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Are we heading into a new Ice Age?

What the science says...

Select a level... Basic Intermediate
Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years.

Climate Myth...

We're heading into an ice age
"One day you'll wake up - or you won't wake up, rather - buried beneath nine stories of snow. It's all part of a dependable, predictable cycle, a natural cycle that returns like clockwork every 11,500 years.  And since the last ice age ended almost exactly 11,500 years ago…" (Ice Age Now)

According to ice cores from Antarctica, the past 400,000 years have been dominated by glacials, also known as ice ages, that last about 100,000. These glacials have been punctuated by interglacials, short warm periods which typically last 11,500 years. Figure 1 below shows how temperatures in Antarctica changed over this period. Because our current interglacial (the Holocene) has already lasted approximately 12,000 years, it has led some to claim that a new ice age is imminent. Is this a valid claim?

Figure 1: Temperature change at Vostok, Antarctica (Petit 2000). The timing of warmer interglacials is highlighted in green; our current interglacial, the Holocene, is the one on the far right of the graph.

To answer this question, it is necessary to understand what has caused the shifts between ice ages and interglacials during this period. The cycle appears to be a response to changes in the Earth’s orbit and tilt, which affect the amount of summer sunlight reaching the northern hemisphere. When this amount declines, the rate of summer melt declines and the ice sheets begin to grow. In turn, this increases the amount of sunlight reflected back into space, increasing (or amplifying) the cooling trend. Eventually a new ice age emerges and lasts for about 100,000 years.

So what are today’s conditions like? Changes in both the orbit and tilt of the Earth do indeed indicate that the Earth should be cooling. However, two reasons explain why an ice age is unlikely:

  1. These two factors, orbit and tilt, are weak and are not acting within the same timescale – they are out of phase by about 10,000 years. This means that their combined effect would probably be too weak to trigger an ice age. You have to go back 430,000 years to find an interglacial with similar conditions, and this interglacial lasted about 30,000 years.
  2. The warming effect from CO2 and other greenhouse gases is greater than the cooling effect expected from natural factors. Without human interference, the Earth’s orbit and tilt, a slight decline in solar output since the 1950s and volcanic activity would have led to global cooling. Yet global temperatures are definitely on the rise.

It can therefore be concluded that with CO2 concentrations set to continue to rise, a return to ice age conditions seems very unlikely. Instead, temperatures are increasing and this increase may come at a considerable cost with few or no benefits.

Last updated on 1 September 2010 by Anne-Marie Blackburn.

Printable Version  |  Offline PDF Version  |  Link to this page

Further reading

Tamino discusses predictions of future solar activity in Solar Cycle 24.

Acknowledgements

Many thanks to Sami Solanki for his invaluable advice and feedback as well as John Cross for his very helpful comments.

Comments

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Comments 51 to 100 out of 358:

  1. Here's an interesting figure, derived from a compilation of ice core CO2 data.

    From the file history: "connect it to the glacial cycles by marking 230 ppm as a transition level and colored "glacial periods" blue and interglacial periods yellow. There's a clear 80,000-110,000 period of repeating glacier even if they vary in quality."

    I'm not aware of any credible evidence for 15k year glacial cycles or any factual support for suggestions that we're heading into an ice age. What I have seen are mis-statements of fact:
    "Some say we are "nearing the end of our minor interglacial period", and may in fact be on the brink of another Ice Age." Incredibly this statement is linked to a source, which says very little of the kind: "We currently are nearing the end of a small, minor interglacial period ".
    Of course, this figure doesn't include our own increase in CO2 to 390 ppm, but it does make it obvious that glacial stages don't happen in high CO2 environments -- in our current plate tectonic/ocean circulation setting. You're not in the Ordovician any longer.
  2. I have been thinking about this topic for a bit and I am somewhat curious as to where the assertions that the
    "These two factors, orbit and tilt, are weak and are not acting within the same timescale – they are out of phase by about 10,000 years. This means that their combined effect would probably be too weak to trigger an ice age. You have to go back 430,000 years to find an interglacial with similar conditions, and this interglacial lasted about 30,000 years"

    comes from. From my understanding of Ruddimans work we were heading into an ice age until anthropogenic influences kicked in. Ruddiman in his real climate post seems to defend this assertion well... http://www.realclimate.org/index.php/archives/2005/12/early-anthropocene-hyppothesis/
  3. The link for the Tamino post in the Further Reading section is broken. The correct link location is:

    http://web.archive.org/web/20080501114257/http://tamino.wordpress.com/2007/10/13/solar-cycle-24/

