NASA’s Hansen: Would recent extreme “events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?” The “appropriate answer” is “almost certainly not.”

“It is likely that 2012 will reach a record high global temperature.”

Our top climatologist has a must-read, chart-filled analysis, “How Warm Was This Summer?

The two most fascinating parts are

  1. Hansen’s discussion of how scientists should answer questions about the recent record-smashing extreme weather events
  2. Hansen’s analysis of what is coming in the next couple of years.

Let’s start with the extremes:

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

However, if the question were posed as “would these events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?”, an appropriate answer in that case is “almost certainly not.” That answer, to the public, translates as “yes”, i.e., humans probably bear a responsibility for the extreme event.

In either case, the scientist usually goes on to say something about probabilities and how those are changing because of global warming. But the extended discussion, to much of the public, is chatter. The initial answer is all important.

Although either answer can be defended as “correct”, we suggest that leading with the standard caveat “you cannot blame”¦” is misleading and allows a misinterpretation about the danger of increasing extreme events. Extreme events, by definition, are on the tail of the probability distribution. Events in the tail of the distribution are the ones that change most in frequency of occurrence as the distribution shifts due to global warming.

For example, the “hundred year flood” was once something that you had better be aware of, but it was not very likely soon and you could get reasonably priced insurance. But the probability distribution function does not need to shift very far for the 100-year event to be occurring several times a century, along with a good chance of at least one 500-year event.

I think that is very good advice.

Dr. Kevin Trenberth, head of the Climate Analysis Section at the National Center for Atmospheric Research, has gone further, arguing, “It’s not the right question to ask if this storm or that storm is due to global warming, or is it natural variability. Nowadays, there’s always an element of both.”  Trenberth discussed his perspective in an interview with me:

I find it systematically tends to get underplayed and it often gets underplayed by my fellow scientists. Because one of the opening statements, which I’m sure you’ve probably heard is “Well you can’t attribute a single event to climate change.” But there is a systematic influence on all of these weather events now-a-days because of the fact that there is this extra water vapor lurking around in the atmosphere than there used to be say 30 years ago. It’s about a 4% extra amount, it invigorates the storms, it provides plenty of moisture for these storms and it’s unfortunate that the public is not associating these with the fact that this is one manifestation of climate change. And the prospects are that these kinds of things will only get bigger and worse in the future.

Second, you may recall that NASA predicted in January 2009 that 2010 would likely set a record.  In this paper, he explains “It is likely that the 2005 and 2010 calendar year means will turn out to be sufficiently close that it will be difficult to say which year was warmer, and results of our analysis may differ from those of other groups. What is clear, though, is that the warmest 12-month period in the GISS analysis was reached in mid-2010, as shown in the Rev. Geophys. preprint.”

Again, this is impressive because we are just coming out of the deepest solar minimum in a century.  Hansen provides this figure:


Now Hansen explains why 2012 is likely to set a new record.  He notes “Projections of trends over the next few years are possible based on the following considerations”:

  1. the planet is out of energy balance by at least several tenths of one W/m2 due to the rapid increase of greenhouse gases during the past few decades, as confirmed by measurements of changing ocean heat content
  2. inertia of energy systems that assures continuing growth of atmospheric CO2 by about 2 ppm per year for the next few years
  3. expectation that the solar irradiance will climb out of the recent long-lasting solar minimum, as shown in Figure 5
  4. model projections suggesting that the current La Nina may bottom out near the end of 2010.

He then concludes:

Given the dominant effect of El Nino-La Nina on short-term temperature change and the usual lag of a few months between the Nino index and its effect on global temperature, it is unlikely that 2011 will reach a new global record temperature.

In contrast, it is likely that 2012 will reach a record high global temperature. The principal caveat is that the duration of the current La Nina could stretch an extra year, as some prior La Ninas have (see Nino 3.4 index at the bottom of Figure 3). Given the association of extreme weather and climate events with rising global temperature, the expectation of new record high temperatures in 2012 also suggests that the frequency and magnitude of extreme events could reach a high level in 2012. Extreme events include not only high temperatures, but also indirect effects of a warming atmosphere including the impact of higher temperature on extreme rainfall and droughts. The greater water vapor content of a warmer atmosphere allows larger rainfall anomalies and provides the fuel for stronger storms driven by latent heat.

So 2012 may top 2010 as the hottest year on record with more extreme events.  And it’s a presidential election year.  If only we had a president who actually talked about climate to the public….


57 Responses to NASA’s Hansen: Would recent extreme “events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?” The “appropriate answer” is “almost certainly not.”

