Hansen wants your feedback on “If Its That Warm, How Come Its So Damned Cold?”

Essay by four NASA scientists explains why 2005 (not 1998) was the hottest year, what caused recent cold snap, and the source of the “gullibility” of those “so readily convinced of a false conclusion, that the world is really experiencing a cooling trend”


The bottom line is this: there is no global cooling trend. For the time being, until humanity brings its greenhouse gas emissions under control, we can expect each decade to be warmer than the preceding one. Weather fluctuations certainly exceed local temperature changes over the past half century. But the perceptive person should be able to see that climate is warming on decadal time scales.

The quote and figure are from a fascinating draft essay, “If It’s That Warm, How Come It’s So Damned Cold?” by NASA’s James Hansen, Reto Ruedy, Makiko Sato, and Ken Lo.  It is posted on Hansen’s Columbia University website, and he sent out a note to his email list asking for comments:

Criticisms are welcome. This is a draft essay that I wanted to get out because we are releasing our December and annual surface temperature analysis on the GISS web site. We will prepare a write-up on 2009 temperatures for the GISS web site next week.

If you post comments I’ll get them to him.

Yes, Dr. Ruedy had told me they were going to get their write-up out Friday (see “Breaking: 2009 hottest year on record in Southern Hemisphere and tied for second globally“).  But apparently there are just too many issues they wanted to address in it, including the long-term trend vs. the cold snap.  The trend is unmistakable, you might even say unequivocal:

The long”term trends are more apparent when temperature is averaged over several years. The 60″month (5″year) and 132 month (11″year) running mean temperatures are shown in Figure 2 for the globe [above] and the hemispheres. The 5″year mean is sufficient to reduce the effect of the El Nino – La Nina cycles of tropical climate. The 11″year mean minimizes the effect of solar variability – the brightness of the sun varies by a measurable amount over the sunspot cycle, which is typically of 10″12 year duration.

The draft essay goes into great depth on how NASA knows 2005 was warmer than 1998 and why their dataset is better than the Hadley/CRU dataset (see also “Why are Hadley and CRU withholding vital climate data from the public?” and Finally, the truth about the Hadley/CRU data: “The global temperature rise calculated by the Met Office’s HadCRUT record is at the lower end of likely warming”).

There is a contradiction between the observed continued warming trend and popular perceptions about climate trends. Frequent statements include: “There has been global cooling over the past decade.” “Global warming stopped in 1998.” “1998 is the warmest year in the record.” Such statements have been repeated so often that most of the public seems to accept them as being true. However, based on our data, such statements are not correct.

The origin of this contradiction probably lies in part in differences between the GISS and HadCRUT temperature analyses (HadCRUT is the joint Hadley Research Centre, University of East Anglia Climate Research Unit temperature analysis). Indeed, HadCRUT finds 1998 to be the warmest year in their record. In addition, popular belief that the world is cooling is reinforced by cold weather anomalies in the United States in the summer of 2009 and cold anomalies in much of the Northern Hemisphere in December 2009.

Here we first show the main reason for the difference between the GISS and HadCRUT analyses. Then we examine the 2009 regional temperature anomalies in the context of global temperatures.

A key takeaway message is this:

Why are some people so readily convinced of a false conclusion, that the world is really experiencing a cooling trend? That gullibility probably has a lot to do with regional short”term temperature fluctuations, which are an order of magnitude larger than global average annual anomalies.

Short-term weather fluctuations are vastly greater than the long-term global warming anomaly in the climate (so far).  Weather isn’t climate.


67 Responses to Hansen wants your feedback on “If Its That Warm, How Come Its So Damned Cold?”

  1. Dean says:

    One reason that some people are confused is that what seems normal has already been influenced by global warming. I heard that despite its length and the intense coverage, the recent cold snap that covered most of the US set very few low temperature records. This would have been a normal cold snap some decades ago, but now it seems extreme. By contrast, the heat wave we had here last July didn’t just set specific-day high records, many cities had all-time high records set.

    We deal with this where I live by pointing out that 100 years ago, if there was a cold snap, the Columbia River would freeze over – you could cross on foot. Now even when we have what seems to be an extreme cold snap (early Dec in our case), it doesn’t even get close to freezing over, just some ice at the edges. And in those days, before the dams, the water had a stronger current, which makes it harder to freeze. The Columbia now really is just a series of dam-connected lakes. It gives perspective to what is now, and what used to be, an unusual cold snap.

  2. Wit's End says:

    Dean, I came across this concept of shifting baselines as described here:

    It’s a very useful concept that explains how most people miss slow changes and judge current standards by yesterday’s condition, not that of many seasons ago.

  3. Leif says:

    I was living in the Columbia George the last time the Columbia froze over and “foggy” dates put that in the late 50s, early 60s. However we must keep reminding ourselves that we are only looking at ~0.5C world wide average temperature rise. If you live in North Dakota in the winter that is the difference between minus 20F and -19F, still mighty cold. On the other hand the total energy absorbed by the earth to achieve that increase, which include the oceans down a thousand feet or more, is gigantic. An effort by some of CP commentators,, to grasp daily energy input of the earth energy imbalance, produced numbers in the range of 35 to 66 thousand nuclear explosions a day popping off. or- Melt eleven, (11), JFK class aircraft carriers every second of every day. Since evidence shows that the majority of the warming has taken place in the polar regions we are thus “dropping” the majority those melted carriers into the Arctic Ocean. That amount of energy surely is enough to intensify a storm, rain event, bump established weather patterns from normal patterns, melt polar ice, intensify Arctic winter outflow events, nudge jet stream patterns, evaporate extra water which in turn must condense to increased rain, floods, or even SNOW in the winter.

    Think Global Climatic Disruption!

  4. Jeff Huggins says:

    Clarity First

    Although I’m pretty sure I understand what the following sentence (from the post) is intended to mean (mainly because I have a scientific background and know the difference between point-to-point fluctuations/variances, and trends), I don’t think that the sentence is stated clearly for those who don’t already have a sense of what it might be intended to mean:

    “That gullibility probably has a lot to do with regional short-term temperature fluctuations, which are an order of magnitude larger than global average annual anomalies.”