    The Yooper
  4. Research noctilucent clouds. Me thinks they are purposely ignored due to their suggesting carbon dioxide build up leads to quick cooling of the globe. That makes Robert Felix' theory (if you can call it that) even more non-threatening to the robber-baron fossil fuel industries than the global warming theory but makes them both quite unlikely. Carbon dioxide leads to more methane thought to be the main source of the high altitude ice crystals of noctilucent clouds first noticed at the start of the industrial revolution and steadily increasing since then to record extent last year. There is research that suggests they block one percent of the incoming sunlight during the summer months when they peak. That is ten times more solar variation than what has been observed during humanity's existence in the sun's changes in output. It was just found that the mesosphere, where these clouds happen, is now coldest recorded. The jet stream is observed to be at record speeds as well as unusually low, blamed for both the floods in Pakistan and the heat wave in Russia. Recently, Bolivia had their worst environmental catastrophe as normally tropic areas plunged to record cold killing millions upon millions of wildlife and hundreds of people. Tens of thousands of sheep just died in New Zealand due to record cold. Wild gorillas in Rwanda Africa just died from record cold. Germany just saw the most recorded rain for an August. Canada is suffering significant crop destruction from record rains. If the record precipitation persists into the winter, it is liable to bury whole cities under snow and ice. Here is a video made by NASA on the noctilucent clouds: http://video.google.com/videoplay?docid=-8920558797349908992&ei=NfVUS-rYNJWUqAOzmfzEAw&q=noctilucent# "Are you tied to our destiny?"
  5. Despite local variations, this past summer/winter (depending on where you are) was exceptionally warm in terms of the global scale, not exceptionally cold: 2010 — How Warm Was This Summer? The global scale is of course the significant scale of "Global Warming."

    Here's a nice roundup of recent work in noctilucent clouds as they relate to climate change, including a really nice photographic example of what they look like: Increase in Shining Clouds Highlights Climate ‘Weirding’. Not a peer-reviewed item but includes links to actual research.
  6. Tom Loeber wrote : "Research noctilucent clouds. Me thinks they are purposely ignored due to their suggesting carbon dioxide build up leads to quick cooling of the globe."


    To state that they are being "purposely ignored" and finish up with a link to a NASA video about them, is a bit confusing. There is also a WIKIPEDIA page all about them, which shows lots of studies into them. Hardly "purposely ignored", surely ?


    As for your assertions about 'cold records' :


    Bolivia had their coldest temperatures in nearly 50 years and that, combined with low water levels due to drought (plus, possibly, disease), led to the massive loss of fish.
    Nature


    Parts of New Zealand have experienced cold and snow (perhaps the worst since the 70s), unfortunately at the same time as lambing is progressing -

    However, it is important to remember that many parts of the country have experienced benign weather at the same time, leaving many people wondering what all the fuss was about.
    NZ Met Service

    SMH


    Four gorillas died back in May in Rwanda :

    New Times


    If you were trying to prove that AGW is leading to more and more extreme events (albeit the cold ones not being as significant records as the hot or wet ones), then well done.
    Or were you trying to show something else...perhaps about a coming ice-age ?
  7. Tom Loeber at 02:10 AM, Tom I tend to agree with you. Virtually nothing is discussed here about noctilucent clouds, I think because of the fascination with what occurs at the TOA which seems to be considered as being the tropopause.
    I think TOA is a misnomer anyway as it is actually more so the top of the weather with water vapour and CO2 extending above it as well as all the other gases that form the atmosphere.
  8. Thank you JMurphy for the heads up about the Rwanda gorillas. Robert Felix's web site slants news to suit his theory and I grabbed that off of there as a recent phenomenon. As far as noctilucent clouds, does the IPCC use them in their considerations? I know Robert Felix doesn't mention them at all in his ramblings. Here is an article that wonders why the thermosphere is shrinking more than expected from just the solar minimum alone. Carbon dioxide build up is blamed for that cooling but only partially. Something else in the make up of the thermosphere is leading it to shrink, to cool. Shrunken Thermosphere

    Appears the increase in noctilucent clouds comes from rising methane emissions and it is thought that the disturbances from rising carbon dioxide lead to weather extremes that push water itself up to the mesosphere. Here is an article talking about unusually low, split and faster jet stream leading to weather extremes: Wayward Jet Stream

