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El Nino, Global Warming, and Anomalous U.S. Winter Warmth

Filed under: — mike @ 8 January 2007 - (Slovenčina) (Svenska)

It has now become all too common. Peculiar weather precipitates immediate blame on global warming by some, and equally immediate pronouncements by others (curiously, quite often the National Oceanic and Atmospheric Administration in recent years) that global warming can’t possibly be to blame. The reality, as we’ve often remarked here before, is that absolute statements of neither sort are scientifically defensible. Meteorological anomalies cannot be purely attributed to deterministic factors, let alone any one specific such factor (e.g. either global warming or a hypothetical long-term climate oscillation).

Lets consider the latest such example. In an odd repeat of last year (the ‘groundhog day’ analogy growing ever more appropriate), we find ourselves well into the meteorological Northern Hemisphere winter (Dec-Feb) with little evidence over large parts of the country (most noteably the eastern and central U.S.) that it ever really began. Unsurprisingly, numerous news stories have popped up asking whether global warming might be to blame. Almost as if on cue, representatives from NOAA’s National Weather Service have been dispatched to tell us that the event e.g. “has absolutely nothing to do with global warming”, but instead is entirely due to the impact of the current El Nino event.

[Update 1/9/07: NOAA coincidentally has announced today that 2006 was officially the warmest year on record for the U.S.]
[Update 2/11/08: It got bumped to second place. ]

So what’s really going on? The pattern so far this winter (admittedly after only 1 month) looks (figure on the immediate right) like a stronger version of what was observed last winter (figure to the far right–note that these anomalies reflect differences relative to a relatively warm 1971-2000 base period, this tends to decrease the amplitude of positive anomalies relative to the more commonly used, cooler 1961-1990 base period). This poses the first obvious conundrum for the pure “El Nino” attribution of the current warmth: since we were actually in a (weak) La Nina (i.e., the opposite of ‘El Nino’) last winter, how is it that we can explain away the anomalous winter U.S. warmth so far this winter by ‘El Nino’ when anomalous winter warmth last year occured in its absence?

The second conundrum with this explanation is that, while El Nino typically does perturb the winter Northern Hemisphere jet stream in a way that favors anomalous warmth over much of the northern half of the U.S., the typical amplitude of the warming (see Figure below right) is about 1C (i.e., about 2F). The current anomaly is roughly five times as large as this. One therefore cannot sensibly argue that the current U.S. winter temperature anomalies are attributed entirely to the current moderate El Nino event.

Indeed, though the current pattern of winter U.S. warmth looks much more like the pattern predicted by climate models as a response to anthropogenic forcing (see Figure below left) than the typical ‘El Nino’ pattern, neither can one attribute this warmth to anthropogenic forcing. As we are fond of reminding our readers, one cannot attribute a specific meteorological event, an anomalous season, or even (as seems may be the case here, depending on the next 2 months) two anomalous seasons in a row, to climate change. Moreover, not even the most extreme scenario for the next century predicts temperature changes over North America as large as the anomalies witnessed this past month. But one can argue that the pattern of anomalous winter warmth seen last year, and so far this year, is in the direction of what the models predict.

In reality, the individual roles of deterministic factors such as El Nino, anthropogenic climate change, and of purely random factors (i.e. “weather”) in the pattern observed thusfar this winter cannot even in principle be ascertained. What we do know, however, is that both anthropogenic climate change and El Nino favor, in a statistical sense, warmer winters over large parts of the U.S. When these factors act constructively, as is the case this winter, warmer temperatures are certainly more likely. Both factors also favor warmer global mean surface temperatures (the warming is one or two tenths of a degree C for a moderate to strong El Nino). It is precisely for this reason that some scientists are already concluding, with some justification, that 2007 stands a good chance of being the warmest year on record for the globe.

A few other issues are worthy of comment in the context of this discussion. A canard that has already been trotted out by climate change contrarians (and unfortunately parroted uncritically in some media reports) holds that weather in certain parts of the U.S. (e.g. blizzards and avalanches in Colorado) negates the observation of anomalous winter warmth. This argument is disingenuous at best. As clearly evident from the figure shown above, temperatures for the first month of this winter have been above normal across the United States (with the only exceptions being a couple small cold patches along the U.S./Mexico border). The large snowfall events in Boulder were not associated with cold temperatures, but instead with especially moisture-laden air masses passing through the region. If temperatures are at or below freezing (which is true even during this warmer-than-average winter in Colorado), that moisture will precipitate as snow, not rain. Indeed, snowfall is often predicted to increase in many regions in response to anthropogenic climate change, since warmer air, all other things being equal, holds more moisture, and therefore, the potential for greater amounts of precipitation whatever form that precipitation takes.

Another issue here involves the precise role of El Nino in climate change. El Nino has a profound influence on disparate regional weather phenomena. Witness for example the dramatic decrease in Atlantic tropical cyclones this most recent season relative to the previous one. This decrease can be attributed to the El Nino that developed over the crucial autumn season, which favored a strengthening of the upper level westerlies over the tropical North Atlantic, increased tropical Atlantic wind shear, and a consequently less favorable environment for tropical cyclogenesis.

If a particular seasonal anomaly appears to be related to El Nino, can we conclude that climate change played no role at all? Obviously not. It is possible, in fact probable, that climate change is actually influencing El Nino (e.g. favoring more frequent and larger El Nino events), although just how much is still very much an issue of active scientific debate. One of the key remaining puzzles in the science of climate change therefore involves figuring out just how El Nino itself might change in the future, a topic we’re certain to discuss here again in the future.

360 Responses to “El Nino, Global Warming, and Anomalous U.S. Winter Warmth”

  1. 151
    DIck Veldkamp says:

    Re: Can we attribute one hot winter to GW? (see also #66)

    No, we can’t, but as the loaded dice post (#51) tells us, we can find the (low) probability that such an anomaly occurs on the assumption that nothing is happening really (the environmentalists are making it all up, you know).

