RealClimate logo

Technical Note: Sorry for any recent performance issues. We are working on it.

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. 201
    SecularAnimist says:

    Barton Paul Levenson wrote: “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 was a thread a while back on RC about the meaning of terms like “runaway” greenhouse effect. What I took from that discussion is that “runaway greenhouse effect” is not a scientifically-defined term and thus may be legitimately used with different meanings, but people should be certain to be specific about what they mean when they use such phrases.

    I think the person who posed the question of whether we are seeing the early signs of a “runaway greenhouse effect” may have been definining it in the way that I do, namely, a greenhouse effect that has been increased by anthropogenic GHG emissions to the point where the resultant heating triggers self-reinforcing feedbacks (e.g. release of carbon & methane from melting permafrost, decreased polar albedo from melting sea ice, die-off of oceanic phytoplankton, etc) that are then entirely beyond human control and will continue to increase the greenhouse effect and heat the Earth’s biosphere to the point of global ecological catastrophe (e.g. mass extinction of much, or most, of life on Earth, as has happened in the past) even if humans ceased all anthropogenic GHG emissions.

    It seems to me that this process need not proceed to the Venusian scenario to be properly characterized as a “runaway greenhouse effect”.

    And in the sense that I defined the phrase above, I would say it seems to me very likely that we are seeing the early stages of a “runaway greenhouse effect” because the feedbacks that I mentioned are, in fact, all being observed already.

  2. 202
    Eli Rabett says:

    Perhaps assigning numbers to each such argument, with the refutation as a link, such as:

    Do you really believe climate was so stable during the last 2000 years = 7

    Believing the hockey stick curve = 19.

    So that #198 could be replaced by

    Michol posts #7 and #19.

    would suffice. It would lead to some interesting dialog: #22. No #4. I disagree it is clearly #17.

  3. 203
    Eric Swanson says:

    Re: #194

    Dave Cooke,

    Yes, I do think it’s rather strange that the data from Key West is indicating record temperatures for January, while the SST anomaly data from satellites shows below average temperatures.

    In a event report from Key West, it was noted that:


    The day before, they reported:



    Since Key West is a small island surrounded by lots of ocean, it’s unlikely that this warmth is in any way the result of mankind’s influence. Of course, the instrument used to take the measurement may be faulty in some way. However, there were also a few instances of record warmth reported from other locations in South Florida as well.

    There’s another winter storm brewing in the U.S. Mid-West. Looks like another warm/wet mix as it’s raining over the Southern Plains and snowing towards the north. Rain in January?? I’d better get the snow shovel ready again.

  4. 204
    cat black says:

    #202 (Modest Proposal) That is just about the funniest thing I’ve read on RC. More so for being much in the spirit of what goes on here. Though serious most of the time, some of the common denialist claptrap verges on comedy. Especially when they #8 and #42 in the same post, with strawman #11s for good measure. You gotta love that!

  5. 205
    cat black says:

    re #200 (“stealth” anti-GHG) In fact, I’ve been watching and wondering what the insurance industry is going to do. I understand they’ve been quietly collecting data and rejiggering their actuarial databases to factor in *anticipated* losses from massive hurricanes, coastal flooding in urban areas, and who knows what else (they don’t want to discuss it, obviously) in what I imagine is a mad scramble to cover their soon-to-be mounting loses. I further imagine that their industry, while rich, is perhaps on the verge of becoming extinct, or maybe a luxury item, when they become squeezed between what people can actually pay in premiums verses the real losses the industry must absorb. Certainly we can’t expect wages and income to go up just because insurance prices rocket. And if the insurance industry prices you out of the market you can bet it’s for a reason, and that should be all the signal you need to get the hell out of the way of whatever they *know* is coming.

  6. 206
    Lynn Vincentnathan says:

    RE #178 & “New Zeland Cooling”…

    And not a moment too soon! Apparently there are huge amounts of methane clathrates off NZ’s coast (a potential time bomb) that could really jumpstart runaway (from human) heating conditions. See:

    So let’s hope this cooling trend continues (which even if it does, does not a GLOBAL cooling trend make, of course).

    And BTW, re #178, I think it’s just fine for laypersons to use the term “runaway warming,” since we tend to think in human & not geological or venusian terms. As I’ve mentioned many times before, “runaway” does not in and of itself indicate permanent runaway, but could indicate limited runaway (or positive feedback situations) that eventually stops, stabilizes, then reverses. So, to me, when speaking about earth in the current epoch, any mention of “runaway warming” would refer to this limited type, while speaking of earth, say, 3 or 4 billion years in the future, perhaps the term “runaway” might indicate something more like what’s happening on Venus.

    The point is we laypersons NEED A WORD for this, something simple, and the problem with “positive feedback situation” or even more scientific jargony & lengthy phrases and sentences to capture the same meaning would lose the audience after the first 2 words. Another problem is that “positive” feedback, sounds like something good, and people may not understand it. There are lots of people who still think GW has to do with hairspray causing an ozone hole; and now some may be confusing GW with el nino….since these 2 are mentioned in the same news stories these days.

