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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.

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Comments 60251 to 60300:

  1. Weather records due to climate change: A game with loaded dice
    mc, while the hailstorm and consequences were dramatic, I have a few doubts about the reports of 2-4 or 4-8 feet of hail actually falling (is there a better source than news media?) - I suspect those measurements were mostly from drifts where the flash floods piled the ice up. I don't doubt that there were large rainfall and hail totals however! And I don't want to take away too much from the weirdness of that weather - the video of the flash flood loaded up with ice is scary, the power, shape and destructiveness of the flood has more in common with a volcanic lahar than even a typical flash flood!
  2. Return to the Himalayas
    Get ready for another onslaught from the echo chamber: Some Asian glaciers 'putting on mass' Prediction: The use of models to reach this conclusion will be ignored. And this tidbit will also be under-reported: ... between 1999 and 2008 the mass of the glaciers in this 5,615 sq km (2,168 sq miles) region of the Karakoram increased marginally, although there were wide variations between individual glaciers. See the Nature article here.
  3. Polar bear numbers are increasing
    TOP @36 and DB inline comment, TOP's reference to the terms of use are a deliberate distraction. I will not be distracted - but see below. The important point that TOP is trying to distract from is that he is trying to represent a report that says polar bears are at risk as not saying that polar bears are at risk. Indeed he continues to do so, saying that "it is the habitat and not the bears that are at risk according to the article" (my emphasis). TOP is entitled to form and put forward any view he likes about the risk to polar bears. He is not entitled to misrepresent the opinions of others about that risk, and he is certainly not entitled to put forward those misrepresentations as evidence for his own opinions. As TOP's attention has been drawn to the misrepresentation, and as he persists in it regardless, the only reasonable supposition is that the misrepresentation is deliberate. Lest there be any doubt about this, the article says in its lead section: "Red List Category & Criteria: Vulnerable A3c ver 3.1" Where "Vulnerable" means: "A taxon is Vulnerable when the best available evidence indicates that it meets any of the following criteria (A to E), and it is therefore considered to be facing a high risk of extinction in the wild:"(my emphasis) So the article directly states that polar bears are "facing a high risk of extinction in the wild", which TOP represents as saying that it is "... not the bears that are at risk according to the article." The numbers after the classification indicate that polar bears are facing ...
    "A. Reduction in population size based on any of the following: ... 3. A population size reduction of ≥ 30%, projected or suspected to be met within ... three generations, ..., based on (and specifying) any of (b) to (e) under A1."
    ... where A1 (c) specifies the reason for the risk as ...
    "(c) a decline in area of occupancy, extent of occurrence and/or quality of habitat"
    . So, contrary to TOP, it is habitat degredation, specified as being due to global warming in the article, which is claimed as the reason why the polar bears are facing "a high risk of extinction". The only reasonable conclusion at this point is that TOP is willing to straightforwardly misquote and misrepresent articles as saying the exact opposite of what they do so to further his cause. Everything he says should be understood in that light. Returning to TOP's attempted distraction, I note that terms and conditions do not apply to publicly accessible portions of the website, but only to those sections requiring login. What is more, limited quoting such as I have done constitutes fair use under copyright law, and the resulting product (my post) would constitute a "derivative work" under the terms and conditions even if they did directly apply. If TOP disagrees with my assessment, he is quite welcome to contact the IUCN, and I will modify my comment to comply with their directions. Indeed I would look forward to his doing so, for I would like to see their public comment on TOP's use of the material from their site.
  4. Weather records due to climate change: A game with loaded dice
    Weather records, indeed. April 11, Amarillo Texas: 4-8 feet of hail, followed by flash flooding as it melted. Quoting the anchorman, "I have never, ever, ever seen what you're about to show us."
  5. Return to the Himalayas
    Steve Case#16: "the IPCC tells us that in a warmer world there will be more precipitation." Indeed. But there's no prediction of the sort you made that precipitation will fall where you'd like it to. See "The wet get wetter, the dry get drier." Precipitation is projected to increase in the near-equatorial regions, which tend to be wet in the present climate. In subtropical land areas — places that are already relatively dry — precipitation is projected to decrease during the 21st century.
  6. Daniel Bailey at 07:04 AM on 16 April 2012
    Return to the Himalayas
