, he's stated it perfectly. You are taking graphs showing deltas (changes) from a baseline, and claiming that absolute values you derive from them (which are not present in just those graphs) are inaccurate. This is quite simply an incorrect use of the data on your part, completely without basis. Your insistence on continuing to do this over 50-60 posts on this thread indicates to me that you need to step back, and reconsider your approach.
  10. The value of coherence in science
    Eric, I don't follow your reasoning on MEC (mutually exclusive catastrophes, :=) ). Would you please sketch that out a little more fully?
  11. Global warming is accelerating the global water cycle
    Johnd and LukeW, Luke: "Pan evaporation rates have been reported to be decreasing not increasing, a reduction in windiness being a key driver" It is important to note that it has been demonstrated that pan evaporation can not be used to infer ET from the terrestrial land surface, especially vegetated surfaces. Brutsaert and Parlange (1998) showed that "although these studies are valuable, pan evaporation has not been used correctly as an indicator of climate change." Golubev et al. (2001, GRL) used parallel observations of actual evaporation and pan evaporation at five Russian experimental sites to callibrate the pan evaporation data. From their abstract "....we recalibrate trends in pan evaporation to make them more representative of actual evaporation changes. After applying this transformation, pan evaporation time series over southern Russia and most of the United States reveal an increasing trend in actual evaporation during the past forty years. " IMO, the take home message here is that pan evaporation data, while useful for some applications, should be used with caution when inferring trends in actual ET. Also, it is likely, that when handled properly, the pan data suggest that actual ET has actually been increasing. I cannot access the GRL paper by Roderick et al. (2007), so I am not sure if they considered or allowed for Golubev et al's or Brutsaert and Parlange's findings.
  12. Carbon Dioxide - Everyone's Favorite Pollutant
    ...before going after CO2, why not first target the processes that are creating unwanted amounts of CO2 such as combustion of petrolium and coal? How exactly do we "target" these processes without identifying why we'd be doing so? Ignoring the very reason why we'd make changes in processes obviously leaves the question of rationale hanging in the air. Coal-fired generation plants liberate C02 as part of their operation, emissions which have been found detrimental to the continued desirable functionality of the atmosphere. Failing acknowledging the C02 itself, there's no reason to add expense and reduce efficiency of coal-fired generation plants. Short of a rationale, nobody is going to tamper with the economics of coal-fired generation plants. Once a rationale has been established and acknowledged, the operators of coal-fired plants are not going to act unless compelled by regulation. The comment is rhetorical... Yes, I think we're clear on the rhetoric part, considering that's all that's on offer.
  13. It's the sun
    @Ken, why are you looking for absolute values in graphs that show relative changes?
  14. Climate Cherry Pickers: Falling sea levels in 2010
    Ok BP, I think I get it. In a nutshell, your hypothesis implies that because of cultural matters tide gauges are located mostly in places where isostatic adjustment is such that, taken together, the population of tide gauges produces a false impression of rising sea level. Is that about right?
  15. Global warming is accelerating the global water cycle
    Dr. Masuda, Thank you fro dropping by, very much appreciated.
  16. Global warming is accelerating the global water cycle
    Dr. Mandia, Thanks for that link @29. I forgot about Zhang et al. (2007), good paper. The observations (1925-1999)used in their paper show an increasing trend in zonally-averaged P (over land surfaces) in most latitude bands. The exception being 0-30 N, where data show a drying trend. Re Spencer. From what I know Scott, at least for thunderstorms, precipitation efficiency decreases as vertical wind shear increases. I am not aware of any papers which show a link between precipitation efficiency and temperature. That said, it is my understanding that a decrease in environmental lapse rates (i.e., leads to weaker updrafts and more entrainment)and/or a drier/warmer sub-cloud layer (more evaporation of precipitation) will reduce precipitation efficiency. Personally, I think that Spencer is being overly pessimistic. The land-surface component of the GCMs has received much attention in recent years. What they need to do is get the horizontal grid spacing down (to less than 20 km) so that they can use superior convective parameterization schemes and also better resolve convective systems (as well as eddies and currents in the oceans). Hopefully Moore's law continues to hold, b/c doing so is mostly a question of brute computing power.
