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Breaking the silence about Spring

Filed under: — eric @ 11 April 2009

Did you know that in 1965 the U.S. Department of Agriculture planted a particular variety of lilac in more than seventy locations around the U.S. Northeast, to detect the onset of spring — in turn to be used to determine the appropriate timing of corn planting and the like? The records the USDA have kept show that those same lilacs are blooming as much as two weeks earlier than they did in 1965. April has, in a very real sense, become May. This is one of the interesting facts that you’ll read about in Amy Seidl’s book, Early Spring, a hot-off-the-press essay about the impacts of climate change on the world immediately around us – the forest, the birds, the butterflies in our backyards.

The brilliant title of Seidl’s book was one of the reasons that it caught my attention. The other was that I have realized I need to better educate myself about the impact of climate change on everyday life. I’ve been dismissive of the idea that the average person can really detect the impacts of recent warming on, for example, the timing of the apple-blossom season, but I’ve been taken to task by several of RealClimate’s readers for this. If you are paying attention, they have argued, the changes are actually rather obvious.

Of course, Amy Seidl is not the average person. Rather, she’s a trained ecologist with a Ph.D. (as well as an avid gardener) and she’s clearly paying extremely close attention. Her book is the first one I have read that effectively brings home the tangible impacts that global warming will have – is having – on our everyday lives. “We are increasingly familiar,” she writes, of images of melting glaciers, “but how do we give them relevance in our lives? From my window I see no glaciers.” She answers her own question with a series of vignettes, some from her own experiences, many more from her extensive research (well referenced throughout the book).

Cardinals, robins and cowbirds are all arriving earlier in Vermont than they did a century ago. Kingfishes, fox sparrows and towhees are not. Why the difference? The answer, as Seidl explains, is that the former group has the ability to respond ecologically to the changes, because these birds cue their arrival to temperature. The latter, it appears, respond more directly to temporal cues, that won’t change even as climate does. It’s obvious from this example that the make up of bird life in Vermont – the species distribution – will change over time. This may not necessarily be a bad thing of course. On the other hand, it turns out that the robins are the most important host for West Nile virus; the early bird gets the worm, so to speak, and passes it along to humans.

Maple seedlings need about 100 days of below-freezing weather. As this becomes rarer, fewer maples will populate the forests. This, Seidl explains, is why species-range models predict the decline and eventual loss of sugar maple (at least in New England) in the future. But, she notes, the models don’t take into account the full complexity of the system, such as the impact of competition among different species. So we don’t really know what will happen, or how fast. What we do know is that maple-sugar farmers have noticed – and documented – an earlier maple sugaring season over the last few decades.

There are many other examples in Early Spring both of clear climate-related changes (such as the early arrival of robins), and of less clear-cut changes (the maple sugaring season). Seidl doesn’t make the common mistake of assuming that the more ambiguous examples are necessarily due to climate change. For example, she quotes a maple-sugarer who points out that technological changes have allowed them to tap maples earlier, and hence that the timing of sugaring is a weak measure of climate change. The point though, is that even rather minor changes are, after all, being noticed. And if much larger changes do occur, as predicted, they will most certainly have impacts we can’t ignore, even if we don’t live in the Arctic or in Bangladesh. In other words, Seidl tells us, listen to the farmers and gardeners, and the observations of regular people: they are meaningful.

The soberness of Seidl’s approach to the subject of climate change impacts contrasts starkly with that of many books before it. It couldn’t be further, for example, from Mark Lynas’s book, Six Degrees, which is a truly alarming read. In my comments on Six Degrees, I said that it wasn’t an alarmist book. I stand by that characterization, because – and this is what I liked about it – it doesn’t go beyond what is in the scientific literature. However, while Lynas’s book is a straightforward reading of the scientific literature, it is a somewhat uncritical one, and hence tends to emphasize what might happen in the future over what will happen; this is a point that many readers of my review seem to have missed. Seidl’s book, on the other hand, is focused on the more certain – and often less dramatic — things, and on the impacts we are likely to see in our own lifetimes.

The calm demeanor of Seidl’s book, and the very personal nature of it, could lead one to think that it is primarily just a philosophical reflection on the climate change story. Indeed, Bill McKibben, in his introduction to Early Spring, says that in the face of changes we may not be able to prevent, “one of our tasks is simply to bear witness”. Certainly, the book is partly that. But Seidl’s voice, like Rachel Carson’s before her, has the authentic and authoritative voice of a scientist, made all the more compelling for being very much rooted in the author’s own story and experiences. And she doesn’t pull punches when she has something definitive to say: “One thing is clear:” she writes, “we will not be able to manage the climate”.

Early Spring has the potential to be immensely influential, a real turning point in the popular appreciation of climate change impacts among laypersons and scientists alike. Read it.

Note that we review books on a fairly ad hoc basis. For earlier reviews of other books, see here.

347 Responses to “Breaking the silence about Spring”

  1. 1
    Walt Bennett says:

    Let this serve as the early warning that we are already in the mitigation and adaptation phase of AGW. Let the public policy planning proceed accordingly.