    Another way to detect that something is going on, is looking at how often weather records are broken. Suppose all winter temperatures are drawn from some distribution (say the observations of 1850-1900 give us a normal distribution with some mean winter temperature, and let us assume for argument’s sake that the standard deviation is 1 deg).

    Now suppose we start taking down winter temperature records from 1900 onwards. Then we would get something like this (numbers were found with random generator experiments):

    Record 1 after 1 year, at 0 degrees above average
    Record 2 after 5 years, at +0.9 deg
    Record 3 after 21 years, at +1.6 deg
    Record 4 after 45 years, at +1.9 deg
    Record 5 after 146 years, at +2.5 deg
    Record 6 after 1145 years at +2.8 deg

    Obviously the time between successive records gets longer and longer, which is not quite what we see happening now.

    Of course this is just hand waiving, but it might be worth somebody’s while to get into it more seriously (although personally I see enough evidence already).

  2. 152
    Ark says:

    Here in The Netherlands, the moving temperature average over a period of one month (31 days) has consistently been 4 degrees C (7 Fahrenheit) higher than normal (1971-2000) from July through December, with the exception of August. This made 2006 by far the hottest year since reliable measurements started 300 years ago. January 2007 sofar beats everything. Temperature average over the first 10 days of January has been approx 9 C (normal value for end of April), vs. a normal value of 2.6 C.

  3. 153
    Tony Heller says:

    Fort Collins weather data

    Deviation from normal since Dec. 17 has averaged -6 degrees. [trash talk edited out...]

    17 -5
    18 -6
    19 -5
    20 0
    21 -6
    22 -15
    23 -9
    24 -6
    25 -16
    26 -1
    27 3
    28 1
    29 -5
    30 -9
    31 -12
    1 -10
    2 -11
    3 0
    4 13
    5 -9
    6 -16
    7 -12
    8 -2
    9 -4
    average -5.92

  4. 154
    Tony Heller says:

    [more trash talk eliminated] here is the actual data from Fort Collins. We are averaging ~6 degrees below normal. High temperatures have been averaging more than 10 degrees below normal. It is by far the coldest and snowiest winter I have seen here in 15 years.

    Dec 17 -5, 18 -6, 19 -5, 20 0, 21 -6, 22 -15, 23 -9, 24 -6, 25 -16,
    26 -1, 27 3, 28 1, 29 -5, 30 -9, 31 -12, Jan 1 -10, 2 -11, 3 0, 4 13,
    5 -9, 6 -16, 7 -12, 8 -2, 9 -4, 1

    average deviation -5.92

    [Response: We and several commenters above have pointed out the cherry-picked nature of the numbers you're citing. Now, if you have a problem w/ NOAA's numbers, report it to them. But we're not taking any more comments from you on this thread. -mike]

  5. 155
    Larry Vetter says:

    What effect, if any does the gulf stream have on the weather conditions for the east coast of the U.S.? Thank you.

  6. 156
    Dianne Humphrey says:

    Please send this article to the major news outlets. I was so happy to hear it on NPR because just last night on Brian Williams NBC evening news they were parroting that old thing that this unusually warm winter is nothing to do with climate change and is only due to El Nino.Given my understanding that the frequencies and strength of the ElNino’s have changed due to climate change that is no consolation. It is time the scare the complacent public into pushing for immediate climate action. Like Al Gore, this has interested me for the past thirty years, but nothing happens to change things. This president has been the most disasterous of all. We need to energize Americans to change their ways whether or not Russia and China and India are going to change theirs. Every little bit hopefully will help.

  7. 157
    Jodro says:

    Here in SW France it’s the same story as noted by #152 in Holland, with temperatures WAY, WAY, WAY above average… as is also described by many others above. Now, having scanned this whole discussion am I missing the question that must be playing on everyone’s minds, or has it not been posed, or am I the only one this paranoid? Anyway, my question is: what are the odds that we are seeing the first signs of a runaway greenhouse effect?

    Some scientists have for years been warning that global warming may not necessarily develop gradually, but that there’s a risk of a sudden feedback mechanism causing a runaway warming effect… Are there signs that this may now have occured?

    In addition, here in Europe the weather is strongly affected by the warm gulf stream. Last year we had an unusually cold winter, and there was talk that this was due to a weakening of the gulf stream. Is there any evidence that this is still happening, and if so, how does this tie in with the dramatically warm winter weather?

  8. 158
    Chris Hawkins says:

    Sorry to hear the past couple weeks have been so cold in Ft Collins, but 2006 was the second warmest year on record there.

    [Response: Thanks, why don't we close of this particular sub-thread on this note. The focus here was supposed to be on the larger-scale, longer term (i.e., seasonal or longer) trends, not weather in specific locations. -mike]

  9. 159
    Tony Heller says:

    Cherry picked numbers? The numbers I listed above are *all* of the data for the winter so far -i.e. every single day. High temperatures have diverged even further. Other than four warm days in mid-December it has been below normal nearly every day for the last six weeks. Again, please look at the link-

    Additionally, the forecast high temps for the next week are-
    26, 17, 18, 19, 14, 27, 26 F. We normally are about 45 this time of year.

    When I saw the map and text in this article saying that we have been above normal this winter, I realized how little I can trust the information being presented by global warming proponents.

    [Response: I think what we have here is a failure to communicate. If you look at the GISS data for Fort Collins (up to 2005), there are clearly large adjustments that have been made from the raw data. These relate to biases from the time of day of observation, station movements etc. In particular, it looks like the adjustments at Fort Collins are large; 1934 annual mean for instance changes by over a degree, 1981 by 0.5 degrees. I have no idea what those adjustments are specifically due to in this case (the Colorado Climate Center may be able to help), but given that - any raw analysis of the station 'normals' is bound to be different. The point is, that raw data always need to be analysed for such corrections and that the NOAA data - far from being inaccurate - are actually much better quality controlled. (And incidentally, NOAA are not usually described as global warming proponents!). A paper that analysed some of these issues was: Hansen et al (2001) - gavin]

  10. 160
    Hank Roberts says:

    >155, Larry Vetter, “what effect … does the Gulf Stream have …”

    Google will help with this if you paste your question into the search box. A few examples:

    The dominant feature of the North Atlantic is the warm Gulf Stream and its eastward extension, the North Atlantic Drift. ….