    And I think “runaway” is something people can understand. People do understand the idea when a horse runs away with a rider, or when a kid releases the parking brakes by mistake or mischief and the car starts rolling downhill, with no one to stop it, except a tree or house. I don’t think people automatically think of “runaway” as necessarily being a permanent state; more often than not the thing stops or gets stopped.

    If you can think of a better word than “runaway warming” for this positive feedback situation (carbon emissions–>GW–>more carbon emissions–more GW–>still more carbon emissions…and so on until it stabilizes and reverses), then please let me know. And “Rumplestilskin” is not okay.

  7. 207
    Urs Neu says:

    A view at the NCEP Reanalysis data (thanks to Ilewelly for the nice link, NCEP Reanalysis Derived data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at shows the following:
    - Over the last five years (2002-2006), December temperature anomalies (compared to 1961-1990) were most positive over the Arctic, especially around Spitsbergen, over the Northern part of North America and Northern Europe, most pronounced over Western Canada (5 to 7 K). December 2006 had the same centers of positive anomaly (Spitsbergen, Western Canada and Scandinavia), but more pronounced (7 to 14K) with strong positive anomalies extending farther into the midlatitudes (including Siberia) and slight negative anomalies over the Arctic sea ice.
    - January temperature anomalies over the last five years were most positive over the Arctic Sea Ice and Spitsbergen and to a smaller extent over the U.S.
    - There are no persistent patterns for monthly means, neither over the 5 years nor over the winter months, although Western Canada and Spitsbergen have strong positive anomalies during most of the winter months of the last 5 years.
    - The winter mean (DJF) over the last five years shows (accordingly) strongest warm anomalies around the North Pole and Spitsbergen, and to a lesser extent over Western Canada and over the sea East and West from Greenland.
    Thus: The geographical patterns mostly seem to be �weather�, the long-term signal is consistent with polar amplification of global warming. Maximum regional anomalies for individual months are stronger in the last two years than the three years before.

    Winter (DJF) trends of spatial averages since 1970 are
    - North of 75N: 0.83K/decade
    - North of 60N: 0.57K/decade
    - North of 45N: 0.47K/decade
    - 60-75N: 0.51/decade
    - 45-60N: 0.39/decade

    Thats what the NCEP2 reanalysis says. However, I have some troubles with the NCEP data concerning the Alpine area. The measurements show a winter trend for Switzerland since 1970 of about 0.4K/decade while the NCEP data has a slightly negative trend. I will have to ask the specialists at NOAA…

  8. 208
    cat black says:

    #195 [weather metrics] Here in California, today and the rest of the week we’re having record cold. It’s being handled as severe weather, with a radio announcement from the Governor and everything. This comes on the tail of eerie, record warmth the several weeks prior. I can predict now that denialists will say “oh look now it’s record cold again! it’s just weather!” but even the NWS is saying that this cold snap is Arctic air, which CA almost NEVER sees. Our prevailing winds come off the Pacific Ocean, which for 2 years running has had an anomolous SST some several degrees F warmer than usual just off our shores. I don’t know what the SSTs are now, but having Artic air blowing in from a strange direction and killing the citrus and any plants that were blooming in the unseasonal warmth is just as weird as the warm days before. Point being, we’re seeing savage, wild swings of the weather pendulum this week and it is looking *real* scary here in the mid-latitudes.

  9. 209
    Hank Roberts says:

    > numbers
    This would certainly facilitate playing Global Warming Skeptic Bingo.

    >Key West is a small island surrounded by lots of ocean, it’s unlikely
    >that this warmth is in any way the result of mankind’s influence

    Human activity warms the oceans; warm oceans warm the islands they surround.

  10. 210
    L. David Cooke says:

    RE: #203

    Hey Eric;

    Actually, there was a small tongue about 82 to 80 Deg. W and 25 to 28 Deg. N of warmth that whipped around through the Straights of Florida about the time you have marked. However, the short duration of such an event is not representative of anything special. Though it would be interesting if you had an explanation of what contributed to this small anomaly.

    This only goes to reinforce Dr. Mann’s earlier call for a reduction in the discussion of one off events and a reference to the “loaded dice theorem”. Variations in patterns are normal, that an average temperature is given only establishes the middle of the range. It is when you look at the range that you begin to discuss possible GW drivers. Though the high and low temperatures for a day temperature may be between 76 and 38, they average out to 57 Deg. F and so do 67 and 47 Deg. F.

    Where 67 and 47 Deg. F may not be abnormal, 76 for the high or 38 Deg. F for the low may be cause for concern, as they are less likely to occur; hence, the concern over long term shifts, not spot events. The problem with using averages is that the indicated change when you have a lot of data points is there is an abnormal weighing of the average towards the middle.

    This is part of why what is considered normal is determined to be within windows of time, for which the recent trends are not over burdened with a long history of values reducing the impact of the variation. Another way to point to interesting trends is to look at the high temperature for a specific date averaged over many years. However, the greatest impact is looking at the range of historic temperatures and checking the trend for recent temperatures within that range for a given date or for a collection of subsequent dates.

