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  842  843  844  845  846  847  848  849  850  851  852  853  854  855  856  857  Next

Comments 42451 to 42500:

  1. In Wall Street Journal op-ed, Bjorn Lomborg urges delay with misleading stats

    Here's his latest along these lines:

    Don’t blame climate change for extreme weather

  2. Medieval Warm Period was warmer

    Spoonieduck @189, the relevance of modern photos of Greenland and Iceland is that current temperatures in those nations are comparable to those in the MWP.  If Iceland is more verdant now (as it clearly is), it follows that it was more verdant then - and the name "Greenland" is, therefore, not explicable by the unusual greenness of the land.

    I am unsure why you want to explore a counterfactual hypthetical.  Greenland (or at least, those portions of it colonized by the norse) was not "a pile of frozen rocks fit only for arctic wildlife".  Colonies were established there, and survived several centuries.  So Norse settlers decieved by Eric's clever naming would have found a land less verdant than those from which they came, contrary to what the name suggests - but one in which it was still possible to survive and make a living.

    In any event, we do not need to speculate as to why Eric called Greenland "Greenland":

     

    " Eirik and his people were outlawed at Thorsnes Thing. He prepared a ship in Eiriksvagr (creek), and Eyjolf concealed him in Dimunarvagr while Thorgest and his people sought him among the islands. Eirik said to his people that he purposed to seek for the land which Gunnbjorn, the son of Ulf the Crow, saw when he was driven westwards over the ocean, and discovered Gunnbjarnarsker (Gunnbjorn's rock or skerry). He promised that he would return to visit his friends if he found the land. Thorbjorn, and Eyjolf, and Styr accompanied Eirik beyond the islands. They separated in the most friendly manner, Eirik saying that he would be of the like assistance to them, if he should be able so to be, and they should happen to need him. Then he sailed oceanwards under Snœfellsjokull (snow mountain glacier), and arrived at the glacier called Blaserkr (Blue-shirt); thence he journeyed south to see if there were any inhabitants of the country. He passed the first winter at Eiriksey, near the middle, of the Vestribygd (western settlement). The following spring he proceeded to Eiriksfjordr, and fixed his abode there. During the summer he proceeded into the unpeopled districts in the west, and was there a long time, giving names to the places far and wide. The second winter he passed in Eiriksholmar (isles), off Hvarfsgnupr (peak of disappearance, Cape Farewell); and the third summer he went altogether northwards, to Snœfell and into Hrafnsfjordr (Ravensfirth); considering then that he had come to the head of Eiriksfjordr, he turned back, and passed the third winter in Eiriksey, before the mouth of Eiriksfjordr. Now, afterwards, during the summer, he proceeded to Iceland, and came to Breidafjordr (Broadfirth). This winter he was with Ingolf, at Holmlatr (Island-litter). During the spring, Thorgest and he fought, and Eirik met with defeat. After that they were reconciled. In the summer Eirik went to live in the land which he had discovered, and which he called Greenland, “Because,” said he, “men will desire much the more to go there if the land has a good name.”]"

    Eirik the Red's Saga

    A counter argument based on assuming the alternative to a Greenland less verdant than Iceland is a Greenland having no colonizable lands at all is hardly a sound basis to reject the reasons given by the Nords themselves, and attributed directly to Eric.

  3. Medieval Warm Period was warmer

    Spoonieduck:

    The problem is that your "detailed discussions" of Vikings amount to uninformed speculations about behaviour you know nothing about.  Your suggestions that your vague knowledge of Viking sagas, presented here without any documentation, is "historical evidence" is worthless.   Have you ever read a Viking saga or a reasoned analysis by someone who has read them?  I have.  Link to a scholarly article summarizing the sagas and I will discuss it with you.  Discuss what you learned in elementary school at WUWT.  There is a wealth of archaelogical data and saga analysis about early Viking settlements, some of it referenced in Collapse (which I have read so I know more than an elementary school student). 

    This is a scientific board.  Speculations about how you might feel when you arrived in Greenland and it was too cold for crop farming are completely inappropriate.  It is currently warmer in Greenland than it ever was for the Vikings.  The Vikings were not able to grow vegetable crops like those currently grown in Greenland. They raised cattle and sheep.

    A significant part of the reason Vikings went to Greenland was to obtain walrus ivory, polar bear skins and Gyrfalcons. Perhaps the settlers were ecstatic because of the Gyrfalcons and did not care about farming.  Why havn't you mentioned these items which were available on Greenland?    Because you don't know what you are talking about.  Provide citations to support your opinions or stop bothering us.  Looking back through this thread you have provided not a single reference to support your wild speculations.

  4. Arctic sea ice delusions strike the Mail on Sunday and Telegraph

    Well if US courts respect and uphold climate science, presumably a Press Complaints Commission might follow legal precedent.