  1. BobbyBob says:

    I think it should be pointed out that if you ask a scientist if the sun will rise tomorrow, they will respond with “probably” or “almost certainly”.

  2. Peter M says:

    The President did a poor job explaining health care to the public- I do not know how successful he would be warning the public about ACC, and the increasing ‘load of the dice’ as Hansen says we will likely face – in 2012.

    If in 2012 experience more weather more extremes, heat and drought- a specific event that severely impacts the US – like a summer long heat wave and drought in our agricultural heartland- The President could be in a better position to address the nation to say these kind of ‘events’ will increase and become commonplace in the very near future.

  3. Owen says:

    Sustainable Energy Futures Symposium in Berkeley by Philomathia Foundation
    October 1-2.
    Use the webcast link on the left not on the right. Speaker list is also given.

  4. Claudia F. says:

    @ BobbyBob,

    I had this dicussion with Gavin Schmidt once. To make the significance of probabilities clear to me as a non-scientist, he mentioned exactly that example. He asked me how sure I was whether the sun would rise tomorrow. I said to him that the probabilities don’t translate for the public. Ninety percent probability means that there are still significant questions, that science is still “out”. The lack of meaningful translation of climate science for the public is one of the profound tragedies of the IPCC process. This applies especially to a country where people with the most modest understanding of science for some odd reason feel that they can have an opinion about highly complex matters that require extremely specialized training and experience.

  5. Doug Bostrom says:

    An HTML version of Hansen’s remarks is here.

    Joe, I wish you’d have a word with the folks at MIT’s “Knight Science Journalism Tracker,” or at least point out to them Hansen’s thoughts on attribution when covering extreme weather in the popular press. The site is a sort of thought-leader for science journalists and seems to be on a crusade to make sure journalists always commit exactly the sort of coverage mistake Hansen points out. In point of fact, it seems they ought to be encouraging journalists to follow the suggestion of actual scientists such as Trenberth and Hansen.

  6. mike roddy says:

    I’m not sure that extreme weather events of 2012 will translate into political urgency. The media has been well trained by the oil and coal companies to treat extreme floods and droughts as independent events without causation, and to wag their fingers at scientists who connect them to GHG caused global heating.

    Probabilities and patterns don’t translate well to a poorly educated population that prefers both certainty and magical thinking. Sophisticated right wing media spokesmen such as Milloy and Watts exploit this distrust of data well. In 2010, they will once again try to drag scientists into a “debate” over weather events, and the scientists will be left with probability bands and chains of evidence. Watts, for example, will try to find a bigger drought or storm at some point in the distant past.

    Progressives need to anticipate this and prepare well reasoned summaries, and get ready to ignore and humiliate the oil and coal company funded spokespeople who will try to stir up arguments with them. The denier oeuvre is so wrong, and so ridiculous, that they need to be scornfully responded to with evidence, not in the form of obtuse and hedged statements.

    You’re pretty good at this, Joe. You need to be cloned in newsrooms everywhere.

  7. mike roddy says:

    correction in second paragraph: “2010” should read “2012”.

  8. Ron Hill says:

    Who cares about 100 or 500 year events? There are so many places in the world that can potentially experience them, so it’s nothing special.

    It’s just like the lottery. The chances of any person winning the lottery is incredibly small, but since there are so many people playing, it’s normal to have a winner once a week.

  9. MapleLeaf says:

    I read this yesterday and was impressed. Umm, why has Hansen not received a Nobel for physics yet?

    Excellent work again Dr. Hansen.

  10. john atcheson says:

    Rather than counting on the interviewer to ask the right question, or rephrasing the question (which might seem deceptive to a confused public) an answer along these lines would be both correct, and less confusing:

    “It is certain we are seeing extreme events of this kind as frequently as we are, because of human’s have emitted huge amounts of greenhouse gasses into the atmosphere.”

  11. john atcheson says:

    Correction: strike the “of”

    “…because human’s have emitted …”

    Or, alternatively we could say, “It is certain we are seeing extreme events of this kind as frequently as we are, because human’s are burning fossil fuels and emitting huge amounts of greenhouse gasses into the atmosphere.”

  12. Norris Dale says:

    I’ve heard an interesting way of dealing with the improperly framed question. Goes like this:
    “I wouldn’t put the question quite that way, George. Now, if you were to ask me whether these extreme events would be occurring without the rising greenhouse gas levels, I would say, definitely not . . . .”

  13. homunq says:

    “Climate disruption caused this [event].”

    “How can you be certain?”

    “I can be 100% certain that we would not be having the same day-to-day weather without climate disruption. Therefore this [event] would not have happened.”