    Steve, you make a specious point. It is quite possible for glaciers to gain mass in a warming world (even though the majority of the world's glaciers are in retreat). Glaciers can put on mass as long as the gains made in their accumulation zone outweigh the losses from their ablation zone. In the case of many of the Himalayan glaciers, increased precipitation in the accumulation zones is causing some to gain mass, despite increased losses in their ablation zones. These glaciers serve as storage depots for a great portion of the world's populations, buffering them against the lack of rainfall during the non-monsoon seasons. Despite the hand-waving to the contrary, this is all well-understood and well-documented. And non-controversial, despite the best efforts at denialists to manufacture controversy.
  7. Return to the Himalayas
    Rob Honeycutt "Warming is anticipated to enhance the hydrological cycle. That means both wetter and drier conditions" No comment. Muoncounter So are glaciers disappearing due to a lack of precipitation or a warming climate? If it's a lack of precipitation then you have to deal with the fact as I pointed out earlier in the other thread, the IPCC tells us that in a warmer world there will be more precipitation. If they're disappearing due to warming, and precipitation is at least the same, then you have deal with the question of what happens to the water. The claim was that fresh water supplies would disappear.
  8. funglestrumpet at 06:16 AM on 16 April 2012
    Global Warming in a Nutshell
    I would like to see a link to this article a prominent feature of the home page. If that is not possible, perhaps it could be linked to from the 'Newcomers Start Here' section. Unfortunately, if it were to form such a feature, then it would be necessary to either delete the comments, or preferably take the second comment’s string of unsubstantiated opinion and rebut each point raised. I would imagine anyone who would find the article a significant source of information on the topic may well hold the same opinions (it is after all what the mainstream media would have us believe) and thus the rebuttals would be of added value to them. Who knows, a certain member of the British aristocracy might learn something, seeing as said peer seems to hold many of the same misguided views on the topic and is even proud to parade his ignorance to all who will listen (and run away when challenged with the facts of the matter).
  9. The Critical Decade - Part 2: Climate Risks
    Thanks Larry, link fixed.
  10. Return to the Himalayas
    Steve Case#13: There are sufficient data to show without question that diminishing snowpack results in decreased river flow. See this SciAm article about the western US: Snowpack in the northern Rocky Mountains has shrunk at an unusually rapid pace during the past 30 years, according to a new study. ... the plummeting snowpack could have serious consequences for more than 70 million people who depend on water from the runoff-fed Columbia, Colorado and Missouri rivers. So no, your "If a glacier disappears, it will still rain and snow in the watershed where the glacier was and the rivers in such watersheds will still flow" is wishful thinking at best.
  11. Polar bear numbers are increasing
    @Tom I take it you have read and agree to Section 4 here. I read the article. I pointed out that it is the habitat and not the bears that are at risk according to the article. There were a plethora of possible events that could or are putting them directly at risk and that are currently responsible for their reduced numbers the chief of which is human/bear interaction. The last two assessments of their status flip-flopped which suggests they are borderline vulnerable right now. It would seem that limiting or changing human/bear interactions would have a far greater effect on their current survival. Hunting bears just for the fun of it is just sick.
    Moderator Response: [DB] The materiel cited earlier complies to the IUCN policies per these terms.
  12. Rob Honeycutt at 04:13 AM on 16 April 2012
    Return to the Himalayas
    Steve @ 13... "This discussion will eventually boil down the difference in melt rates between ice and snow." Don't you think this is exactly the problem? Warming is anticipated to enhance the hydrological cycle. That means both wetter and drier conditions. Glaciers, as I understand it, act to buffer the normal variation in wet/dry cycles of weather. This would act to keep the water supplies downstream more consistent, and is why large populations have developed in these regions. If we deplete that source of fresh water then those downstream populations will be subject to greater extremes. Times of extreme flooding and times of extreme low water conditions. Being that many of these populations are also poor their capacity to adapt to the extremes is very limited, which brings on a whole host of other problems.
  13. Climate Scientists take on Richard Lindzen
    Bob. All very real possibilities, no doubt. FWIW, I don't see integrity a boolean, all or nothing; it's more of a real number.
  14. climate rainbow at 02:14 AM on 16 April 2012
    Global Warming in a Nutshell
    Just thought it's worth mentioning, that there is up-to-date information for all of these subjects available. Best summary sheet that I've found for up-to-date records of the temperature data set providers is here:- http://junksciencearchive.com/MSU_Temps/Warming_Look.html The temperature graphs it plots also show the CO2 levels from the Mauna Loa observatory in Hawaii. Arctic sea ice extent (as well as Antarctic sea ice extent) can be found here:- http://nsidc.org/arcticseaicenews/ The problems with determining ice volume are discussed in a RealClimate.org article here:- link Sea level information is collated here:- http://sealevel.colorado.edu
    Moderator Response: [RH] Added hot link to fix broke page formatting.
  15. Return to the Himalayas
    At the moderator's request, I am posting here.