  5. One Planet Only Forever at 15:41 PM on 14 September 2013
    Debunking 97% Climate Consensus Denial

    Tom Curtis, I appreciate that your comment indicates the cost of mitigation should be comsidered to be less than the future costs created without tat mitigation, but that is still playing into the delayer/denier game of discussing the relative evaluation. They will claim there is no concensus about the relative values.

    It is simply unacceptable for a current generation to enjoy benefits from actions that create any potential problem for a future generation. It is even more uncceptable to discuss the comparison of the magnitude of the problem being created with what the current generation thinks they deserve to benefit from.

  6. Medieval Warm Period was warmer

    Michael,

    I know that you don't care about my grade school recollections but the issue is nevertheless significant.  This site shows abundant sophisticated charts, graphs and calculations and I am duly impressed.  Still, most of these graphics are, in a real sense, highly indirect, when they apply to climatic events many hundreds of years ago.

    Most of this evidence--tree rings, Sagasso Sea sediments even ice cores--is indirect and subject to various interpretations.  Historical evidence, despite its problems, is more direct.  Yes, there are problems with Viking Sagas.  Most weren't written down until 300 years or so after the events, leaving plenty of room for error.  Prior to this they were oral tales, probably recited for entertainment.

    The other problem with the Sagas is that the events are very much local.  It is quite conceivable that Southwestern Greenland was relatively warm, maybe even warmer than today, 1000 years ago.  It is even possible that the frost line along the East coast of North America was farther north 1,000 years ago than it is at present.  Maybe.

    Even if true, none of this proves that the entire world was warmer then nor does it disprove that the earth is presently entering a dangerous warming trend.  It certainly doesn't disprove that excessive atmospheric CO2 is contributiing to the current warming trend.

  7. Medieval Warm Period was warmer

    Tom,

    How are photographs of Iceland apropo to conditions in southwestern Greenland between A.D. 1,000 and A.D. 1,400?

    Detailed discussions of Viking violence are probably a bit afield for this specific topic but Erik didn't directly deceive anyone.  He had been outlawed in both Norway and Iceland for successive murders, which is why he traveled west to Greenland [Saga of the Greenlanders].

    Your other iteration that Erik was simply trying to convince.....etc. is simply a repeat of your previous statement.  I'll try to put it another way.  What if you were deceived into putting your entire family at the considerable risk of a hazardous sea voyage in an open boat?  What if, on reaching your Greenland destination you found it a pile of frozen rocks fit only for arctic wildlife?  Of course, I don't know how you would have reacted but I would have been truly upset.  At a bare minimum, I would have packed up my family and left as soon as it was feasible--that is, if we didn't starve or freeze to death in the meantime.  I certainly wouldn't have celebrated Erik as a great chieftain. 

  8. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    Another important fact to bring up whenever the models "fail to predict" a particular lull in the real-world data is that the climate models are not meant as forecasts like the weather. They are not modeling what the temperatures will be five years from now.

    They are not concerned with the particular timing of any given event, be it a La Nina dominant decade or a huge volcanic eruption or a particularly lengthy solar minimum.

    So of course the models don't "predict" the apparent pause from the last decade or so. They aren't supposed to be predicting any decade's metrics precisely. They are not a prognostication of what will happen in the real world the way a five-day forecast of the weather is supposed to represent what will really happen.


    What they are supposed to do is model the physics that determine the underlying long-term patterns. The particulars of those experiments are determined by scenarios that are not expected to be crystal ball pronouncements; they are only expected to give certain inputs that the climate model will then churn through and produce an output based on our best understanding of how the climate works. You don't run a climate model to determine that there's a 70% chance of strong El Nino conditions this time four years from now, so dress light.

    This lack of "weather forecast" functionality for climate models need sto be emphasized more often and more loudly. We often say that "climate is not weather" when it is time to discuss why a massive blizzard doesn't mean global warming stopped. We also need to start saying that "climate models are not weather forecasts."  As long as people think that they are forecasts, we will hear this zombie argument moaning from the grave. It's bad enough that we all hear the lame refrain "They can't even predict the weather tomorrow, how are they supposed to predict the climate?"

  9. Arctic icemelt is a natural cycle

    In reference to my own question at #59: in case anyone else encounters this argument, I dug up the answer myself.  This is from Joe Romm, and addresses that "single factor" talking point nicely:

    Study: “It is clear … that the precipitous decline in September sea ice extent in recent years is mainly due to the cumulative loss of multiyear ice.”

  10. Debunking 97% Climate Consensus Denial

    Absolute agreement with following:

    (29:One Planet Only Forever)

    "The understanding that it is essential to develop truly sustainable ways of life that all humans can develop to and improve on forever needs to be the fundamental principle guiding all decisions about "acceptable human behaviour".

