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Linking the climate-ecology attribution chain

Filed under: — group @ 19 February 2009

Guest commentary by Jim Bouldin, Department of Plant Sciences, UC Davis

Linking the regional climate-ecology attribution chain in the western United States

Many are obviously curious about whether certain current regional environmental changes are traceable to global climate change. There are a number of large-scale changes that clearly qualify—rapid warming of the arctic/sub-arctic regions for example, and earlier spring onset in the northern hemisphere and the associated phenological changes in plants and animals. But as one moves to smaller scales of space or time, global-to-local connections become more difficult to establish. This is due to the combined effect of the resolutions of climate models, the intrinsic variability of the system and the empirical climatic, environmental, or ecological data—the signal to noise ratio of possible causes and observed effects. Thus recent work by ecologists, climate scientists, and hydrologists in the western United States relating global climate change, regional climate change, and regional ecological change is of great significance. Together, their results show an increasing ability to link the chain at smaller and presumably more viscerally meaningful and politically tractable scales.

For instance, a couple of weeks ago, a paper in Science by Phil van Mantgem of the USGS, and others, showed that over the last few decades, background levels of tree mortality have been increasing in undisturbed old-growth forests in the western United States, without the accompanying increase in tree “recruitment” (new trees) that would balance the ledger over time. Background mortality is the regular ongoing process of tree death, un-related to the more visible, catastrophic mortality caused by such events as fires, insect attacks, and windstorms, and typically is less than 1% per year. It is that portion of tree death due to the direct and indirect effects of tree competition, climate (often manifest as water stress), and old age. Because many things can affect background mortality, van Mantgem et. al. were very careful to minimize the potential for other possible explanatory variables via their selection of study sites, while still maintaining a relatively long record over a wide geographic area. These other possible causes include, especially, increases in crowding (density; a notorious confounding factor arising from previous disturbances and/or fire suppression), and edge effects (trees close to an
opening experience a generally warmer and drier micro-climate than those in the forest interior).

They found that in each of three regions, the Pacific Northwest, California, and the Interior West, mortality rates have doubled in 17 to 29 years (depending on location), and have been doing so across all dominant species, all size classes, and all elevations. The authors show with downscaled climate information that the increasing mortality rates likely corresponds to summer soil moisture stress increases over that time that are driven by increases in temperature with little or no change in precipitation in these regions. Fortunately, natural background mortality rates in western forests are typically less than 0.5% per year, so rate doublings over ~20-30 years, by themselves, will not have large immediate impacts. What the longer term changes will be is an open question however, depending on future climate and tree recruitment/mortality rates. Nevertheless, the authors have shown clearly that mortality rates have been increasing over the last ~30 years. Thus the $64,000 question: are these changes attributable in part or all to human-induced global warming?

Yes, argues a pair of December papers in the Journal of Climate, and a 2008 work in Science. The studies, by Bonfils et. al. (2008), Pierce et. al. (2008), and Barnett et. al. (2008), link observed western temperature and temperature-induced snowmelt processes to human-forced (greenhouse gases, ozone, and aerosols) global climate changes. The authors used various combinations of three GCMs, two statistical downscaling techniques (to account for micro-climate effects that aren’t resolved in the GCMs), and a high resolution hydrology model to experiment with the various possible causes of the observed climatic changes and the robustness of the methods. The possible causes included the usual list of suspects: natural climatic variability, the human-induced forcings just mentioned, and non-human forcings (solar and volcanic). Climate models were chosen specifically for their ability to account for important, natural climatic fluctuations in the western US that influence temperature, precipitation and snowpack dynamics, particularly the Pacific Decadal Oscillation, and El Niño/La Niña oscillations, and/or their ability to generate the daily climatic values necessary for input to the hydrologic model. The relevant climate variables included various subsets of minimum and maximum daily temperatures from January to March (JFM), their corresponding monthly averages, degree days (days with mean T>0ºC), and the ratio of Snow Water Equivalent (SWE) to water year precipitation (P). In each case, multiple hundred year control runs were generated with two GCMs to isolate the natural variability, and then forced runs from previous model intercomparison projects were used to identify the impacts of the various forcings.

The results? The authors estimate that about 50% of the April 1 SWE equivalent, and 60% of river discharge date advances and January-to-March temperature increases, cannot be accounted for by either natural variability or non-human forcings. Bonfils et al also note that the decreases in SWE are due to January-to-March temperature increases, not winter precipitation decreases, as the observational record over the last several decades shows. The April snow is a key variable, for along with spring through early fall temperatures, it has a great bearing on growing season soil moisture status throughout the western United States, and thus directly on forest productivity and demographic processes.