  2. 2
    Charles Raguse says:

    I was born and raised in the Middle West (in my case, Wisconsin). During the 1940’s there was a saying \When the leaves on the oak tree are the size of a squirrel’s ear, it is time to plant corn.\ Also, the \unclear\ match of the sugar maple season with other markers such as the arrival of the robin is likely due to a significant damping because of soil temperature.

  3. 3

    The harbinger is always timely for Spring. Thanks.

    How very fortunate we are to observe this in flowers, whereas in Alaska, with some of the greatest warming, homes and land disappear into the sea as the foundational permafrost melts. See report from Living on Earth on Alaska’s Changing Climate. Includes some NOAA before and after photos of one storm erosion.

    It seems like we have avoided direct experience of serious changes.

  4. 4
    Nick Gotts says:

    You don’t seem to understand what “mitigation” means in this context. It means, precisely, measures to reduce the anthropogenic causes of climate change, principally greenhouse gas emissions – which you oppose.

  5. 5
  6. 6
    Hank Roberts says:

    “Vermonters at the frontiers of science. Hosted by Amy Seidl, the program delves into such topics as energy, transportation and the technology of social sciences – all with a Vermont perspective. The series is designed to educate and inspire – and to document the success of Vermont’s scientific community.”

  7. 7
    Will Denayer says:


    This is OF, but I just found (and bought) Nigel Lawson, 2009, An Appeal to Reason. A Cook Look At Global Warming, Duckworth, London, NY. (166 p.).
    Lawson is in his own words a ‘Tory radical,’ (sic) wanting to prove that conventional wisdom and the science from the side of the alarmists is deeply flawed, that global climate change is a hype etc. etc. The conservative press gave the book extremely good reviews, as can be expected.
    It’s embarrassing enough and also there will be elections this year in the UK. In some areas, the BNP (the extreme rightwing British National Party) is doing better in the polls than Labour.

  8. 8
    Brian Carter says:

    I live in Birmingham, in the centre of England. When I was a child (in the 1940’s and early 50’s) The only time I saw palm trees was when we holidayed at the seaside on the South coast. Now I have a 10-foot tall cabbage palm in my own garden, and a 7-foot tall Chusan palm. I have a 10-foot tall rhododendron falconeri currently covered in flowers, according to books more than thirty years old this is impossible to grow away from the West coast warmed by the Gulf Stream. I have many other examples, but that should suffice to show that the weather is milder and the spring earlier than it was in my youth. The changes are real and obvious. As yet they are harmless but I wonder how long it will be before that changes?

  9. 9
    Dave Werth says:


    Part of that mitigation has got to be to limit the ultimate reach of climate change as much as possible. Until we stop making the problem worse any other mitigation actions will be largely ineffective in the long run.

  10. 10
    Ike Solem says:

    Sounds like a worthwhile read… here is a past discussion on the changes in the timing of the seasons:

    [Response: The paper was “The Seasons, Global Temperature, and Precession, D. J. Thomson, Science, 268 (April 1995), pp. 59-68.”. We did a followup study on this in ‘96:
    Mann, M.E., Park, J., Greenhouse Warming and Changes in the Seasonal Cycle of Temperature: Model Versus Observations, Geophysical Research Letters, 23, 1111-1114, 1996.
    Turns out, its a bit more complicated than at first blush. Tim Osborn of CRU/UEA in the UK has also done some work on this problem. -mike.]

    It’s interesting to look at that paper’s conclusions in the light of the past twelve years of data:

    “If, as the models predict, the dominant influence on annual-cycle amplitude A(t) and phase P(t) stems from high-latitude sea-ice decreases, the signature of global warming is scarcely evident in the observational data…”

    “It is possible, probably likely, that the observed trends in the seasonal cycle represent a combination of internal variability, enhanced greenhouse effects and external forcings.”

    Now, we are seeing rapid sea ice decline and sea ice thinning, along with generally warmer winter temperatures, though highly variable – see the BBC report for a general overview:

    “The 30-year trend shows the maximum annual sea-ice cover, usually seen in March, is shrinking by 2.7% per decade.

    Only 10% of the cover consists of relatively durable ice that has formed over more than two years, a record low.

    P.S. the reason why people focus on ice shelves and sea ice is that there are poor observational records of ocean and surface temperatures in remote polar regions. Ice (like animals and plants) “sees” the temperature all year long.

  11. 11
    Jim Bouldin says:

    Thanks Eric, nice article. I agree with McKibben; one of the most important things we can do is document change and present the findings to the world There is no doubt that these changes can be observed first-hand, have been rapid in many cases, and that the general public is highly important in monitoring them. In the course of the article in February, the following citizen-science based observational programs were mentioned. I collate them here for reference and as a jump-start for other relevant links people may have:

    NCAR’s Project Budburst:
    North American Breeding Bird Survey:
    Netherlands Nature Calendar:
    UK Woodland Trust Phenology Network:
    various UK Biological Records Centre recording schemes
    British trust for ornithology (BTO) surveys:

    ALL of these efforts could use help.

  12. 12
    Arthur says:

    Haven’t humans always been in the mitigation and adaptation phase concerning climate changes. If as Seidl says – we can’t manage the climate – then what are we doing other than spending billions of dollars on a futile effort to manage the unmanageable.