    Popularity cannot be allowed to influence decisions about what is acceptable. "

    ==================

    How can there be any argument with that?  We are reaping the consequences of NOT adhering to these simple declarations.   In a closed system "what goes around comes around".

    Everywhere you look, there are UNsustainable realities:  population, city growth, pollution, water use, etc etc...  All interrelated, nothing separate.

    What is civilization "worth"?  What is the human race "worth"?  What is all life on this planet "worth"?

     

  11. Medieval Warm Period was warmer

    spoonieduck @185, ok, you have convinced me.  How, after all, could this not be considered a greenland:

    Whoops.  Sorry, wrong picture.  That is Iceland, where before Norse settlement "Birch and willow forests like this one at Lake Mývatn used to cover much of Iceland's interior."  In contrast even the inhabitable portions of greenland have never sported more than grasses:

    Oddly, Iceland was names as such because, during an early attempt at settlement, drift ice was spotted in the harbour in winter.

    This is the first reason why your argument fails.  No matter what else, Eric was trying to convince settlers (whether from Norway or from Iceland) to move into a harsher, less productive environment.  If it were ill advised to do that due to the "Vikings were truly violent people", then it were ill advised whether he used a bit of subtle persuasion by his choice of name.

    The second basis on which your argument fails is that the "Vikings" were not a truly violent people, or at least not more so than most other European peoples of the time.  The norse have a reputation for violence because they went viking (ie, on naval expeditions for raiding).  To conclude from that that they were unusualy violent would be like concluding the English were unusualy violent based on French accounts of Agincourt (or on reading Shakespears plays).  Yes, the Norse could be violent at home, but were not unusually so.

    The basic fact you must account for is that even those small parts of Greenland that are ever green are not so when compared to Iceland or Norway.  Therefore the name Greenland, even if only confined to those locations, must involve some creative embelishment. 

  12. Medieval Warm Period was warmer

    The paleoclimate scientific community seems to agree that southern Greenland was warm during the Medieval Period. See the spatial pattern below from Mann (2009).

     

    Most of the world was much cooler than present though (as shown above). This is why sea level in the equatorial regions was falling throughout the Medieval Period. No such thing is happening today because the current human-caused warming is globally coherent.  

  13. Medieval Warm Period was warmer

    Spoonieduck,

    Instead of speculating about what conditions were in Greenland in the 1,000's why don't we read something scientific about it!!  What a novel idea, find out what is already well known instead of making up stories!!  According to Collapse by Jahred Diamond, it was too cold to raise any vegetables in Greenland during the Viking settlements.  They did collect forage during the summer for their cattle, but no plant farming.  Currently there are over 100 tons of potatoes grown along with plentiful cabbages.  It is only in the last 20 years that it has become warm enough to grow potatoes.

    This is a scientific board.  No-one cares what you remember from elementary school.  Provide citations for your opinions or stop your nonsense.

  14. Medieval Warm Period was warmer

    No, Rob, I'm not.  Apparently only parts of southwest Greenland were habitable by Europeans with European technologies at the time.

  15. Medieval Warm Period was warmer

    Tom,

    I thought I already addressed part of your statement.  We were taught as children that Erik the Red falsely promoted Greenland as a Green Land  to lure unwary and naive Scandinavians to his new colony.

    Let's examine that belief a little more closely.  The Vikings were truly violent people as retold in my of their Sagas and retold in the AngloSaxon Chronicle amongst others.  Now let's say a group of Norwegian or Icelandic Vikings bought into Erik's propagandistic lie that Greenland was a Green Land and a great place to settle and raise a family.  After sailing with their families--women and children--and livestock ater a long, nervous voyage in open Knorrs over dangerous northern seas, they come to southwestern Greenland, little more than frozen, barren rock with little more to eat than birds' eggs, fish and walrus blubber.  How long do you reckon that Erik would have lasted?

    Now, the Vikings did settle in southwestern Greenland.  Archaeologists have found their settlements complete with church and structures that were probably animal overwintering facilities.  I don't know if you have much experience with livestock but, obviously, they must be fed year round, not just in the summer.  In northern climates, farmers put up hay in the plentiful summer months to feed their stock during the winter months.  This presupposes the presence of quite a lot of grass and other forage during the warm months of the year.