  17. Carbon Dioxide - Everyone's Favorite Pollutant
    RSVP, You keep changing your argument. see ricarrdo for the answer you want now. If I put 15 grams of fertilizer, a basic ingredient to the life cycle of plants, on my garden, that is food for the plants. If 15,000 tons of fertilizer washes into the ocean that is pollution. There are many pollutants that are natural products like CO2. Scientists propose going after CO2 by regulating processes that release CO2 like burning coal and oil. How else could you regulate CO2? Natural CO2 like animals release is not what would be regulated. You are the only one who suggested regulating natural products. The difficulty is you are not clear in your argument and you keep changing your emphasis. This is becasue what you say is not logical. Since you have trouble being understood when you are retorical I suggest you try to stay on the point.
  18. Global warming is accelerating the global water cycle
    I did a blog post on climate change's impact on water resources that some may find useful: O Water, Water, Wherefore Art Thou Water?
  19. Carbon Dioxide - Everyone's Favorite Pollutant
    RSVP, this is really quite simple. CO2 is the source of the problem (along with other greenhouse gases). Thus CO2 is what needs to be targeted. Coal and petroleum aren't the only sources of CO2. Some other major sources are cement production, agriculture, landfills, etc. Your conclusion that labeling CO2 as a pollutant is "lip service...in light of the current hysteria" is completely absurd and wholly unsupported by everything you've said. Your argument still consists of "I don't like it, therefore it's wrong."
  20. Skeptical Science housekeeping: Comments Gluttony
    Congratualations, John, it is hard to keep up with the stream of information coming from this site, but it is a superb resource! Hope it's not OT to say that. :(
  21. Berényi Péter at 02:19 AM on 9 October 2010
    Climate Cherry Pickers: Falling sea levels in 2010
    #59 doug_bostrom at 03:12 AM on 8 October, 2010 the nut of your objection seems to come down to a hypothesis that, overall, continents are sinking below the waves, but you don't offer any details to support this remarkable claim. No, I was talking about neither rising nor sinking of continents (relative to the terrestrial center of gravity), just the temporal derivative of this motion, that is, its acceleration. But come to think of it, continents must be sinking, after all. Or let's be more accurate. Vertical motion averaged over the entire surface of solid Earth should be zero, provided volume of the planet does not change. However, tide gauges are not scattered just randomly over the surface, they are located along coastlines, per definitionem. Now, at the end of the last glaciation when the huge Laurentide and Fennoscandian ice sheets melted away, there was an almost step-like 120 bar pressure increase over marine basins, including continental shelfs. In other words at locations far from the previous ice sheets a pressure difference was built up between the interiors and margins of continents, therefore some isostatic rebound should have happened worldwide, with an opposite sign of course compared to sites close to previous ice sheets, but of smaller magnitude. Due to high viscosity of mantle stuff, it is likely not finished yet. Rate of vertical motion above land is not easy to measure, but average rate of sinking along coastilnes can easily be as large as 0.4 mm/yr (with a considerable dispersion). Just for a taste of the complexity of the issue see: Global and Planetary Change Volume 57, Issues 3-4, June 2007, Pages 396-406 doi:10.1016/j.gloplacha.2007.02.002 Geocentric sea-level trend estimates from GPS analyses at relevant tide gauges world-wide G. Wöppelmann, B. Martin Miguez, M.-N. Bouin and Z. Altamimi
  22. Carbon Dioxide - Everyone's Favorite Pollutant
    michael sweet #128 Why are you straying from the question and attempting to obfuscate things I say. The comment is rhetorical and only finds its context in the idea that CO2 (a basic ingredient to the life cycle on Earth) be considered a pollutant. It is not a suggestion, just a question that I will repeat one more time...that is, before going after CO2, why not first target the processes that are creating unwanted amounts of CO2 such as combustion of petrolium and coal? The difficulty with the question is that it reveals the underlying weakness in this movement. Put another way, labeling CO2 as a pollutant is basically a form of lip service or appeasement in light of the current hysteria.
  23. Climate Cherry Pickers: Falling sea levels in 2010
    kdkd #50 Looks like BP #49 has gob-smacked the Sea level debate again. Just 1.9mm/year - that's below my 2.1mm year from Jason, and near to the ice melt alone number of 2mm/year. Could this Sea level rise be 'flattening' kdkd?