  13. 13

    Have you read “The Long Summer” by Brian Fagan and “Collapse” by Jared Diamond? These two books are more relevant to what is happening to humans. Over the past several thousand years, a few dozen civilizations have collapsed because of really minor climate changes. A fraction of a degree change can cause the rain to move hundreds of miles in a year, making agriculture impossible. Typically, 99.99% of the people die, mostly of starvation, but some people are hunted and eaten by their neighbors. Have you noticed droughts and fires in Georgia, Texas, Oklahoma, California, Greece, Darfur, South Australia, etc. or floods in Iowa, Illinois and Dakota? Food will not grow with either no water or under water. The rain has moved already, and our food supply has changed. So far, there are no shortages in the US, but there are shortages in Darfur. There is no guarantee that food will grow on the land where the rain will fall next year. We are in peril of a collapse of civilization. Nobody knows the time frame.

  14. 14
    markr says:

    My own personal experience as a gardener in Michigan, detected a few years ago now, was that spring was arriving around March 1st. Later confirmation of a three-week increase in spring bird migrations confirmed my informal observations. While there certainly has been variability in this date over the past seven years, winter here has surely become more inconstant and variable, from bitter cold to spring-like temperatures.

  15. 15
    Ray Ladbury says:

    Walt, part of mitigation is diminishing the severity of the consequences. The only feasible way to do that right now is to decrease carbon emissions. Just because climate change is already happening does not imply that we cannot make it worse–and perhaps much worse.

  16. 16

    #1 Walt Bennett

    This is a good example of the lack of specificity, context and substantiation I was referring to in the other thread. In other words, you are too ambiguous for us to derive sensibility from your words… unless that is your desire in that you don’t want anyone to be able to have something specific to address?

    Your idea of letting the market forces drive climate change policy is backwards thinking. You may as well join Bjorn Lomborg.

    If we don’t utilize the reasonable science to drive forward thinking policy, then we are accepting that we want more expensive solutions as opposed to more reasonable solutions.

    We need to get ahead of this one, not behind it.

  17. 17
    Nick Gotts says:

    “Haven’t humans always been in the mitigation and adaptation phase concerning climate changes.” – Arthur

    No. Certainly human beings have always adapted to climate. Mitigation, as I noted@4, has a very specific meaning in this context: taking action aimed at reducing human effects on the climate. And while we certainly can’t “manage the climate” if this means determine exactly what course it is going to take, we most certainly can and must take action to limit those effects, as I am sure Seidl would agree.

  18. 18
    Arch Stanton says:

    Agreed Jim (#11). Here’s another one for anyone in the US that would like to participate in documenting when the signs of spring come:

    USA National Phenology Network:

  19. 19
    Thomas says:

    Considering that the frequency with which American families move is fairly high, (I remember something like once every seven years), I think changes in the natural world due to climate change are overwhelmed by changes of climate zone, for a large portion of the population. Even for relatively local moves, in some places climate zone differences can easily overwhelm the gradual warming of the climate in general. For instance where I currently live in California, a good rule of thumb for summer high temperatures, is one degree farenheit per mile from the ocean. Except for that small portion of the population who has lived for decades in areas characterised by fairly homogeneous climate, I think the AGW changes will seem insignificant.

  20. 20
    David B. Benson says:

    Arthur (12) — We certainly can manage the climate; the combined actions of all 6.7 billion of us “manage” it on a daily basis; an example of Garret Hardin’s Tragedy of the Commons.

    Actual management requires co-operative actions and, well, a manager. Fund me as well as the sum total of all the monies spent on the world’s militaries and I’ll do a tremendously good job of it. What the heck, I could almost get by with what the U.S. spends for so-called national security; DoD budget alone wouldn’t do it.

    All that is required is the will to co-operate on a large enough scale. I am less than fully optimistic.

    [Response: I am sure that Seidl’s point is that there is going not going to be a magic bullet via geoengineering. Although not all our colleagues would agree, we at RealClimate are in general very much in agreement with Seidl on this point. See e.g. here–eric]

  21. 21
    Theo Hopkins says:

    Will Bennett
    @ post #1

    I will let the European birds and flowers know that they should abandon European social democracy and embrace the American liberal free market philosophy as the only way to stave off extinction. I am sure they will post a “thank you” on this site.

    Theo H

  22. 22
    Lawrence Brown says:

    Re Comment #1: The only thing mitigated is the damage done by the previous administration. Dumbya and his henchmen can no longer stand in the way of progress in curbing AGW.

  23. 23

    Hi Eric

    thanks for the nice post!
    For those of you who are interested in recent peer reviewed papers that connect climate change with phenology and early advance of spring in parts of Europe, you may have a look at (and references therein)

    Rutishauser, T., Luterbacher, J., Defila, C., Frank, D., and Wanner, H., 2008: Swiss Spring Plant Phenology 2007: Extremes, a multi-century perspective and changes in temperature sensitivity. Geophys. Res. Lett., 35, L05703.

    Rutishauser, T., Luterbacher, J., Jeanneret, F., Pfister, C., and Wanner, H., 2007: A phenology-based reconstruction of interannual changes in past spring seasons, J. Geophys. Res., (Biogeosciences), 112, G04016.