  16. The Pacific Ocean fills in another piece of the global warming puzzle, and puzzles Curry

    Kevin, yet another addendum:

    The mentioned offset in the volcanic forcing in the Potsdam or Meinshausen et al. 2011 data, resp, is in fact a deliberately chosen nominal positive forcing of 0.2 W/m2 in order to obtain consistency between the historical period and the future forcings. The idea is to account for the average planetary energy imbalance caused by past volcanic eruptions. The very imbalance which causes the climate to warm as soon as a volcanically quiet period occurs. Or in other words, it is the forcing equivalent to the volcanic deep ocean cooling I mentioned earlier, which tends to cool the planet for a very long time (in the way hypothesized above). Of course, it is a crude average estimate, but better than nothing. Preferably, the CMIP5 GCMs would be spun up for a millenium or so before the actual simulation period of interest is run (in order to make sure the model is in quasi-equilibrium according to historic volcanic activity). See Gregory et al. 2013 for more details (I just had the pleasure to listen to a talk of Jonathan, during which everything became crystal clear all of a sudden ;-)).

    So everything correct. I just didn't connect the dots properly.

  17. Medieval Warm Period was warmer

    Spoonieduck...   I just want to clarify something.  You're not assuming the most of Greenland was actually green, are you?

  18. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    keitho, consider the following graph by John Nielsen-Gammon:

    In it, he shows the linear trend for El Nino, ENSO neutral, and La Nina years seperately.  Each trend is approximately the same, and none of the three trends shows any slow down.  Given this, we must conclude that either:

    1)  The underlying temperature trend has remained unchanged over recent years, with any apparent slowdown being primarilly the result of ENSO fluctuations; or

    2)  The apparent slow down in the temperature trend is real, the apparent ENSO related patterns in the graph are coincidental, and ENSO has no influence on global temperature.

    Which conclusion do you accept?

    Because if it is not one, it is you who is running headlong from the data to preserve your favoured theory!

  19. Medieval Warm Period was warmer

    spoonieduck @178, although at the time of Eric the red, some (small) sections of southern and western greenland were green (grass covered) in summer, they were less so than the settled areas of Iceland, and certainly less so than Norway and Denmark.  Furthur, it is highly likely that Eric, having determined to establish an independent colony would want to attract fellow norsemen to his cause (thereby increasing his stature and power should he ever "go viking").  Of course, that explanation presupposes that some part of Greenland was at least sufficiently green that Eric wanted to settle there.

  20. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    Keitho:

    Do you agree or disagree with the following statement by James Hansen:

    "Climate is a complicated system but there is no change at all in our understanding of climate sensitivity [to carbon dioxide] and where the climate is headed," he said. "Our understanding of sensitivity is based on the Earth's history, not on climate models, and we have good data on how the Earth responded in the past when carbon dioxide changed. So there is no reason to change the forecast for the long term." 

    Source: Global warming has not stalled, insists world's best-known climate scientist by Damian Carrington, The Guardian, May 17, 2013

  21. Debunking 97% Climate Consensus Denial

    OPOF @29, you have clearly misuderstood what I wrote.  I specified the range of damage estimated that IMO can reasonably be held regarding BAU.  The lower end of that range is costs significantly greater than the cost of mitigation.  Nothing in that statement implies in anyway that it is acceptable to incur those costs against future generations for the benefit of reduced costs by avoiding mitigation today.  Indeed, for the majority of still living humans (anyone under 40) the cost within their lifetime of not mitigating is likely to be higher than the cost of mitigating.

  22. Medieval Warm Period was warmer

    Spoonieduck

    Instead of describing vague "sagas" you have read about on the internet you could refer to peer reviewed studies of Greenland.  Jahred Diamond summarized much of this work in his book Collapse, on how societies in the past have collapsed from environmental change, some of it self inflicted. In spite of your vague suggestions, it is actually well known what conditions were in Greenalnd during Viking occupation.  Why don't you do some serious reading and find out what is known?

    As you have been told before, this is a scientific site.  Vague descriptions of "sagas" without any references are handwaving and have no place in scientific discussion.  Please start to present sources for your wild speculations. 

  23. Medieval Warm Period was warmer

    DSL,

    I wrote "goats' when I should have written "sheep."

  24. Medieval Warm Period was warmer

    DSL,

    I forgot to list a sixth possibility i.e. the Vikings could have been lying.  We were taught, as children that Erik the Red's naming of "Greenland" was a propaganda ploy to lure naive Icelandic and Norwegian settlers to Greenland [this is extraordinarily unlikely given the violent nature of the Vikings].  Conceivably, his successors might have been using propagandistic terms to describe the North American "Vinland".

    On the other hand--and directly apropo to this site--it all may have been the literal truth.  Southwestern Greenland may, indeed, have been a Green Land i.e. grassy, during the warmer months, one thousand years ago.  The sagas tell us that the settlers were able to graze cattle and goats close to their several settlements.  Not only that, but they were able to overwinter their stock which means that the settlers were able to harvest enough forage during the warm months to feed their stock during  the snow-bound winter. 