    The effect of these currents on the terminal weather around the coastal area of the Atlantic varies with the time of year, the type of air mass involved, and the direction of flow. …

    “… Midlatitude cyclones develop off the Carolinas during winters and move north producing gale-force winds, ice, and heavy snow. ….
    “… This research investigates … nine years of data on the Gulf Stream position and East Coast winter storms … quantitatively indicate that Gulf Stream-induced wintertime baroclinicity may significantly affect the regional intensification of East Coast winter cyclones.”

    Lots more available including realtime satellite maps, etc.

  11. 161
    SecularAnimist says:

    If, as British scientists say is likely, 2007 does develop into the hottest year yet recorded worldwide, this could have serious consequences, and soon. It was only a few years ago that an unprecedented heat wave killed tens of thousands of people in Europe. If this unusually warm winter proves to be a harbinger of what 2007 has in store, it could be a very, very bad year.

  12. 162

    Re “More important, “solar constant” is no more significant, you should speak about total and spectral irradiance. For example, UV effect on stratosphere (and climate) are not presently integrated in GCM as a TOA forcing. But these UV do have an influence on climate and are studied by photochemistry and physics models. If a solar forcing is considered for 1750-2000, you should probably add this effect.”

    Your suggestion that the Solar constant is irrelevant to climatology is, to put it mildly, bizarre. Again, I maintain that finding obscure solar indices to fit bits of climatology does nothing to prove your point. Provide a clear mechanism, and find a way to test it empirically, and you will have something to say. So far you don’t.

  13. 163
    Steve Bloom says:

    Re #156: Based on the number of other blogs linking to it, this post has already spread far and wide. The blog reactions link shows 129 just now. I don’t know if that’s a record for RC, but regardless of that it’s pretty impressive considering that the post hasn’t even been up for 48 hours. People do seem to care about the weather! Perhaps this is evidence that people need to see and feel climate change to be able to respond to it in any kind of urgent way. We shall see.

    BTW, in case it’s not obvious, the blog reaction counter (at the bottom of each post, although it doesn’t show in the comment window) can be clicked on to see a listing which is in turn clickable to go to the individual linking blogs.

    [Response: I'm not sure those numbers are accurate. If you click through, the number of blogs appears to be much less. If anyone knows why, please let us (and technorati!) know. -gavin]

  14. 164

    Re “In Earth’s past, long before human beings and industry, the climate has warmed and cooled. Some chatter on about Record tempatures, however, it is misleading, since it is only as long as we have kept records on meterological data which is perhaps 150 years or so. I may be off on that number but a couple of centuries is nothing in geologic time.
    Note too-Greenland 1000 years ago was not covered in ice but very much like new England is now, hence the name GREENLAND.
    But my overall point is, look to the Sun if one wants real answers as to why our climate is chnaging. Remember too, it is always changing.”

    1. Yes, it has warmed and cooled in the past. And when it has done so very rapidly, mass extinctions have usually been the result.

    2. Direct temperature measurements only go back to about 1850, to be sure (1650 in the case of the UK, but that’s a quibble). However, we are able to reconstruct earlier temperatures by the use of proxies such as tree rings, lake and ocean sediments, ice cores and the O16/O18 ratio in seashells. The ice core evidence goes back 650,000 years.

    3. Greenland got its name from the Vikings, who deliberately misnamed it to direct people there instead of the equally misnamed Iceland. The ice cap on Greenland is tens of thousands of years old, if not hundreds of thousands.

    4. The Solar constant has not varied significantly in 50 years. But global warming has turned up sharply in the last 30 or so years. So it’s not the Sun.

    It’s anthropogenic greenhouse gases generated by burning fossil fuels and clearing forests.

  15. 165

    Re “RE: #122, very true Ms. Phillips, and an excellent study was done at Duke U. recently about how the solar variances are very much underestimated in the AGW debate, for obvious reasons.”

    The most obvious reason being that there’s no clear connection between the Sun and recent temperature changes, and no believable mechanism for one has been observed. You do know that we’ve been measuring the Solar constant directly with satellites such as Nimbus-7 and the ERBE array, don’t you? The Solar constant is up perhaps 1 watt per square meter over the past 50 years, if that. To get the observed temperature change you’d need 12-20. Want to see the math?

  16. 166
    Jim Cross says:

    #158 Mike’s Response

    Let me second the call not to hear more about how warm, dry, cold, wet, dry, or whatever it is somewhere.

    I haven’t heard much discussion about whether El Nino is likely to become more frequent or intense with global warming, although there were some teasers about some controversy surrounding this issue in the initial post. It might also be interesting to hear opinions about whether the El Nino phenonmenon might augment or moderate the effects of global warming.

  17. 167
    Sally says:

    Technorati gives 74 now, which is impressive enough, I think. It shows that RC is a formidable force on this important issue

  18. 168
    P. Lewis says:

    Re #161

    What the Met Office bods actually say is:

    “Global temperature for 2007 is expected to be 0.54 °C above the long-term (1961-1990) average of 14.0 °C;
    There is a 60% probability that 2007 will be as warm or warmer than the current warmest year (1998 was +0.52 °C above the long-term 1961-1990 average).”

    I thought it was us Brits that had the propensity for talking about the weather at every opportunity. It’s our national pastime.