    Possibly noctilucent clouds are a missing piece of the puzzle that cinches the Hamaker hypothesis which is detailed in a 1989 film you can get here: 1989 film "Stopping the Coming Ice Age"

    Incidentally, those ice crystals of the noctilucents, they apparently collect dust from micrometeorites as well as stuff maybe that gets blown up from the surface turning them into first surface mirrors. Seems increasing carbon dioxide in the atmosphere and its consequences are coating the planet with highly reflective mirrors far above the greenhouse gases: Why noctilucents are inordinately reflective.
  9. Perhaps SkS should start a separate thread on noctilucent clouds, which apparently are predicted to be both more common as well as moving into lower latitudes w/warming of the atmosphere. Meanwhile, here's an intriguing article about a powerful laser being borrowed from Europe by the Australians and hauled to Antarctica with the objective of further investigations:

    Scientists use giant laser to measure cloud temperature
  10. Looking at some of the assumptions that seem to underly the lead article, NOAA used to have a page on their web site where a credentialed scientist was lamenting how the Milankovitch theory of ice age cycling was used to date ocean sediments then the sediments' dating used to bolster the Milankovitch theory but that page disappeared during the last Bush administration, apparently. Ever hear of the Devil's Hole Nevada crystals analysis for oxygen isotopes ratio over the last couple of hundred thousand years that was released in 1988? Devil's Hole Oxygen isotope ratio analysis. Do some in depth research into it and you find their resulting time line puts the start of the last two major ice ages at peak concentrations of carbon dioxide. That study has been repeated with analysis of similar crystals from deep pristine wells around the planet with some rather convincing agreement but, seems the Milankovitch theory still predominates despite the accumulating evidence that atmospheric gases concentration plays the major role in the cycling of the ice ages: Carbon dioxide concentrations play leading climate determining role.. The Milankovitch theory totally lets the fossil fuel robber barons off the hook so, is it any wonder you find recent studies purporting to prove it on the basis of an announced match of one cycle change?: Milankovitch theory proved? Want to buy some swamp land?. There are coral deposit studies that suggests major ice ages start immediately after global warming: Global warming starts ice ages? How long do we have to wait for the science to take hold and blow all these fossil fuel serving lies to smithereens? Who knows. It has been found though that major swings to ice age conditions can happen quite fast, like, within a years time: One of actually many findings that ice ages can come on incredibly fast.

    From Jared Diamond, in his book "Collapse: How Societies Choose to Fail or Succeed," one can see that climate change plays a major role in how human social experiments end. A "Secrets of the Dead" PBS program shared some convincing evidence how climate fluctuation was perhaps the major reason why Rome fell. Human social experiments simply don't have the information handling acumen to predict and prepare. What with the fossil fuel companies basically ruling behind these ruses we call societies today, is it any wonder the very dangerous repercussions of carbon dioxide increase would be squelched, nay, suppressed, censored? There was wide spread record cold in the southern hemisphere this last winter, Africa, South America, New Zealand, Tasmania, Australia and I understand even Antarctica had record cold. What's going to happen to the north hemisphere this winter? I'm afraid you wont see much of it on the war profiteering fossil fuel controlled media channels but you might just feel it or get to see some of your family die from it.
  11. Tom Loeber wrote : "There was wide spread record cold in the southern hemisphere this last winter, Africa, South America, New Zealand, Tasmania, Australia and I understand even Antarctica had record cold."


    I have previously commented on your "widespread record cold", i.e.it's not true, so I don't understand how you can repeat that without coming up with some evidence to back up your assertion.
    Do you have any evidence for any of those claims of "wide spread record cold" ?
  12. Record cold in a number of S. America countries. 8/5


    Argentina is colder than Antarctica. 8/3


    Huge fish & other wildlife die-off from cold in Bolivia. 8/3


    State of emergency due to cold for 2/3 of Peru. 7/27


    6 country S. America cold snap kills 175+. 7/20


    I'm just getting started. Give me some more time and I'll stretch that back some more where, if I recall correctly, you see widespread record cold happening in all of the places I mentioned. Amazing that colony of endangered penguins was hurt hard by a widespread cold snap in South Africa recently. Penguins, hurt by cold? Wow. Australia is the sketchy part of my claim however we'll see as I go through my archive. I do seem to recall some widespread record cold on its West and North coasts. Hmmm, come to think of it, on their northeast coasts as well. Hope to give that some substance shortly but, I do have a life you know. :~)


  13. Note the blue smudge over South America in the map at lower right.

    Always good to look at all the data.
  14. Tom,

    Cherry-picking at its extremes and confusing regional weather events with long-term global trends.