    According to my dictionary, the word ‘anomaly’ means: 1. Deviation or departure from the usual or common order, form, or rule. 2. One that is peculiar, irregular, abnormal, or difficult to classify. …

    So, is the sentence intended to mean something like the following, in essence? …

    That gullibility probably has a lot to do with regional short-term temperature fluctuations, which are often substantially larger than the trend in the global average temperature over time.

    This “try” of mine, above, is still not as clear as it might be, but the use of the word ‘anomalies’ in the post – although I’d imagine that it’s technically correct given the jargon and given that the writer already knows what he is trying to say – will probably not be clear to the audience, if the audience is supposed to be a general audience. OR, is the writer trying to say that short-term fluctuations (as in from season to season, or day to day) are an order of magnitude larger than the year-to-year fluctuations in global average temperature, up and down, without even mentioning the multi-year and longer-term upward trend?

    In any case, it’s not clear, to me anyhow, what the actual sentence is trying to say. My suggestion, of course, is that if some piece of writing is intended for a general audience, intended to partly address the gullibility problem, then it should be written in plain English and be quite clear. Ideally, each sentence should be able to stand alone and should not require that the reader already understand what the sentence aims to convey, before he/she even reads it.

    Also, there are other (additional) factors involved. As Simon and Garfunkel sing, “a man hears what he wants to hear and disregards the rest.” And, as Mark Twain wrote:

    “The average man is destitute of independence of opinion. He is not interested in contriving an opinion of his own, by study and reflection, but is only anxious to find out what his neighbor’s opinion is and slavishly adopt it.”

    So, given the latter two factors, when you have lots of people getting their climate change info from Fox News, there’s a natural problem. And, even The New York Times (although I’m not sure why I’m saying “even”) does not communicate clearly and prominently on these matters. Indeed, it’s not clear whether they understand them, and in any case, they seem to place more importance on highlighting the “controversy” than on conveying credible understanding that will actually serve the public good.

    Clear communication of temperature data is only part of the battle. Other larger factors also serve, feed, and enable the gullibility to thrive. Those need to be addressed, too.



  5. MADurstewitz says:

    This is no “cold snap”. When I was a kid in the 60s and 70s, it was no big deal for the Delaware river to freeze and create huge ice heaves. We had automobile and motorcycle racing on Greenwood lake in NY state. We had all night bonfires on Pompton Lake (in the town where I grew up). People even occasionally drove cars onto Pompton Lake, but the cops frowned on that. It was also very common for the temps to drop below zero at night in January and February.

    Now, none of these things happen anymore. Everyone should stop whining about this “cold snap”.

  6. Dano says:

    Now, none of these things happen anymore. Everyone should stop whining about this “cold snap”.

    I clearly remember motorcycle racing on Lake St Clair when I was young. Do the lakes even freeze up any more (slight exaggeration)?

    Does anyone there make the connection between less cargo and less ice?



  7. MarkB says:

    One argument I read often is something like “global warming means it’s supposed to get warm everywhere, so the cold weather this week in invalidates global warming”. Such an argument implies that weather has never existed.

    Excellent essay by Dr. Hansen.

  8. Kari Dempster says:

    Joe Bastardi says February will make you shiver. on this I will deliver. Storm Brewing Texas to Mid/North Atlantic Late Week.&ctr=2
    Look at the last few El Ninos.

  9. David says:

    What is “the source of the “gullibility” of those “so readily convinced of a false conclusion, that the world is really experiencing a cooling trend”?

    Many folks just don’t “believe” in global warming. They…
    1. Can’t see or feel past their own nose: They say, “Because it just IS cold, stupid!”
    2. Don’t have a global perspective: They don’t realize that when it’s cold in the Northern Hemisphere, it’s hot in the Southern Hemisphere.
    3. Don’t understand the difference between weather and climate.
    4. Don’t do Math: They can’t relate to the concept of “global Average temperature”.
    5. Can not relate to Graphs and Scientific Terminology: “Temperature Anomaly (deg. C)”, “decadal time scales” … WTF?
    6. Can not relate to problems that might or will occur in the year 2100.
    7. Believe that humans can Not change Nature, and that those who think they can are just arrogant or heretics.
    8. Are locked into a right-wing Political Ideology: They say that Warming is a HOAX, perpetrated by Al Gore and other liberals.
    9. Listen to FOX News, Sarah Palin and Rush Limbaugh, and believe that the fiction writer, Michael Crichton, was a scientific authority.
    10. Don’t want to change to alternative energy sources.
    11. Don’t want to pay higher taxes for any reason…period.
    12. Don’t think.

  10. Dano says:

    To the authors:

    o In my view it is important to state the actual average temperature to provide context, not just departure from norms. Actual temp is something concrete people can grasp and relate to, reinforcing the graphs (which are clear and cogent and convey change very well).

    o I think section topic headers would make the doc more readable.

    o There is linkrot (invalid link) on the ‘frogbandit’ comment on page 6.

    o In my view Figure 9 is a very compelling graphic and explains much, yet is buried at the end of the document. In the future, such graphics should be worked in to essays with more prominence to give reinforcement to the message in the text.

    Thank you for the opportunity to comment.


    D (contact info available to JR above)

  11. john atcheson says:

    I believe metaphors and analogies are the best means of communicating the difference between climate and weather. For example, weather is to climate as journalism is to history.


    A trend is what happens over a longer time span or distance — for example, climbing Pike’s Peak one goes uphill on net, even though there may be short periods on the journey when one is going downhill.

    Or — create better ones … the key is to ground the metaphors and analogies in experiences people understand in their everyday lives.

    As for why people are gullible, behavioral economics has some useful insights into why people behave irrationally — status quo bias; gambler’s fallacy; motivated cognition (seeing things as wish they were, rather than as they are).

    The latter, when combined with Joe’s earlier insights about conservatives not accepting climate change because they don’t like the solutions — it means they must accept an active government role intervening in the market, which is anathema to them.

    In short, if you are predisposed to reject the need for government, and cognition is heavily biased by what you wish were so, you will be doubly motivated to perceive things as you wish they were, not as they are.

    The antidote? Reveal the motivation behind the misperception; try to divorce the policy prescriptions from the science in messaging; and simplify the message.

  12. Lamont says:

    Just patiently wait for the final 2010 numbers, and hope that we don’t get a volcano.