    Anyway, the world JFM forecast by the UK Met office can be found here:

    So perhaps a few cold waves are on their way; or not, given the 3-month forecast accuracy

  19. 169
    Plato says:

    Signs of Global Warming

    Global mean surface temperatures 1856 to 2005. –> see chart here (Add the imagnery 2006 year as the warmest ever on top of this chart.)

    Anomaly weather patterns.

    More energy inside our global climate system means more energy fluctuations. This leads to weather anomalys like when it snows it snows heavy, or much rain in short terms. Every single weather pattern will be act more powerfull, relative/compareable to the increase of energy flux.
    Heating the planet surface triggering positive feedbacks, first from heat trapping GHG mainly CO2 emission and induced further more positive feedbacks, which we can measure and come slowly into play but will than rise abrupt.(See to find out how at 1 point all of the methane bubbled up once the ocean warmed up.)
    Example of abrupt climate change in earth history, the PETM Event

    Positive Feedbacks:

    Further global warming (positive feedback)

    Some effects of global warming themselves contribute directly to further global warming, in a vicious circle, the nature of which may be difficult to predict in advance.

    Scientists warn thawing Siberia may trigger global meltdown
    Methane clathrates (frozen methane-water deposits on the ocean floor) might thaw and release more methane into the atmosphere (the clathrate gun hypothesis).
    The melting of permafrost and ice caps appears to be causing the release of large amounts of additional carbon dioxide or methane from decaying vegetation trapped beneath [52] [53] [54].
    There have been predictions, and some evidence, that global warming might cause loss of carbon from terrestrial ecosystems, leading to an increase of atmospheric CO2 levels [55] [56]
    Melting could also lead to increased heat absorption because ice reflects more solar radiation (i.e., it has higher albedo) than land or water. Because sea ice and seasonal snow cover are more reflective than the underlying sea, any meltback may lead to further warming.
    Warmer temperatures in the oceans reduce the productivity (growth) of ocean phytoplankton (algae). This is expected to reduce the amount of carbon dioxide taken up by photosynthesis in the ocean [57][58], which would again increase the effects of anthropogenic CO2 releases on the overall amount of CO2 in the atmosphere, and hence increase the greenhouse effect. This is a concern because ocean photosynthesis is as large a part of the planet’s overall carbon balance as land photosynthesis.

    Warming worry: Potent gas bubbling up faster
    Methane ‘coming out a lot, and there’s a lot more to come out,’ expert says
    MSNBC staff and news service reports
    Updated: 9:19 a.m. ET Sept. 7, 2006

    Methane, a gas 20 times more potent than carbon dioxide in trapping heat in the atmosphere, appears to be bubbling up from thawing permafrost at a rate five times faster than originally measured, scientists reported Wednesday.

    The effect, reported in this week’s issue of the journal Nature, is seen mostly in Siberia in a type of carbon-rich permafrost that was flash frozen about 40,000 years ago. A new, more accurate measuring technique found that methane bubbling from that permafrost under Siberian lakes was higher than previously recorded.

    �The effects can be huge,� said lead author Katey Walter of the University of Alaska at Fairbanks. �It�s coming out a lot and there�s a lot more to come out.� (subscriber only).

    Aware of positive feedbacks we can now connect the dots, but the diffrent now is, and this is eminent important, the speed of the Co2 emission.

    The speed of current Co2 emission into the atmosphere was never as fast as now. And it is accelerating!
    Fossil fuel combustion of mankind is now starting to trigger positive feedbacks.

    Industries and companys who change now to renewable energy ressources will have an advantage and a good position on the new energy markets. The turn comes now, be a pioneer and help to sustain life on earth for future generations.

  20. 170
    stephanie says:

    This is more of a quiestion than a comment.

    I live in Muskoka, Ontario.
    I was wondering what is really going on with our current weather conditions?
    Is it this El Nino event?
    Because we have just gotten our first snowfall that has left snow on the ground, about three days ago now.
    Up until then, it was unaturally warm for winter.

    I am currently researching Global Warming for an independent study unit for science, and was wondering if anyone could give a helping hand.
    What we are to do is to research global warming to find current scientific thinking with respect to possible connections between global warming and its impact on these weather systems.

    any help at all, would be wonderful.
    even a good website.


  21. 171
    Hank Roberts says:

    > Colorado
    Colorado was in the warm area until about this particular day:

    See the green area to the southeast that looks like, er, Florida? That’s the edge of the huge area of excess warmth all across the middle of the continent.

    Click ‘back’ a day at a time and you’ll see that area of green covering Colorado (it’s that brick shaped state in the lower left of the extra warm part of the map) consistently.

    Click ‘forward’ a day at a time and you’ll see that lobe of extra warm temperatures withdraw from Colorado and stay outside the state’s boundaries starting around the 16th or 17th.

    Focusing on Colorado and a few particular weeks isn’t informative — look at the overall largearea of excess warmth, in the whole North American continent, over the larger span of time.

    The little bump of temperature change over Colorado is a little bump of temperature change. Get the big picture.

    Look how warm it is in north central Canada, eh?

  22. 172
    Plato says:

    A good start of the study on global warming are the movie An inconveniet truth from Al Gore, visit
    Than for a more indepth study i recommend the wikipedia wikis about “global warming”, and “mitigation of global warming”. During the read you come across most of the relevant wiki links.

    Next is to hook up specific analyzes and science based discussion here on, use the search function and start here , at the topic index.

  23. 173

    Re #106 – “Yet, in one of the world’s most economically and powerful regions (around Boston, New York and Washington), the impacts will be relatively benign at least in the foreseeable future — implying of course that there will be relatively little impetus for strong action.”

    We live in Washington DC, and we are beginning to look at the plant catalogues for cold resistant banana plants. We have had no – zero – snow, and only very light frost on a few nights since November, and all the anomalies – forsythia blooming today, January 10, for example. We’re on the 38th parallel. The Washington Post published a story a few days ago saying that NOAA has moved us climatically from where we used to be to the equivalent of southern Virgina.