    (Sorry for monopolizing this post today, I will step back and watch to see what others have to say on the subject of temperature trending of observed patterns versus unknown; but, suspected sources. Have a great day y’all!)

    Dave Cooke

  11. 211
    Hank Roberts says:

    > … Key West is indicating record temperatures for January,
    > while the SST anomaly data from satellites shows below average….

    You’ve given us a link to the December _2003_ SST anomaly data.

  12. 212
    Hank Roberts says:

    Current and archive for SST anomaly maps:

  13. 213
    llewelly says:

    Eric, please see NCDC’s week of jan 3, 2007 SST anomaly. (Thaks to Hank Roberts and Cooke for pointing out other issues with your post).

  14. 214
    Gareth says:

    I suspect that “runaway” is often used as an (inaccurate) synonym for “rapid”. Looking at the figures in #207, you could make a case for a “rapid” shift in climate, at least as perceived by anyone living in the relevant regions. Which leads to the problem of definition. If climate is defined by a 30 year average, changed once a decade, how do you describe a climate shift where the underlying rate of change is significantly faster? In the case of Urs’ figures there is confirmation of projections and a hint of faster change more recently. The layman. seeing this, may conclude that climate has changed, is changing, and that the rate of change is increasing. This could be described as “runaway”, and – frankly – I wouldn’t blame them.

  15. 215
    Mike Burnett says:

    As I view it, climate is the average of the weather. So climate change cannot cause a change in the weather. Rather, changes in the weather are reflected in changes in the climate. It’s like in baseball. A hitter might be a great hitter and hit .400. But the fact that he hits .400 doesn’t make him get the hits. Weather is the hits, climate is the batting average.

    [Response: Nice analogy. One could take it a step further. Greenhouse gases are to the climate as steroids are to the batting average. If a player on steroids hits a home run, you'll never know if it was because he was taking the steroids. However, the use of steroids is likely to be clearly reflected in an improved batting average. In baseball, steroids have of course been banned. -mike]

  16. 216
    Eric Swanson says:

    Re: # 210, 211, 212, 213

    Thanks guys. I somehow went from David Cooke’s link in #185 back to 2003. But compare:


    That last one shows a warm “hook” between Cuba and New Orleans, which is probably the loop which has been reported in the Florida Current as the flow shifts back from the flow entering the Gulf from the Caribbean Sea. One is left to wonder why the two versions appear different.

  17. 217
    Jodro says:

    “I think the person who posed the question of whether we are seeing the early signs of a “runaway greenhouse effect” may have been definining it in the way that I do, namely, a greenhouse effect that has been increased by anthropogenic GHG emissions to the point where the resultant heating triggers self-reinforcing feedbacks.”

    Thanx #201, this is indeed the way I meant it. Was not thinking of Venusivian catastrophes. Runaway simply means self-reinforcing, or, perhaps ironically, ‘positive’ feedback that we humans can’t control anymore. So one question here, why are all the feedback mechanisms ‘positive’? Why aren’t there feedback mechanisms that work the other way, ie towards cooling? Or are there? Or can we create some?

    And also, is the current dramatically warm weather in Europe and North America mirrored anywhere else on the planet? Ie, has most of the planet been way above average in recent months, or are significant other sections below average?

    Then, according to the World Development Movement (,,1984815,00.html) the UK began emitting more carbon than is sustainable in 1830. It seems that we’re over our heads in it, and given the way our political systems work, our societies won’t make any dramatic changes in emissions until catastrophes have already happened…

    In this context, is there anyone here who thinks we have realistic chances of turning this whole thing around? Or are most of you in agreement with Lovelock, who predicts Armageddon? In the latter case, what do people suggest? Everyone intelligent move to Canada and Norway in the next few years? But I haven’t heard of mass migration among climatologists, so…

  18. 218
    Lynn Vincentnathan says:

    RE #214, yes, I think we should talk about “rapid” warming, if applicable, but “runaway” is something much more than that. For instance, if human GHG emissions are causing this current warming, then we might expect more rapid human GHG emissions to cause more rapid warming. The warming would still be under human control — just reduce emissions and the warming would reduce.

    In a limited runaway scenario (which some scientists refer to as “hysteresis,” and it is the main focus of Lovelock’s REVENGE OF GAIA), at some point the increasing warming caused by human emissions would trigger nature to start (net) emitting GHGs. Maybe you could say that the warming is “forcing” the GHG emissions from nature, such as warming causing GHG emissions by melting permafrost & frozen ocean methane clathrates. And the warming might cause other effects that feed back into further increased warming — such as (1) heat, drought, floods, ocean acidification, GW wind-whipped brush fires killing plants that would have absorbed CO2, and (2) human-induced warming melting snow and ice (which we know reflects light & heat back away from earth), leaving darker soil and ocean, which absorb heat and lead to further warming, leading to further ice/snow melt. One could do an experiment to prove this — just place a black blanket over some snow and a white blanket over some snow, and see which one melts faster. Oh, yeh, a lot of typically snowy places don’t have snow this year. Well, I’m sure there’s some other experiment one could do.