    Then newspapers can start writing retrospectives on the 2008-2009 “decade of cooling” controversy, and we’ll start getting a few deniers waking up and writing “i used to be a denier” confessionals.

    If you want to have a laugh, check out Antony Watt’s response to the UAH record Jan numbers. The deniers are going into massive denial mode — denying the possible existence of “global temperature” or any ability to measure it, rendering *any* discussion of the climate meaningless. Only the willfully mentally blind won’t recognize that as a cop-out.

  13. Dean says:

    Yet two other things also intensify the perception that this cold snap was extreme. First is the fast and extensive TV coverage. Just how much time would TV news spend on a cold snap 50 years ago? Secondly, did they grow so many oranges in Florida then? Maybe so, I don’t know, but I doubt people nationwide heard days and days of speculation about the economic impact on the fruit crop.

    Shifting baselines is an important concept, thanks to Wit’s End for the link to the article.

  14. espiritwater says:

    It’s NOT that cold! Where I live (NE United States), it’s been like spring for the last 10 months. All we ever get is spring weather and lots of rain! We had the heat on only for a few days until January. Even now, we have our heat off most of the time and our windows cracked! Until a couple of weeks ago, I thought we weren’t even going to have winter this year, it’s been so warm! The other day, I was all dressed up in winter attire and could hardly breath because it was like spring outside. (We did have about 3 days in which it was real cold, but not unusually so).

    Years ago, it was so cold this time of year, we had to wear several layers of clothes when going outside. Even about 12 years ago, we had blizzards that covered our cars. But for the last five years or so, we often see people outside jogging with shorts on in December! I’ve often riden around with my window down during December and January, the last 5 years or so. And it’s fruitless to put Christmas wreaths up outside– they turn brown after a couple of weeks! It’s NOT that cold! It’s unusually warm!

  15. Lou Grinzo says:

    This is going to sound far more negative than is intended, but it needs to be said: This paper is a perfect example of why scientists have no trouble communicating with scientist wannabes (like me) and can’t get to first base with mainstream consumers and voters, the very same people the deniers are reaching. (I’m assuming that’s the audience for this piece.)

    The problem is the writing style and tone. I would nuke and rework the whole thing, end to end. There’s a compelling story in there, backed up with hard data and real science, but the average mainstreamer won’t get past about the third graf before his/her eyes glaze over.

    I have a long background in bridging this gap between experts and lay people (having written and edited for several computer magazines), so I know how hard it is to be accessible and accurate without becoming the writing equivalent of a 50-something white guy who has one too many drinks at a wedding reception and decides to dance with the teenagers.

    I’m looking for a way to get involved with helping scientists communicate with the public. I’ve been researching and writing about energy and environmental issues for six years (it takes a lot to overcome formal training in economics, you know). I will gladly volunteer my effort to work full time on such projects, and this one sounds like a great place to start. If there’s interest, I can do a rework of this piece and let the authors (and CP readers?) decide where on the spectrum of writing styles the authors should aim.

    Joe: If you or Dr. Hansen or anyone else you know wants my resume, e-mail me directly. I e-mailed Richard Brenne and about this kind of project, matching up experienced tech writers with scientists, but have yet to hear from either. It’s time for us to be as coordinated and smart as the deniers are deceptive.

  16. Wit's End says:

    Lou, I am not sure what the solution is but I have to agree that the average person will not be able to follow this paper. Perhaps it is aimed at teachers, journalists, and scientists in fields other than climate.

    This morning I got an email from the Environmental Defense Fund inviting recipients to take part in a Q and A with scientists. You have to assume most of the questions came from people who are concerned about pollution and climate change since they’re on the EDF mail list, but even so the level of ignorance was appalling.

    One representative question was why ocean levels will rise, since an ice cube melting in a glass of water doesn’t affect the level. Apparently this person was not aware that ice sheets on the continent of Antarctica and Greenland are based on bedrock!

    Dean, I suppose shifting baselines is an obvious notion but I found it sort of revelatory – it explains everything from marriage to why people don’t notice their degrading ecosystem, never mind follow the implications to their inescapable outcomes!

  17. Doug Bostrom says:

    Lou Grinzo says: January 16, 2010 at 4:04 pm

    Hopefully your offer will be accepted.

    It’s a fascinating essay but way too dense. As somebody else mentioned, analogy and metaphor are our friends here; if the basic points of the paper were translated into familiar terms it would be a big help. Stuff the details to the rear, in a thorough appendix.

    There’s a lot about climate science that’s not tractable to brief explanations but confusion between weather and climate is not in that group.

  18. From Peru says:

    Well, (at least for now) the cold snap ended, and ANOMALIES in North America are back in the 5-10ºC ABOVE average again:

    Will Anthony Watts post about this?
    Or his reports are melting like the snow right now?

  19. From Peru says:

    By the way, looking into the graph:

    If we were in the 1990s, the “cooling trend” would have been a lot stronger than the “2000s cooling”(and that make sense as the decade began with Pinatubo Eruption, but … then was the 1997-1998 Super El Niño…). A lot of confusing data ready to be used if there were deniers then!

    But if Denier’s method were to be used for the 1990s, then all their “arguments” will fall apart, because TWO DECADES(1990-2009) of “Global Cooling” is a SO MONSTROUS LIE that they will lose any credibility.

    So, let’s do the analysis, and then trown it in face of the deniers!

    (warning: you must be careful, or you will fail as did the Shoes of Al Zahidi that missed Bush’s face in 2008…)

  20. Wit's End says:

    I think this analogy is apt – but significant other says it’s lousy:

    Think of the earth as a large garage. It’s a closed system, after all. We’re all sitting in a car with the engine running. Invisible but toxic fumes are gradually filling the garage. Eventually we get sleepy, then comatose, then we die.

    It’s not exact of course. But it enables the average person to relate to the notion that just because greenhouse gases are invisible that doesn’t mean they aren’t potent, even lethal, to humans and vegetation alike.

  21. From Peru says:

    What happened to the SST Anomaly timeseries graph at the GISSTEMP site?

    I could not find it anymore …

  22. From Peru says:


    “Winter Temperatures and the Arctic Oscillation” (Posted January 9, 2010)

    To trown in the face of Antony Watts!

  23. Bill W says:

    We really need to know the intended audience of the paper, but I agree that if it’s for a general audience, it needs to be, well, “dumbed down” significantly.