    Schleip, C., Rutishauser, T., Luterbacher, J., and Menzel, A., 2008:, Time series modeling and central European temperature impact assessment of phenological records over the last 250 years, J. Geophys. Res., 113, G04026.

    Luterbacher, J., Liniger, M.A., Menzel, A., Estrella, N., Della-Marta, P.M., Pfister, C., Rutishauser, T., and Xoplaki, E., 2007: The exceptional European warmth of Autumn 2006 and Winter 2007: Historical context, the underlying dynamics and its phenological impacts. Geophys. Res. Lett., 34, L12704.


    [Response: Thanks for the heads up for our readers Juerg–comments from our professional colleagues of this sort, pointing out relevant peer-reviewed literature they can go to for more details, are extremely helpful, and we’d love to have more comments like this. In this spirit, I’ll gratuitously plug my own past forays into this area, Cook et al (2004) and Cook et al (2005) – mike]

  24. 24
    Bryan Walker says:

    When you reviewed Mark Lynas’s book you ended with the questions: “If a reading of the published scientific literature paints such a frightening picture of the future as Six Degrees suggests – even while it honestly represents that literature – then are we being too provocative in the way we write our scientific papers? Or are we being too cautious in the way we talk about the implications of the results?”

    It rather matters which of those two possibilities is the more likely, particularly for us non-scientists. My layman’s understanding of what the scientists are saying has made me profoundly alarmed by the prospect of human-caused global warming. I wrote about Lynas’s book when it received the Royal Society prize for science writing, and briefly noted your favourable review. I didn’t mention your questions, but was aware of them and thought there was probably more substance in the second than the first. Now you seem to criticise Lynas for emphasizing what might happen over what will happen. Surely in the climate change area no one is able to say precisely what will happen until it has happened. Gentle changes in the garden are worth recording, but isn’t part of their significance that they point to further and larger changes to come? Doesn’t the importance and urgency of climate science for humans (and other species) lie in what it predicts?

  25. 25
    David B. Benson says:

    eric response to comment #20 — Thanks, but to clarify, I don’t propose any magic bullet geo-engineering, just the hard and somewhat expensive slog of removing all the excess carbon currently being added to the active carbon cycle, about 10 GtC yearly; in addition, starting to remove some, yearly, of the 500 GtC which has been added to the active carbon cycle since the beginning of the industrial revolution. This won’t come cheap, mind you.

    [Response: There is a neat new idea how to do *some* of this, here: carbonscape”.–eric]

  26. 26
    Johnno says:

    Combine ‘Early Spring’ with ‘Late Autumn’ and you have ‘Short Winter’. Despite firestorms Down Under I’ve also noticed a trend towards cloudy summers which seems to inhibit plant growth. If cold suddenly hits late developed autumn crops they may not mature. I think this will lead to major crop failures in some regions and an increasing trend towards controlled atmosphere growing ..the more greenhouses effect.

  27. 27
    Chuck L says:

    I would be interested in how the paper cited below in any way validates the information Amy Seidl’s book “Early Spring.” Even though it is from Pielke Sr’s website, I hope that any comments or reactions are measured, calm, and factual.

    New Paper In Press “Intercomparison, Interpretation, and Assessment Of Spring Phenology In North America Estimated From Remote Sensing For 1982 To 2006″ By White et al.2009
    Filed under: Climate Change Metrics — Roger Pielke Sr. @ 7:00 am
    There is a very interesting paper in press that updates our understanding of spring pheonology in North America. There have been statements that spring leaf out has become earlier in recent years (e.g. see page 77 in CCSP, 2009). This claim appears to be incorrect. The paper is

    White, M.A., K.M. de Beurs, K. Didan, D.W. Inouye, A.D. Richardson, O.P. Jensen, J. O’Keefe, G. Zhang, R.R. Nemani, W.J.D. van Leeuwen, J.F. Brown, A. de Wit, M. Schaepman, X. Lin, M. Dettinger, A. Bailey, J. Kimball, M.D. Schwartz, D.D. Baldocchi, J.T. Lee, W.K. Lauenroth. Intercomparison, interpretation, and assessment of spring phenology in North America estimated from remote sensing for 1982 to 2006. Global Change Biology (in press).

    The abtstract reads

    “Shifts in the timing of spring phenology are a central feature of global change research. Long-term observations of plant phenology have been used to track vegetation responses to climate variability but are often limited to particular species and locations and may not represent synoptic patterns. Satellite remote sensing is instead used for continental to global monitoring. Although numerous methods exist to extract phenological timing, in particular start-of-spring (SOS), from time series of reflectance data, a comprehensive intercomparison and interpretation of SOS methods has not been conducted. Here, we assess 10 SOS methods for North America between 1982 and 2006. The techniques include consistent inputs from the 8 km Global Inventory Modeling and Mapping Studies Advanced Very High Resolution Radiometer NDVIg dataset, independent data for snow cover, soil thaw, lake ice dynamics, spring streamflow timing, over 16 000 individual measurements of ground-based phenology, and two temperature-driven models of spring phenology. Compared with an ensemble of the 10 SOS methods, we found that individual methods differed in average day-of-year estimates by +/- 60 days and in standard deviation by +/- 20 days. The ability of the satellite methods to retrieve SOS estimates was highest in northern latitudes and lowest in arid, tropical, and Mediterranean ecoregions. The ordinal rank of SOS methods varied geographically, as did the relationships between SOS estimates and the cryospheric/hydrologic metrics. Compared with ground observations, SOS estimates were related to the first leaf and first flowers expanding phenological stages. We found no evidence for time trends in spring arrival from ground- or model-based data; using an ensemble estimate from two methods that were more closely related to ground observations than other methods, SOS trends could be detected for only 12% of North America and were divided between trends towards both earlier and later spring.”