Link o’ chain, meet link o’chain.

Update: The new USA National Phenology Network is described here.

254 Responses to “Linking the climate-ecology attribution chain”

  1. 51
    Michael says:

    Appologies, I said ‘seasonal’, I meant ‘year to year’ temperature variation.

  2. 52
    Jim Bouldin says:

    SecularAnimist, 26:

    Some took an oath to say only what is warranted by the available information, no more and no less. Any other approach is speculation, which is fine for conceptualizing possibilities to explore, but not as evidence.

    David, 27:

    I know of studies trying to use ring widths and statistics to tease out CO2 fert. effects (e.g. Graumlich, 1991, Ecology 72:1-11), but not wood density. The usefulness of diameter-based tree carbon estimates depends on the precision needed–they are fine for many purposes, and are only one way to estimate terrestrial C uptake. Calibrating biometry-based estimates against atmospheric-based estimates from CO2 flux towers and atmospheric inversion methods is a very active area of carbon cycle science.

    Lynn, 30: Thanks for the kind words Lynn.

    Tony, 37:

    I agree, but even then you have to pick your examples carefully. It’s always hard to illustrate something that follows a stat. distribution using one or a few cases.

    Sekerob, 38:

    1 metric ton (= tonne) = 1000 kg = 10^6g = 1.1 english tons.
    1 Megagram = 1000 tonnes = 10^9 g. This is the unit most often used for per hectare terrestrial carbon storage amounts.
    1 gigatonne (Gt) = 1 Petagram = 1 billion tonnes = 10^15g. These are the units usually used at large scales, including global.

    Paul, 39:

    Aspect/soil depth are unlikely to be important, for a couple of important points. Most importantly, we are talking about trends over time and even if they’re unequally distributed among e.g. aspects or soil depths, there’s still a trend that needs to be explained. Second, using aspect as an example, only 13% (10) of the plots showed no increase in mortality rate. Even if all such plots were on north-facing aspects, you’d still have more (37% = 28) occurring on north aspects that DID show mortality increases, assuming about half the total plots fall on north vs south aspects. Expectation under the hypothesis of no effect of aspect would be that 5 each of north and south facing plots would have shown no increase. So aspect might at best explain part of the observations, but would certainly not explain the majority of them.

    I thought their explanation of ozone not being a likely culprit was fine, since the geographic patterns of mortality do not match those of ozone. I’d be interested in any references you can provide regarding nitrogen-induced tree mortality in mature conifer forests. Thanks.

  3. 53
    Jim Eager says:

    Re larrydalooza @19: And what was the height of the air column in the terrarium, and thus the total depth of CO2 and other greenhouse gases that heat had to travel through, by radiation or convection, before it could escape to space. Oh, right, it could not escape to space because both convection and radiation were blocked.

    And were water and non-CO2 nutrients held constant, or were they varied as well as CO2?
    Were natural diurnal temperature ranges simulated?
    How about normal day-to-day, week-to-week and month-to-month temperature variations?
    How about wind? Was humidity varied? Were drought conditions simulated?
    How about El Nino-La Nina oscillations?

    And some people dismiss numerical general circulation models?

  4. 54
    previewed comment says:

    The things that Aaron has noted in his post at 24 are similar to what has been noticed in different ways all over the world. Some in their armchairs might say that it merely represents a readjustment of species to an evolving sequence of weather states. Some in their armchairs might view it as an opportunity for certain species to gain competitive advantage over others in a natural process of niche exchange. Many, out in their gardens and wandering the country lanes, are perturbed. What is being witnessed is an unravelling. It is an unraveling that is disturbing because the bedrock and soil structures that support the plant, insect, bird and other life systems are not shifting around. For those who have explored the relationships between bedrock, soil and living systems, there are strong connections. There are high levels of correlation between the various species and soil / bedrock maps and to induce a CO2 shock in the atmospheric blanket may well cause the moveable species to shift but the underlying systems that underpin them cannot shift around.

    What is emerging is a state of rest deprivation, in which the periods (autumn and winter) that Nature normally uses to recuperate are being squeezed out in favour of perpetual awakenness. That is not a good thing, as it favours burn out. And as these plants and insects and birds and others burn out (in the same way that humans burn out if they are not permitted to sleep) there comes a weakening, which goes hand-in-hand with vulnerability to infestation and other mechanisms of breakdown. Already wheat crops are being hit with increasing incidence of fungi with warming; investigation of wheat crop losses over recent years illustrates the potential for food risk.

    Taken together the bits of the jigsaw that are being seen do not suggest a nice picture.

    (Slightly off topic, I noticed some posts about attributing single events to climate change. Sometime in the future, when the last bit of ice melts at one of the poles, will someone turn around and ask if that specific event is connected with climate change?)