    So the point is, runaway in lay terms means “runaway from human control” (people in general would be more interested in this than “permanent runaway” warming on Venus or on earth 4 billion years from now).

    In the rapid warming scenario, it’s still within human control. All we have to do is cut back at any time to reduce the warming. In the runaway warming scenario — even if it isn’t as rapid as the “rapid scenario” — the situation is in the long run a lot more dangerous. It means there’s a point at which even if humans go down to zero GHG emissions, the warming we have caused to that date will trigger nature into an upward spiral of warming, perhaps making lots of species go extinct and killing off large chunks of humanity. I’m not sure how fast this would happen, once this point it reached, but past such “limited runaway” warmings happened over thousands of years, stablized at very hot for 80,000 to 200,000, then gradually returned to “normal” (like today’s conditions). The PETM 55,000 mya & end-Permian 251,000 mya are examples of this type of “limited runaway” warming of which we speak.

    So it’s not the “rapid” that is ultimately as dangerous as the “runaway,” even though “regular” AGW — which we can reduce by reducing our GHG emissions — promises to be very harmful indeed.

    Maybe a good analogy would be this: “regular” warming is like heating one’s house with a thermostat…Junior keeps turning it up (people emitting GHGs), so it keeps getting hotter, until Mom comes and turns it back down (gets people to reduce their GHGs), and the heat goes down. In “runaway” warming, Junior keeps going back and turning up the thermostat, until the heat gets to be so much it short-circuits something and the house goes up in flames — and the fire rages out of control, engulfing many houses around it (making many species go extinct); eventually the fire burns out and after many many years someone comes and builds a new house.

  19. 219
    Hank Roberts says:

    > # 210, 211, 212, 213
    You got to the image from 2003 by clicking the back-link on the page mentioned in #185 — it should go ‘up’ to 2006. It goes to 2003 instead; I emailed their webmaster. Good catch, ‘tho _it_ caught _you_.

  20. 220
    Plato says:

    #197 Paul M., 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.

    Couldn’t said it better, thanks.

    Sincerly, Plato

  21. 221
    llewelly says:

    Eric, the base period of those two SST anomaly maps is quite different. The first (NCDC) uses a 1971-2000 base period, whle the second (OSPD) uses ’1984-1993, with SST observations from the years 1991 and 1992 omitted due to aerosol contamination from the eruption of Mt. Pinatubo.’

  22. 222
    cat black says:

    re #205: Regarding my post about insurance companies running for cover, this little gem just popped up in my inbox:

    Regarding the verdict (and the threat of punitive damages), Robert Hartwig, chief economist for the Insurance Information Institute in New York, said “It adds even more cost and more uncertainty to the other problems that already exist in the Mississippi homeowners insurance market.”

    Read: If the courts make us pay, we might not be able to insure.

    You read it here first.

  23. 223
    Grant says:

    Re: #217

    … is there anyone here who thinks we have realistic chances of turning this whole thing around?

    I think we have a realistic chance of averting Lovelockian disaster. Don’t get the wrong impression; it’s gonna be bad. But we may be able to avert the worst case.

    Perhaps the best way to accomplish this is to make global warming the #1 issue at the voting booth. When politicians are faced with extinction…

  24. 224
    Occam says:

    These statistical conventions sound “scientific”, but are they? No, they are just another language code. The sentence “one warm season can’t be attributed to climate change” is the same as a historian, fx. a roman historian in 410 saying: “one lost battle can’t be attributed to our Empire collapsing.” Or a scientist studying mudslides saying “just one tiny particle slipping away can’t be attributed to a whole mudslide taking place.”

    The problem is this: we think we know what climate change is, based on geological records, meteorological etc. But we don’t. Our thirty years averages are pure statistical convention. Because the globe has problably never seen as fast a rise in CO2 levels as happening now before – we can’t know anything about what they’ll mean to the global climate. This has never happened before. Maybe climate change/warming by now is growing so fast, because the atmosphere has crossed a threshold, that the effects are litterally exploding from year to year. We haven’t got the time to wait and see, the risk is too huge. We must act before we know for sure.

  25. 225
    Grant says:

    Re: #224

    Because the globe has problably never seen as fast a rise in CO2 levels as happening now before – we can’t know anything about what they’ll mean to the global climate.

    I think the point is, in large part, valid, that we are in unexplored territory and it’s very difficult to “expect the unexpected.”

    But it’s not impossible. The history of science is replete with predictions of phenomena which had never before been observed or even conceived of. The existence of antimatter is one example.

    I’m not saying we know enough about climate to predict reliably its future course. There’s a lot we don’t know. But there’s a lot we do know. Your statement seems dangerously close to the “we don’t know everything, so we don’t know anything” argument (which usually comes from denialists).

    So while I agree that there are likely some big surprises to come from rising CO2 levels, in my opinion there are some things that we can reliably predict. Mainly this: it’s gonna get hot in here.

  26. 226
    Peter Backes says:

    Re: #215

    Both nice analogies.