    The conclusion of the paper states in part

    “Trend estimates from the SOS methods as well as measured and modeled plant phenology strongly suggest either no or very geographically limited trends towards earlier spring arrival, although we caution that, for an event such as SOS with high interannual variability, a 25-year SOS record is short for detecting robust trends. Increased greenhouse warming since the late 20th century would seem to argue for increased, not decreased, shifts in spring during our study period, indicating that processes such as succession, changes in community structure, land management, or disturbance may be more important than previously recognized. Seasonal temperature changes may also be linked to a trend reversal in SOS in the early 1990s.”

    The finding, with the cavaet that the record is still relatively short, that any early leaf out is, at best, geographically limited, raises questions on claims that spring has been arriving earlier.

  28. 28
    David Horton says:

    A timely book indeed. In Australia (and elsewhere) the continuing presence of trees, the major feature of the natural environment seen from a car window, has helped to make people think that not much is going on ( But trees are starting to be lost, and when these are trees of considerable age (100 plus years) it makes it more difficult (though not impossible) for denialists to argue that “there have been droughts before”. Trees average out, dampen down, changes in weather patterns over long periods, and if they are beginning to die it strongly indicates change beyond the ordinary. Undoubtedly many changes are happening among smaller plants and among animal species, but these will be much harder, well nigh impossible, for the ordinary person to detect.

  29. 29
    Theo Hopkins says:

    Yes, thanks Eric for this post.

    I’ll buy the book a soon as available in the UK.

    I just happened to want to find out early spring happenings in the UK earlier this week, and all the links I need are coming up.

    I sometimes plant a few tree saplings each year – fifty or so – and I like to get them in before the saplings bud up . A couple of times in recent years I have been caught by things now happening earlier than expected.


  30. 30
    David B. Benson says:

    eric reply to comment #25 — Interesting variation on slow pyrolysis. But the rub to any biomass solution is the inefficiency of photosynthesis: even with algae I don’t know how to do better than about 10 GtC/ha/yr with just air capture. That means, doing this alone, around one gigahectare of algae tanks and ponds. That’ll be about a tenth more than the entire Sahara Desert:

    so I’ll need some of the'_al_Khali

    as well. Worse, we’ll need to use sea water, there not being enough fresh to go around, so we’ll have to pump it. That means even more algae to provide the fuel to run the pumps. So may have to spread even further:

    Then one has to bury the biochar, so even more energy is required. There went another desert for growing even more algae:

    or maybe even two or three of those. Anyway, certainly won’t be cheap.

  31. 31
    Hank Roberts says:

    Though Google finds hits at WTF making a big deal of this in-press paper abstract, it’s no surprise. Of course individual methods would differ greatly — this is ecology. You don’t expect to find lockstep correlation between different measures. And that’s been studied.

    Perhaps they address this in the full text. Let’s see.

    Meanwhile, for those who think satellite data is automatically more convincing than field work, do look at the kinds of thing that happen. Here, picking at random a few from recent work found searching “global change biology” and “start of spring”:

    “… We show that a change in timing of spring plankton events in warm years led to the paradox of lower mean water temperatures during the growth period, favouring cold-adapted diatoms over cyanobacteria, and within the diatoms, some cold-adapted centric forms over pennate forms. Under high P : Si ratios, the increased time between phytoplankton and cladoceran peaks opened a loophole for filamentous cyanobacteria (Oscillatoriales) in warm years to establish dominance after the diatoms, which are silicate limited. Therefore, the warming trend promotes filamentous cyanobacteria, a well-known nuisance in eutrophic lakes, and surprisingly, cold-adapted diatoms.”

    The arctic pulse, Chapter 9

    Has prey availability for arctic birds advanced with climate change?
    Hindcasting the abundance of tundra arthropods using weather and seasonal variation

    “… We investigated weather-related and seasonal
    patterns in abundance of surface-active arthropods during
    four years in the tundra of Taimyr, Siberia. The resulting
    statistical models were used to hindcast arthropod abun-
    dance on the basis of a 33-year weather dataset collected in
    the same area. Daily insect abundance was correlated closely
    with date, temperature, and, in some years, with wind and
    precipitation. An additional correlation with the number of
    degree-days accumulated after June 1 suggests that the pool
    of potential arthropod recruits is depleted in the course of
    the summer. The amplitude of short-term weather-induced
    variation was as large as the seasonal effect. The hindcasted
    dates of peak arthropod abundance advanced by 7 days
    between 1973 and 2003. The timing of the period during which
    birds have a reasonable probability of finding enough food to
    grow changed as well: dates with the highest probabilities
    have also advanced. At the same time the overall length of
    the period with probabilities of finding enough food have
    remained unchanged. This results in an advancement of the
    optimal breeding date for breeding birds….”
    Cross-scalar satellite phenology from ground, Landsat, and MODIS data