    Here’s my pet analogy for the line “How can they claim to predict the climate for the next 100 years when we can’t even predict next week’s weather?”: We can’t predict the exact path that any given commuter will follow, but we can darn well predict that the freeway is going to be full of cars after 5:00 PM. Weather is like cars, climate is like traffic.

  24. Andy says:

    #3 Leif: a change of global temps of 2 or 3C or more degrees doesn’t mean that high temps will be 2 or 3C above what they are today. Think of it like this. The average temp of Chicago is about 55F. The average temp of Houston is about 70f. Think of a change of 3C (5F) as moving Chicago one-third of the way south towards Houston. Or giving Chicago the climate of Memphis.

  25. Deech56 says:

    P 1: The phrases “warmer than climatology” and “warmer than in the period of climatology.” are confusing.

    The information and charts are excellent. Maybe some headers or bullet points would get the most important information. Maybe Lou Grinzo could lend a hand – his blog is quite readable.

  26. Deech56 says:

    Hmm…had problems posting before – maybe including a url was not a good idea. I also think that this could be a good opportunity to discuss the decrease in stations that was another so-called smoking gun in the showed aired in San Diego. Gavin had a good explanation on RC (“Unforced variations 2”, in-line for comment 972). There a germ of an explanation on p 3, last paragraph.

    Also p 2 – maybe some sources for the “cooling” quotations, or else make just a general statement.

    I see this as a technical paper. A one or two-page summary for the lay reader would be helpful (with FAQs that this document answers?).

  27. Lou Grinzo says:

    Let me expand a bit on my prior comment; I know from experience such discussions can lead to some completely innocent but still bothersome misunderstandings.

    I am NOT in any way in favor of dumbing down the science. My goal is not to take anything away, but to add something: Better writing and presentation geared for a mainstream audience.

    The critical element that many (and I do mean many) people overlook in writing, from science papers to business reports to fiction, is the need to “tell a story”. Develop a narrative arc, set a narrative hook, use imagery, use colloquial language where appropriate, use repetition and parallel structures, make the most of climax and tempo, etc.

    Is this kind of writing hard? You betcha. It’s just about the ultimate example of something that looks effortless when it’s done well. I’ve been at it in one form or another since 1980, and I’m still working hard to get it right.

    My point is that we should no sooner expect climate scientists to have this particular skill set than we should expect a crime novelist to know the intricacies of ice dynamics, GHG radiative forcings, and the carbon cycle. Therefore, WE NEED TO WORK TOGETHER. This fight is far too important for us not to use each other’s skills to the fullest extent possible.

    Anyone who wants to work with me on this can drop me a note directly at lougrinzo [stupid at sign]

  28. Leif says:

    Andy, #24: There has been an illustration floating around. There are fifty people in a bar and the average income is $50,000. Bill Gates walks in and they are all millionaires. Numbers can be slippery little devils, sometime.

  29. David B. Benson says:

    Off-topic, but a upbeat article on Lackner’s air catcher.

    Can CO2 Catchers Combat Climate Change?,1518,672072,00.html

  30. David B. Benson says:

    Yes, the last quoted sentence needs changing to avoid specifically climatological language (which I used to find rather confusing).

    [Ninth attempt (a record) to post this comment.]

    [JR: Weird. Maybe I fixed it. Send me an email next time.]

  31. Berbalang says:

    It just hasn’t been as bad of Winter as the news media tried to make it sound. Certain areas of the country did get temperatures they hadn’t seen it years, but this should have been a tip off to the older generation that the climate has changed since those temperatures used to be more common.

    The professional deniers are not going to change no matter what the evidence, since they are paid to deny, no matter what. Arguing with them is pointless.

    The deniers that do it for free seem to fall into two groups. One that believes Global Warming is a hoax perpetrated by unnamed people and the other that really wants the truth, but has been so mislead by the professional and conspiracy types that they have little hope of actually getting to the truth unless they are first shown that they have been deceived, which is something many do not want to admit.

    One thing I recently found out about the conspiracy types is that the conspiracy they believe in is the good old Illuminati conspiracy. Of course they are rather cagey about admitting this and will first lead you through a series of clandestine meetings before you get to meet someone who will give you the “Truth”. To see this in action watch the Jesse Ventura’s CONSPIRACY THEORY episode on Global Warming where he does just that.

    The episode on HAARP was also quite humorous, especially Jesse’s end comments.

  32. Peter Heywood says:

    Thanks for posting the Hansen et al paper which I found interesting and helpful. As I tried to understand it I summarized the information as follows. As the authors are aiming for a general audience (like me) I feel that something like the outline below might make this important story clearer.

    1. There is variation between GISS and HadCRUT datasets – base period, interpolation and extrapolation in GISS. If use the (?) same base period and the same areas get a similar result (need some explanation of what masking means and clarify whether the base periods have been adjusted).
    2. There are other sources of variation –
    a. El Nino-La Nina – use 5 year mean to smooth this effect.
    b. Sunspots – use 11 year mean to smooth this effect.
    c. Urban warming – adjust using nearby rural data.
    3. Then compare GISS with model – does this mean that adjustments for the sources of variation in points 1 and 2 have been made? This gives an estimate of error over time.
    4. When take these variations into account and make adjustments for them a long-term trend is still apparent.
    5. Having done all this, what is the hottest year?
    6. What accounts for the December 2009 anomaly (i.e. back to the title) – the Arctic Oscillation.

  33. Mike says:

    My feedback would be to re-iterate most of the points made by Dano #10 and Deech56 #25.

    Furthermore, I found the comparison of the GISS to HadCRUT record very instructive.
    Some of the text/explanation surrounding Table1 and the identification of the warmest year was more difficult to follow. For example: “Integrating over the tail of the distribution and accounting for the 2005-1998 temperature difference being 0.61°C alters the estimate in opposite directions”. Also should that be 0.061 not 0.61?
    Perhaps a figure showing all the warmest years each with std dev uncertainty bars and demonstrating how the 1998 and 2005 std dev’s don’t overlap would be a good way of visualizing this? Even if the answer is more complicated than that.

    As a report for scientifically literate people this is good. Perhaps a shorter lay report could be built around fig1a/2a, fig5a integrated with fig8 and fig 9. This could provide a good story for and answer to the title question “If It’s That Warm, How Come It’s So Damned Cold?”