    Forgive me if I can’t resist taking it another step further: And the fossil fuel companies and their political allies are like the steroid pushers?

  27. 227
    Rhampton says:

    Exxon may be warming to greenhouse gas rules
    Reuters, January 11, 2007

    Exxon in 2006 stopped funding the Competitive Enterprise Institute, a nonprofit advocating limited government regulation, and other groups [e.g. TCS Daily] that have downplayed the risks of greenhouse emissions. Last year, CEI ran advertisements, featuring a little girl playing with a dandelion, that downplayed the risks of carbon dioxide emissions…

    “The fact that Exxon is trying to debate solutions, instead of whether climate change even exists, represents an important shift,” said Andrew Logan, a climate expert at Ceres, a coalition of investors and environmentalists that works with companies to cut climate change risks.

    In a report last year on how oil majors are addressing global warming emissions, Ceres gave Exxon a 35 — the worst score. Oil majors BP Plc and Royal Dutch Shell got 90 and 79, respectively.

  28. 228
    Guest says:

    RE: #222 Jury awarded the policyholders $2.5mm in punitive damages. On to the Fifth Circuit, undoubtedly.

  29. 229
    Craig Allen says:

    Re #217

    Like Europe and North America, Australia too is experiencing extreme climate.

    See the “2006 Annual Climate Statement from the Australian Government Bureau of Meteorology “ for a short but informative summary of what came our way last year.

    2006 was the 6th hottest on record (averaged across the continent). In the drought stricken southeast we had record warm daytime temperatures.

    However, it is the rainfall that is behaving really anomalously.

    The Annual rainfall deciles for 2006 map within the above climate statement demonstrates this really well. regions in the far south west and east have experienced their lowest rainfall on record (on top of five years or more of low to very low rainfall in many areas). In the north and west the rainfall is very much above average or highest on record.

    Of course this could all just be a statistical hiccup being hyped up by climate alarmists at Australian Bureau of Meteorology!

  30. 230
    Hank Roberts says:

    To veer back on topic:

    January 11, 2007

    “… The upper ocean heat content since April 2006 has been modulated by oceanic Kelvin waves …. Four distinct Kelvin waves have occurred in the last nine months (Fig. 4), with the amplitude of each wave exceeding that of its predecessor. The most recent Kelvin wave (bottom of Fig. 4) reached the west coast of South America during the last half of December 2006, resulting in a warming of the subsurface and surface waters along the coasts of Ecuador and northern Peru.

    “… In the absence of any further Kelvin wave activity, the upper-ocean heat content should return to near average in a few months. However, there is considerable uncertainty in this outlook, given the resurgence of MJO activity in late December 2006. It is possible that the enhanced precipitation phase of the MJO, which is currently entering the western tropical Pacific, might trigger a more persistent pattern of cloudiness and precipitation over the anomalously warm waters of the central equatorial Pacific during the next several weeks. If that occurs, then the equatorial easterlies over the central Pacific will likely weaken possibly leading to the initiation of a fifth Kelvin wave. …”

  31. 231
    Joseph O'Sullivan says:

    Re: 15 Mike Burnette and Mike’s response

    Analogies work. Trial lawyers use them to explain to explain complex topics to people who are not familiar with them.

    I personally like sports analogies. The batting average is a very good one. Weather is like one game, where climate is like a season. For example, to determine who wins the batting title you have to look at who had the highest batting average over the entire season, not just a few games.

    The extremists on both ends who are like fans who insist their favorite teams are going to win the championship (insert world cup, super bowl, world series etc. ;) ) even though their teams have no chance of winning.

    Finally cherry picking is like gathering all the MLB films that show all the times that Cal Ripken Jr struck out out then arguing that he should not be in the hall of fame, but if you look at his entire career its a no brainer that he should be in the baseball hall of fame

    But as for analogies for someone who is not a sports fan, I have not thought up good ones yet :)

  32. 232
  33. 233
    mohammed abdulrahman says:

    I have noticed that the study concentrate on the effect of el nino on north america,have there been any study done on its effect on other parts of the world such as the middle east. Many thanks

  34. 234

    Re 215


    You wrote “nice analogy” in reply to your namesake Mike Burnett, who had written “climate is the average of the weather” and then went on to compare climate to batting averages. It is a nice analogy of climate but not of the climate system. There is a confusion between climate, as average weather, and the climate system which at a local level is more like an El Nino. The climate is found by taking the average over 30 years, but the climate system can change within as short a period as three years. See Richard Alley’s description of the ending of the Yonger Dryas in his book “The Two Mile Time Machine.”

    Section 1.1.1 of the IPCC TAR concludes “We must understand the climate system, the complicated system consisting of various components, including the dynamics and composition of the atmosphere, the ocean, the ice and snow cover, the land surface and its features, the many mutual interactions between them, and the large variety of physical, chemical and biological processes taking place in and among these components. â��Climateâ�� in a wider sense refers to the state of the climate system as a whole, including a statistical description of its variations.” So although the IPCC recogises the difference, they are still mixing up the statistics with the system. That is why the Heretical Concensus of the IPCC are falling out with the Realists who know that the climate is a dynamical system. (Don’t confuse RealClimate-ists with Climate Realists. They are the complete opposite!)