    “Oh, you’re talking about the butterfly effect. So, OK, climate disruption caused this particular [event], but without it something else just as bad might have happened.”

    “If you’re not talking about actual events, but probabilities for what might tend to happen or might have happened, you’re talking climate. And then, yes, of course, without climate disruption, we would certainly have a more manageable climate.”

  14. Colorado Bob says:

    “Well you can’t attribute a single event to climate change.”

    When one looks at the larger pattern though, it’s a different story . The smaller pieces all make a puzzle of a much larger picture , and that one is an arrow pointing up.

    Dr. Masters made an excellent point about this back in the summer. I can’t claim that the high in Climax , Colorado was because of climate change. But it happened in the same month that all the walrus in Alaska waters hauled out because their ice platform was gone, and in a week where 2 feet of rain falls on the eastern seaboard. Walrus know nothing of thermometers , or rain gauges.
    But all tell the same story.
    I have a bad habit of looking at records, there is another trend in them , their “youth”. More and more these things are breaking younger and younger records.

  15. grypo says:

    While scientists are expected to be reticent, the opposition can say whatever it wants, including comparing scientists to witch burners and murderers.

  16. Richard Brenne says:

    Ron Hill (#8) writes: “Who cares about 100 or 500 year events?”

    I’d say everyone that experiences them, which will be virtually everyone on Earth within some small number of decades, most likely within just a decade.

    So everyone in Wilmington and many other places on the Eastern seaboard right now, at least 15 million in Pakistan, more in Russia, and I’m sure each of those in the 17 nations on four of the five most populous continents that experienced their nation’s all-time heat record, typically in the 117 to 128 degree range.

    The majority of houses in a flood plain and most houses with basements will be flooded within the expected life span of the house, most within some small number of decades and many within a decade.

    That’s who cares, or at least will care.

  17. Berbalang says:

    Ron Hill @ 8:
    There is a problem with your analogy. It isn’t just a case of there being so many places in the world that a 100 or 500 year event was likely to happen somewhere. It is a case of 100 or 500 year events happening all over the place. It would be like having lots of winners every week winning the lottery over and over. In both cases something is obviously wrong.

  18. Colorado Bob says:

    Arizona set 22 highs yesterday, for both day and night . 14 were 10 years old or younger.

  19. TomG says:

    It seems to me that there is a lot of single events all happening at the same time…

  20. Colorado Bob says:

    100 or 500 year events –

    There’s another change in these events. The 1993 Mississippi Valley floods were rains falling for days over a large area. Rain fall rates of as high as 3 to 4 inches a hour are quite common now. That is a very different ball game, if you’re under them.

  21. Richard Brenne says:

    “Was global warming the cause of the 2010 heat wave, Pakistan floods, etc?”

    Yes, it was a cause. Together with natural variability, human-caused global warming affects all the weather we experience now, and all the weather we ever will experience in the future.

    If natural variability or standard deviation remains the same and you raise the baseline of temperature and thus energy and water vapor in the system, you are going to get more heat than cold records, and more dramatic precipitation events of all kinds, you just don’t know where or when.

    We’re done with the tired cliché that “One weather event cannot be blamed on global warming.” That was always illogical, misleading and just plain stupid. Instead, “Every weather event fits into a pattern of averages we call climate, and so every weather event, put in the perspective of patterns over a big enough area and long enough time illustrates climate change. Even a cold record does this, because there are now fewer of them.”

  22. John McCormick says:

    RE # 15

    Richard a great response to Ron:

    “The majority of houses in a flood plain and most houses with basements will be flooded within the expected life span of the house, most within some small number of decades and many within a decade.”

    I think about the millions of American homeowners living along the coasts and in flood plains who will suffer huge property damage from flooding and struggle to return to that same home. Why? They have no option if the mortgage has not been paid up and the housing market has vanished for obvious reasons.

    Will we have to buy them out of their uninsured property if only to end their misery?

    John McCormick

  23. Wit'sEnd says:

    The CDC can’t prove that an individual case of lung cancer was caused by smoking. But they can predict with great accuracy how many new cases will be diagnosed each year, because of smoking.

  24. rick says:

    “Was global warming the cause of …[extreme events of 2010]…? The standard scientist answer is “you cannot blame a specific weather/climate event on global warming.” That answer, to the public, translates as “no”.

    However, if the question were posed as “would these events have occurred if atmospheric carbon dioxide had remained at its pre-industrial level of 280 ppm?”, an appropriate answer in that case is “almost certainly not.” That answer, to the public, translates as “yes”,”

    And to the general public, this appears as a contradiction that demonstrates that scientists don’t know what they’re talking about. But it’s of course because the “general public” is ignorant of probability and statistics. It’s demonstrated by how easily they are fleeced using lotteries.