    On this thread: Global Warming in a Nutshell

    Gary M writes:

      What happens when the planet gets warmer? ...receding glaciers have consequences, such as ... disappearing fresh water supplies for billions of people.

    I replied:

    If a glacier disappears, it will still rain and snow in the watershed where the glacier was and the rivers in such watersheds will still flow.

    This answer followed:

    The amount of water that flows in a river is a function of the precipitation that falls in the water shed minus evaporation and plus or minus the contribution of receding or advancing glaciers if there are any.

    Currently many glaciers are receding, and as such more water flows in the rivers than is falling as rain or snow. When the glaciers either stop receding, or disappear, flow of water in the rivers will decrease.

    If "Global Warming" schemes actually prove out to be successful in stopping the recession of the world's glaciers, the reduction of water flow in these areas will occur sooner.

    This discussion will eventually boil down the difference in melt rates between ice and snow.

  16. Global Warming in a Nutshell
    @John Hartz: Thanks, the name and link have been updated. @Eric (skeptic): That's a fair criticism, as some polar bear populations may survive. I changed the word "extinction" to "decline".
  17. The Critical Decade - Part 2: Climate Risks
    The link to the full report, "The Critical Decade", gives "file not found", but the report can still be found here.
  18. Polar bear numbers are increasing
    TOP @35, the IUCN report says, among other things:
    "Polar bears rely almost entirely on the marine sea ice environment for their survival so that large scale changes in their habitat will impact the population (Derocher et al. 2004). Global climate change posses a substantial threat to the habitat of polar bears. Recent modeling of the trends for sea ice extent, thickness and timing of coverage predicts dramatic reductions in sea ice coverage over the next 50?100 years (Hassol 2004). Sea ice has declined considerably over the past half century. Additional declines of roughly 10?50% of annual sea ice are predicted by 2100. The summer sea ice is projected to decrease by 50?100% during the same period. In addition the quality of the remaining ice will decline. This change may also have a negative effect on the population size (Derocher et al. 2004). The effects of sea ice change are likely to show large differences and variability by geographic location and periods of time, although the long term trends clearly reveal substantial global reductions of the extent of ice coverage in the Arctic and the annual time frames when ice is present."
    (My emphasis, the sentence you quoted is underlined.) Straightforwardly, the sentence immediately preceding the sentence you quoted directly contradicts the conclusion that you wish to draw from the quote. That means whether deliberately or by incompetence you have quoted the report out of context, and in a deceptive manner. You suggest that Polar Bears are a flexible breed, but the report says:
    "While all bear species have shown adaptability in coping with their surroundings and environment, polar bears are highly specialized for life in the Arctic marine environment. Polar bears exhibit low reproductive rates with long generational spans. These factors make facultative adaptation by polar bears to significantly reduced ice coverage scenarios unlikely. Polar bears did adapt to warmer climate periods of the past. Due to their long generation time and the current greater speed of global warming, it seems unlikely that polar bear will be able to adapt to the current warming trend in the Arctic. If climatic trends continue polar bears may become extirpated from most of their range within 100 years."
    (My emphasis) Clearly the report adresses your claim and contradicts it. As counter evidence you provide us nothing more substantive than the infallibility of TOP speaking ex cathedra. Finally, you say that the article says that it is the habitat, not the bears at risk, whereas the report says:
    "There is little doubt that polar bears will have a lesser AOO, EOO and habitat quality in the future. However, no direct relation exists between these measures and the abundance of polar bears. While some have speculated that polar bears might become extinct within 100 years from now, which would indicate a population decrease of >50% in 45 years based on a precautionary approach due to data uncertainty. A more realistic evaluation of the risk involved in the assessment makes it fair to suspect population reduction of >30%."
    (Again my emphasis) A population reduction of greater than 30% in 45 years or less is a clear indication of a population at risk. Therefore in claiming that the article claims it is the habitat, not the bears which are at risk you have straightforwardly misrepresented the article. What is more, the article explicitly categorizes polar bears as "vulnerable", which is defined as meaning:
    "A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable (see Section V), and it is therefore considered to be facing a high risk of extinction in the wild."
    (My emphasis) So you have quoted out of context, directly misrepresented the articles contents, and contradicted the article without supporting evidence. Why exactly are we supposed to take anything you say seriously?
  19. Data Contradicts Connection Between Earth's Tilt and the Seasons
    You can check the original here. Figure 1 is labelled as thousands of years before 1950. The term 'before present' may the source of the confusion: see the Wikipedia article on the technical use of the term.
  20. Global Warming in a Nutshell
    @LarryM: The contents of your “Links to Additional Information” box should be updated to reflect the fact that the Pew Center on Climate Change was transformed into the Center for Climate and Energy Solutions (C2ES) in Nov, 2011.
  21. Daniel Bailey at 22:57 PM on 15 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    lurgee, it is hardly skeptical to view things in terms of "Sides" (or "Tribes", as some put it). This "Side" discusses climate science in view of what the actual science has to say, viewed through the lens of the scientific method. The other "Side" you refer to prefers to employ insinuation, false balance, character assassination, misrepresentation and cognitive/confirmation bias in lieu of the science and scientific method. Unless you have a fascination for train wrecks. Then carry on.
  22. Data Contradicts Connection Between Earth's Tilt and the Seasons
    I said : "Greenland ice cores tell us that 6,000 years ago was a bit warmer than today". Moderator says: "Incorrect. Greenland ice cores show temps in the period you reference were similar to those of Greenland in the latter part of the 20th Century. Which are cooler than those of today." I say: Richard B Alley, The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews Volume 19, Issues 1-5, 1 January 2000, Pages 213-226. http://www.ncdc.noaa.gov/paleo/pubs/alley2000/alley2000.html The Alley 2000 data is available online. Here is an annotated graph of a portion of this data, clearly showing periods warmer than today in the past 10,000 years. Could you please explain your blunt dismissal of this objective observation?
    Moderator Response:

    [DB] The Alley referenced data set uses a zero reference of 1950 (unless otherwise specified, ice core records are zeroed to 1950 by convention). Thus 95 years before present is 1855, not 2012.