  24. Global warming is accelerating the global water cycle
    Kooiti Masuda at 22:14 PM, Kooiti, thank you for your response,I hope that you become a regular visitor here. Though seemingly off-topic, understanding how such systems work or change over time is relevant to understanding the global water cycle. Not only for understanding how the cycle manifests itself under current climate conditions, but how it may manifest itself under changed conditions. I tend to agree with the oceanographers in that the IOD and ENSO are distinct entities as looking at them from the Australian regional view, being in the middle, the nett result delivered upon us will at times be due to them working in unison, feeding off one another, whilst at other times they are offsetting each other, with all sorts of combinations in between. This seems particularly evident when examining how drought develops over Australia, that perhaps giving some of the relevance to the water cycle. It is also relevant when considering whether or not everything that occurs in the region that is attributed to ENSO, may at times be attributable to the IOD thus perhaps downgrading the influence that ENSO is thought to have.
  25. Dikran Marsupial at 01:38 AM on 9 October 2010
    Positive feedback means runaway warming
    Karamanski@20: The exchange of CO2 between the ocean and atmosphere isn't governed only by temperature, it is also governed by the difference in partial pressure of CO2 between the atmosphere and the surface oceans. Loosely speaking CO2 leaving the oceans has to push against the partial pressure of CO2 in the air, so as more CO2 is added to the atmosphere the comes a point where the increased partial pressure balances the effect of increased ocean temperature, and you get a new equilibrium. If the climate did not have equilibrium states formed by the balancing of positive and negative feedbacks, it is unlikely we would be here to see it! HTH
  26. Positive feedback means runaway warming
    Climate senitivity must be lower than the IPCC calculates. The ice age was ended by slight changes in the earth's orbit and rotation which melted some ice which enhanced the initial warming. Also a warming ocean gave up more carbon dioxide to the atmosphere further reinforcing the warming. These feedback loops continued until the present interglacial began. What I'm curious about is why did the warming stop. Wouldn't the warming have continued to feed on itself until all the ice sheets were gone and when the ocean ran out of carbon dioxide to emmit? Because of this there must be a negative feedback that we don't understand that well. Please explain this.
    Moderator Response: Try reading the "Advanced" tabbed page here. Is there some particular part of that, that you have a question about?
  27. It's the sun
    KR #637 "1750 has perhaps the best (not perfect) chance of being at equilibrium of those three dates - 900 temps have a steady downward trend, part of the Little Ice Age, I suspect, while 1880 is in early industrialization with numerous forcing changes from early CO2. But as the various forcings move around, the climate can only follow, only hitting equilibrium if (a) forcings don't change for a period long enough for the oceans to catch up, or (b) forcings reverse and pass climate change going the other way." Well I agree with you that AD1750 at near the Maunder Minimum would be closest to equilibrium so the temperature 'trajectory' is close to zero. Having said that - you seem to then confuse Temperature trajectories with forcings. I notice that none of ya'll (Ned KR, kdkd) seem to accept my basic point that the area under ALL the forcing curves represents the total energy gained or lost by the Earth system. I have found a summation of the 10 Radiative forcings from your chart at #623, here: http://www.brighton73.freeserve.co.uk/gw/GISS_forcings.gif Now this is interesting because if you take the areas under the "Sum of 10 Forcings" composite curve - you can see that from 1850 to about 1915 all the area under the curve is negative. According to this The Earth system has lost energy from 1850 to 1915 so we should see cooling. There is no significant cooling in temperatures in this period - in fact all charts show increasing temperatures since 1850. Clearly the only forcing which could maintain temperatures and add energy to offset the negative area was Solar, but this has been 'chart zeroed' at 1850 and has negligible area under its curve. If a S-B IR cooling response curve was added which corresponded to a temp rise of about 0.1 degC (probably more)in that period then another -0.4W/sq.m of IR cooling would add to the negative area under the combined curves. The only conclusion is that Solar should not have been zeroed, but entered the chart in AD1850 at about 0.2W/sq.m+, in order to maintain a positive area under the composite curves to support a 0.1 degC+ warming in that period. The same argument follows on for the rest of the chart up to date.