  24. 174

    Question: Does anyone know of recent work done on soil bacteria metabolism as affected by a warming clmate?

  25. 175
    Barbie B. says:

    Wrong? Right? Lose the schoolyard attitude children. Scientists study phenomena, non-scientists offer commentary on the phenomena being studied. I think the real point here (the one inspiring the large amount of passionate responses) is that we all need to step back and change our “wicked” ways. We all know that we need to put our energy consumption into check, if for no better reason than to simply prove that we have the strength and fortitude to do so. Global warming (or the concept of GW) simply gives us a damn good reason for doing it, if nothing else. I must also add that I have not enjoyed such good reading in a long time and would like to thank each and every one of you for that. There is a reason that people have always discussed the “weather”, (not just for a lack of a better subject either) that is because it directly affects our lives. I believe the “weather” ( I am using this term all-inclusivly..indicating climate as well) is doing an excellent job of communicating with humanity. Whether or not we will be able to decipher what is being communicated is another story and like I said…makes for damn fine reading.

  26. 176
    Plato says:

    Climate Experts Worry as 2006 Is Hottest Year on Record in U.S.

    By Marc Kaufman
    Washington Post Staff Writer
    Wednesday, January 10, 2007; Page A01

    Last year was the warmest in the continental United States in the past 112 years — capping a nine-year warming streak “unprecedented in the historical record” that was driven in part by the burning of fossil fuels, the government reported yesterday.

    According to the government’s National Climatic Data Center, the record-breaking warmth — which caused daffodils and cherry trees to bloom throughout the East on New Year’s Day — was the result of both unusual regional weather patterns and the long-term effects of the buildup of carbon dioxide in the atmosphere.

    “People should be concerned about what we are doing to the climate,” said Jay Lawrimore, chief of the climate monitoring branch of the National Oceanic and Atmospheric Administration. “Burning of fossil fuels is causing an increase in greenhouse gases, and there’s a broad scientific consensus that is producing climate change.”

    The center said there are indications that the rate at which global temperatures are rising is speeding up.

    Average temperatures nationwide in 2006 were 2.2 degrees Fahrenheit higher than the mean temperatures nationwide for the 20th century, the agency said. It reported that seven months in 2006 were much warmer than average, and that last month was the fourth-warmest December on record. Average temperatures for all 48 contiguous states were above or well above average, and New Jersey logged its hottest temperatures ever.

  27. 177

    #170, I suggest El-Nino being part of a larger world wide longitudinal shift in location of “cold high pressure ” and “warm / low pressure” areas, it makes practically no sense that El-Nino is responsible for everything, the Climate world doesn’t rotate around the West coast of Peru. When a cold zone shifts from continent to the ocean it gets warmer world wide, ENSO is a pure ocean bound cycle with a more dominant wind driven upwelling of cold water in the East Pacific during La-Nina’s. It is not the only place in the world where something similar happens.

  28. 178
    Gareth says:

    Just have a look at what we’re up against down here. I don’t know whether to laugh, or cry.

    Global And NZ Temperatures Are Cooling, Not Warming
    Wednesday, 10 January 2007, 4:31 pm
    Press Release: New Zealand Climate Science Coalition

    10 January
    Global And NZ Temperatures Are Cooling, Not Warming

    Figures just released by the U.S. National Space Science and Technology Center (NSSTC) show that mean global temperature for 2006 was 0.24 deg C cooler than it was in 1998.

    The seven years 1999 to 2005 were also cooler than 1998.

    Unlike air temperature measured by thermometers on the ground, NSSTC data comes from highly accurate measurements by satellites, correct to one tenths of a degree C.

    NSSTC is a research organization partnership between NASA’s Marshall Space Flight Center, Alabama universities, US federal agencies and industry. click here

    “This data suggests global warming might have stopped eight years ago, in line with what might be expected from the natural cycles of warming and cooling that are common features of climate” said Professor Augie Auer, chairman of the scientific panel of the New Zealand Climate Science Coalition.

    “It comes two days after the statement by the NIWA National Climate Centre that New Zealand can expect cooler but drier than average conditions over the next three months. This prompts the question: how much more cooling will have to occur before NIWA will admit that global warming is not happening.

    “We know that emissions of carbon dioxide are still occurring, which prompts a further question: for how much longer can NIWA support claims by the present government that CO2 causes catastrophic warming, and needs to be curbed by the imposition of special taxes or emission charges. Surely it’s now time to put a stop to these sensationalist claims, which are not supported by verifiable scientific data” said Professor Auer.

    It is, at least, risible.

    [Response: I suggest you read what Tim Lambert has to say about the so-called "New Zealand Climate Science Coalition". It should tilt you to the laughter side of the spectrum. p.s. don't skip the comment at the end! -mike]

  29. 179
    Margie says:

    Your comparison of a 30-day mean and a 90-day mean temp anom was odd, considering you could have compared the two 30-day means from Jan 5 from 2005 and 2006:

    Comparing like to like, the range of temp anom for the last 30 days is similar to 2005, with, generally speaking, the main difference being the distribution in temp anom across the northern tier of the continental US due to El Nino.

    So news stories about daffodils in the northeast US really are about nothing more than an El Nino year. It is the distribution of the temps that indicate the El Nino, making it much warmer than usual in the northeast. The more interesting thing is that both last year and this year at this time, there were temp anom up to nine degrees in the north central US, where I live. And January this year is shaping up very similarly to last year, regardless of El Nino. The consistencies of the high temp anomalies in both Jan 2005 and Jan 2006 says much more about potential climate change to me, than the supposed differences you tried to make a case for by the comparison shown in those two diagrams.