  34. Chris Dudley says:

    The Perceptive Person is introduced towards the end of the note as someone who can notice the effects of warming. I would be more cautious. Saying that the perceptive person needs to be near retirement age is good (around in the 1950s) but to be a good observer, the person has to be in the same place for all observations. Also, according to fig. 9, the perceptive person in Eastern South America or Western Africa would notice temperature stability. Maybe it would be better to say that the perceptive person is more likely than not to be able to notice a change under the right observing conditions. My neighbor who has lived here all his life talks about skating in the Winter but there is no ice now (except last week) but my other neighbor would not notice since he did not grow up here. He notices other things but does not have the baseline to notice that. Both are perceptive and have lived long enough.

  35. We are asking a renown scientist to deliver a bumper sticker message.

    Tough request. But that is what is needed.

    We should recall that a few years ago, there were big debates about what to call the climate changes we are experiencing right now. One suggestion was “Global Climate Destabilization” Now phrase choice is delivering its lesson.

    Greenhouse gasses are disrupting our atmosphere and making our climate unstable. We have climates today that are unlike anything humans have ever experienced. And it will get worse. There is more destabilization to come. This means extreme, erratic weather events of all kinds – not just heat. Expect stronger storms, wetter rains, dryer droughts, colder cold snaps, and plenty of heat waves. This is all part of a destabilizing global climate that is reacting to greenhouse gasses and other pollutants.

  36. Richard Brenne says:

    Dr. Hansen, Dr. Ruedy, Dr. Sato and Dr. Lo:

    There is an apparent typo on Page 3 in the caption for Figure 3 where it reads “1988” it should read “1998.”

    On page 9 you mention that “the climate dice are already strongly loaded” and I’m very familiar with this having read and heard much of Dr. Hansen’s critically important work. But there is no reference to this earlier in the paper so it should not be assumed the reader is familiar with this term, and so it either needs to be explained or removed.

    On page 9 you might consider adding this to your sentence: “The perceptive person (including professional or amateur meteorologists, outdoor ice skaters and ice fishers, glacier and waterfall ice climbers, farmers and gardeners, skiers and snowshoers, wildlife and bird photographers and watchers, river and stream rafters, kayakers, canoeists and fly fishers) who has been around since the 1950s or even 1970s should be able to notice that seasonal mean temperatures are usually greater than they were during those decades, although there are still occasional cold seasons.”

    Your paper is excellent, precise and of course extremely logical. As others mention, unfortunately at this unique moment in history that by itself is not always enough. I suggest taking Lou Gringo’s and Jeff Hughes suggestions (and I’m getting back to each of you about setting up this consulting service for scientists) in this way: I’d add a one-page abstract that is more accessible to the general public than your 10-page paper. In fact I wouldn’t call it an abstract, but an overview.
    Next I’ll give you some suggestions about what it might say that you may use however you’d like, as examples or in any other way.

    I’m a friend of Climate Progress, McKibben’s and many top climate scientists and you can always e-mail me at if you’d like to discuss more. Others might want to suggest what should go into this one page overview as well. (And as usual I’m a little long, with the most expendable stuff at the end.) Please see next two postings for more. . .

  37. Richard Brenne says:

    Rrs. Hansen, Ruedy, Sato and Lo:

    As promised, a sample draft of the kind of overview you might consider using that is simpler and more accessible than the data used to support statements like this must be. Again I think your excellent 10 pages can remain, but suggest adding an overview like this and then anyone who wants to delve deeper and see the math, data and methodologies you use can:


    This is a one-page summary of the 10-page report that follows with more detail, graphs, maps and evidence to support what we say here. Given the importance of climate change to each of us, we’re going to be uniquely blunt.

    No matter what you hear from any other source that is not representing sound science or working, publishing climate scientists, the Earth is not cooling. It is warming. It took a 100-year record El Nino to produce the then-record warm year 1998, but just a moderate El Nino to break that record in 2005 because the Earth’s temperature has been consistently rising before, between and since those years.

    In fact 1998, 2002, 2003, 2006, 2007 and 2009 all are in a virtual statistical tie for the second-warmest year in the climate record.

    Sometimes global warming goes into melting ice or warming the ocean and sometimes the overall warming trend is temporarily masked by slightly lower solar output or La Nina events or global dimming from volcanoes or human activity, but the overall trend is clear.

    It is unfortunate for Americans’ understanding of global warming that the 1.5 per cent of Earth’s land mass that comprises the contiguous United States recently had one of the coolest summers and Decembers of any place on Earth. The December and January cold snaps were quite persistent in many places in the U.S. but few cold records were set.

    Just for comparison to a time of significantlty cooler climate, in February of 1899 a cold snap sent air temperatures down to -2 degrees Fahrenheit in Florida, -9 in Atlanta, -30 in Tennessee, -47 in Nebraska and -61 in Montana. The Mississippi River froze solid all the way to New Orleans and discharged ice into the Gulf of Mexico. Many other American rivers and lakes that have frozen solid many times in the historic record rarely if ever freeze solid across their breadth anymore.

    Since January 1, 2000 there have been over twice as many heat records as cold records in the contiguous 48 states, and that ratio is expected to jump to 20 to 1 by 2050 and 50 to 1 by 2100. Because climate models also project more dramatic precipitation events of all kinds, where it is cold enough to snow we might well see even an increase in many snow records.

    This overall trend of warming is like the history of the stock market during the 20th Century or climbing a ridge on most of the world’s great mountains from the Matterhorn to Mt. Everest – despite the overall upward trend, there will be inevitable temporary downturns.

    Any reputable climate scientist will look at the overall upward trend and not cherry-pick data from a record high year to sometime before the next record.

    As the paper which follows shows, we feel the NASA global data does the most complete job of extrapolating measurements into every grid on Earth where measurements are not yet possible. We feel our extrapolations are both scientific and conservative.