    The same is likely true of "Vinland".  Not only did the Vikings describe a "grape land", but they also stood amazed at its bounty.  Of course, everything may simply be comparative.  Even if Greenland were relatively lush 1000 years ago, Nova Scotia, at some distance South of the Greenland settlements, must have seemed bounteous, indeed.

    Moderator Response:

    [DB] This is NOT a site to discuss speculative fiction.  If you have a citation to a reputable source to support your claims, then please provide it.

    Failing that, please refrain from such and instead discuss matters of science.

  25. One Planet Only Forever at 02:34 AM on 14 September 2013
    Debunking 97% Climate Consensus Denial

    Tom Curtis@28

    I would encourage you to stop legitimizing the denialist argument that "Reasonable estimates range from economic damage significantly greater than the cost of mitigation...".

    The comparison of the "cost of mitigation faced by a current generation" with "that current generation's estimate of the future economic damage it is inflicting on a future generation" in not a "reasonable thing to do".

    More important is how sustainable a human activity is. Humanity should be planning to be living forever on this one and only planet. That would mean developing ways of living that can be continued forever. The way of living that has recently developed due to the burning up and consumption of non-renewable resources is fundamentally not sustainable. It is definitely popular, but everyone cannot develop to live the life of the most fortunate which is socially not sustainable. Actually, even just the few most fortunate would not be able to live their lifestyle forever.

    The understanding that it is essential to develop truly sustainable ways of life that all humans can develop to and improve on forever needs to be the fundamental principle guiding all decisions about "acceptable human behaviour".

    Popularity cannot be allowed to influence decisions about what is acceptable. That won’t have a 97% consensus of popular opinion, but it is the only way for humanity to have a better future for all life on our ones and only planet.

  26. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    Keitho, models can always be improved.  I wouldn't call model projections of surface temp "seriously wrong," though.  After all, observed GMST is still within the 95% confidence range for CMIP3 ensemble modeling.  True, GMST has swerved negative relative to the ensemble model mean, but if you can tell me what the ensemble model mean is worth in terms of science, I'd be much obliged.  If you want seriously wrong, try Arctic sea ice projections.  Ocean heat content is rising as expected.  Sea level is rising at the top edge of projections.  Changes to general circulation are happening as expected.  Global ice mass loss is happening as expected.  The physical mechanism of AGW, the greenhouse effect, remains unchallenged.  Natural forcings are net negative over the last 50 years.  Regardless, people continue to look for some way to say, "it's not happening."

  27. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    Keitho - Two points:

    "You really can't go on about "the science" if empirical measurements don't support your position".

    First: I don't have a position. Everything I've stated, or alluded to, is entirely consistent with current climate science. On climate change science, I don't need a 'position' any more than I need an opinion. I read the science, and simply report what it says, in full or in summary.

    Second: The empirical evidence does support what I've said in my post. Surface temps are increasing, but at a slower rate than in previous decades. Oceans are warming, which we know by dint of an accelerating rate of sea level rise, and by sticking a thermometer in the water and reading what it measures.

    (And thanks to CBDunkerson for stalwart services)

  28. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    @DSL . . If you hear hoofbeats don't start by looking for Zebras. (-snip-). Time for some deep thought wouldn't you say?

    Moderator Response:

    [DB] Off-topic & sloganeering snipped.

  29. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    True enough, keitho, but of course if we do, in fact, know that the oceans are getting warmer, and we know that there's a top-of-atmosphere energy imbalance.  Yes, there's uncertainty involved with both, and there's always the chance that aliens are manipulating our instruments or that we're brains in vats being fed a Matrix-like "reality."  Science does not provide absolutes, regardless of the public clamoring for such.  The question, then, is what happens when people who are convinced that we don't know what's going on encounter pretty solid data that says we do know?  Do such people adhere to the standards they have for critical thinking in other people?  The evidence--and there is plenty--suggests that some do and many don't.    

  30. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    an additional contribution to reduced heat in the near term can be derived from the cooler sea surface temperatures which reduces the amount of tropical thunderstorm activity which results in a decrease in moisture transport to the lower stratosphere. This effect is also compounded by a recent decline in stratospheric ozone. When there is less water vapor in the lower stratosphere the radiative forcing declines. this is seen as contributing to the reduction in atmospheric heating. Jeff Masters wrote an excellent article on this on his blog:

     

    www.wunderground.com/blog/JeffMasters/stratospheric-water-vapor-decline-credited-with-slowing-global-warming

  31. It's not bad

    an additional contribution to reduced heat in the near term can be derived from the cooler sea surface temperatures which reduces the amount of tropical thunderstorm activity which results in a decrease in moisture transport to the lower stratosphere.  This effect is also compounded by a recent decline in stratospheric ozone.  When there is less water vapor in the lower stratosphere the radiative forcing declines.  this is seen as contributing to the reduction in atmospheric heating.  Jeff Masters wrote an excellent article on this on his blog:  www.wunderground.com/blog/JeffMasters/stratospheric-water-vapor-decline-credited-with-slowing-global-warming

     

  32. Arctic sea ice delusions strike the Mail on Sunday and Telegraph

    We have set our hearts on hauling the Mail in front of the Press Complaints Commission.