    [Response: I think you've missed the point. We're interested in climate, not weather. So a seasonal meteorological winter mean (DJF) is what we'd really like to look at. We have that for last winter. We don't have that for this winter yet. The best we can do is look at the winter so far, a bit more than a month long now. The temperature anomalies observed in the northeastern U.S. so far this winter are several times larger than typically observed in even a large El Nino winter, and this is at best a moderate El Nino so far. You are correct that the most prominent anomalies both in last year and this year's (so far) pattern are in the north central U.S. It is intriguing, if nothing else, that, as shown in the article, this is where the predicted anthropogenic warming is also greatest. -mike]

  30. 180
    Margie says:

    Seeing our phrase “missing the point” struck me kind of funny, because I thought the same thing when writing my original post.

    I knew you were trying to make a comparison to the winter mean, and we aren’t there yet, at the end of the first week in January. But 30-day temp anomalies are usually going to be more extreme than 90-day temp anomalies, so making a comparison between the two is not kosher. By the end of this winter, the 90-day anom probably won’t look so terribly different from a year ago. So, if you compare the Jan 5 2007 30-day mean with the Jan 5 2006 30-day mean (the one I posted), and subsequently also compare the 90-day mean so far, with last year’s, that would be comparing like with like, even if that 90-day mean at this point in time is for the most part OND. Otherwise, wait until the end of Feb to make the comparison with last year’s winter mean temp anomalies.

    Those two images you compare also make it appear that you’re focusing on the higher range of the anomalies, in the northern midwest, not that you’re simply focusing on the northeast. You also don’t say that you’re emphasizing the northeast; you state, “the anomalous winter U.S. warmth.”

    Finally, you also have to consider something about this year’s El Nino. It ramped up really fast, and caught up fast, in spite of the late start. It is so strong right now that the strongest previously-documented El Ninos that exceeded it on this date, going by either the MEI or ONI, can be counted on the fingers of one hand. That could have a bearing on why the amplitude of the anomalies in the northeast is so strong. This (possibly very short-lived) El Nino has been a very impressive one, and has had an equally impressive effect. So trying to leverage the temp anomalies in the northeastern US in this interesting El Nino year, is not going to be a strong argument for warming due to climate, not weather, especially when there are many places in the northern hemisphere that might be more appropriate to look at, where temp anom cannot be so closely tied to the effect of El Nino.

  31. 181
    Margret says:

    How strucky Margie,

    1. Go and read the complete article again.

    2. Read the comment from a climate scientist, replying to your statement.

    3. If you think you found something what is not right, than note this to the author but wait before you base a hypothesis on this. Because the way you act here is not science.

    4. This year El Nino is weaking at the momeent.

    5. It is not kosher how you overlooked the basic point, that we dont have a 90 day anomaly chart yet, because of an ongoing season. (Read the comment to your “introduction” post). And that is why temperature varies on the images due to the diffrent time period. Maybe you learned now how to read these images.

    6. Your personal wrong assumption can not downplay the extreme seasonal anomalys. And you should read the complete article when you contribute here to a scientific discurs. (You can’t pin down special weather events – We need to see the big picture and temperature trends.) In fact it is irrelevant too, because this is climate sience – not seasonal weather forcast (Again read the provided comment in your initial post).

    7. And finaly your El-Nino-Anomaly-Weather hypothesis is proofed wrong by measurable data from past and this year El-Nino.

    It is remarkable here how you try to denie global warming. It is hard to understand the full spectrum of consequences to our everyday lifes. Seek here on RC for more infos to understand the big picture, good luck.

  32. 182

    Re “Anyway, my question is: what are the odds that we are seeing the first signs of a runaway greenhouse effect?”

    Effectively zero. A runaway greenhouse effect is what happens when the oceans boil away, the water vapor is dissociated by the sun, the hydrogen is lost to space and the oxygen combines with the rocks, leading to conditions like those on Venus. There is no prospect of that happening to the Earth any time soon. Triggering geochemical feedbacks even in the worst scenarios only lead to a total warming of 5-10 K. This would be disastrous for humans, but it wouldn’t make the Earth into Venus.

  33. 183
    Kieran Morgan says:

    Re 131

    If Lovelock is right about us facing a Thermal Maximum and during the course of that we lose civilization then that’s it. Humans would face a permanent stone age with no possibility of advancing to bronze or iron ages again as pretty much all easily accessable ores have already been mined over the millenia. We face an equally grim fate if we fail to phase in alternate sources of energy to oil before it peaks and starts to run out.

  34. 184
    pete best says:

    Dear RC

    There are a lot of way of the mark points in this thread it seems to me compared to this time last year and a lot more posts to, getting towards 200+ on the last two alone. This site is becomming popular and although your threads are very scientific and accurate they do not seem to be appeasing a lot of skeptics found here. More skeptics than alarmists to be honest. As I am a english speaking person living in Europe the message from here is more ‘alarmist’ than not, even the EU itself has just released new legislation to lead the way in the cutting CO2 emissions that hopefully when it has been shown to be economically viable the world can and will use. It is this ‘alarmism’ which may have politically motivated the EU and other EU states to try to act on CO2 emissions.

    Is anything going on in the USA in this regard when the message seems more skeptical (right wing patriots – way of life under threat etc) than alarmist (left wing doomongers – cut back on prosperity etc) to me. Are any individual states doing anything as seemingly the government currently are not although I now understand that the democrats plan to now that they have some power to wield.

  35. 185
    L. David Cooke says:

    RE: #180

    Hey Margie;

    Looking at the data regarding the NOAA indicated SST anomalies I suggest this El Nino event is nearly dissipated, if you look at the most recent animated weekly Pacific SSTs.

    The reference:

    As to the total amplitude, I disagree, this El Nino was marked with small pools of elevated temperatures and not a contiguous event. The obvious character was of a concentrated region that simply moved along the Equator to dissipate quickly in the Eastern Pacific. It is more likely that this event was either more of a interim indication of an extended El Nino to come or it could be an early release valve such that the energy does not build up.

    I suggest that the question becomes more of whether we are going into a period in which short lived El Nino/La Nina events switch out every year. There is the possibility the former idle periods are going to end and at some level, you will have one or the other event every year.