    Second half follows. Thanks, Richard Brenne

  38. Richard Brenne says:

    Drs. Hansen, Ruedy, Sato and Lo:

    Okay, because of the deep gratitude, admiration and affection I have for each of you and my many climate scientist friends at NCAR, NOAA, etc this might be a little over-the-top in places, but I feel these sentiments need to be communicated in the most appropriate ways by each of us at every opportunity. Remember you can contact me at

    And let me say thank you so much for all your work and dedication and standing up to power in all of its most ugly forms. You are true American heroes. I frequently ask climate scientists who the Robert Oppenheimer of all climate science is (the one who can most synthesize all the various disciplines), and I hear your name, Dr. Hansen, more than any other. And when I ask people like Paul Krugman who they’d most like to be on a panel (I produce and moderate such panels) with, I also hear you name mentioned most often. Krugman called you, as McKibben and many others have also, “A hero for the ages.”

    Please know that there are many of us who think of you fondly and admire your work daily, and let’s all keep intensifying our own versions of your grandson’s “Never give up fighting spirit.”

    OVERVIEW, continued:

    While there will always be disagreements about details, we feel the vast majority of the world’s working climate scientists agree with our basic assessments. This is not a conspiracy, because the science of human burning of fossil fuels leading to higher CO2 emissions that warm the climate has been known for 114 years and the IPCC Reports including the work of thousands of scientists from 130 nations make the idea of such a conspiracy completely ludicrous.

    There are many powerful vested interests that do not want all of us to address climate change openly, honestly and courageously, and there is much wishful thinking that climate change is not really happening. But it is happening. Wishing does not alter facts or reality.

    There have even been libelous and slanderous remarks made in the media and on many websites questioning NOAA’s National Climactic Data Center data and NASA data and conclusions. This insults, slanders and libels every conscientious meteorologist and climate scientist that have meticulously acquired, compiled and interpreted this data for 130 years, and these charges say much more about those making these comments than it does about the scientists themselves.

    Science is based on integrity more than anything else, and there is no human endeavor we know of that has a finer track record. While honest mistakes are made and corrected through the peer review and other rigorous scientific processes, cases of deliberately fudging data and committing scientific fraud are so rare in all the sciences that these infrequent episodes live in infamy down the decades and even centuries. And we know of no such cases of fraud involving temperature data by anyone at NOAA, NASA or any comparable institution.

    Frankly, those of us working in climate science are left shaking our heads at the tactics, ignorance and vehemence of the nonsensical, ignorant and outrageous statements made against our work. It is time for each of us to be honest, open and courageous about facing climate change and to leave behind bullying, intimidating and shouting tactics. And it is time to face the facts, without making up our own.

    Thank you, Richard Brenne

  39. Edward says:

    Lou Grinzo: There is something else we need: A daily talk radio show to compete with Rush Limbaugh. It has to happen while most people are driving to or from work so that they will listen to it while driving. It has to match Rush Limbaugh for psychological hooks and simplicity. And, of course, it has to be funded. Since none of this is going to happen, ….

  40. Edward says:

    To James Hansen: The temperature difference means nothing to most people. Talk about consequences. Start by reading “The Long Summer” by Brian Fagan and “Collapse” by Jared Diamond. The change that ordinary people can relate to is famine. The denialists are big bible “experts”, so talk about the famine that caused the collapse of the Canaanite empire. Talk about the collapse of wheat and rice farming in Australia. Talk about the civil war in India. Ignore the famine in the Sahel, that isn’t happening in countries that are like the United States.

  41. Edward says:

    To James Hansen: Tell the truth about Rush Limbaugh! Since the average person believes every word Rush utters, you are going to get nowhere until Rush Limbaugh becomes the subject and the controversy. Do this first.

  42. Richard Brenne says:

    Regarding my #36 comment: Lou, I meant Grinzo! not Gringo as I typo-ed. Other than this one typo, my slurs are never ethnic. And today I’ll get to that e-mail I’ve been wanting to send you!

  43. Edward says:

    I have had some success in telling young people that the Mississippi froze over so you could drive a truck on it at Davenport, Iowa in 1968, and the Mississippi froze over so you could drive a Conestoga wagon on it at St Louis in the 19th century. That is how St Louis came to be known as “the gateway to the West”. Ice on the river is new to them this year.

    I also tell them that where I grew up, in western New York state, it snowed 450 inches per year in the 1950s and 60s, but it snows only 96 inches per year now.

  44. Bob Wallace says:

    The HadCRUT3 dataset was begun in 1850 and uses measurements taken from land bases and ship/buoys at sea. It doesn’t adequately measure temperature changes in the Arctic where the most extreme temperature changes are occurring.

    GISS/NASA data is what should be used if one wants to talk about global temperatures rather than sub-polar region temperatures.

    (If one wants to cherry pick the data that best fits their “political” needs they might want to look at HadCET which was begun in 1659 and measures only central England temperatures. ;o)

    BTW, a friend used to own a cabin at Donner Lake in the Sierras. She has pictures of men with teams of horses and sleds cutting large blocks of ice from the middle of the lake in the pre-refrigeration days. The ice was shipped to SF, stored in warehouses insulated with sawdust, and used to cool food in the summer.

    These days the lake rarely freezes enough for ice skating, and then only for the brave/foolish.

  45. Wit's End says:

    Richard Brenne, #37, a tour de force!

    The only modification I would suggest is to remove or replace the word “feel” anywhere it appears, because it reduces facts to opinions. The scientists do not “feel” their data is accurate, they “know” it and can “prove” it!

  46. Anand says:

    Why do the authors cite three papers from their own group in this article?

  47. Bob Wallace says:

    Anand – Perhaps it’s because they are experts in their area and publish a lot of good data.

    That’s pretty common in research. People rarely branch off into new areas, but build on their own work. As one reads the literature in an area of research there are papers that seem to be cited over and over. They are the important works in the area which make important points on which other research is based.

    I’ve published papers in which almost all of the referenced papers came out of our labs because we were the leaders in our somewhat specialized area. (Read – tiny niche.)

  48. Mike#22 says:

    Drs. Hansen, Ruedy, Sato and Lo:

    Clearly, by using “damned cold” in the title, you are aiming at a wider audience than is usual. Yet, as others here have pointed out, the material which follows the title requires a level of background knowledge not generally present in the public.

    Richard Brenne’s suggestion to add an overview for the general public would bridge this knowledge gap.

    In my view, a third writing could be added. A short press release which states the facts about the temperature record and that there is no global cooling trend. You briefly touch on the issue of the massive failure of the main stream media to carry out their responsibilities with respect to this: “In addition, popular belief that the world is cooling is reinforced by cold weather anomalies in the United States in the summer of 2009 and cold anomalies in much of the Northern Hemisphere in December 2009…” Would that we have the time for the media to correct itself, but we don’t.