    Should anyone here wish to help out or read all about it probably the best place to start is at "The Great White Con"

  33. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    I'm having a hard look at the recent Fyfe, Gillett, Zwiers, "Overestimated global warming over the past 20 years" (Nature), with intent of doing so reported

    • http://hypergeometric.wordpress.com/2013/08/28/overestimated-global-warming-over-the-past-20-years-fyfe-gillett-zwiers-2013/ 
    • http://hypergeometric.wordpress.com/2013/09/06/p-values-are-random-variables/

    and shared with the authors of the original (Zwiers). My emphasis is upon the statistical technique adopted, and my technical interest is how a Bayesian assessment of the same data might differ from their bootstrap-based result. This is just a note for future reference.  I'm writing something up and sharing it for criticism by the authors, and, after I get their comments, I'll put it up on arXiv.org, with a link from http://hypergeometric.wordpress.com/.

     

  34. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    "but all over the world people are peering at the sky and ground, the oceans and the ice, and declaring that something seems amiss"

    When I was studying medicine in the 70's there was a well known effect that most of us experienced. When studying a particular disease it was common to experience some of the symptoms ourselves even though we were perfectly healthy. It was because we were made aware of these symptoms and so could easily ascribe them in ourselves, albeit for a short period. I'm sure you get my point.

    If the air isn't getting warmer and we don't know what the oceans are doing despite your "certainty" that something is going on then, objectively, nothing is going on. You really can't go on about "the science" if empirical measurements don't support your position. 

  35. Medieval Warm Period was warmer

    Just a passing note: the first essay on history I did in college was over Helge Ingstad's Westward to Vinland.  Well-written, but I can't recall what Helge said about the development of the name 'Vinland'.

  36. 2013 SkS Weekly News Roundup #37A

    ubrew12 @5.
    As you sort of suggest, the changing pattern of precipitation under AGW is more defined than whether or not total global precipitation will increase.

    The links are to AR4, since when we have had five more years to add to the record which have included the two rainiest years on record. So it will be interesting to see what AR5 has to say on the matter.

  37. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    Tom Curtis @17,

    My earlier comment has been removed, but it seems to me you are saying what I was trying to say, only you put it much better. I wll read and learn. Thanks. :)

     

  38. Medieval Warm Period was warmer

    Tom,

    I'm aware of no Viking Saga stating that grapes were grown in Greenland.  Around A.D. 1,000 the Vikings sailed West from Greenland, coming across a barren land they called "Markland", presumably Labrador.  They sailed South and, as I can recall, they called their southernmost discovery, "Vinland" or "land of the grapes".  We believe this is present day Nova Scotia where a Viking settlement was discovered at L'anse d'Meadows.

    Note:  The Vikings never grew domestic grapes, at least not in North America.  The "grapes" they found may have been wild grapes, presently found no farther north than New England.

    Possible explanations:  1.  The Vikings misidentified their wild 'grapes'.  2.  We are misinterpreting the word "Vinland".  3.  The Vikings did discover wild grapes but, since then, wild grapes have disappeared from Nova Scotia for reasons other than climate.  4.  The Vikings sailed as far south as New England.  5.  Nova Scotia was significantly warmer then than now.  Take your pick.

  39. Greenhouse Effect Basics: Warm Earth, Cold Atmosphere

    Regarding 89 and 96:

    I need to make a correction for my calculation of the population of the first excited vibrational state for the bending mode of CO2. The ground state wave function is indeed non-degenerate and the first excited state is doubly degenerate, so there is a degeneracy factor of 2 for the Boltzmann distribution calculation. At 25C (77 F) the equilibrium percent of CO2 in the first excited state is 7.4%.

  40. 2013 SkS Weekly News Roundup #37A

    wili@3:  I may be totally off base here, but I'll hazard a guess.  If CO2 warms the atmosphere, it holds more water vapor.  That doesn't mean it evaporates more water vapor off the Earth's surface, just that it can hold more.  Of course, there's the matter of the energy imbalance, yet that is quite small as a fraction of the total values of solar energy and Earth radiation.  So, there might be a smidge more actual evaporation going on, but (I'm guessing) just a smidge.  In that case, there would be little to no actual increase in condensation either (mass balance).  If true, then why would evaporation/condensation increase its surface 'cooling effect' in a globally warmed world?  Yes, the cycle is kind of a heat-pump, but why would this heat-pump become more efficient in the future as a 'negative feedback' to AGW?  (this is different from saying the kinds of cloud cover might change to favor clouds that cool rather than warm).