    This is all fully detailed in the SkS skeptic meme rebuttal "Most of the last 10,000 years were warmer". If you wish to pursue your claim further, take it there.

    Perhaps you are unaware, but Jo Nova's blog is a known dissembler venue. And not credible.

    Please resize all graphics posted to 450 pixels width or less. Thanks!

  23. Eric (skeptic) at 22:42 PM on 15 April 2012
    Polar bear numbers are increasing
    Tom, you are right that it isn't simple or cheap: e.g. in the case of Florida panthers http://alyxia.umd.edu/teaching/files/Pimm_et_al.pdf "These [studies of rescues prior to Florida panthers] show the benefits of added genetic diversity. The compendium of such direct studies is still so small that it provides scant support for managers justifying expensive rescues.." To their methods I would add artificial insemination to preserve desired traits. Old Mole, I agree that the Inuit have an immediate financial interest in more bears, and there is not enough information to determine what habitat changes have occurred and what those imply for the bears. See http://www.researchandpractice.com/articles/2-2/dowsley-1.pdf for a diverse and thorough survey of Inuit opinion.
  24. Michael Whittemore at 20:47 PM on 15 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    I wonder why Shakun et al. 2012 did not use all the proxy data that was utilized in the Clark et al. 2012 paper. I understand that some of the proxy's used in the Clark et al. 2012 were for precipitation data, but it still looks like there was a lot more temperature records used compared to Shakun et al. 2012. Below is a comparison of the two papers with Shakun et al. 2012 on top and Clark et al. 2012 on the bottom, the blue dots on the Clark et al. 2012 graph are precipitation proxy's and I am not sure if these could also be used as temperature records.
    Moderator Response: [RH] Fixed image width.
  25. Shakun et al. Clarify the CO2-Temperature Lag
    William Haas #97
    There is no empirical data uncovered by this article to show that in the first 2,500 years since LGM that the green house gas, an increase in average atmospheric H2O did not have some role in global warming. At this point, how much of a role is speculation.
    I may be missing some subtlety here, but surely the figure of 7% proposed by Shakun et al for the initial, pre CO2 warming includes any feedback due to water vapour - as also does the 93% for the CO2 de-gassing ? Hence the percentages for warming can be equated with forcings, and considerations of water vapour can be ignored.
  26. Which plants will survive droughts, climate change?
    Well, that's genuinely interesting. In my role as a professional Revegetation Officer I thank you for this article, John.
  27. Global Warming in a Nutshell
    I prefer to expand the scope to describe it as geological impacts of our anthropogenic era - and to atmosphere and lithosphere. Changes would include: global warming - climate change leading to ocean acidification, sea level rise, ice cap melt leading to isostatic rebounds & earthquakes. Humans have been amazingly powerful.
  28. Shakun et al. Clarify the CO2-Temperature Lag
    I should add, thanks to Dana1981 for a very thorough, but easy to follow summary of the paper. Now that I've got my head around that, I might venture over to WUWT to see what the Other Side are saying.
  29. Michael Whittemore at 15:55 PM on 15 April 2012
    Shakun et al. Clarify the CO2-Temperature Lag
    lurgee @95 You have made it quite clear that one proxy temperature data is not a good global representative and you have also made clear what you think about proxy data when you said "So feel free to provide evidence that the experts regard the ice core record as 'clean' and relaibale, rather than a confused, torturous mess which, unfortunately, happens to the best we've got, and ever will get." You go on to say that “Now it turns out 93% of the interglacial temperature increase followed the CO2 increase something that had previosuly been obscured by focusing (understandably) on Antarctic ice cores, which were among the 7% where the temperature increase preceded the CO2 increase.”. The paper only says that 93% of the warming happened after CO2 rise, when I graph all the proxy’s I find that only the far north of the planet lagged behind CO2 increase, when the latitudes 30N to 90S are averaged out, which can be seen here . Also to say that a particular proxy lagged CO2 you would have to compare it to the CO2 record. Each proxy data used is individually graphed here here here here here here But due to area weighting done in the paper, it would be hard to determine what proxy data was averaged together, without knowing this you could not compare your results with the paper. Like I explained before, I think that the only reason why when all averaged out the proxy data shows a temperature lag behind the CO2 rise, is due to the increased cooling seen in the north which bring down the other proxy’s when averaged out. I also found a serious issue with one of the proxy data sets, the (TR163-22) Lea et al., 2006. It had over ten proxy data records that were -999 degrees Celsius !! You can find the excel data sheet for all the proxy’s used here William Haas @96 You are missing the basic points of the Shakun’s paper, you say “If a green house gas was involved to enhance the warming in the first 2,500 years then it had to be H2O which covered most of the globe in some form or another at that time.” There was only warming in the far north, look at figure 