    It maybe that the old nature that held the higher temperatures in place, that were associated with El Nino events, may have changed in that the heat energy may not rise to the former sustained levels. It may be the widespread intensity of ENSO or SIO events are weakening as examplified in SSTs. Until we have sufficient examples, it is going to be difficult to know.

    Likely or not, we may be able to look to the Arctic for clues. I am now curious whether there may be a mode in which strong sustained NAO events may indicate weaker and short lived ENSO events, likewise the inverse. Much more study is required to see if the correlation (@r2=.49) of ENSO to NAO may have more then one mode. So much to do and so little time�.

    Dave Cooke

  36. 186
    Chris O'Dell says:

    I found a link to the global December 2006 Land Surface Temperature anomaly,
    from NASA-EOS (thanks to my colleague here at ECMWF) based on satellite measurements of the skin temperature:

    As a caveat though, this is as compared to a 2000-2005 base period and is from MODIS data (the MODerate resolution Imaging Spectroradiometer).
    You can see that, as stated above in one of the previous comments, the northern hemishpere land masses were anomalously warm, but the same is not true for the southern hemisphere. I’m more of a satellite person than a climate person so I can’t really say this is more or less attributable to El Nino or AGW or whatever, but it is interesting I think.

  37. 187
    Dr. J says:

    Re: #165, to Barton Paul Levenson:
    As them for their math, I think they have it.

  38. 188
    Leonard Evens says:

    This topic has come up in media I frequent twice within recent days. The Chicago Tribune had a front page article attributing the anomalously warm weather in the US this winter clearly to global warming. Although El Nino was mentioned in passing, the article totally ignored any subtlties. The other was an interview on NPR of Michael Mann, who was described as ‘a meterologist’. He did the best he could with the questions he was asked, and I’m sure they edited it eliminating some extra illuminating comments. But I was disappointed that they didn’t spend more time on it. Also, characterizing him as ‘a meterologist’ seemed to me the understatement of the year, and probably annoyed the NOAA people no end.

    [Response: Thanks for your comment Leonard. For those who are interested, the interview is available online here (click on "listen" link). In NPR's defense, my primary appointment at Penn State is in the Department of Meteorology (and my Ph.D training was largely in that subject area). Also in NPR's defense, while they did indeed cut some (and so my "dice rolling" analogy didn't get described in sufficient detail), they did devote a good 5 minutes to this, on a day when there was lots of other new to discuss. As an aside, I found Robert Siegel to be an unusually affable interviewer. -mike]

  39. 189
    Dan Allan says:

    re 180:


    Your point seems to be that, if the anomaly comparison were apples-to-apples, then the 2005-2006 anomaly would be just as dramatic as the 2006-2007 anomaly. Interesting…considering that 2005-2006 was a La Nina winter. I can only presume that you are therefore arguing that ENSO has no effect whatever on the anomaly, since it is just as pronounced during La Nina as during El Nino.

    In other words, your point directly contradicts your conclusion in the following paragraphs.

  40. 190
    Oyvind L says:

    Hi – I see some want to know the european story. Well, my good collegues at the norwegian met-office has viewed 2006 in a century perspective ( . only in norwegian but the graphs should be easy grasp). As bottom line, 2006 is the warmest year on record (el nino or no el nino). December 2006 is represnted by really huge anomalies. We also see evidence of ‘polar amplification’ when we consider Spitsbergen. December had mean temperatures up to 9 deg C above normal and 2006 was 1.3 deg warmer than any previous year measured (back to 1912), including the warm 1930′s and was 5 deg. C above normal.

    And point is? As neatly stated by Mike above, anthropogenic effects are not to be used as explanation for the exact temperature-pattern this day, month or winter as little as ENSO should be used to explain the global warming over the last century.
    when the global mean goes up – the extreme anomalies will follow if the amplitude remains stable. Now, that may of course not be the case.

    greetings from bergen on the 75th concequtive day of precipitation!

  41. 191
    L. David Cooke says:

    RE: #187

    Hey Dr. J;

    Actually, we have had a fairly long discussion regarding the study by Dr. Scafetta on this site this past Fall. The indications are that there reamins additional work to be done, as the periodic events that Dr. Scafetta linked to did not seem to have a valid reflection in down-welling measurements. Even if you apply the Granger Causuality lag for the statiscical verification the period detected by the ACRIM experimental package did not match up with the observed data. I had even sugested to Dr. Scafetta, when he visited us at Elon, that the character of the coupling of the insolation to the observations appeared questionable and that might be worthy of review.

    Dr. Scafetta continues to try to demonstrate what is in character a capacitive coupling or a near linear rise to a peak and then a drop. My point was the input was more similar to an inductive coupling in which there was very little change until a point in which a variable achieved maximum capacity and then the level would quickly rise and just as quickly fade out. (More of a reflection of the input energy.)

    The point is the insolation may not be directly measureable. Instead it may be that the increasing energy level of a variable has a separate period. (Similar to how you can ring a conductor with a pulse of shorter amplitude.) In addition, with the simple TOA solar constant 1-3% variability and the 13 Deg. C to 20 Deg. C average ambient surface varibility window, with a 0.6 Deg. C noted increase or approximately an 8.6% increase does not seem to track very closely.

    However, that was only my interpetation, Dr. Benestad and others here seem to have other concerns. In the meantime, I have been reviewing the site for the past 6 years and have not seen a dramatic change at in the surface down-welling detected in either the longwave or the shortwave bands. I am hoping the recent changes in the pyrometers, as to having a more descrete bandwidth and a wider spectrum, may provide a better indication of radiative budget effects. On the other hand we still have additional work to do regarding the ICME and CR correlations.

    Do you have additional observations you would like to explore in regards to the solar participation? If so it is possible that Dr. Schmidt or Dr. Benestad may be willing to entertain a review of this in another thread, providing there is new or improved data to be discussed.