    Hill in #8 is in principle correct. A few 500-year events don’t prove anything. They’re even expected: if there are say 1000 independent event-locations, we expect around 2 a year. I haven’t seen a proper statistical analysis. But look at this previous post: Two 500-year events in the past 11 years in one location is almost certainly an indicator of climate change.

  25. Mark says:

    Wit’sEnd says:
    October 1, 2010 at 3:45 pm,……. smoking comparison….

    best simple explanation I have seen.

  26. Rob Honeycutt says:

    Ron Hill said
    “Who cares about 100 or 500 year events? There are so many places in the world that can potentially experience them, so it’s nothing special.”

    I keep hearing this rationalization and it’s just wrong. Think of it. Define how many “places” there are in the world. Cities? Square miles? Square feet? The probability of the event can’t change with how you define “places.” The place and the probability of the event are independent of each other.

    Or think of it this way. On a previous thread the poster was saying because there were some 30,000 cities of at least 200k people then there are 500 year events taking place once a week someplace. Or, by the same thinking 1000 year events would be happening twice a month. Somewhere. That means that there were a hundred 1000 year precipitation events this past year. And that is just NOT the case!

  27. Rob Honeycutt says:

    To continue… That means this past year there were a hundred precipitation events like that experienced in Pakistan this year. And there were also a hundred heat wave events like that seen in Russia in the past year.

    You see how stupid this is?

    But as stupid as it is… it keeps getting repeated over and over. This is something like the 10th time I’ve encountered this argument. I do not know where it is coming from.

  28. Richard Brenne says:

    Dr. Hansen:

    In addition to my comments above at #16 and especially #21, when you reference the “2010 heat wave in Moscow” you might consider the “2010 heat wave in Western Russia, Belarus and Ukraine, which each set their all-time national heat records.”

    Similarly in referencing the “all-time record high temperatures reached by many Asians nations in 2010” you might consider “the 17 all-time national heat records including South America, Europe, Africa and Asia with most records in the 117 to 128 degree Fahrenheit range. Thus far there have been no all-time national cold records in 2010.”

    I know that’s longer than your concise sentences, but still think these can be helpful points. This is another superlative, impeccable paper. I wouldn’t change any other content, but would have all who communicate climate change make each of your points and all others that are scientifically accurate in the punchiest, most pointed and clear language possible. I think Joe and many of his commenters are masters at this, so I hope you visit here often.

  29. At what point will the public go from disinterested to panic. I suggest there may be no in between.

  30. rick says:

    @Honeycutt: Most people don’t have your (and my) intuition and so need the numbers. Let’s do that. If my city (Vancouver) experiences an extreme weather event, I’m sure Seattle and probably even SanFran will see it as well. LA not so much; in fact this summer was abnormally cool for them, but normal for us. So this sets a scale of about 1700km, or in area, 3 million km^2. The earth has about 150million km^2. Thus there are only about 50 areas that from extreme weather point of view can be considered to be independent. One expects a 500-year event somewhere every 10 years or so.

    And we’re seeing it FAR more frequently than that.

  31. Aaron Lewis says:

    #8 Ron Hill

    We care about 500 year return events, because because engineers are trained to plan for and build infrastructure for certain (usually smaller )return events. Then, when we have an event that exceeds what the engineer planned for, the infrastructure is damaged. If the structure is damaged, we lose the utility of the structure. Insurance companies lose their payout. Bond and/or mortgage holders lose. Owners lose capital and value. And, people die.

    Our entire financial system (and hence civilization) is based on being able to predict the life span of capital assets. Climate change results in a lack of predictability. Lack of predictability makes insurance and finance very difficult. And, people die.

  32. adelady says:

    I think all climate scientists should be trained to recite “Wit’s End”s mantra about likening the lung cancer/smoking connection to the extreme weather/ climate connection. Somehow, some way there must be a formulation to explain connections and this is far and away the neatest logical / physical analogy I’ve seen.

  33. caerbannog says:

    Frankly, I hope that some large, GOP-dominated Midwestern-Southern cities in the USA get “Moscowized” in August 2012. A lot of GOP’ers deserve weeks of 110+ heat-index daytime highs plus overnight lows of 90+. Not days, *weeks*. And throw in lots of choking smoke from wildfires burning through dried out forests. Yes, they deserve it.