    Did you know that 2010 likely going to be the warmest year in the instrumented record?

    Did you know that 17 nations this year have set all time record high temperatures, while only one nation has set an all time record low? (H/T Jeff Masters)

    Did you know that:

    "The June–August worldwide land surface temperature was 1.00°C (1.80°F) above the 20th century average of 13.8°C (56.9°F)—the warmest June–August on record, surpassing the previous June–August record anomaly of 0.92°C (1.66°F) set in 1998." [from NCDC]

    Did you know that so far this year the S. Hemisphere has had its second warmest year on record? [NCDC]


    Please read this and have a look at the figure below:




    Also look at Fig. 21 in this
  15. You beat me to it Doug! :)
  16. Cool, I see a blue smudge over Australia too. Could you post the source of that please?
  17. Oops, sorry!

    Here you go:

    GISS Surface Temperature Analysis: 2010 — How Warm Was This Summer?
  18. Tom Loeber, your first newspaper article mentions some days of low temperatures due to a cold front in certain areas of Southern Brazil, Northern Argentina and Uruguay, and one claim of worst for 47 years - lots of dead fish in Bolivia.
    Your second article mentions "coldest winter in [Argentina in] 40 years".
    Your third piece is a blog which re-iterates the number of dead fish in Bolivia (See your first link also).
    Your last link mentions "coldest temperatures in 10 years" in Argentina and a general "cold spell" in South America.
    The LAHT link about Peru wouldn't load for me but I doubt whether there is anything there more unusual than the rest of your links.

    So, am I right in thinking that when you mention "widespread record cold" you are basing your views on newspaper articles ?
    What records have been broken in any of those articles, that can compare to record high temperatures ? You know, the temperatures that have been the highest in ALL records ?
  19. That GISS link Doug provided in #67 makes about how the question, 'was weather event XYZ caused by global warming', is usually answered which has bothered me for a long time;

    -------------------

    "Finally, a comment on frequently asked questions of the sort: Was global warming the cause of the 2010 heat wave in Moscow, the 2003 heat wave in Europe, the all-time record high temperatures reached in many Asian nations in 2010, the incredible Pakistan flood in 2010? The standard scientist answer is "you cannot blame a specific weather/climate event on global warming." That answer, to the public, translates as "no".

    However, if the question were posed as "would these events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?", an appropriate answer in that case is "almost certainly not." That answer, to the public, translates as "yes", i.e., humans probably bear a responsibility for the extreme event."
  20. It strikes me that the combination of Tom's articles in with what looks like an innocuous slight negative anomaly over parts of South American serves as a handy reminder that seemingly insignificant average anomalies can translate into dramatic local weather events.
  21. Good point Mr. Murphy. Not much registering of broken records in those articles. It is me stretching that probably they were but not recorded. Sorry about that. I do think though that, so far I have answered your question "Do you have any evidence for any of those claims of "wide spread record cold?" in the affirmative at least a bit since your question is relatively extreme. Hope to cement that a bit more with time. Really should go do some physical work on my B100 consuming car. Got a schedule to keep.
  22. Here's a report of the cold in New Zealand killing "tens of thousands of lambs" though no record is mentioned as being broken it states its the worse since 1972: Tens of thousands of New Zealand lambs killed by cold. 9/22

    Strong winds, heavy snow and record cold across Tasmania. 9/17

    South pole has record cold. 7/31

    Much of New Zealand experiencing record cold. 6/2

    Queensland, Australia towns get record cold. 5/22

    Cold snap hits Argentina, Paragua, Uruguay & Bolivia. 7/18

    Record low temperature in Brazil. 7/15

    At least this one is a record for 82 year old Juana Benitez: Cold snap hits several South America countries. 7/10

    Well, how about coldest SE Australia in some 60 years?: Unusual widespread cold in Australia. 6/30

    Here's the story about S. Africa penguins though it doesn't mention any records being broken. Maybe it is a record that over half of the penguin chicks died from the cold this time. One island hardly qualifies as wide spread though: Cold rain kills %50+ endangered S. Africa penguin chicks. 6/15

    There was some widespread crop damage from cold in S. Africa but it doesn't mention any records being broken: Severe cold & frost damages S. Africa crops. 7/15

    Oh, don't get me going on the widespread cold in the northern hemisphere over the last couple of years. Notices of those far out weigh those for the southern hemisphere. Two years ago, my mom died due to complications in what I understand was Washington state's first ever state of emergency due to record cold and snow. I truly expect the cold and snow to be worse this year across the northern hemisphere and there are some long range predictions suggesting that too.
  23. @Tom: And yet 2010 is on par to be the second hottest year in the Southern Hemisphere.