    There is an opportunity here, with so much of the media and the public operating under a set of dangerous falsehoods, to initiate some of that desperately needed correction.

  49. Aaron Lewis says:

    These were WARM storms. The were full of water vapor and they dropped a lot of snow. Snow makes a winter storm unpleasant, and people confuse unpleasant for cold.

    “Cold” winter storms are dry, and produce little precipitation.

  50. Leif says:

    Good morning all. I posted this on another thread but feel that most is appropriate for this discussion as well. If feel that our efforts at increasing awareness “out there” should be focused on making BIG MONEY and Corporations “feel the heat.” Those Movers and Shakers are not dumb, like some that shall remain nameless, just short sighted and thus vulnerable to reason.? You think?

    Chad, #75: Environmentalist did not kill Nuclear, Nuclear killed Nuclear and you know it. In the rush to profit the industry rushed construction and sighting requirements. Loaded the public with insurance obligation and long term storage responsibilities. Security obligations? Again societies problem. All those costs are conveniently left out of the kW costs as well as many others. Just as the cost of environmental impacts of consuming fossil fuel is conveniently ignored to keep the price artificially low. In the end the Public turned against Nuclear because it became obvious that the Nuclear industry was only “into it” for the profits and not in fact, for the well being of humanity. Like wise, it is clear to anyone who cares to look, you will find that “vested corporations” in the fossil industry will spend, say, and do whatever is necessary to protect and promote the status quo, humanity be damned! Nuclear killed nuclear, just as “capitalism will certainly kill capitalism as we know it! Unless of course humanity is unable to take rational control of its destiny and becomes toast. At which point capitalism is toast as well. So big money? Are you going to get on the bus? It looks like a lose, lose situation, no matter how you play it. I suggest that you fold while you still can. Lick your wounds, you still have a lot of money to play another round. You have played humanity to the door step of doom. Humanity is “ALL IN” and if we do not win??? Well it is all over but the shouting, near as I can tell…

    I say “Make the bastards squirm!”

  51. keith says:

    Re #1 et al.,
    – exactly right. I check the record lows in the daily weather almanac found in my local paper here in upstate NY and we have not been anywhere near the record lows for this region in January or December. Enough with this spin on record cold in the US, please!

  52. Peer G. Dudda says:

    I’d say the changes are observable even to this 36-year-old. The snow and weather we’ve had this season in Minnesota was normal when I was a kid. It stopped happening in my early teens. That means this is the first “normal” winter Minnesota has had in 20 years!

    (And now temps are at about 0C after three weeks of -15C, so everyone’s out in shirtsleeves, which is as good an illustration as any of how people can adjust their perceptions of warm vs. cold very quickly!)

  53. VicDiesel says:

    “Global mean temperature, as shown in Figure 1a, was 0.57°C (1.0°F) warmer than
    climatology (the 1951‐1980 base period).”

    How can you be warmer than a science, and what does that parenthetical remark have to do with the start of the sentence?

    “warmer than in the period of climatology”

    Have they stopped doing climatology?

    This sort of sentences if probably understandable to the insider, but to me it’s gibberish.

  54. Chris Dudley says:

    Peer (#52).

    That is a good point. Why do we need older people? Since there is variability on a timescale of decades, the warming you notice may have occurred by chance while the warming that an older person notices is more likely to have a component that it certainly owing to greenhouse gas induced warming. It is not just what you notice but what the cause is for what you notice that have to come together. Hansen is making a major departure here by saying that warming is self-evident to anyone who cares to look. Before, we needed proxies like the change in hardiness zones (geographic averages) but now we can simply notice warmer winters where we live, for example. But, you still have to notice over a long enough period for the change to be climate of the sort we affect.

    Sadly, while we have a bunch of older people making policy on this issue, they live much of their lives away from where they grew up so that, no matter how perceptive, they don’t have direct experience of warming since they are holed up in Washington, DC away from where the direct experience is available to them. Thus, Oklahoma will wither while its politician sits in ignorance.

  55. Chris Dudley says:

    It seems to me that the explanation of the Arctic Oscillation Index may differ from that of other groups. NSIDC calls the negative phase the time when the Arctic Sea Level Pressure is high Similarly here:

    The present note would seem to come into agreement with those descriptions if high pressure is switched with low and low with high. Then, a negative excursion in the Index still leads to low temperatures (here) in all descriptions and makes more physical sense in terms of how wind patterns respond I think.

  56. fftf says:

    Great article. I can only hope the blog author plays the same amount of attention to the other recent publications by Dr. Hansen, and to his advocacy of nuclear energy as indispensable part of our efforts to replace carbon fuels. The only one which has a track record of displacing carbon fuels, actually.

    [JR: I can only hope you’ll read this blog and see that I probably write more about Hansen’s pubs than just about any other blogger, but he is no energy expert.]

  57. Bob Wallace says:

    fftf – Hansen is an expert in his field, but not an expert in all fields. He’s not an expert in alternatives to fossil fuels, economics, or politics and it sometimes shows.

    To use his advice to turn to nuclear would be just as dangerous as taking your word that only nuclear has a track record of displacing carbon fuels.

    We’ve had wind power on our grids for decades. We’ve been using solar power for decades. We’ve been using hydro and geothermal for even more decades. None of these are new ways to generate electricity, some of them have longer track records than does nuclear. And they have proved themselves to be faster to install, less expensive to install, and less problematic than is nuclear.

    We built a lot of nuclear a few decades ago, discovered how expensive it is, and finally admitted that we have no solution to the nuclear waste problem. And over time we’ve seen the cost of building nuclear rise and rise again and again.

    At the same time we have refined our other methods of electricity generation, making them more efficient, faster to install, and less expensive.

    Nuclear was a grand experiment. And it failed. Time to install what works, works soonest, and works cheapest.

  58. gecko says:

    Lake Placid site of two Olympics in upstate New York, one local described winter as being about a month late this year where the temperatures can often be in the -20s and -30s; more below-zero days last month than all of last winter; it has been typical that the temperature often changes by as much as 50 degrees in 24 hours.