    Dave Cooke

  42. 192
    Eric Swanson says:

    Re: #145

    Right, and there is still another problem with Christy and Spencer’s results for the Antarctic. In a paper in the GRL, I pointed to a difference between sonde data and the 2LT in the seasonal cycle. See:

    “R. E. Swanson (2003), “Potential error source in Microwave Sounding Unit tropospheric temperature trends due to sea-ice influence in polar regions”, doi:10.1029/2003GL017938.

    Alao, as far as I’ve been able to learn, Spencer and Christy never actually documented the method which they used to produce their 2LT algorithm. I suspect it’s based on the lapse rate found in the U.S. Standard Atmosphere, which is rather off-base over the polar regions. The folks at RSS who produced another analysis of the MSU using the 2LT process do not include any results southward of 70S, noting the impact of the high surface elevations there. Yet, Christy continues to post his analytical result, even though it may be flawed. Not only that, but Christy is frequently quoted in media reports, whereas the other workers in the field are mostly bypassed.

  43. 193
    Eric Swanson says:

    I occasionally look at the data for daily record temperatures which are reported through the U.S. NWS. The last few weeks have been rather interesting as the record warmth was quite a bit above previous records. This is weather, of course, but still, there are often more than 100 years of data included in some of the records.

    What I found most interesting was the occurrence of a string of record high MINIMUM temperatures lately at Key West, FL. This location is far out in the Gulf of Mexico and very near the Florida Current, which “drains” the Gulf of Mexico and loops around the East Coast of Florida. The flow continues to the north, eventually becoming the Gulf Stream as it turns towards the east off North Carolina. My guess is that the current is also rather warm, perhaps the result of the lack of large tropical storms over the Gulf last season. The latest northward flows of warm, moist air may also be related to extra thermal energy from the warm Gulf of Mexico.

    Just a thought from a non-expert…

  44. 194
    L. David Cooke says:

    RE: #193

    Hey Mr. Swanson;

    Actually, I suspect that the GOM may be a bit cooler this year then even last year. Not that the temperatures are lower then normal, just fewer temperatures higher then normal. Take a look and compare the last few years AM/PM values and share your observations. (The historic data is under the specific regional images…) (BTW: Take a look at the Caribbean Basin near Cuba, even here there appears less of a ramp up this year, of course this is just the beginning of the season. The real clue is going to be to observe the GOM and Eastern Caribbean results in late Feb through early Apr.)

    The reference:

    Dave Cooke

  45. 195
    Alexander Harvey says:

    Is there a metric for the “amount” of weather?

    By this I mean weather as defined as the varinace from the expectation (climate) of temperature, humidity, rainfall, wind speed , etc., at a particular location, date and time.

    Such a metric would not suffer from cold spells aguing against the evidence of hot spells etc. It would be the square (always positive) of the amplitude of the difference from the mean (climate) that would be significant.

    Obviously this would not measure climatic change in the sense that it is normally considered, but an increase might indicate the system is moving into a higher gear with more work being done due to the increased energy available.

    Personally I fear that initially and in the short term it will be the weather that will cause as all a lot of grief.

    It may turn out that we are not longer able to predict the weather and the seasons in the way that we, and the rest of nature, are used to. If so, systems both agricutural and ecological might just start breaking down.

    I realise that freak weather events are counted and catalogued but I was thinking about something a bit more general and continuous than that.

    So is such a metric currently available?

  46. 196
    Gaudenz Mischol says:

    No way to get my comment through. What’s wrong with it?
    Anyway, it’s to late for the answer, forget it and continue censoring your blog.

    [we're not sure what comment you're referring to]

  47. 197
    Paul M says:

    If the predictions as little as thirty years ago came true, there would be no oil left in the ground and the ozone layer would cover only one fourth of the earth. There was no talk of human induced global warming back then, only of stopping the aerosols. Any scientist can make a case for global warming or not, just as many intellectuals can make a case for intelligent design. While I hesitate to call proponents of intelligent design idiots, I also hesitate to call intelligent people who believe climate change is not human induced names as well. The human race is on the verge of new paridigms in space and technology, but socially we are still in the 600′s. The intelligent scientist as well as the moron will perish side by side as the earths atmosphere and terrestial biology disconnect.

  48. 198
    Gaudenz Mischol says:

    I been posting three times (including the last one).
    Here it is again:
    Re 84: dy you really believe, climat was so stable during the last 2000 years (believing in the HockeyStick Curve)?
    Everybody who is interested in historical climatology, which ist perhaps more known in Europe, will see that there have been quite important flucutations in the climate and men has been able to adapt to it.
    With this statement I do not mean to continue in business as usual, but I would not expect the climate to stay “stable” by cutting down our CO2-emissions.
    And up for now we have no real alternative for fossil fuel to cover our demand on energy and as we as men and women are not that good at limiting our energy cosumption without external forcing (hopefully not from climate change), I don’t see no solution so far.

    [Response: Read our comment policy focusing on item #7 , and you will understand why comments like this often don't make it through. You repeat specious talking points that have been debunked countless times before on this site. In short, your comments adds "noise" not "signal". It was admitted this time only to make a point. -mike]

  49. 199
    Steve Sadlov says:

    RE: #177 – Noting also, the collective impact of convective activity in both the West Equatorial Pacific Warm Pool as well as the East Indian Ocean. Consider them as sort of a “dipole transmitter” capable of greatly affecting the global heat engine. ENSO is only one element of the system.

  50. 200
    Steve Sadlov says:

    RE: #184 – in fact, in the US there is a massive forward momentum in terms of what I’d term “stealth” anti GHG efforts. It is more action than talk. It is being led more by the business community than government (and to fend off the predictable “Exxon” this and that, Exxon is but one company – overall, corporate America are true believers in killer AGW – I know, I am part of one that is). Not if but when the US quietly invests in cap and trade, and even more draconian emission controls than found in the EU, you will see the true magnitude of this.

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