    As for a cold winter in the NH last year, you certainly didn't come to Canada. It was very mild overall.

    The problem is that you seem to believe anecdotal evidence trumps measured averages. It doesn't, and therefore your theory that we are in a cooling trend does not stand scrutiny.
  24. Tom, picking local cold spell doesnt mean anything. Look at the global average temperatures. As to the storm that hit here - well it was bad but it was just a storm, unfortunately at bad timing after a very mild winter and otherwise early spring. Effect on NZ annual average temps - not much. Global warming does not preclude cold spells. There is more energy in the weather systems, more humidity, and if temperatures go below zero, you will get heavier snow.
  25. I think it was Professor Hansen stating that mantra that weather doesn't indicate climate about the record cold in the US NE and Europe not too long ago while actually there was record cold on all six continents at the time. Anecdotal evidence only pertains so far, you know. You can be killed by an anecdotal occurrence. If it is anecdotal that the whole planet is being pushed to collapse into the more stable set of conditions as evident by its holding way over 90% of the planet's existence at least in the last million or two years, well, heck, quick snap to major ice age conditions will be but an anecdotal odd and absolutely not average happening.

    Get it right. What I'm suggesting is that the record global warming is leading to a propensity to snap into extreme widespread cold. I'm not denying that there was record heat but I think the idea of a tipping point should be considered. What does the planet tip to? Just look at the record. Interglacials come and go. They are the transient phenomenon. The planet apparently gets tipped into its most stable set of conditions, ice age conditions, and they come on anecdotally and rapidly, beating the average trends quickly.

    I know it is a difficult concept. The ways to avoid global warming make sense to avoid quick snap to extreme global cooling except for the idea of using Hydrogen gas as a fuel. That would most likely lead to more of those noctilucents as suggested on the Wikipedia on the phenomenon. Hey, earth's climate system is not a linear process. It is dynamic with repeated seriously differing cycles. The change to something serious, what ever we might be tipping to, will be anecdotal. It will not be an average outcome. It will be new and looks like it is going to catch most quite off guard. Good luck all!
  26. @Tom: I'm not sure you understand what "anecdotal" means.

    In any case, there is no indication we are about to enter a very cold period. There were more heat records broken than cold records last year. The warming trend is strong, and shows no sign of reversing.

    Glacial periods are most likely the results of Milankovitch cycles, not of delicate "tipping points" that would be reached by increasing heat.

    You don't seem to be making much sense, I'm afraid.
  27. Ah, me thinks the idea of Milankovitch cycles borders on blaming astrology for the ice ages. There is a much better explanation and it is lighting up the skies over both hemispheres ever more with each year.
  28. Tom Loeber writes: Ah, me thinks the idea of Milankovitch cycles borders on blaming astrology for the ice ages

    Please don't be a troll.

    The association between Milankovich geometry and glacial/interglacial cycles is very, very well established. The mechanisms by which this works are not completely understood, but we do know a lot about it.

    The very short version is that a reduction in seasonal insolation during high-latitude Northern Hemisphere summers allows snowpack to persist through the summer, leading to the inception of ice sheets. When summer insolation around 65 North begins increasing again, this process reverses itself.

    If you don't understand how this works, check out Bill Ruddiman's textbook (Earth's Climate) or David Archer's eminently readable book (The Long Thaw).
  29. Oh, don't get me going on the widespread cold in the northern hemisphere...

    Agreed, it's apparent there would be little point in that, so please don't start. Clearly you're not a fellow to be swayed by collated data permitting of useful conclusions, meanwhile the strong preference here is to stick w/exactly that sort of information.
  30. @TL: "Ah, me thinks the idea of Milankovitch cycles borders on blaming astrology for the ice ages."

    Cute. Completely wrong, but cute.

    "There is a much better explanation and it is lighting up the skies over both hemispheres ever more with each year."