    It's often mentioned that precipitation patterns will change with AGW.  More droughts expected, but also more flooding when rain does fall.  However, I don't think the amount of evaporation/condensation going on is supposed to shift greatly, on a global basis.  I'll admit I'm guessing here, but if so perhaps others can correct me.

  41. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    Yves at #2:

    "Moreover, more knowledge now means more uncertainties now, this is a kind of paradoxical law of science but quite logic..."

    This reminds me of the missing-link argument of Creationists, where every evolutionary link found between two species simply raises from the Creationists claims of ever-more missing links, as if this somehow weakens evolutionary theory rather than supporting it.

    The parallel between this and the 'gap'-finding by deniers of climate science makes my skin crawl when I think of it.

  42. The Pacific Ocean fills in another piece of the global warming puzzle, and puzzles Curry

    @Kevin C:

    Re the volcanic response, I am not sure whether I got your last sentence in the 4th paragraph. If ENSO is included (which it already is in the first figure of the toy model), the lag time for volcanoes in the response function should be less than 30 years (which is the current default lag time). It seems that 5 years are more appropriate. With longer lag times, wouldn't there be the danger of "double counting" in case ENSO is partly volcanically modulated?

    Re your last paragraph, there is an interesting paper by McGregor et al. 2013 which came out a week ago, argueing that ENSO might indeed be capable of responding to external forcing. While physically plausible, they present intriguing paleoclimatic evidence for that.

    So far, it is thought that stronger (pos.) external forcing tends to produce less frequent El Nino events or to reduce its magnitude, resp. If this holds true also for short term forcings, negative volcanic forcing would increase the likelihood for El Nino events. And indeed, most volcanic eruptions are followed by an El Nino. As a result, a considerable energy imbalance builts up in the climate system, an imbalance which has to be overcome somehow ... and the easiest way to do that is to have stronger La Nina events in the decades that follow. I am not aware of any proposed mechanism for that, which is why I am very careful to connect the current La Nina preponderance with a delayed Pinatubo response. I just mentioned it before as one conceivable reason for that, while I consider it much more likely to be the case for past eruptions. I rather think of the current La Nina phase as a counterbalancing response to the strong GHG forcing (in agreement with some anecdotal paleo-evidence; see e.g. Mann et al. 2009). This way, everything would be fairly consistent, apart from the fact the many climate models suggest a different response. Nothing we should be too worried about in my opinion. The fact that things have looked different in the course of the past century could be easily explained by the highly spatially heterogeneous and temporally variable aerosol forcing. Above all: Stochastic internal variability!

    Hope that makes sense to you, though it might not bring us closer to the "response function truth".

  43. 2013 Arctic Sea Ice Extent Prediction

    I'm posting this here because the 'Arctic ice loss is natural' thread has benne dead since 2010 (a problem that wouldn't exist if the website had an email notification option!):

    I'm debating a Watt-bot and he's claiming that Arctic ice decline is all due to changes in wind patterns. He's posted several articles, but the broadest claims are made here:

    Wind contributing to Arctic ice loss, study finds

    Anything in the article that points out this doesn't question climate change's role he describes as spin - even though the study itself only seems to attribute 30-50% of the ice loss to changing wind patterns, according to the article.  

    Apparently this line is the dominant response to Arctic ice loss at WUWT other than the occasional rallying cry of "Recovery" (such as we are currently hearing). Any thoughts on this?

    Moderator Response:

    [DB] Again, NO THREADS ARE DEAD at SkS.  Regular participants follow the Recent Comments thread, so that no matter where ANY comment is made, it will be seen.  And then responded to.

    Please repost this on this thread, where others will then appropriately respond to you:

    Arctic icemelt is a natural cycle

    This comment will be deleted in a little bit.  Parties interested in responding to Dvaytw, please do so at the link.

  44. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    Shoyemore @12, I think you have been confused.

    The effect of the ocean is that it has a very large heat capacity.  Therefore, for a given change in radiative forcing it takes a long time (centuries) to reach the equilibrium temperature.  Without the ocean, the Charney equilibrium temperature would be reached in a few decades at most.  Consequently, in a situation of radiative imbalance, the ocean cools (or warms) the Earth temporarilly relative to what the temperature would be without the ocean, but by no more than (approsimately) the difference between the Charney Climate Sensitivity and the Transient Climate Response.  In current conditions, that is about 1 or 2 degrees C.

    That analysis ignores the effects of the existence of the ocean on the radiative balance itself.  Absent an ocean, we would have no water vapour feedback, and no ice/snow or cloud albedo.  Further, the the albedo of the areas currently covered by ocean would be that of desert (much higher).  The net effect would be a much colder Earth, although I have not seen a study of by how much.