4. It is clear as day, no global warming.. The orbit warming only affected the far north which caused the (AMOC) to stop. H2O would have had played a part in this small warming up in the north, because in that region there was warming from extra sun hitting that area. More sun means higher temperatures, means more H2O in the atmosphere, but only in the far north because H2O is temperature dependent. Due to the (AMOC) stopping the north cooled and the south warmed, H20 would have also played a part in this initial warming in the south. But what you fail to understand is, the north regions of 30N-90N are cooling due to no warm water coming in from the (AMOC). But due to the rise in CO2, and the fact there is no way H2O being produced in the south could make its way up to the north where it is much colder, CO2 is the only GHG that could have done it.
  30. Polar bear numbers are increasing
    Eric@27 I wouldn't bet the farm on the most recent survey results from Hudson's Bay if I were you. That survey was done by different people (the government of Nunavut instead of the government of Canada) using different methodologies (aerial survey instead of capture, tag and release) which by themselves could account for the slight increase. I think it is also pertinent to look into the "local knowledge" of the Inuit inhabitants that convinces them that the population isn't declining ... that they are seeing more bears in remote settlements where they had not ranged before. They could be right ... but it also might be that since Hudson's Bay isn't freezing over until November in recent years, and freezes for six weeks less on average, that bears with no natural sources of food who wake from hibernation with hungry cubs start looking for food in places they wouldn't ordinarily go. The more cynical might say that the Nunavut government's decision to raise the polar bear harvest quota last October from eight to twenty-one might have a bearing on it, particularly as hunters from farther south with more money than brains typically pay upwards of $50,000 for the opportunity to do the "harvesting". Best wishes, Mole
  31. Polar bear numbers are increasing
    Eric (skeptic) @31, the problem with non-natural feeding is that, should we follow BAU, temperatures are expected to be elevated for tens of thousands of years. If we do not let the polar bears gather the majority of their diet, the will become "domesticated" within a few tens of generations. That is, they will loose intelligence, sensual acuity, strength, and probably other essential traits for survival in the wild. That probably doesn't matter so much if they are "returned" to a wild in which there are no comparable top predators. Domestic cats do very well when they go feral in Australia, where the "top predators" are 4 foot long monitor lizards and a variety of very deadly snakes. I believe they become lunch if they go feral in Africa, and "domesticated" polar bears will fair similarly poorly if required to feed themselves in an area with a genuine top predator. That assumes that it will be possible for them to be returned to the wild state, which assumes the large scale survival of a variety of seal species. Again, these can be kept alive in zoos in which case they will loose much of the ability to feed themselves in the wild. Or they can be kept alive in smaller refuges than are required for polar bears (because you do not require as much territory to sustain a large enough population for genetic diversity), but only if they have no predators in which case they will loose their ability to avoid predators within a few generations. I am sure care programs can be implemented that avoid many of these problems. It will not, however, be simple or cheap. As to whether it would be more expensive than providing adequate refuges without supplementary feeding? I could not say.
  32. Eric (skeptic) at 14:34 PM on 15 April 2012
    Polar bear numbers are increasing
    I was hoping the document I linked would have some cost estimates but alas it did not. The cost is somewhat speculative but zoos are relatively cheap and feeding a "reserve" area overpopulated with polar bears (somewhat like a large zoo) is an in-between case. If we require strictly natural feeding then costs would be much more substantial and it may be impossible.
  33. It's not bad
    Manny#235: "If malaria is not currently spreading to balmy Florida" This just in from balmy Jacksonville, Fla (2010): Duval County health officials issued an unusual warning Wednesday: Beware of malaria. Tests show that a 31-year-old Jacksonville woman has become infected with the typically tropical disease despite having no history of international travel, the health department announced. For the present, US wealth and infrastructure can control diseases that are normally found in tropical climates. Fast-forward to a time when tropical climates are more widespread and demands on under-funded public health services are overwhelming their capacities. What will you tell us then?
  34. Polar bear numbers are increasing