    TSI has been going down, and we are past the Holocene Climatic Optimum. If it was up to natural cycles, we should be cooling, not warming up.
  31. Tom Loeber, there was no "widespread cold in the northern hemisphere over the last couple of years", just as there has been no "widespread record cold" over the southern hemisphere more recently.
    You would save yourself a lot of bother if you look into the facts and figures of these situations, rather than rely on exaggerated and over-the-top headlines, especially those from the likes of ICECAP.COM.
  32. My understanding is that when Milankovitch first proposed his theory he suggested gravitational influences from stars other than our own play a part in the comings and goings of ice ages besides eccentricity of orbit, influence of other planets, etc.. That seems pretty outrageous to me, tantamount to astrology. BUT that theory totally absolves humanity from having to watch what it does to the atmosphere as far as avoiding the threat of tipping the climate into its most stable state, ice age conditions. Most likely people reading this have college and university experiences. Look at who provides scholarships, awards and "prizes" more than any other source of money. It is the fossil fuel and the otherwise military associated companies that play a major role in determining funding, who gets degrees, who gets well paying jobs and who gets to be teachers. Do you think this does not lead to across the board mistaken assumptions that downplay the danger of burning fossil fuels?

    The way I have come to describe it, the interglacial is like a house of cards. It takes a long time to build but can collapse fast. The Hamaker hypothesis appears to fit the evidence better than the Milankovitch theory. Unlike the Milankovitch theory, the Hamaker hypothesis has led to experiments that strongly suggest its relative validity, real time experiments. The Hamaker hypothesis is not just dependent on the interpretation of past events like the Milankovitch theory is, solely. Many small and large scale experiments show soil remineralization greatly increases biomass and carbon dioxide sequestering.

    The Milankovitch theory does not explain noctilucents. They get in its way so I see, such as in the following article they are ignored, not even mentioned, though earth albedo is found to be the driving factor and not solar insolation Interglacials, Milankovitch Cycles, and Carbon Dioxide 2/10

    Scientific understanding has been found to be quite wrong before despite a vast majority of established scientists, teachers, lecturers, politicians etc. holding most vehemently to the mistaken assumptions. It is even more easy to have those mistaken assumptions when they absolve any danger of the promulgation of the main money making enterprise of the richest fraction of the population.

    Noctilucents, a fly in your ointment, gentlemen.
  33. Mr. Murphy, there is so much. The record cold that destroyed the livelihood of Mongolian herders, killing their livestock, the record cold across the whole south of China that was said to be the worst in more than 700 years, the record cold and snow in Washington state and descending into Oregon that helped kill my mom two years ago. The NE US and Europe cold that Professor Hansen explained away as weather not climate. England is stated as having their coldest winter on record within the last two years. I could give you a list as long as my arm of record cold events, widespread and on all continents and it appears since they just don't fit your hypothesis you can't see them.

    It is my opinion that the greatest danger we face is epistemic relativism. Might does not make right. Majority opinion does not determine truth. Observe to formulate opinions ad infinitum. Don't opinionize to formulate what you can and cannot observe.
  34. The Milankovitch theory does not explain noctilucents. They get in its way so I see, such as in the following article they are ignored, not even mentioned...

    Tom, if you'd actually read replies to your comments, you'd already have learned that noctilucent clouds are not being ignored. A further two minutes w/Google Scholar would also help you realize that the flies are actually in your ointment, screaming with their tiny voices for your attention.
  35. Tom #82: Noctilucent clouds are believed to be CAUSED by global warming... and thus hardly constitute a 'fly in the ointment'.

    From what I can gather I think you are arguing that noctilucent clouds indicate cooling and thus are contrary to global warming. Of course, noctilucent clouds are found in the mesosphere... which of course cools as greenhouse gas concentrations increase and 'trap' heat in the lower atmosphere.
  36. Tom Loeber - There will always be some extreme weather with unfortunate consequences, including the events that affected your family (which I'm very sorry to hear about).

    However, singular events are weather. If you are looking at climate (long term trends), you need to look at the statistics and numbers of many events, hot and cold.

    If you look at the relative numbers of hot and cold events, maxima and minima, you will see that individual cold weather doesn't disprove global warming. There are simply more extreme highs than extreme lows over the past 30 years.

    What we personally experience has strong effects on our beliefs - how could it not? But if you want to look at global changes, you need to look beyond personal direct experience to the global data.
  37. I've just looked up that Hamaker fellow and it appears he was predicting a shortening of growing seasons, before we fall head-long into an ice-age.

    Any proof ?


    An increasing number of studies have reported on shifts in timing and length of the growing season, based on phenological, satellite and climatological studies. The evidence points to a lengthening of the growing season of ca. 10–20 days in the last few decades, where an earlier onset of the start is most prominent.