    The problem is that the ordinary scientist understands statistics, but is unfamiliar with feedback. Thus he can visualise a smooth transition that happens when negative feedback predominates, but has no concept of the abrupt change that can happen when positive feedback takes over. This is partly due to the fact that he has never expeienced rapid change. When positive feedbacks dominate the system is unstable. It then rapidly changes until a new stable state is reached. There it remains. Thus a system does not spend 50% of time with positive feedback and 50% with negative feedback. This would imply that it is unstable 50% of the time. Most of the time the system is stable, and only unstable for very short periods. No one living has experienced unstable climate, so they believe it cannot happen.

    However, a few scientists know from past climates that rapid climate change can happen, for instance Richard Alley, Wally Broecker, and James Lovelock. It is time you RealClimate-ists came out of your safe concensus bunker and joined the climate realist who can see the dangers facing the world.

  35. 235
    Sally says:

    Re:195. “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.”

    I’m in favour of an index of extreme or anomalous weather events. I thought of an acronym for it. Planetary heuristic of weather events, or PHEW!

  36. 236
    Sally says:

    With reference to the discussion about sea surface temperatures I would like to see a critique of the various sites available online. My personal favourite is where you can get archived charts by going to the home page.

  37. 237
    Jeffrey Davis says:

    A “runaway greenhouse effect” to my naive understanding happens when the feedbacks from CO2 forcing eclipse the size of the CO2 forcing itself. I don’t know if that’s possible.

  38. 238
    L. David Cooke says:

    RE: # 233

    Hey al-Sayyid Abdulrahman;

    There are a few studies available from the and in the annual summaries there appears to be some references in the sites. However, as to extensive studies in regards to near equatorial countries other then South America (because it would directly be affected), ENSO or SIO events have not, to date, demonstrated a definitive global impact.

    Activity in the Nile Valley, South Africa, the Horn of Africa, some regions of Iran, Yemen, and Western India do have some studies as relates to patterns in the western Indian Ocean. The question is whether the effects of ENSO are a global signal or more of a regional event.

    Based on the newest evidence, it appears that there is a possibility of a global event effecting atmospheric patterns, such as ENSO, SIO and NAO then we have had in the past. Most of the recent data improvements have come about as our tools have improved and more technology has been employed. If there were more interest in the region of your concern and a desire to add to the pursuit of data I am sure there would likely be more studies and data available there.

    If you look at the recent SST interaction between the Western Pacific and the Central Southern Pacific you realize that there is some form of interaction occurring. At the same time when you see the build up of SST’s off Madagascar you have to suspect they are playing a part in the apparent cooling in the NW Indian Ocean. (Note: This is based on the SST anomalies links we have been discussing a lot in this thread.)

    As to a direct study of ENSO and Western Indian Ocean activity I have not seen much. That does not mean the region of your concern is unimportant. It more likely means that the region that is being addressed has more people that are interested in funding the research of weather/climate and the impact of global changes.

    Are you aware of any Middle Eastern atmospheric monitoring activities or weather organizations? It is possible there may be data that is kept locally and is not published. It would be interesting to have the ground based feedback to the remote sensing provided by the current satellite systems where there currently may not be any.

    Dave Cooke

  39. 239
    yartrebo says:

    Re #237:

    A runaway greenhouse effect happens when the forcing from the feedbacks (dE_feedback/dT) is greater than the extra radiation that the Earth emits from being warmer (dE_radiation/dT). If (dE_feedback – dE_radiation)/dT is positive, then a slight warming will push the Earth even further out of equilibrium and the warming will accelerate. Eventually whatever is causing the feedback will become saturated or the radiation component (roughly T^3, or the derivative of T^4) will overwhelm the feedback and the Earth will settle at a new, much higher temperature (perhaps 300C instead of the 13C we had before).

    With the current conditions on Earth, it’s impossible.

  40. 240
    Eric Swanson says:

    Re: #221, 236 and previous,

    llewelly, the base period for the first link (1971-2000) suggests that this plot is derived from the re-analysis of several sorces of weather data. The other plot is most likely calculated only by using satellite data. For what it’s worth, the satellite data may be more accurate, as it is calculated from one type of data.

    Sally, the UNISYS ocean surface temperature plot is interesting, but the anomaly plot gives more information about changes:

    As I write this morning, there’s lots of rain falling over middle America. The low level circulation around a surface high is producing the air flow which is feeding warm, moist air from the Gulf towards the north. Could be another batch of record high temperatures in Mid-America today, not to mention the effects of the clash of warm and cold air masses.

  41. 241
    L. David Cooke says:

    RE: #234

    Hey Mr. Mc Donald;

    I have a question, if you are looking to establish the baseline for climate I think I agree that the statistical averaged over 30 years is appropriate. However, if you are trying to establish a trend for temperature change would this not be a false indicator? It would seem if you want to track one value out of a number of values you would likely want to collect 30 values under nearly equivalent conditions to establish whether or not the a value is a normal distribution.