    Unfortunately, lots of innocent folks will suffer as well, but if there are going to be nasty global-warming-induced heatwaves and wildfire outbreaks, let them occur where they will cause the maximum possible amount of discomfort amongst the right-wing yahoos who have stalled meaningful climate action over the past 20 years or so…

  34. Lewis C says:

    Dr Hansen –

    given the focus on communicating the jeopardy effectively within your characteristically brilliant paper, I’d like to offer on small but potentially seminal change in language for your consideration, and dissemination if you saw fit.

    For decades scientists have dutifully shot themselves in the foot when speaking to the commercially oriented media, by expressing the professional scientist’s caution in the statement that:
    “No specific weather event can be attributed to global warming.”

    The fact of the ubiquity of global temperature as a driver of climate and thus as a central component of weather is entirely missed by this standard disabling line. If there is any other that is more valuable to the deniers, then I’ve yet to spot it.

    Therefore, with the accelerating rate and scale of extreme weather events now shocking even previously complacent politicians such as Medvedev and Harper, perhaps it is time to improve both the statement’s accuracy and its cogency, as follows:

    “No specific weather event can be attributed solely to climate destabilization.”



  35. David B. Benson says:

    Were the Mayans right about the year 2012?

  36. Hot Tropics says:

    Sea walls the norm?

    As Hanson states “The greater water vapor content of a warmer atmosphere allows larger rainfall anomalies and provides the fuel for stronger storms driven by latent heat.” He is on the ball here and, it is a reasonable forecast of things to come anytime from 2010 onwards and not way into the future. As a recent CSIRO (2010) discussion paper from Australia shows, of the effect of sea level rise on the frequency of major storm events (including cyclones/hurricanes) and the possible heights they will reach.

    This is particularly relevant to coastal planners and councils (local government) who consider approving or not approving coastal development, buildings and infrastructure. Some councils may decide to build sea walls while others may choose a planned retreat. If you were moving into a coastal neighbourhood you would be just as interested.

    Fig A below shows the increasing frequency of storm events as sea level rises. For example, a 1-in-100 year event today may happen every 9 years with a 1 metre sea level rise (5th column).

    10 mm = 0.39 ins
    1 metre = 3.28 ft Sea level Rise (m)

    Current Event 0.2 0.4 0.6 0.8 1.0 m SLR
    1-in-50 31 19 12 7 4 yrs
    1-in-100 61 38 23 14 9
    1-in-500 306 188 115 70 43
    1-in-1000 613 375 230 141 86

    Fig B below compares current storm tide events on the east coast of Australia (Moreton Bay) and how high they would be with sea level rise.

    SLR(m) now 0.2 0.4 0.6 0.8 1.0 m
    1-in-50 2.3 (m) 2.5 2.7 2.9 3.1 3.3
    1-in-100 2.5 2.7 2.9 3.1 3.3 3.5
    1-in-500 3.2 3.4 3.6 3.8 4.0 4.2
    1-in-1000 3.5 3.7 3.9 4.1 4.3 4.5

    King tides up to 3 metres or more (additional) occur during the cyclone (hurricane) season. The worst case scenario for northern Australia (and many other places in the world including the USA) would be a cyclone (hurricane) occurring on top of a king tide. The odds of this happening increase with the number of severe tropical storms and cyclones, which increase as the temperature rises.

    The above tables put SLR into perspective. People living in tropical and sub-tropical zones will be hit very hard on occasions and, the frequency will increase as temperature rises.

    Coastal Inundation Under Climate Change, CSIRO 2010

  37. Omega Centauri says:

    Rob @26 and Rick @30. It depends upon the correlation of the different “sites”. For some events, a local cloudburst or hailstorm, the strong effects may be highly localized, so we effectively have a very large number of sites, and 500year events would seem common. For larger events, statewide heatwaves, basinwide flooding events, etc. the number of effectively independent sites is much more limited. It is a good question, but I don’t think we have an effective way to gage how common media reported 500year events should be. For more specific things, like the number of tornadoes, I suspect the climatologists could come up with some decent methodology.

  38. Lewis C says:

    I wish Dr Hansen could spare one of his staff for a little while to provide a graph showing the actual track of global warming, alongside its track calculated to remove the contribution of the solar cycle shown above, alongside that solar cycle track.

    Having a simple graph, from an organization as prestigious as NASA, that could be shown to those who cling to the excuse that “it may be the sun,” would be really helpful.



  39. adelady says:

    So, hot tropics, your figures mean what exactly for Australia’s playground, the Gold Coast. I know that surveys show that Australians generally feel that GC development is one of our prime eyesores, but what do your figures mean for all those high rises overshadowing the beach?