    Observed changes in growing season length


    Field and satellite data at the community and biome levels indicate a lengthening of the growing season across much of the Northern Hemisphere (1–6) and—where data exist—in the Southern Hemisphere (5, 7, 8), yet life history observations of individual species suggest that many species often shorten their life cycle in response to warming (9–12).


    Not a very good start for Mr Hamaker, it would appear...
  38. KR, extreme weather but over wide areas of the planet? When extreme weather becomes the norm should we still discount it?

    I am not denying global warming. I do think if the planet does snap into ice age conditions that will be a singular event and it will be climate and weather. I think there is a great deal of evidence that is happening but seems most are going to have to learn the hard way and that means a lot of death and destruction, maybe too much for humanity to survive, IMHO.
  39. Mr. Murphy, no one is perfect. John Hamaker was apparently totally unaware of noctilucents though they appear to be a very strong indication that his theory is largely sound. Did you get a chance to see that movie I linked to earlier? Those small and large scale experiments in remineralizing soils offers so much to help us secure this planet. How come it is not a UN sponsored strategy? Seems remineralizing soils rather than using fossil fuel derived fertilizers would help the situation no matter what theory you believe. Hmmm, could fossil fuel companies wanting their cash cow of fertilizers to remain unchallenged be playing any role?
  40. Tom Loeber wrote : "Mr. Murphy, there is so much. The record cold that destroyed the livelihood of Mongolian herders, killing their livestock, the record cold across the whole south of China that was said to be the worst in more than 700 years, the record cold and snow in Washington state and descending into Oregon that helped kill my mom two years ago. The NE US and Europe cold that Professor Hansen explained away as weather not climate. England is stated as having their coldest winter on record within the last two years. I could give you a list as long as my arm of record cold events, widespread and on all continents and it appears since they just don't fit your hypothesis you can't see them."


    Firstly, last Winter here in the UK was the coldest since the late 70s overall. Hardly the "coldest winter on record". Feel free to post evidence that shows otherwise.

    Mongolian herders were indeed affected by a very cold Winter following the previous season's drought - a double whammy, as some of your other news articles for other countries have shown. Record cold ? Only if you want to believe so.

    I have read news articles about the cold Winter in China, a couple of years ago, suggesting the coldest since anywhere between 20 to 100 years. 700 years ? Over to you.

    You are still relying on news outlets for your opinions, but also, it would appear, your own personal loss. I can understand how this would make you want to see everything in catastrophic terms.
  41. Tom,

    With respect, you are simply not listening or comprehending the replies to your posts. You keep citing cold weather events, that is confirmation bias. I'll repeat it again, only one nation around the globe has set all time record cold low in 2010. In contrast, so far this year 17 nations around the world set all time high records, and 2010 is on track to be the warmest on record. In the USA warm temperature records are out pacing cold records by over 2:1 so far this year, and similar stats are emerging elsewhere.

    We are not rapidly changing the tilt of the earth's axis Tom, there are still going to be seasons, including cold snaps during the winter months. The long term trend is global temperatures is up, and for the past 30 years the planet has been warming at almost 0.2 C/decade.

    The cold weather in parts of Europe and Eurasia last winter were because of the Arctic Oscillation (internal climate variability) flipping into an extremely negative phase, which meant the Arctic was relatively warm while the aforementioned areas were colder than average (not all time record lows as far as I can tell).

    Sorry, but unless you up your game and stop moving the goal posts, I'm tuning out.
  42. Mr. Bostrom, so if the data does not lead to "useful conclusions" it should be ignored or discounted totally? I've yet to go into all the links you provided but that last one, he shows a graph of 45 years and determines that noctilucents are really of no concern. Hmmm, first surface mirrors peaking at summer when solar input is supposed to be the most coating the planet far above the green house gases not a concern? How about this graph from NASA going back to when noctilucents were first recorded. I think that tends to skew the data presented in the paper you link to towards a different conclusion. My understanding is that over the last few years the noctilucents have grown in frequency and duration to record amounts repeatedly, beating practically each year's extent and duration.

  43. Tom Loeber, noctilucent clouds = cooling mesosphere = warming surface. For example;

    Summer: Warm at the surface. Cold in the mesosphere.
    Poles: Showing the greatest surface warming. Coldest region of the mesosphere.
    Increasing CO2: Warms the surface. Cools the mesosphere.

    Noctilucent clouds require temperatures of about -120 C to form... which even the mesosphere, the coldest region on Earth, seldom reaches. That is why they are seen in Summer near the poles... the coldest time and region of the mesosphere. As CO2 concentrations increase the mesosphere as a whole gets colder and noctilucent clouds become more common, but the planet's surface gets warmer.