    I have always marveled at the temperature trends that get thrown around in relation to trying to describe temperature curves. Recent work that has been broken down into 30 year groupings are more likely going to produce poor trend data for a single variable, though it is very good for establishing a mean value. If you are looking for trend data, would you not want to establish the mean for each random sample window and then trend the sample?

    (If you take 30 years of a temperature on say the 30th of July globally, you will get a very different value then if you take 30 samples of July 30th when the humidity, the barometric pressure, the aerosol density/composition, and cloud densities are all within 5% for a given site.)

    It comes down to question of whether random samples will dismiss the all the other variables or not. The problem with this is you no longer can specify a date, month, season or even a year. In short, you have to look at all data within the descriptive window regardless of any categorization. This would seem to mean that even the 30 year baseline is invalid if you are tracing a single variable by a specific date, or you are trying to establish the mean for that 30 year period. So the question is do you try to link mean temperatures into a trend or do you try to trend data which is collected within a similar environmental window?

    (Note: There is going to be a problem with any 30 year window for temperature mean as the mean is apparently always shifting higher in the current ice age emergent environment. This means that you cannot establish a mean by a simple 30 year window for use in a standard statistical model. Your analysis will nearly always demonstrate a skew towards the higher range limit.)

    I am just sharing observations from the edge. My apologies if the points I am raising were outside the range of your point; however, when we are discussing these items it would be nice that the common definition was mentioned, especially in the presence of laymen, such as myself.

    Dave Cooke

  42. 242
    SecularAnimist says:

    Jodro wrote in #217: “In this context, is there anyone here who thinks we have realistic chances of turning this whole thing around?”

    In my personal opinion, which is only that of a “civilian” who tries to follow the climate change issue as closely as possible: No. We do not have a realistic chance of “turning this thing around”.

    CO2 emissions have been growing rapidly for over 15 years and are now growing faster than ever, around two percent per year, which is double the rate of only a few years ago.

    The International Energy Agency forecasts that by 2030, world energy consumption will increase by 50 percent above today’s levels, with resultant GHG emissions increasing by 52 percent.

    If there were 100 percent commitment by every single person on Earth — including all governments and all corporations, including the fossil fuel corporations — it would be an enormous challenge to slow down this growth, let alone reverse it, and actually reduce GHG emissions by the amounts and in the time frame of 10-15 years that scientists such as James Hansen say are needed to avoid global ecological catastrophe. And clearly we do not have such a commitment, and indeed there are very powerful and wealthy interests who are doing everything they can to prevent such a reduction.

    And the opinion of other scientists such as Lovelock, that we have much less time than Hansen believes (if indeed it is not already too late) cannot be discounted. Meanwhile there is mounting evidence of self-reinforcing warming feedbacks that could produce much greater GHG emissions from “nature”, that could be beyond human control soon, if they are not already. So the time available to “turn this thing around” through major reductions in GHG emissions may be only a few years.

    The bulk of the GHG emissions are from the developed industrialized countries, e.g. the USA, the UK, Europe and Japan, with a large and rapidly growing contribution from the major industrializing countries, e.g. China and India.

    Will the USA reduce its GHG emissions by 90 percent, as journalist and author George Monbiot says will be needed if global GHG emissions are to be reduced “equitably”? Will China and India forgo all further development of coal-fired electricity generation and other fossil fuel energy sources that they can legitimately claim are needed for the economic development of their countries? Will both of these things happen within the 15 year period in which the IEA projects energy use and GHG emissions are going to increase by 50 percent? It seems to me extremely unlikely.

    Of course we should try — and try mightily — and up to the point where feedbacks take over beyond our control it is always possible to achieve an outcome that is not as bad as it would be if we don’t try.

    But realistically, I find that I am extremely pessimistic.

  43. 243
    Juerg Luterbacher says:

    For those who are interested in the ENSO influence on European climate during the last centuries, please have a look at the recent February 2007 Climate Dynamics issue.

    Broennimann, S., Xoplaki, E., Luterbacher, J., Casty, C. and Pauling, A., 2007: ENSO influence on Europe during the last centuries, Clim. Dynam., 28, 181-197.

    there is a review paper coming out soon by Stefan Broennimann in Review Geophysics:
    Broennimann, S. (2007) The impact of El Niño/Southern Oscillation on European climate. Reviews of Geophysics, in press.


    [Response: Thanks Juerg. -mike]

  44. 244

    Re #237 and #239 First, you have to realise that a runaway greenhouse will not continue running away for ever. Venus stopped when the surface temperature got to about 480C, 860F. The earth has never been as warm as 100C, 212F. But a jump to 40C, 100F is not totally impossible. There are places in the world where this temperature is reached today.

    The increase in CO2 is already melting the mountain glaciers and the Arctic sea-ice. As they disappear, the albedo of the planet decreases, and the warming from the increased solar absorption is far greater than that from the enhanced greenhouse effect. Therefore, the positive feedback CAN exceed the CO2 forcing.