    I’d be happy if those ugly things had never appeared, but I’m even less thrilled about the idea of uglier bunkers defacing the remnants of the beaches to protect them. Any computer graphics from the local councils displaying just how pretty the new arrangements will be?

  40. Brent Sullivan says:

    @#31 Aaron Lewis
    “Our entire financial system (and hence civilization) is based on being able to predict the life span of capital assets. Climate change results in a lack of predictability. Lack of predictability makes insurance and finance very difficult. And, people die.”

    Spot on and it is for this reason we should talk about Climate Instability rather than Global Warming or Climate Change. Those two terms imply ‘a new normal’ that we can adjust to–just move crops a couple hundred miles north and build a few dikes, no big deal. As I understand it, that ‘new normal’ could be a long time in coming–preceded by instability and unpredictability.

    _There’s nothing business hates more than instability and unpredictability_. To get them on the right side of the argument in time to do something useful, we have to speak in their language–talk about _Climate Instability_ and you’ve got a shot at harnessing the corporatocracy.

  41. Deborah Stark says:

    Some direct observations here:

    Yesterday, October 1, we had an 80+ degree morning here in Boston, MA and extremely high humidity for this time of the year. In fact the entire last week had been unseasonably warm and humid. The storm moving up the East coast yesterday fortunately did not have a major impact on the Boston area, although it was extremely windy here the first half of the day.

    I have noticed over the last 10 years, and the last 4-5 years especially, that autumn in our region is significantly warmer and more humid than what we have been used to. This year in particular feels almost tropical. The leaves are falling off many of the trees either still green or just plain dead brown. In other words, many of the leaves are falling from the trees without having turned their usual beautiful colors.

    Last year on the third Saturday in November I went down to the Boston Common to support a “Wake Up, Sleep Out” event organized by The Leadership Campaign at which Jim Hansen was scheduled to speak (he also camped out on the Common with the students that evening and was arrested.) It was an unseasonably warm day. On my way to the train station I noticed that several shrubs and small trees were RE-BUDDING. I later spoke with friends in Concord and Springfield, MA and they also reported that bushes and shrubs in their yards and neighborhoods were re-budding and even re-flowering that weekend.

    On December 17, 2007 I walked to a bus stop on my street to wait for the 7:20am bus to the subway station. I noted narcissus and crocus in bloom in many of the yards I passed along the block. We’re talking a week before Christmas here. In Boston.

    I’ve been saying for years that it feels like the air in our region is “coming from a different place.” I think it IS coming from a different place. Our atmospheric circulation patterns have been messed up due to overheating. Prevailing seasonal circulation patterns that were once reasonably predictable can no longer be counted on.

    Another observation from August 2002: I made a trip to Albuquerque, NM having not been down there in five years. This was my sixth trip to NM in a 15-year period. When I arrived and walked out of the airport (I will never forget this) the air was extremely heavy and humid and the sky was overcast with the remnants of persistent, spreading contrails criss-crossing through the cloud cover. I felt like I had arrived in Miami rather than the desert southwest I knew and loved. It was quite a shock.

    So, yeah, I would say there’s a great deal more moisture in the troposphere these days, and that the additional moisture is holding more heat down on the surface here. I can FEEL it. The other thing I have noticed is that during the summers it does not cool off at night the way it used to. In other words, the nighttime lows are higher in general than they used to be. This has been very difficult for people with chronic respiratory problems. A week of daytime temperatures in the upper-90’s can be tolerated IF it at least cools down at night. When that doesn’t happen, it’s not a good thing.

    One last note: I have been keeping an eye on AIRMAP New England’s (University of New Hampshire at Dover) atmospheric CO2 concentration monitoring for years now. Readings are done every 15 minutes around the clock, 365 days a year. For the last year, CO2 has generally been up around 400ppm on average in the eastern New England region.

    This is all I have time for this morning. Thank you to Jim Hansen, Joe Romm and Bill McKibben for your courage, integrity and tireless work on behalf of all of us who who are concerned about the issues at hand and care very deeply about the kind of world we are leaving to our children and grandchildren.

  42. Richard Brenne says:

    Deborah Stark (#41) – Thanks for your wonderfully-written observations. This is exactly what we need, is many people as possible like you who are very observant making very detailed observations over a wide area relative to what things have been like in the past, because this is the best way to convince people that global warming is real, is happening, is already impacting their lives and will impact them much more than they could ever imagine, especially if we do nothing to control emissions.

    You and Gail at Wit’s End (Google this and go to her wonderful blog) should get together with your very detailed observations.