  28. Berényi Péter at 01:00 AM on 9 October 2010
    Climate Cherry Pickers: Falling sea levels in 2010
    #69 TimTheToolMan at 21:11 PM on 8 October, 2010 I agree that accumulation of energy below the thermocline occurs primarily through conduction and my understanding is that the timeframes are measured in centuries. No, it is not he case. Thermal conductivity of water is 0.58 Wm-1K-1. To calculate power flux through a surface, one has to multiply it by temperature gradient perpendicular to that surface. Now, even at the thermocline temperature gradient seldom exceeds 0.04 Km-1 (1°C difference in 25 m). Therefore in this layer power flux by conduction is less than 25 mW/m2. However, as we go deeper, temperature gradient decreases rapidly; below 1000 m it is about 0.0007 Km-1, implying a downward power flux of 0.4 mW/m2 by conduction. On this rate it would take a million years to increase abyssal temperature by 1°C. A bit more than "centuries". On the other hand there is a geothermal heat flux from below at the bottom of oceans, some 100 mW/m2 on average, that is, hundreds of times more than heating by conduction from above. So conduction is absolutely negligible, except perhaps in the very vicinity of the thermocline, but even there it fails to be dominant. If there were no poleward mass transport above the thermocline at all, the conductive power flux at it would lower the thermocline by about 20 m in a century. However, there is one, so average depth of the thermocline is pretty stable. It is mass transport alone that is able to influence heat contents of deeper layers in oceans on these short timescales, both wind or tide driven turbulent mixing and thermohaline overturning due to density differences. But I don't think this transport could exceed geothermal heating rate by much.
  29. A detailed look at climate sensitivity
    When I said "only .8 degrees celsius" I was comparing the global warming so far to what is projected for the future. A rise of .8 degrees celsius a very steep increase relative to the known paleoclimate record. I also was not saying that warming has stopped. This decade was indeed the hottest on record and 2010 is on track to tie or exceed 2005 as the warmest calender year on record. Even though warming may continuing the rate of global temperature increase is steady and is not accelerating. From what I think, assuming that climate sensitivity isn't super high, I find it diffult to think that we will have a temperature increase of 3 degrees celsius by 2100. For example, thermal inertia might be much larger and slower than expected. I'm still very skeptical of the accuracy of climate models. For instance, they did not predict the halt in the increase of methane concentrations over the past decade. Arctic sea ice predictions by climate models are 40 years behind real observations. Please explain this.
  30. It's the sun
    Ken #649: "The Earth's temperature in AD1750 which according to you and the AGW community is 0.8 degC COOLER than today's temperature." The 0.8 C figure is warming since the global temperature record began in 1880 AD. Most paleoclimate reconstructions have 1750 being somewhat cooler than that. That said, in 1750 TSI was around 1365.5 w/m^2. In order for TSI alone to cause a 0.8 C increase in global temperatures it would have to increase to about 1370 (a level never seen in the planet's entire history) rather than it's current level of about 1365. I pulled all of this TSI information from the 'Advanced' version of this article. Hadn't you read it?
  31. It's the sun
    Ken Lambert - I would agree, there is one TSI for one equilibrium temperature of the Earth, with all other variables held constant. Of course, if you change (for example) CO2 levels, the equilibrium temperature for a particular TSI will change, as the radiative efficiency of the Earth will change. But all other variables are not held constant. The other radiative influence changes are much much larger over the last 150 years. This is a multi-variate issue, and you're only looking at TSI vs. Temperature!!! So: - You insist upon equilibriums, when it's obvious from the temperature record that temps were not at equilibrium in 1750 (cooling slightly), - You don't recognize that existing forcings at any baseline date are incorporated in the temperature trajectory entering that baseline (your offset concerns), - You're going on about equilibrium TSI, when the TSI deltas are an order of magnitude less than the other forcing changes, - And most importantly, you're not (in any of the recent comments here, here, or elsewhere) including the CO2 or aerosol radiative deltas in your 'equilibrium' considerations. This horse has been flogged to death, Ken - you are hunting for a solar cause, you are not considering the relative magnitudes and importance of the radiative factors, and have ceased to add content to the discussion some time ago. I'm out of here...
  32. Eric (skeptic) at 00:23 AM on 9 October 2010
    The value of coherence in science
    in #40 BPP asks "A question that I have for any of the skeptics here is - What evidence would you find sufficient to change your mind about ACC?" My position on AGW has been consistent and coherent for more than a decade. I don't need any evidence for AGW (without the Catastrophe) because I believe the theory is sound. I don't even care if it is warming or cooling because I believe that natural factors modify sensitivity to AGW on various time scales, for example the blocking weather patterns which may be caused by lower UV. A question for you: what makes the CAGW position coherent? If the important catastrophe is stronger, more frequent storms and heat waves now, then sensitivity is low and the Greenland melting catastrophe is way out of range and not worth worrying about. If the more important catastrophe is Greenland melting, then there cannot be stronger and more frequent storms now because those lower sensitivity. In case someone wants to propose paleo evidence for sensitivity, there's a thread for that http://www.skepticalscience.com/detailed-look-at-climate-sensitivity.html with my assertion at #37. The bottom line is that a coherent CAGW theory can only choose one type of catastrophe, not both.