    Your premise seems to be 'as goes the mesosphere so goes the planet'. In reality all available evidence indicates the opposite... a cooling mesosphere means a warming planet.
  44. Mr. Albatross, thank you for posting your name. Only one nation? That is not worthy of any effort to refute. It is you being highly unreasonable and inaccurate. I am warmed by your deciding to tune out.

    I see that you folks pretty much have your minds made up and no amount of contrary evidence can be tolerated. I expect to be banned or something like that soon, eh?
  45. No, Tom. It's almost impossible to be banned here. You can expect to be ignored.
    Response: Also, Tom, individual comments will be deleted if they are off topic of the page on which they are posted. You need to continue discussion of individual weather events on the relevant thread It’s freaking cold!.
  46. Tom,

    Please read this

    Those are actual weather data form various weather agencies and climate groups around the world. You continue to fail to support your assertions with facts and data.

    And a correction to my previous post. No nations have set record cold temperatures in 2010, not one:

    "No nations set record for their coldest temperature in history in 2010. Jeff Masters erroneously reported in his blog earlier this year that Guinea had done so. Guinea actually had its coldest temperature in history last year, on January 9, 2009, when the mercury hit 1.4°C (34.5°F) at Mali-ville in the Labe region." [from above link]

    "I expect to be banned or something like that soon, eh?"

    John Cook is very patient and open to criticism, and you'll find that is you can support your arguments with facts, people here will be very tolerant. That said, this site has a comments policy and you seem to be doing your best to break the rules and antagonize people, why?

    Again, time to up your game and start substantiating your claims with facts from reputable sources, this may be a blog, but it is a science blog.
  47. Tom Loeber - I don't believe you'll be banned; I don't know of anyone who has, quite frankly.

    However, your arguments about noctilucent clouds are (as CBDunkerson pointed out, reversing the causal relationship - more noctilucent clouds are expected with warming, not fewer.

    Extreme weather conditions are to be expected with natural variability - but extreme maxima are occurring twice as often as extreme minima over the last few decades. Your insistence on scattered news reports and anecdotes does you no favor in this discussion - the data contradicts you on that.

    And as per the main topic of this thread, we appear to be moving away from ice age conditions, when normal cycles indicated we should be moving towards an ice age - we're getting further from ice age conditions all the time. You have presented roughly zero evidence for an immanent ice age.

    So, while I don't know if anyone gets banned (although individual posts get cut, and if someone has nothing but insults or off-topic posts, it may seem that they're cut), you are at this point not going to be taken seriously by anyone on this site unless you develop a more evidence-based line of discussion.

    Not banned. Ignored, I'm sorry to say, is fairly likely. I would really encourage you to look at and consider the evidence for global changes (watching out for confirmational bias), and remain in the discussion.
  48. Tom Loeber wrote : "I see that you folks pretty much have your minds made up and no amount of contrary evidence can be tolerated. "


    Unfortunately, you have no "contrary evidence" : you have newspaper articles, online news stories, personal theories and personal experience.
    Doubly unfortunate is that you cannot see that you don't have any "contrary evidence".
    If you don't actually provide any, you can indeed expect to be ignored or repetitively shown the evidence that has already been shown but which you are ignoring because you have a pre-determined need to believe what you want to believe.
    Provide some real evidence, please.
  49. Tom #94: "Only one nation? That is not worthy of any effort to refute."

    Why?

    It would be so EASY to prove that you are right. Especially since in post #96 Albatross says it turns out that "one country", Guinea, actually had its all time record set LAST year.

    So all you have to do is cite one country, anywhere in the world, which had its all time record coldest temperature set this year. Just one. That's really 'too much effort'? After all the other posts you've made? Typing out the name of a country is too much work?

    Or is it not worth refuting... because it is TRUE?
  50. Tom: "I see that you folks pretty much have your minds made up and no amount of contrary evidence can be tolerated."

    Tom, you know the same could be said of you. You simply don't (or choose not to) recognize that in terms of amount, the evidence against what you claim is mountainous compared to your molehill's worth. I'd like to see the mechanism you propose that would cause a sudden cooling snap (no global instrumental temperature record displays a cooling trend excepting TOA). Can you model the tipping point for us? How long do we have? Or are you simply picking over the mass of collected data and choosing the bits that support your "shocking" pseudo-theory?

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