    What I suspect you are thinking of is the difference between the actual temperature of the Earth, established by the radiative/convective equilibrium relative to the temperature we would have in the absence of heat transfer to the upper troposphere by convection.  Absent convection, the Earth would indeed be much warmer.  Indeed about 36 C warmer as you indicate, as shown by Manabe and Wetherald, and discussed here (see the top figure on page 9). 

  45. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    somib, climate 'energy budget' studies take the energy used in converting ice to water into account. While this is a 'large' amount in absolute terms, it is actually only a small fraction (~2%) of the total energy from global warming... as can be seen here.

    The thing is that atmospheric temperatures actually aren't "lower than projected". They are within the span of results produced by various model runs for the greenhouse gas levels we have observed. Climate scientists (and people capable of rational thought in general) have always known that fluctuations would occur... this denier idea that temperatures should rise in a continuous straight line is one of their dumber (and that's saying something) positions. There were temperature fluctuations before human induced global warming and no reason to imagine that they would stop after it.

    Put another way... the difference between the 'slower atmospheric warming' observed over the past ~15 years and the 'rapid atmospheric warming' observed the 15 years prior to that is less than 1% of the total energy from global warming.

  46. Global imprint of climate change on marine life

    Jelly fish increasing??  The turtles should do well, that is if we allow them to breed.  Perhaps we will be eating turtle soup instead of tuna. 

  47. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    How much of the excess heat absorbed in the oceans causes ice melt?   This heat would melt ice floating on water.   Melting of ice on land would keep the surface temperature from rising.    In my high school physics class, I was told that it takes a large amount of energy to go from ice at 0 degrees centigrade to water at 0 degrees.  Perhaps the melting of the floating ice and ice on land is keeping the tempeatures lower than projected?   

  48. Global imprint of climate change on marine life
    One of my favourites is Cheung et al (2013) doi:10.1038/nature12156which shows the remarkable nortward migrations of fishes in the last three decades. Fig 1 is compelling.sidd
  49. Global Warming’s Missing Heat: Look Back In Anger (and considerable disbelief)…

    And by "recent geologic history," Composer99 means the last 300 million years.  Honisch even suggests that it may be unprecedented, period.  The argument extends to atmospheric concentration, since atmospheric and oceanic carbon are tied tightly together.  It's possible that life in general has never experienced a carbon spike of this rate, and if temp follows (likely), then life in general may experience an unprecedented rate of increase in temp.  Evolution occurs at different speeds in different species.  The longer an ecosystem is at effective equilibrium, the more integrated and tuned the ecosystem's species become.  Rapid change across the spectrum of climate (temp, precipitation, wind, circulation, ice) means ecological dis-integration, and the species that evolve slowly are more likely to become extinct.  

    This may all sound rather alarmist and fanciful, and it may be hard to see from the perspective of a single human life, yet we are warming at between 10x and 30x the rate of PETM warming right now, and 55 million years ago there weren't seven billion human beings wrapped up in a complex, highly-integrated global economy, half living in cities and highly-dependent on the consistent delivery of cheap food, water, and energy.  Physics says the warming will continue for centuries.

    Here's the abstract from Johanson & Fu 2008:

    "Observations show that the Hadley cell has widened by about 2°–5° since 1979. This widening and the concomitant poleward displacement of the subtropical dry zones may be accompanied by large-scale drying near 30°N and 30°S. Such drying poses a risk to inhabitants of these regions who are accustomed to established rainfall patterns. Simple and comprehensive general circulation models (GCMs) indicate that the Hadley cell may widen in response to global warming, warming of the west Pacific, or polar stratospheric cooling. The combination of these factors may be responsible for the recent observations. But there is no study so far that has compared the observed widening to GCM simulations of twentieth-century climate integrated with historical changes in forcings. Here the Hadley cell widening is assessed in current GCMs from historical simulations of the twentieth century as well as future climate projections and preindustrial control runs. The authors find that observed widening cannot be explained by natural variability. This observed widening is also significantly larger than in simulations of the twentieth and twenty-first centuries. These results illustrate the need for further investigation into the discrepancy between the observed and simulated widening of the Hadley cell."

    That's already happening: significant changes to general circulation.  During the PETM event, parts of general circulation flipped.  You don't think something like that will have a significant, complex, and resonant impact on human agriculture?  

  50. It hasn't warmed since 1998

    Thanks for posting the email, MrGibbage.  The response clarifies Fyfe's position quite a bit.

Prev  842  843  844  845  846  847  848  849  850  851  852  853  854  855  856  857  Next



The Consensus Project Website

THE ESCALATOR

(free to republish)


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