  33. It's the sun
    Ned #645 Clearly the waste heat thread went pear-shaped after I left. Ned: "Yes, you do mention the OLR negative feedback that leads all forcings to decay towards 0 over time, as the planet's outgoing radiation increases or decreases. But you are still blindly ignoring this when you talk about your imaginary "equilibrium TSI". In fact, there is a continuous range of TSI values, any one of which can be balanced by a corresponding OLR value, leading to some particular stable temperature. There is no reason why one particular TSI value can or should be artificially promoted as the uniquely special equilibrium TSI that the Earth wants to be in balance with. If you still don't get this, someone else can take over, because I'm done." Ned, you have just confirmed exactly my contention about a 'unique' TSI corresponding to a particular 'Equilibrium' temperature. Let's repeat what you say above: "In fact, there is a continuous range of TSI values, any one of which can be balanced by a corresponding OLR value, leading to some particular stable temperature." Question: And can you guess what that particular temperature of interest is? Answer: The Earth's temperature in AD1750 which according to you and the AGW community is 0.8 degC COOLER than today's temperature. And what follows from that is that we have a TSI AD1750 corresponding to Temp AD1750. Pray tell me then Ned what is the value of TSI AD1750? And after you have done that you should than be able to advise what particular TSI value corresponds to an Earth temperature 0.8 degrees higher than that of AD1750.
  34. Global warming impact on tropical species greater than expected
    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.
  35. It's the sun
    CBD, "the possible range of variation here is more than an order of magnitude less than GHG forcings. ... solar forcing for 2004-2007 ... was still less than the IPCC projected for this time period. " I thought those were the salient take-aways, especially in the context of 'its the sun' and 'its only the sun'. Funny how order of magnitude seems to get lost when discussing the role of various deltas.
  36. Skeptical Science housekeeping: Comments Gluttony
    HR #20 The moderation criteria seems to be based on the comments policy. I'm not 100% happy with the way that it all works, but it seems more effective than the nonsense at WUWTF for example. Hopefully in the not too distant future victims of comments deletion may get feedback from the deletionist as to why their comment was deleted.
  37. It's the sun
    KL #various Your "area under the curve" stuff is (from a statistical perspective) just a calculus-centric view of talking about regression models. We've done that to death elsewhere, and it doesn't confirm your over-complex, often illogical, statistically illiterate and difficult to ascertain argument. Come up with something new and I'll be happy to assess your arguments on its merits. This particular dead horse however is well and truely flogged.
  38. Global warming is accelerating the global water cycle
    Kooiti Masuda #23: "Accordingly, the mean residence time of water vapor in the atmosphere becomes longer." If I understand correctly, this model result is a consequence of the same thinking (based on the Clausius–Clapeyron relation) that suggests a warming atmosphere will hold a greater amount of water vapor... rather than an independent verification (since higher evaporation + longer water vapor residence would perforce mean more total water vapor) of it. Do the Syed et al results bring us closer to validating the assumptions underlying these water cycle models? To clarify where I'm going... water vapor feedback is one of the major factors in determining 'climate sensitivity'. I'm wondering if water cycle monitoring and/or modelling are now precise enough to validate the projected positive feedbacks from water vapor. I know that Roy Spencer has recently suggested that an accelerated water cycle might actually lead to negative water vapor feedback due to precipitation outpacing evaporation; "The average amount of water vapor in the atmosphere represents a balance between two competing processes: (1) surface evaporation (the source), and (2) precipitation (the sink). While we know that evaporation increases with temperature, we don’t know very much about how the efficiency of precipitation systems changes with temperature. The latter process is much more complex than surface evaporation (see Renno et al., 1994), and it is not at all clear that climate models behave realistically in this regard. In fact, the models just “punt” on this issue because our understanding of precipitation systems is just not good enough to put something explicit into the models."