    “Phenological records constructed from global mapping satellite platforms (e.g. AVHRR and MODIS) hold the potential to be valuable tools for monitoring vegetation response to global climate change. However, most satellite phenology products are not validated, and field checking coarse scale (≥ 500 m) data with confidence is a difficult endeavor. In this research, we compare phenology from Landsat (field scale, 30 m) to MODIS (500 m), and compare datasets derived from each instrument. Landsat and MODIS yield similar estimates of the start of greenness (r2 = 0.60), although we find that a high degree of spatial phenological variability within coarser-scale MODIS pixels may be the cause of the remaining uncertainty. In addition, spatial variability is smoothed in MODIS, a potential source of error when comparing in situ or climate data to satellite phenology. We show that our method for deriving phenology from satellite data generates spatially coherent interannual phenology departures in MODIS data. We test these estimates from 2000 to 2005 against long-term records from Harvard Forest (Massachusetts) and Hubbard Brook (New Hampshire) Experimental Forests. MODIS successfully predicts 86% of the variance at Harvard forest and 70% of the variance at Hubbard Brook; the more extreme topography of the later is inferred to be a significant source of error. In both analyses, the satellite estimate is significantly dampened from the ground-based observations, suggesting systematic error (slopes of 0.56 and 0.63, respectively). The satellite data effectively estimates interannual phenology at two relatively simple deciduous forest sites and is internally consistent, even with changing spatial scale. …”

    Anyone have an accessible copy of the upcoming paper in full? The footnotes and cites will be interesting. Date of publication?

  32. 32
    Joseph O'Sullivan says:

    Thanks Eric for the review and the heads up for a good read. I have a gift card from a bookstore and I’ll have to pick up a copy of Early Spring.

    I will add to Jim’s list (#11) of projects that can use help, ebird run by Cornell U. and the Audubon Society. It is a great way to get involved.

  33. 33
    Mike says:

    Nd here in Arkansas, the lilacs only bloom if the winter has been COLDER than normal. The lilacs are blooming very heavily this year.

  34. 34
    Craig Allen says:

    David Horton,

    I agree about the tree death. I live in the Otways in Southern Victoria. But regularly travel around rural South Australia and Victoria, observing the landscape with an ecologist’s eye as I go.

    We are seeing landscape-wide declines in trees and understory.

    Some of that is due to remnant trees reaching their twilight years. And some of it is clearly exacerbated by the impacts such as farmers ploughing too close to the base of trees, the compaction of soil by stock, etc. But over the last few years the die-back has started to become really obvious in ungrazed bush in reserves.

    The Otway ranges have one of the highest and most reliable rainfalls in Victoria, but even here the bush is obviously thinning back as species of the canopy and understory increasingly die out each summer, without recruitments in the wetter months being able to make it through the following year.

    In the bush around my house certain shrub species once characteristic of these woodlands are disappearing altogether from ridges and slopes (eg. Prickly Geebung). The decline this summer has been dramatic. I notice that many trees and shrubs will go through a numbers of years where they look crook and loose leaves in the summer, recover a bit in winter, then decline further the next summer, finally succumbing. I’ve been watching perfectly healthy trees cark it over the course of just three or so years.

    After the devastating fires which incinerated vast areas of landscape this year, I think the bush that comes back will have a significantly different structure. Both because of the sheer intensity of the fires (killing trees and baking soil seed banks to a greater extent than the average fire) and because the new climatic regime may not now support a recovery of the same composition of species that previously occurred.

  35. 35
    Lopa Brunjes says:

    Another way climate affects laypeople: anyone in the Rocky Mountain region can tell you that an immense amount of pine trees (2M acres in CO alone, 33M in British Columbia) are being devastated by the pine beetle epidemic. The reason for the outbreak is that warmer winters are allowing more of the beetles to survive longer. One look at the vast swaths of dead forest reminds anyone that climate change is real and affects us all.

    We may not be able to manage climate in totality, but we can of course influence it (or influence our influence upon it) with rapid emissions reduction and responsible implementation of sustainable biochar technology. Biochar is thus far one of the only carbon negative technologies out there, and is an important part of the portfolio of solutions to climate change, soil fertility, and energy. For more info see or

  36. 36
    Lopa Brunjes says:

    And in response to David Benson’s comment: biochar does not have to be buried, it can be incorporated into soil without tilling by simply spreading it on top.

  37. 37
    Danny Bloom says:

    Bill McKibben said it well, in his introduction to the book. We need to bear witness, if nothing else. Even if there is nothing much we humans can do at this point in time to really stop climate change in its tracks before it leads to destructive global warming that may very well lead to the extinction of the human species on this planet, if nothing else, let us all, in our ways, try to bear witness. My speech to the graduating class of 2099, which Bill has seen and told me it works [“….that’s an excellent commencement speech — better than almost all the ones i’ve ever heard…”], has now been picked up by CNN’s iReporter Joe Seydewitz and can be viewed online here. All I am doing is bearing witness:

  38. 38
    dhogaza says:

    There is a very interesting paper in press that updates our understanding of spring pheonology in North America. There have been statements that spring leaf out has become earlier in recent years (e.g. see page 77 in CCSP, 2009). This claim appears to be incorrect

    indicating that processes such as succession, changes in community structure, land management, or disturbance may be more important than previously recognized.