    I’m speaking to garden clubs and the gardeners about just these kinds of observations, and would like to see all gardeners, farmers, bird watchers, outdoor ice skaters, backcountry skiers, ice climbers, glacier climbers, wildlife enthusiasts and the like make just these kinds of observations and communicate those in tandem with scientific studies.

    Those that have established baselines of detailed observations over the longest period and in writing are of course most helpful, but starting to keep written records now is also helpful.

    Anecdotal observations need to feed into scientific studies and statistics, but they are critically important because they connect with real people and they can inform and inspire scientific studies. We need more of both.

    Again, great essay – very heartfelt and precise. Thank you.

  43. Hot Tropics says:

    Inundation Graphics @Adelady

    In the document that I cited it explains what the effects will be at some time to buildings and infrastructure and you can see the tables more clearly as well.

    Hopefully, the Gold Coast will be around for many years and will remain a joy for everyone but at some stage in the future the GC, like many places in the world, will have to come to terms with regular inundation and for some low lying islands it will be permanent. Some councils will build sea defences and some will have a policy for planned retreat.

    In relation to professional inundation graphics, the best I have seen to date are the ones prepared for the Gippsland Lakes in Victoria, Australia. Coastal Councils anywhere could use this standard as a benchmark because you can factor in the 1-in-50 year events and so on. Developers, purchasers, councils, governments and insurance companies will find it very useful and it will save a lot of heartache and expense. That is why we also need accurate data and models of volume loss and SLR from Greenland and Antarctica which will come soon I believe. Inundation Model (high quality)

  44. William P says:

    The Mayan calendar ends in 2012.

    Exactly how hot will it be in 2010, Dr. Hansen?

  45. William P says:

    Sorry, I meant to ask – how hot will 2012 be, Dr. Hansen?

  46. David B. Benson says:

    William P — Easier to make decadal predictions. The 2010s will be the hottest decade in the instrumental record of, by then, 14 decades.

  47. William P says:

    Hot Topic #43

    I don’t think inundation will be on the top of the threat list. Yes, it will happen, but crop destruction will rank #1 in threat to humans and seems likely to appear sooner than substantial inundation.

    This year’s Russian wheat crop loss is a preview. The world is falling behind in feeding Africa now where crops have been lost to heat and drought.

    As global warming increases, perhaps instances of such heating – enough to kill crops – will be more frequent. At some point in this process, the “light bulb” will come on for average people, governments, and maybe even media will report it although they lean toward protection of establishment industries like oil and big coal, and soft pedal any news negative to their sponsors, the fossil fuel industry.

    Another event to be concerned about is, say the “light bulb” comes on to the extent it causes a global level of panic strong enough to start to shut down business as usual – factories, air travel, etc.

    As shown by 9-11 when air travel briefly shut down, less amount of particulate matter and condensation trails (lessening albedo effect) cause a quick temperature rise since more sun hits earth when matter in our atmosphere is reduced.

    Reports said the 9-11 airline shut down resulted in a 1 degree C rise in temperature. This is huge. And that was mainly due to one factor – jet contrails (condensation from jet exhaust) disappearing. Public panic regarding food could cause a much larger decrease or shut down of travel, electrical production, industry and other sources that put particulate matter into our atmosphere. (Ironically, the huge amount of this matter in our skies right now is very probably saving our lives today.)

    There seems little discussion of the impact of less reflective material in our atmosphere even though it is highly relevant and critical.

  48. William P says:

    David #46

    Isn’t Hansen speaking specifically about 2012?

  49. Lewis C says:

    William at 47 –

    your scenario of the loss of coolant aerosols seems highly plausible as a threat, but as it is also clearly visible this far in advance, forward planning of its mitigation is feasible.

    The decision to end all but the most essential of air travel (along with imposing swingeing emissions cuts) would be unavoidable under the massive pressure of a panicking public, despite both major industry and food retailers’ current dependence on it. Yet when that pressure is manifest, the authorities will face the (very belated) choice either of applying the best available means of albido restoration to reduce planetary temperature, or of seeing the electorates suffer an abrupt rise of ~1.0C in the average global temperature.

    Given the differentiation by latitude, that increase equates roughly to a 2.0C rise in the temperate zones, and perhaps an extra 4.0C at the poles. – As a potentially rapid accelerator of the interactive feedbacks this threat is arguably unique.

    If by the point when public unease turns to panic geo-engineering research and deployment has been so limited by the myopic rejectionism voiced by many environmentalists and some of the public, then the damaging release of sulphate aerosols will very likely be applied globally as being the “best available means.” The research and localised proving of optimal means of albido restoration is thus a matter of real urgency.