    The increase in temperature means more water vapour, and this will also produce a positive feedback via its greenhouse effect. However, it will also produce a negative feedback because cloudiness will increase. Eventually the increased albedo from the clouds will compensate for the lost albedo from the ice, and tempertures will stop rising. The question is how high do global temperatures have to rise for there to be enough clouds to stabilise the climate system? And how quickly will the change to this new temperature take, since it is being driven by the positive feedback (runaway effect) from water vapour?

  45. 245
    SecularAnimist says:

    This is somewhat off-topic but I think it worth posting and hopefully not inappropriate, because it illustrates the challenges of educating the public about this issue. Federal Way is a suburb of Seattle.

    Federal Way Schools Restrict Gore Film
    By Robert McClure and Lisa Stiffler
    The Seattle Post Intelligencer
    Thursday 11 January 2007


    This week in Federal Way schools, it got a lot more inconvenient to show one of the top-grossing documentaries in U.S. history, the global-warming alert “An Inconvenient Truth.”

    After a parent who supports the teaching of creationism and opposes sex education complained about the film, the Federal Way School Board on Tuesday placed what it labeled a moratorium on showing the film. The movie consists largely of a PowerPoint presentation by former Vice President Al Gore recounting scientists’ findings.

    “Condoms don’t belong in school, and neither does Al Gore. He’s not a schoolteacher,” said Frosty Hardison, a parent of seven who also said that he believes the Earth is 14,000 years old. “The information that’s being presented is a very cockeyed view of what the truth is…. The Bible says that in the end times everything will burn up, but that perspective isn’t in the DVD.”


    The Federal Way incident started when Hardison learned that his daughter would see the movie in class. He objected.

    Hardison and his wife, Gayla, said they would prefer that the movie not be shown at all in schools.

    “From what I’ve seen (of the movie) and what my husband has expressed to me, if (the movie) is going to take the approach of ‘bad America, bad America,’ I don’t think it should be shown at all,” Gayle Hardison said. “If you’re going to come in and just say America is creating the rotten ruin of the world, I don’t think the video should be shown.”

    Scientists say that Americans, with about 5 percent of the world’s population, emit about 25 percent of the globe-warming gases.

  46. 246
    llewelly says:

    Eric said (#240):

    llewelly, the base period for the first link (1971-2000) suggests that this plot is derived from the re-analysis of several sorces of weather data.

    I agree. The ncdc linked SST does use data from buoys and ships as well as satellites (AVHRR), assuming I have found the correct methodology description. (I am not an expert, and the relevant web pages seem quite disorganized to me.)
    this page has older SST anomaly images from the same series as the NCDC sourced 1971-2000 baseline SST from your first link. It has references and a link to the OISST page which seems to be the same methodology.

    The newest reference has:

    The in situ SST data are determined from observa-
    tions from ships and buoys (both moored and drifting).
    Most ship observations in our period of interest were
    made from insulated buckets, hull contact sensors, and
    engine intakes at depths of one to several meters.


    In late 1981, Advanced Very High Resolution Ra-
    diometer (AVHRR) satellite retrievals improved the data
    coverage over that of in situ observations alone.

  47. 247
    Hank Roberts says:

    Alastair, I don’t know any site with more realistic scientists — possibly because nobody’s been able to publish any current predictive work using contemporary data that would suggest we’re headed into a rapid climate system change.

    But I don’t think — as a reader — the RC people are ignoring this. My impression is they aren’t able to say anything meaningful or publishable about those possiblities simply because we don’t yet understand either how the flips happened in the past or what to be measuring to a anticipate one.

    Would you consider the suggestion that it’s possible we are moving toward a permanent El Nino to be a ‘bunker’ mentality?

    David Cooke — you write
    “the mean is apparently always shifting higher in the current ice age emergent environment”

    I agree with ‘current’ but I don’t think we’re in an ‘ice age emergent’ environment, I think that already happened and wouldn’t be characterized by a slow steady shift of temperature anyhow.

    As far as I know, the last four ice ages ended with a rapid warming followed by a slower cooling, as charted here:

    including the one just past, which also ended that way.

    It looks to me like it’s only when the human influence comes into play, in the last couple of thousand years (see Ruddiman’s work and his topic here) that you start seeing the situation you describe where “the mean is apparently always shifting higher in the current [human] emergent environment” —

    Otherwise, if this had been a typical ice age emergence, we would be in a slow cooling trend now.

  48. 248
    Sashka says:

    Re: 223

    In my view, ve have very close to 100% chance to avoid Lovelockean scenario. There’s no need to do anything. Even continuing business as usual won’t take us there. There’s no basis for his speculation.

  49. 249
  50. 250
    Petro says:

    Sahska wrote:
    “In my view, we have very close to 100% chance to avoid Lovelockean scenario. There’s no need to do anything. Even continuing business as usual won’t take us there. There’s no basis for his speculation.”

    Just a few simple questions:

    How about the scenarios with lesser warming (2-3K), do these worry you?

    Don’t you believe such scenarios will happen, especially if we continue business as usual?

    Don’t you believe such changes are not worrisome?



Switch to our mobile site