    Eric (skeptic) @29, setting aside a single island is unlikely to be sufficient. The space set aside would need to be able to sustain a large ( >> 1000) population of polar bears to maintain genetic diversity. It would need to be able to maintain something like 100 times that number of prey animals. It would need to large coastal extent relative to area because the primary prey animals of polar bears breed in coastal regions and are not able to operate effectively far from water (seals). I suspect that to be sure of polar bear survival other than in zoos you would need to set aside the the entire Canadian Archipelago. I doubt, however, the Canadians or anyone else would be prepared to sacrifice that many resources to preserve the existence of polar bears and NH seals. Despite my suspicion, however, I think the situation is too complex to make any prediction beyond that the survival of polar bears will require a conscious effort by humans, and that the effort required will be substantial in term of economic cost.
  35. Data Contradicts Connection Between Earth's Tilt and the Seasons
    How do we know that comparisons to time periods with no similarity to the present are irrelevant?
  36. Eric (skeptic) at 14:14 PM on 15 April 2012
    Polar bear numbers are increasing
    Tom, thanks for the perspective. Like CO2 and warming the fate of the polar bears lies in policy decisions, although those decisions are much more localized and have clear cut benefits and tradeoffs. Setting aside an island a few centuries from now seems pretty straightforward on one hand and speculative on the other. But the uncertainty will not be scientific, but social structures, policy priorities, etc.
  37. Polar bear numbers are increasing
    Eric (skeptic) @27, the final fate of polar bears with global warming is a subtle issue. In the absence of humans their fate would be fairly predictable in a warming world. Put simply, polar bears would find refuges on Arctic Island where, free from competition from other top predators, they would be likely to survive even if conditions were debilitating for them physiologically. In contrast on the mainland they would face competition from the northward expanding range of various brown and black bears. We know those brown and black bears are better adapted to survival in forests than are polar bears from the current ranges of the respective species. Those forests will be marching north with time and greater warming, and can be expected to reach the northern shores of North American, Asia and Europe within a few centuries with predicted warming, a situation that would coincide with the extinction of Polar Bears in mainland areas. The polar bears surviving on the islands might also go extinct, simply because their population would be low, and species with low populations can go extinct easily as a result of chance events, ie, a virulent disease, or a number of particularly poor seasons in succession. If the do not go extinct in this way they will reduce in size over a period of thousands of years as do all large species trapped on islands. As a result, the descendants of polar bears would survive as a new species of pygmy polar bears, having probably lost their white coat but not their aquatic adaptions (as the ability to swim between islands would greatly increase range and hence survival prospects). The presence of humans greatly complicates things, first because they already inhabit many of the Arctic islands, and will compete for them more fiercely as the Earth warms, making those islands dubious refuges for polar bears. On the other hand, humans may (and probably will to some extent) intervene to preserve polar bears by creating specific refuges either on islands or on the mainland (by culling brown bears entering the area, and imprisoning poachers etc). Consequently it is impossible to predict categorically that polar bears will go extinct in a warming world. What we can predict that efforts to preserve them will both become more onerous, and in greater conflict with human demands for economic development. Polar bears did survive the Eemian on a Svarlbad without humans (and presumably other islands). But will they be able to do so when Svarlbad's population has increased from it's current three thousand to 30 or more thousand as humans take advantage of the one of the few remaining "temperate" climates in the world?
  38. Shakun et al. Clarify the CO2-Temperature Lag
    76 skywatcher Again, thank you for your efforts. Feedbback and forcing are primarily modeling terms and are not laws of nature. Relative humidity varies with weather. As water precipitates out it is often quickly replaces if it is available like over bodies on water or ice or in the presense of clouds. It is the average H2O content of the atmosphere that increase with temperature. That idea is used in modeling CO2's effect on climate because more CO2 increases average temperature which in turn allows the average amount of H2O in the atmosphere to increase which in turn traps more heat. Just exhausting H2O into the atmosphere does little to add water vapor content because it quickly precipitates out but if the atmosphere is warmed it is another story. So at the end of the LGM as the atmosphere gradually warmed so the water vapor content would increase. The source of the heating does not matter. The earth as a green house contains a lot of other gases other than H2O and CO2. These gases are not thermally inert. The entire earth did not freeze over during the recent ice ages. The CO2 level never dropped to zero. According to this article, a significant increase in CO2 did not start to take place until 2,500 years after the start of the warm up had begun and 7% of the warmup had begun. There is no imperical data uncovered by this article to show that in the first 2,500 years since LGM that the green house gas, an increase in average atmospheric H2O did not have some roll in global warming. At this point, how much of a roll is speculation.
    Moderator Response:

    [DB] "Feedbback and forcing are primarily modeling terms and are not laws of nature."

    Incorrect. These are terms used to describe physical, real-world processes and reactions.

    You would be advised to follow the advice you have been given, do more reading and less commenting, as your position contains many holes and inadequacies.

  39. Eric (skeptic) at 13:57 PM on 15 April 2012
    It's not bad
    The primary controlling factor in the U.S. is "prompt diagnosis and treatment of infectious individuals" (from LINK) I find no reason to believe that this will change.
    Moderator Response: [RH] Fixed link that was breaking page format.
  40. Eric (skeptic) at 13:43 PM on 15 April 2012
    Global Warming in a Nutshell
    Impact section is very slightly marred by absolutist "extinction" of polar bears. It's a good piece overall and I am not a "concern troll", I will elaborate in the thread where I made my very first posts at this site on this thread
  41. Eric (skeptic) at 13:42 PM on 15 April 2012
    Polar bear numbers are increasing
    Polar bears may go extinct but probably will not. It's thought that some populations will disappear due to ice loss, but that is currently conflicted based on recent Hudson Bay numbers. Balanced against potential natural losses will be mankind's management: http://www.env.gov.nl.ca/env/wildlife/endangeredspecies/Polar-Bear-Management-Plan.pdf A case could be made that this won't work, or it will result in a polar bear reserve with none elsewhere. But a better case could be made that a high profile species such as polar bears will be relatively easy to manage, but what about the others?
  42. It's not bad
    235, Manny, Perhaps its because we've only yet seen a fraction of the warming we're on course to invoke, and not yet enough to generate a sizable change in something like malaria. Perhaps, also, a major factor in the control of malaria is the elimination of swamps near populated areas, and the vast tracts of urbanized pavement that have replaced much of the swampland anywhere near populated areas. Too, as with any disease, it will thrive better in a population of weak, unhealthy, underfed victims -- hardly a description of today's Florida. What makes you think that if malaria were going to spread it would have done so by now, and if it hasn't, there's nothing to worry about?
  43. It's not bad
    Allow me to revisit the following statement in this article: "Spread in mosquite-borne diseases such as Malaria and Dengue Fever (Epstein 1998)" Like just about everywhere else, malaria was endemic in Florida in the early 20th century. From Malaria in Florida (D. B. Lieux, The Florida Entomologist, Vol. 34, No. 4 (Dec., 1951), pp. 131-135), there was 1,895 cases in 1919. By 1949, thanks in great part to DDT, the US was declared malaria-free (CDC timeline). Florida has a tropical climate, is home to the world's largest swamp and remains largely malaria-free. If malaria is not currently spreading to balmy Florida, what is the basis for your claim that, as the climate warms, malaria will spread to areas that are currently malaria-free?
  44. Global Warming in a Nutshell
    @ R. Gates #1: Yes, the oceans soak up more of the heat retained in the Earth's climate system by global warming than the atmosphere does, which contributes to melting of the Arctic ice cap, and effects on marine life as mentioned in Fig. A2, and also to intensification of hurricanes (which nicely ties into the next comment). @Steve #2: I'm afraid you've misstated how hurricanes form. The primary driver of hurricane formation is energy from warm sea surface temperatures, with overlying rotating air. As ocean temperatures increase, more energy is available, and hurricanes are expected to intensify (on average, of course, as with all things related to global warming). The jury is still out on the expected relationship between hurricane frequency and global warming, but the intensity of hurricanes is strongly correlated with sea surface temperature, and the "power dissipation index" (a measure of hurricane intensity) is observed to be increasing. Please see What is the link between hurricanes and global warming?, and also an entertaining NASA article called Recipe for a hurricane. Regarding the expectation that global warming will lead to extended drought and desertification is some regions, part of the answer lies in the very link that you provided from the IPCC report. The key phrase in your quote is "globally averaged". Overall, in a warmer world there will be more water vapor in the atmosphere and more precipitation in many areas such as the tropics, but not everywhere, and the other part of the quote in the report is the expectation of less precipitation in the subtropics. If you know of a reliable report that polar bear numbers are at an all time high, please provide that reference. Regarding life being easier and heating bills lower in a warmer world, well, I suppose that all depends on who and where you are. For others, life will be harder and cooling bills will be higher.
  45. Global Warming in a Nutshell
    Steve: You need to read the actual reports, not take the pieces you’re looking for and repeat them out of context…. Of course it might also help to actually pay attention to what’s going on in the world. and receding glaciers have consequences, such as less habitable coastal areas, Ice makes a coastline more habitable? No, Steve, when glaciers melt, the water that used to be stored on the continents as glacial ice contributes to sea level rise. If a glacier disappears, it will still rain and snow in the watershed where the glaciers was and the rivers in such watersheds will still flow. No, Steve, actually they might not….
  46. Shakun et al. Clarify the CO2-Temperature Lag
    I again want to thank everyone for the effort they have been putting in here. I apologize that I cannot respond to everyone at once. I am trying to respont but just a little at a time. 75 danieic It seems to be the assumption here that the end of the last ice age was triggered by Milankovitch cycles and hence an increase in sunlight at least to certain parts of the earth at certain times of the year. The initial trigger started 19,000 years ago and the level of CO2 started to rise 17,500 years ago with 7% of the temperature rise associated with the ending of the ice age having taken place. The ends of ice ages have been occouring with regularity over the past half million years and I doubt that over that period any Milankovitch cycle triggering has been missed. Earlier possible Milankovitch cycle triggering misses is beyond the scope of this discussion. Other solar related causes may have been involved but we do not have any data on that. The ocean works as a giant, non-linear thermal capacitor that can keep the effect of additional heating on going for quite some time. What makes bodies of water such a different thermal capacitor than land or ice is internal convection. Melt water would add to this thermal capacity without adding appreciable CO2 to the atmosphere. It is only after larger volumes of existing ocean water are warmed, not just surface waters, that measurable global levels of CO2 would be observed. For 2,500 years the Milankovich triggered cycle triggered the ice sheets to start melting with an appreciable increase in CO2. Melting ice also adds H2O to the atmosphere. If a green house gas was involved to enhance the warming in the first 2,500 years then it had to be H2O which covered most of the globe in some form or another at that time. After 17,500 years ago it is a diffrent story because CO2 was being added to the atmosphere. Please be patient for I realize that I have other posts to reply to.
    Moderator Response:

    [DB] "Melting ice also adds H2O to the atmosphere."

    Incorrect. Melting ice returns once-frozen water back to the water cycle. Only long-term upward perturbations in temperature can raise the moisture carrying capacity of air (humidity). As has been observed with the 4% increase in global humidity over the past 40 years.