    From my POV the foreseeable loss of accustomed coolant aerosols is just one of several reasons justifying the observation that:

    “Efforts to terminate GHG outputs without deploying both forms of geo-engineering is now no less futile than deploying geo-engineering options without terminating GHG outputs.”

    This seems a very unwelcome truth indeed, but it is one of those which has a time constraint – the sooner it is faced, assimilated and acted on, the better our chances.



  50. Roger says:

    Beam Me Up Scotty (#29) makes a what I think is a valid point, and one that keeps me awake at night. Study up on historic examples of public panic. Often it didn’t take much–just a rumor could trigger a ‘run’ on a bank, as another well-known James made famous in “It’s a Wonderful Life.” Just imagine…you’re suddenly appointed the “communicator-in-chief.” You’re thinking about going in front of the lights and the TV cameras in the Oval Office to explain the depth of our do-do to Joe the plumber. Then one of your advisors says words to the effect, “Remember, Mr. President, the only thing 300 million times worse than the sorry situation we have today would be for you to make the case for action SO vivid and clear that people over-react and start to panic!” We need a “State of the Climate” address, but it must be VERY carefully framed.

  51. William P says:

    Lewis #49
    There will not be a “decision” to slow or end air travel. A panic will do it – either slow it or stop it cold. Like after 9-11. Even in the days and weeks after that, people flew much less.

    Replacing reflective material in the atmosphere is not something that can be done quickly. A lot of planning and infrastructure would be needed and that could take a lot of time. Its not a bad idea to start building that infrastructure now. But we can’t even seem to agree global warming exists, is man-caused, etc. let alone prepare to defend against something like loss of reflective material in the atmosphere.

    Beam me Up Scotty hits the bull’s eye again (#29) with his concise observation: “At what point will the public go from disinterested to panic. I suggest there may be no in between.”

    Absolutely true. Recall how quickly stock market panics set in. The same instant panic could happen when the public “gets it” that the food supply is threatened by extreme global warming events. Our media won’t tell the public the full, stark truth about where global warming is leading. Our politicians shy away from frank discussions for fear it will affect their getting elected.

    So that leaves it up to actual events to finally wake up the public – a public who reacts so badly to being told unpleasant truths. Events could include ice suddenly sliding off Antarctica or Greenland causing an instant rise in sea level and coastal inundations of heavily populated places – very much including America. Or the food shortage thing and a panic that would worsen it by causing a run on food supplies.

    Roger’s idea (#50) about a Presidential announcement that eases the public into a real understanding of the seriousness of global warming is a good one. But you know he would be immediately attacked by Fox “News”, Limbaugh and a thundering herd of Republican Congress people for doing it. Big oil and big coal would immediately activate their Denier Corps of news people, “scientists”, and various blabber mouths to attack such an announcement and demean, mock, and smear the President.

    No, I think Mother Nature will have to be the one to break the news to Mr. and Mrs. Joe Public. But that would come very late in the game – bottom of the ninth, two out, and the batter with two strikes and three balls. Not a happy scenario.

  52. Leif says:

    William P, @51: …:bottom of the ninth, two out, and the batter with two strikes and three balls. Not a happy scenario.”

    I would say “top of the ninth.” Nature bats last!

  53. William P says:

    Right you are, Leif.

  54. James Newberry says:

    The President could someday say: The heat our society purchases by oxidizing, or burning, a pound of (mined) hydrocarbon material, which we presently consider as “fuel,” is exceeded by ten thousand in heating the planet during the atmospheric lifetime of the resulting carbon and oxygen molecule, called carbon dioxide, besides acidifying our oceans. We can’t survive this process any longer.

    Therefore, in order to protect our national security, all direct, indirect and externalized subsidies and policies that support this process shall be phased out from the federal budget during my term in office. Furthermore, military activities which burn these fossilized (buried) materials shall be minimized and eventually terminated.

  55. William P says:

    James – you nailed what needs to be said by the President. But we must always ask: What would Fox “News” say about it?

    Sadly, we have to ask that question. Our government and politics is driven to a great extent now by the big right wing media propaganda machine that uses hot button issues (Muslim mosques) to elect Republicans who in turn protect and enhance life, not for you and me, but for corporations.

    Corporations have a fiduciary responsibility to share holders to focus on one thing only – maximizing profit. Using Congress to do that is perfectly acceptable with them. Its a means that really pays off.

  56. with the doves says:

    No need to ask what Fox News will say. It’s obvious.

  57. Mark says:

    Interesting paper on what is in store with a further degree or two of warming judging from the last interglacial. The sea level issue resurfaces.

    [JR: Will be posting on that soon.]