    It seems that we are in a period of unstable equilibrium kind of like a seal balancing a ball on its nose. It rolls to one side it is hot; to the other side it is cold; it rolls in still another direction and it becomes a wildly blusterly day.

  59. Lou Grinzo says:

    Richard: No sweat on the Gringo/Grinzo thing. If I had a buck for every time I heard that innocent mistake, I’d be driving a Tesla.

    I look forward to hearing from you in e-mail. I’m sick to death of “our side” not being coordinated or savvy enough to use our greatest asset–the truth–to educate and activate mainstreamers on this issue.

  60. Dave says:

    Another problem is that the numbers you see reported for various cities for record highs and record lows and past climate were taken at different locations. In the past, they were usually taken at downtown sites often on the roof of buildings. Now, they are taken at airports, which typically are well outside the cities and at higher elevations. Moving 20 miles outside the city and 250′ higher can more than mask the effects of a slight rise in temperatures due to global warming. I don’t think many people are aware of such microclimate effects. I think it would better only to report temperature data to the public that has been taken continuously at a given location, as opposed to stringing together a number of different locations which typically inserts an artificial cooling.

    In any case, if the global temperature anomalies remain high, this point will be moot. People like Watts can’t just keep saying the data is wrong, especially when their beloved satellites say otherwise. Plus, if the global temperatures continue running high, that increases the likelihood of warmer than normal weather at a given location. I’m sure people’s perceptions in places like London, Chicago, and New York will change after the first summer heat wave. People tend to be fickle.

  61. J Bowers says:

    It’s a good essay, but could use a lot of editing IMHO.

    I’d suggest writing two versions; one for policymakers who in all probability could understand the details and wording, and another for the general public.

    I’d also change words like “gullibility” as it may offend the reader.

    For an example of editing I’d suggest…

    “There is a contradiction between the observed continued warming trend and popular perceptions about climate trends. Frequent statements include: “There has been global cooling over the past decade.” “Global warming stopped in 1998.” “1998 is the warmest year in the record.” Such statements have been repeated so often that most of the public seems to accept them as being true. However, based on our data, such statements are not correct.

    The origin of this contradiction probably lies in part in differences between the GISS and HadCRUT temperature analyses (HadCRUT is the joint Hadley Research Centre, University of East Anglia Climate Research Unit temperature analysis). Indeed, HadCRUT finds 1998 to be the warmest year in their record. In addition, popular belief that the world is cooling is reinforced by cold weather anomalies in the United States in the summer of 2009 and cold anomalies in much of the Northern Hemisphere in December 2009.

    Here we first show the main reason for the difference between the GISS and HadCRUT analyses. Then we examine the 2009 regional temperature anomalies in the context of global temperatures.”

    …could instead be…

    “The contradiction between the observed continued warming trend and popular perceptions about climate trends lead to statements such as: “There has been global cooling over the past decade.” “Global warming stopped in 1998.” “1998 is the warmest year on record.” Such statements have been repeated so often that the public seems to accept them as being true.

    The data says such statements are not true.

    Where did this contradiction come from? Probably differences between the GISS and HadCRUT temperature analyses*. HadCRUT found 1998 to be the warmest year in their record. Popular belief that the world is cooling is reinforced by cold weather anomalies in the United States in the summer of 2009 and cold anomalies in much of the Northern Hemisphere in December 2009.

    Here, we shall first show the main reason for the difference between the GISS and HadCRUT analyses, then we shall examine the 2009 regional temperature anomalies in the context of global temperatures.”

    Somewhere further down, to avoid stalling the reader in his/her read of the article further above…

    “* HadCRUT is the joint Hadley Research Centre, University of East Anglia Climate Research Unit temperature analysis”

    They may seem trivial changes, and you may not agree. Personally, I’d approach a journalist to help with the editing.

  62. James Newberry says:

    This year’s continued increase of global temperature is a response to radiative forcing of decades past. When the Earth responds to today’s forcing in decades hence, the bell curve of temperature response will toll for the remains of civilization that knew not of energy and matter. A failed concept is what the matter with energy is, and shall inevitably be our downfall as plutocracy continues to control the hubris of “democracy.”

  63. Dano says:

    It’s a good essay, but could use a lot of editing IMHO.

    I’d suggest writing two versions; one for policymakers who in all probability could understand the details and wording, and another for the general public.

    I’d also change words like “gullibility” as it may offend the reader.

    I serve on a board where our staff commonly writes things that need major overhauls. However we get them to go over with not enough time for a major re-write. Same here. All you can do is fix a little, do section headers and realize some of the text needs to be moved into the relevant section, and move on. Hopefully in the future more attention will be paid to clarity and audience, but that’s no guarantee.

    As Lou implies several times upthread, the right people aren’t writing to the right audience. Communication to the public is important, and someone should be on staff that can do that.



  64. J Bowers says:

    “As Lou implies several times upthread, the right people aren’t writing to the right audience. Communication to the public is important, and someone should be on staff that can do that.”

    I fully agree with that. I do, however, get the impression that the essay doesn’t need to be finished in a day or two. Surely there are journalists out there who would make it work in a day? I specifically mention journalists because they have to work to tight deadlines. Or how about an editor? There must be loads of them out there willing to help out.

  65. J Bowers says:

    “Global mean temperature, as shown in Figure 1a, was 0.57°C (1.0°F) warmer than climatology (the 1951‐1980 base period).”

    That makes no sense at all. How can temperature be warmer than a science?

    [JR: I’m sure you can figure it out!]

  66. Russell B says:

    Back when I was an engineering student, one of the topics we covered was “Control Systems” and one message I took away from that was that a negative feedback controlled system (such as our planet’s climate) that is losing control and turning into a positive feedback, runaway system suffers ever wilder extremes, while the average remains pretty much the same until there is a total catastrophe.
    I look on extreme droughts, abnormal “cold snaps”, major monsoons etc as the extremes that could be evidence of a closed loop system losing its governance.
    I’m not a scientist or climatologist, but I prefer to “hope for the best – plan for the worst” and that means my next house will be at least 75m above current sea levels so it can stay in my family whatever happens!!

  67. Chris Dudley says:


    Gavin made the changes in my #55 at the Real Climate post but just to close the loop, since he is not an author, I’d appreciate you passing that comment it on from here. Thanks.