  39. Global warming is accelerating the global water cycle
    johnd's question to me seems off-topic here, but I try to answer for once. I know that JAMSTEC does both observational and modeling studies about the Indian Ocean, but I am not better at explaining them than the official web site. The Indian Ocean Dipole is an element of interannual variability, something in the Indian Ocean like El Nino in the Pacific. "IOD positive" means sea surface temperature is low near Sumatra (high near Kenya). "IOD negative" is the opposite. While oceanographers tend to view that IOD and ENSO are distinct things, I rather view that both are parts of the Southern Oscillation in the broader sense as first envisaged by Gilbert Walker in 1920s. IOD, as well as ENSO, is not a directly important element of climate change (of longer time scales), but the trends in how often positive and negative IOD events occur can be a subject of climate change with many people's interest. I think that some basic characteristics of the Indian Ocean are more important in the issue of climate change (as well as water cycle). One is that the seasonal reversal of monsoon is the most distinct here. Another is that the intertropical convergence zone can appear on the either side of the equator here. Also, Madden-Julian oscillation (a mode of intra-seasonal variablilty) is usually generated in the equatorial Indian Ocean.
  40. Climate Cherry Pickers: Falling sea levels in 2010
    @Joe Blog I agree that accumulation of energy below the thermocline occurs primarily through conduction and my understanding is that the timeframes are measured in centuries. Accumulation of any energy can only occur with either an increase of energy input into the ocean such as might happen with a change in cloud cover or theoretically a decrease in energy lost from the ocean. This is the mechanism you hinted at with your suggestion increased LW radiation such as would happen with increased CO2, would decrease the LW radiation loss at the surface. But is this really the case? It might surprise most here that the science behind that assertion is at best weak and at worst non-existant. http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/ Explains the issue and you'll be hard pressed to find references to it elsewhere even though its the lynchpin behind AGW.
  41. It's the sun
    muoncounter #641: Yes, I saw that report too. The bit about the magnitude of any solar change being "dwarfed" by the increase in CO2 forcing makes it somewhat of a minor issue AND the researchers note that the results need further verification... but it is certainly an interesting new wrinkle. Unfortunately, if validated it would essentially mean that we can't be sure about precise solar forcings prior to this kind of detailed spectral analysis. Is a solar minimum ALWAYS accompanied by higher output of VISIBLE light or was that the case for this particular minimum but not all? Are solar maximums characterized by DECREASED visible light or exceptionally increased levels? However, again... the possible range of variation here is more than an order of magnitude less than GHG forcings. The report also shows that while the solar forcing for 2004-2007 may have been greater than would have been suggested by looking at total solar irradiance (rather than a specific wavelength analysis)... it was still less than the IPCC projected for this time period.
  42. It's the sun
    Ken writes: Try harder next time Ned. Not going to happen. After the fiasco of the Waste Heat thread, I'm no longer willing to expend indefinitely large efforts on repeatedly explaining the same points over and over again without any evidence of benefit. Yes, you do mention the OLR negative feedback that leads all forcings to decay towards 0 over time, as the planet's outgoing radiation increases or decreases. But you are still blindly ignoring this when you talk about your imaginary "equilibrium TSI". In fact, there is a continuous range of TSI values, any one of which can be balanced by a corresponding OLR value, leading to some particular stable temperature. There is no reason why one particular TSI value can or should be artificially promoted as the uniquely special equilibrium TSI that the Earth wants to be in balance with. If you still don't get this, someone else can take over, because I'm done.
  43. A detailed look at climate sensitivity
    Karamanski #52: "Since 1880, global temperatures have only risin .8 degrees celsius." Only? You do realize that's the most extreme temperature increase, in both amount and rate, since the end of the last ice age right? "In order for global temperatures to rise by 3 degrees celsius by 2100, global warming would have to undergo a very rapid acceleraton. Apparently this isn't showing any signs of happening." It isn't? The actual temperature data seems to show that it is. The graph below shows both linear and quadratic 'best fit' trend lines against the GISS data. Note that the best quadratic fit is an increasing temperature slope. Not particularly surprising given that 2000-2009 was the hottest decade on record and 2010 is thus far the hottest single year on record. "Global temperature increases over the past decade have been on the low end of climate model projections." That's like saying, 'there were ten days at the end of Spring that were on the low end of average temperatures... therefor it seems unlikely that temperatures will increase this Summer'. You're looking at a short term fluctuation, no greater than half a dozen such since 1880, and ignoring the long term trend.