    All processes consistent with warming.

    This might lead one to argue that ecosystem adaptation is thus far, at least, keeping pace with warming, but not, unless one has more data, to argue that …

    1. warming is not happening

    2. continued acceleration in the pace of warming might make succession etc unable to keep pace.

  39. 39
    pft says:

    #35 – Pine beetles tend to kill old, weak, or diseased trees. 100 years ago, much of the forests in the high country of Colorado were logged for lumber or fuel. The composition of today’s forest is a direct result of that indiscriminate logging (and fire). As the forests came back over the past century, protected in recent years with fire suppression and management, they did so largely with the same species . Today, most stands of lodgepole pine are about the same age. It’s a little like the baby boomers today. The trees had their own baby boom -over a century ago- and now the majority of these trees have grown old at the same time and are susceptible to disease, since it is fungus that kills the trees.

    The warming also contributes to protecting the beetles larvae, but it’s not the only factor. Overpopulation and old age are issues in nature as well, and disease and fire is natures way of handling it.

  40. 40
    James says:

    Might I suggest looking at the other end – late autumn/winter – as well? There should be fairly good data on e.g. ski area opening dates. For instance, when I first moved here (the Sierra Nevada) in the late ’70s, it wasn’t unusual to start skiing in October. In recent years mid-December has been more typical.

  41. 41
    Tony O'Brien says:

    Will the reflective geo engineering solutions reduce the difference between seasons? Will be be left with late spring/summer all year?

  42. 42
    Doug Bostrom says:

    Off-topic but in the “Know Your Bamboozler” department there’s a fresh article in the NY Times describing ex-Limbaugh staffer now ex-Inhofe staffer Marc Morano’s expanding career as self-appointed Minister of Climate Misinformation.

    Morano’s drainpipe is funded by The Usual Suspects. Details in the article.

  43. 43
    John Mashey says:

    1) Thanks for the recommendation.

    2) I really think the biological data should gain more prominense, as I discussed a while ago here at RC. In some sense, it’s too bad that Chapter 1 of AR4 WG II is there, rather than in WG I, where most of the evidence is.

    3) As noted there, I really like maps/animations that show:

    a) Poleward spread of something that no one wants (like kudzu or pine beetles) that only survive when coldspells milden.

    b) Poleward/uphill motion of the equatorial-nearest boundary of something people would prefer to keep around, like sugar maple trees.

    c) Effects that simply cannot have anything to do with UHI or human development.

    I like maps because they show a lot of data, and can be quickly recognizable.

    4) Alternatively, I’d love to see compelling visual representations of the spring timing data and similar things. Maybe the book will have some. I speculate that there may be some application of the “small multiples” section in Tufte’s “Envisioning Information”.

    5) In some ways, it is unfortunate that the most common image is that of global temperature since 1880, given that humans tend to focus on jiggles, can’t compute linear regressions in our heads, and don’t always understand the analysis techniques.

    6) Can people point me at:
    a) More examples of good maps/charts like the ones I referenced earlier.
    b) in generally-accessible places.

    I’d love to build a good collection of these things.

  44. 44
    Jim Bouldin says:

    Chuck L. (27)

    The lead author, White, has done work in the past on segregating out areas (“phenoregions”) least likely to be confounded by multi-year climate variability and direct human impacts, based on coarse scale NDVI. Presumably this paper is an in depth analysis of some of those areas.
    That paper is not listed in either the “Early View” or “Accepted Articles” sections of GCB. It must’ve been very recently accepted and Pielke Sr got a copy of it. There is no way to evaluate it until it goes public.

    The differences and mismatches between ground based and remotely sensed phenological observations at other than large scales are well known (e.g. Fisher et al.(2006), Rem. Sens. Env 100:265-; Schwartz et al. (2002), Int J. Climatol 22:1793)

  45. 45
    Slioch says:

    In the UK there has been a long history of recording events that mark the changing of the seasons, most famously the hearing of the first cuckoo recorded in the letters page of The Times.

    In 2000 the following organisation, which encourages people to record various natural events in spring and autumn, was established because of increasing concern over the changing climate:

    It reports that about 50,000 people around the UK have submitted records. These are not only of present events but also of past years recorded in diaries.

    These records give insight into changes in the natural world that raw climate data cannot. For example, a bird called the great tit requires to raise its young at a time when caterpillars are available, feeding on young leaves of deciduous trees. But if the trees come into leaf earlier, responding to warmer temperatures, and the great tit continues to nest at the same time, responding to day length, then the two events become out of synchronism and the chicks starve.

    Obtaining such information into the ‘sundry and manifold changes of the World’ thus provides insight into the effects that climate changes is having and will increasingly have on natural systems.