  47. Rob Honeycutt at 12:33 PM on 15 April 2012
    Global Warming in a Nutshell
    Steve Case said... "extinction of the polar bears, I just saw a report that their numbers are up, maybe an all time high." You didn't spend much time researching this one I take it. http://mediamatters.org/blog/201204090004 There were so many things that were wrong with the shoot-from-the-hip response coming out of denierville on this one.
  48. Data Contradicts Connection Between Earth's Tilt and the Seasons
    Indeed, focusing on three months is too short to draw correct conclusions. Which is why the IPCC looks at the past 1,000 years and tests its models against data from the past 100 years. But how do we know the IPCC's time span is long enough to draw the right conclusion? Greenland ice cores tell us that 6,000 years ago was a bit warmer than today and that the last interglacial, some 130,000 years ago, was much warmer (about 3 C). But why stop there? During the Jurassic 160 Million years ago, atmospheric CO2 was about 8 times today's level and the temperature was nearly 15 C warmer than today. So how do we know that IPCC models tested against one century are correct?
    Moderator Response:

    [DB]"Greenland ice cores tell us that 6,000 years ago was a bit warmer than today"

    Incorrect. Greenland ice cores show temps in the period you reference were similar to those of Greenland in the latter part of the 20th Century. Which are cooler than those of today. You also then infer that those regional conditions in Greenland then were global, which they were not. Unlike modern warming, which is global and is warmer than the period you reference. Even for Greenland.

    Your comments regarding the Jurassic are specious, due to conditions being vastly dissimilar to those of today.

  49. Global Warming in a Nutshell
    Steve Case#2: "Life is easier." Now that you've posted your unsubstantiated opinion, how about a word from science? Here's a good one from 2009: The study notes that decreases in rainfall that last not just for a few decades but over centuries are expected to have a range of impacts that differ by region. Such regional impacts include decreasing human water supplies, increased fire frequency, ecosystem change and expanded deserts. Dry-season wheat and maize agriculture in regions of rain-fed farming, such as Africa, would also be affected. Some of that good news is already upon us.
  50. Global Warming in a Nutshell
      What happens when the planet gets warmer?

    Life is easier. Longer growing seasons, more rain, more arable land and increased productivity due to increased CO2. Less ice and snow, lower heating bills, less winter wear & tear on infrastructures ...

      More extreme weather,

    I see conflicting reports on whether or not this is happening so far*

      disappearing Arctic sea ice,

    So what?

      and receding glaciers have consequences, such as less habitable coastal areas,

    Ice makes a coastline more habitable?

      extinction of the polar bears,

    I just saw a report that their numbers are up, maybe an all time high.

      and disappearing fresh water supplies for billions of people.

    If a glacier disappears, it will still rain and snow in the watershed where the glaciers was and the rivers in such watersheds will still flow.

      The current rate of sea level rise is 3.3 mm/year (Fig. 4), which is cause for concern in low-lying or hurricane-prone coastal areas like Bangladesh or certain disappearing Pacific islands or the U.S. Gulf coast.

    Why has an acceleration of sea level rise not been observed during the altimeter era?

      This becomes a national security and military concern when there are millions of "climate refugees" with nowhere to go.

    The scary stuff requires more than a a great deal more than a 3.3 mm/yr rate in sea level rise.

      They will do what they must to survive, as we all would, and they'll go to China, Australia, the U.S., and elsewhere, and they probably won't be welcomed with open arms.

    Hasn't happened yet.

      Other consequences of global warming include extended droughts and encroaching deserts, The IPCC's AR4 Report tells us that in a "future warmer climate ... Globally averaged mean water vapour, evaporation and precipitation are projected to increase." ipcc.ch/publications_and_data/ar4/wg1/en/ch10

    That's not a recipe for more droughts and encroaching deserts.

      The oceans and marine life are doubly affected by global warming: first by an increase in temperature, which intensifies hurricanes

    *It's not the increase in temperature that intensifies storms, it's the increase in the difference between the air masses involved in the storms. And as the IPCC tells us in a warming world:

      "Almost everywhere, daily minimum temperatures are projected to increase faster than daily maximum temperatures, leading to a decrease in diurnal temperature range. Decreases in frost days are projected to occur almost everywhere in the middle and high latitudes, with a comparable increase in growing season length."

      ipcc.ch/publications_and_data/ar4/wg1/en/ch10

    In other words, the warming will be mainly at night, in winter and in the Arctic; day time, summer time and in the tropics, not so much, meaning that the difference in temperatures between air masses will be less. Which does not mean that the storms will be more extreme.

    Moderator Response: TC: Due to the very general nature of the OP, there is a risk that discussion will become confused with too many subtopics intermingled so that the progress of discussion on any particular topic will be difficult for our readers to follow. To avoid that situation, we ask that all commenters discuss particular topics on threads more directly related to that particular topic, as Eric (skeptic) has in fact done. In particular we ask that responses to Steve Cases' post pick a particular point and discuss it on the more directly related thread; and ask that Steve Case do the same to those responses that have already been made. Thank you.

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