  44. Uncertain Times at the Royal Society?
    "Doubling CO will cause 2-4.5 °C global warming" Clearly you mean CO2 not CO. Also Joe Romm's post on this report at Climate Progress is worth a look. He argues the new report is dangerously conservative: "It doesn’t spell out simply and clearly what will happen if we don’t take action to reduce emissions nor does it spell out the plausible worst-case scenario (which is crucial to how individuals and societies actually make major decisions)."
  45. Skeptical Science housekeeping: Comments Gluttony
    Get personnal, graph the comments by poster, lets see who's posts generate the most heat ;)
  46. Skeptical Science housekeeping: Comments Gluttony
    #4 I was going to ask if the data had been adjusted for deleted comments. Look I'm curious about the moderation criteria. I had a few time consuming posts deleted recently which I thought were mainly if not completely science in content and which were around- if not on-topic (more on topic than some of the surviving posts anyway). Have you started deleting posts you consider plain wrong or misguided?
  47. Global warming impact on tropical species greater than expected
    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.
    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.
  48. A detailed look at climate sensitivity
    Whoops, I should have linked to a graph right here on Skeptical Science--a graph that includes as well some of the IPCC scenario projections for scenarios worse than constant emissions.
  49. A detailed look at climate sensitivity
    Karamanski, the rate of CO2 emissions has been increasing since 1880, so the rate of CO2 concentration increase has been increasing, so the rate of temperature forcing from CO2 has been increasing, so the rate of temperature increase since 1880 has been increasing. Therefore the temperature increase rate can't be extrapolated as a linear increase from 1880 to the present. CO2 emissions will continue to increase. Perhaps the most convincing picture of the consequence is a graph of the temperature increase if CO2 emissions instead remained at their current level ("constant emissions"). That does not mean business as usual, because business as usual means the same amount of CO2 per unit of energy produced. Business as usual means an increasing amount of CO2 emitted, not merely an increasing amount of CO2 concentration resulting from constant emission. That's because increasing industrialization and increasing population will result in an increasing number of sources of and amounts of emissions. Business a usual will result in an increasing rate of CO2 emission. The lower bound of the business as usual scenario is the "constant emissions" scenario, in which the increasing number of sources is offset by reduced rates of emissions from each of the sources. That is the curve labeled "4. Constant emissions" in this figure reproduced at RealClimate. Even in that possibly unreasonably optimistic case, the temperature climbs dramatically because of the continued increase of amount of CO2 accumulating in the atmosphere. The business as usual case will be worse than that--much worse.
  50. It's the ocean
    Karamanski, I believe you're thinking of Keenlyside et al 2008 (full text, pdf) which includes Mojib Latif as a coauthor. The abstract is probably better to read directly rather than letting someone else paraphrase it. The key lies in the words "surface temperature" and regional variability, how much heat is available where we can measure it in various regions of the surface temperature network and different regions of ocean surface. Keenlyside predicted a regional cooling in the North Atlantic area caused by circulation changes in the North Atlantic ocean, sufficiently strong as to cause a change in the overall surface temperature trend, even as other areas of the globe continued to warm. Behind all this is no change in the total amount of energy being retained on the planet, rather a change in distribution. Popular press treatments of this paper conveyed the impression that warming was going to stall or even that the Earth was going to cool, which is wrong in terms of energy being retained on Earth during the period covered by Keenlyside's prediction. Richard Wood explains this in a commentary at Nature accompanying Keenlyside et al: [Keenlyside's] starting point is the ocean. On a time scale of decades, this is where most of the ‘memory’ of the climate system for previous states resides. Anomalously warm or cool patches of ocean can be quite persistent, sometimes exchanging heat with the atmosphere only over several years. In addition, large ocean current systems can move phenomenal amounts of heat around the world, and are believed to vary from decade to decade. Wood goes on, regarding the extent of the predicted cooling: The authors use their model to predict that the MOC will weaken over the next decade, with a resultant cooling effect on climate around the North Atlantic. Such a cooling could temporarily offset the longer-term warming trend from increasing levels of greenhouse gases in the atmosphere. That emphasizes once again the need to consider climate variability and climate change together when making predictions over timescales of decades. On a parenthetical note, it's fun when scientists bet money on validation. Some climate researchers found Keenlyside's analysis and forecast sufficiently debatable as to offer a bet on the outcome.

Prev  2143  2144  2145  2146  2147  2148  2149  2150  2151  2152  2153  2154  2155  2156  2157  2158  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us