    I gather from the above article and comments that no such central recording organisation exists in the USA. I’m astonished! Come on you guys, get something started soon! Maybe the Sierra Club could organise it? I’m sure the above Nature’s Calendar (which is organised by The Woodland Trust and the Centre for Ecology & Hydrology (now with help from the BBC) would be happy to offer advice (if you asked nicely).

  46. 46
    Slioch says:

    “in 1965 the U.S. Department of Agriculture planted a particular variety of lilac in more than seventy locations around the U.S”

    Perhaps someone had been reading T S Eliot’s appropriately named poem, The Waste Land:

    “April is the cruellest month, breeding
    Lilacs out of the dead land, mixing
    Memory and desire, stirring
    Dull roots with spring rain.”

  47. 47
    EL says:

    Many of the effects being witness in the natural world may not be completely caused by the burning of fossil Fuels. Some of the problems being observed may be a side effect of technology itself. In some cases, scientist assume the statistical trends being observed in data correspond to the burning of Fossil Fuels; however, there exist another change, which is not as widely discussed, and that change is the rapid technological advancement of a species. The rapid advancements in technology has allowed mankind to exploit available resources faster and in larger quantities. There has never been a species that could exploit more resources of the environment then modern day humanity.

    The ecosystems around the world are being destroyed. We have implemented technologies that have effects that we do not fully understand. These ecosystems took millions of years to develop and they are intertwined with each other in complex ways. The million dollar scientific question is, “At what point does the worlds ecosystems collapse?”

    I do not bring this up to belittle the idea of CO2 induced global warming. I simply think it’s important to discus other dynamics that may also have an impact. I think we have a very clear danger over the horizon with regards to our resources. I also believe it’s even more complicated to deal with then CO2 because humanity is ever increasingly over-populated. In a nutshell, managing climate is not going to be as easy as some may think.

    [Response: I am sure that Seidl’s point is that there is going not going to be a magic bullet via geoengineering. Although not all our colleagues would agree, we at RealClimate are in general very much in agreement with Seidl on this point. See e.g. here–eric]

    Eric, I look for our government to make such an attempt. I think it’s foolishly dangerous, but I look for an attempt to be made. I don’t worry about the predicted or hypothetical consequences nearly as much as the consequences we are not aware of. The circumstances being presented to governments need to be done cautiously. Scientist hopefully aren’t suffering under a conjured felicity of control as they did in the 1940s.

    We are presenting governments with a picture of destruction. Some people hope that we are going to see a world wide reduction in emissions of CO2. The problem is a large portion of world wide population does not even know how to read, and thus the politics of this may be impossible. Since governments are sensitive to this, they may attempt geoengineering and regard it’s consequences as collateral damage.

    [Response: It is perfectly legitimate to ask whether climate change is the greatest threat to ecosystems. In many cases — perhaps most cases — the answer is no, at least in the short term. Clearcutting, pollution, damming of rivers, etc. are far more destructive. Scientists are perfectly aware of this. The problem is that climate change comes on top of everything else.–eric]

  48. 48

    Gaia is fighting back, see e.g. these publications regarding the effects of climate change on biosphere:

    climate change and demise of lemings, (Nature, 2008), sub. req.:

    climate change and demise of salamanders, (PNAS, 2009, full):

    climate change and demise of canadian managed forests, (Nature, 2008), sub. req.:

    climate change (surface ocean warming) and increased decay of plankton by bacteria (positive feedback) (PNAS, 2009), sub.req.:

    and myriads of other studies…

    I am writing from Slovakia, where we jumped from winter to almost summer… (25°C)

    I would call the book not early spring, but *missing* spring ;-)


  49. 49
    Mark says:

    “Many of the effects being witness in the natural world may not be completely caused by the burning of fossil Fuels.”

    Hmm. Read up on AGW. It says NOWHERE That the effects are completely caused by fossil fuels for ANYTHING.

    As I’ve pointed out before, denialists seem to have this weird dichotomy (probably a projection problem) that they insist that the AGW proponents have CO2 as the SOLE FACTOR for warming. They don’t let this stop them from saying that scientists agree that CO2 isn’t the sole cause and hence there’s “controversy” mind. Yet they also seem to be the ones most likely to promote the idea that there IS a single sole source for all this change: “It’s the sun wot did it!!!” “Volcanoes, just Volcanoes!” et al.

    Yet despite being fixated on ONE SOURCE (as long as it isn’t CO2) they describe the proAGW arguments as being ficated on ONE SOURCE (as long as it’s CO2).

    As to your request that other elements are talked about, read the name of this site. If you want to talk about geoengineering and its results, ignoring the engineers themselves, that’s a political issue: what actions should be taken having been informed by the science (which is what this site is for, discussing what the science is telling us).

  50. 50
    Mark says:

    “I’m sure the above Nature’s Calendar (which is organised by The Woodland Trust and the Centre for Ecology & Hydrology (now with help from the BBC)”

    Ah, see, that’s where the idea falls down.

    To the devout denialist (or, nearly equivalently, the devout Free Market disciple), that merely proves that such information is collected by biased AGWer eco nazis that want us back in caves eating catepillars and quorn.

    The great tit (and the lilac, etc) are all in on it. They’re jealous of our Western Civilisation and are ganging up to bring us down.

    I wish I weren’t so close to the truth with that…