  5. 55
    Jenik Hollan says:

    is the proper link for the African rainforests carbon article in Nature, as regards free Editors’ summary, and more importantly, the beginning of the letter given at the bottom of the page and a free Supplementary material with enough explanations and graphs. A great paper, obviously.

    Jim’s link is to the full text and is a nonfree-one (and non-working due to a final dot I did not notice…), obviously due to clicking 2 mm higher than proper.

    #15 Doug, thanks for the magnificient Oregon forest slideshow and report!
    Seems the carbon-stock maximizing forestry should be reconsidered not just there (I guess it had to include biochar soil enrichment, when logging at all).

  6. 56
    Aaron Lewis says:

    Re 29: Michael – that is exactly what I thought 3 years ago. I was sure that I was seeing things that were simply not there. Even now, using standard daily lows and highs, I can see very little change in average temperature. However, if I look at the number of hours in particular temperature ranges; then I can see more hours in warmer rangers and fewer hours in colder ranges. So, I still have the same number of nights that get down to ~32F, but I have fewer hours at ~32F. The local weather station reports the low for the night as 32F but does not report how many hours plants and critters are exposed to those 32F conditions.

    I thought that I was unique because I lived very close to ridge that divided a temperate climate with frost from a semi-marine climate that does not frost. However, the habitat of various alpine critters has moved upwards more than would have been predicted based on a temperature rise of only 0.1F/decade. For example certain kinds of alpine beetles have moved the lower limits of their habitat upwards by some 900 feet in the last three decades. Based on the global warming number, I would have guessed that they would have moved up less than 100 feet. These beetles live in the Cascades and the Sierra and are able to do move upwards to stay cool as the region warms. Thus, what appear to be de minimis changes in average global temperature can have dramatic effects on local ecosystems. Any climatologist that talks or writes for public consumption about these tiny changes in temperature without putting them in context is being reticent.

  7. 57
    Aaron Lewis says:

    Re 35 Edward Greish – I have no idea what the fruit crop will be this year! It could be that fewer bees will just mean less fruit thinning. However in 5 years, the bloom may be earlier still, with even fewer bees?; or, by then it may be warm enough that honey bees will be active through the winter and there will be more bees? Or, my fruit trees may bloom in December (as the pears did in 2006) and the first night of ~32F will be the end of the crop. Uncertainty for farmers is one of the costs for global warming.

    I have much less hope for the native bees and the native plants.

    These days it costs $30,000 to $80,000 per acre to prepare and plant an orchard or vineyard. Opening up tundra will also include putting in support utilities such as roads and railroads. Given that we do not know how crops will perform in that environment, this is a very high risk adventure. Given that global warming is a long term trend, we may have to change crops every so often which will increase costs. How much are people willing to pay for fruit? Who has the capital for large scale agricultural development? Will polar migration get that capital, or will it go to converting previously temperate areas to tropical crops?

    Before anyone advances a farmer money to farm the tundra, they will ask, “How much rain do you expect?” So, Ed, What would you predict the rainfall on your particular piece of Arctic Farmland to be? _____ That much? Are you sure? With a changing climate, how long will it stay like that?

    Captcha words; “existed Molccans”

  8. 58
    Brian Dodge says:

    “Compared to the 1960s, each hectare of intact African forest has trapped an extra 0.6 tonnes of carbon a year. Over the world’s tropical forests, this extra “carbon sink” effect adds up to 4.8bn tonnes of CO2 removed each year – close to the total carbon dioxide emissions from the US.” Well, that takes care of OUR emissions in the US – what are the rest of y’all gonna do? &;>)

    Seriously, the question of “how much CO2 forests sequester” is complicated (no surprise) – by temperature, moisture, edge effects which become more important as the extant tropical forest is fragmented, age, succession, disturbance, etc, etc. And like all measurements, there are associated inaccuracies(how high up the trunk should the diameter be measured?) – for more info, see

  9. 59
    Pat Neuman says:

    Re: response in #23,

    Jim, good to see you met Lee Frelich and that are familiar with his research on historic forest disturbance
    regimes, among other things.

    Lee’s recommended trees for a warming Minnesota climate which he gave at a Jan 30th presentation was informative to me.

    On the other hand, the “cpa by day and concerned citizen by night” presentation was not, and teaching “global cooling theory” was not helpful to anyone.

    Which brings up a question – What government agency which issues weather and climate predictions has refused to help in public education on climate change?
    Hint: the agency has 124 local offices in the U.S.

  10. 60
    Steve Bloom says:

    This current article by the head of the European Environment Agency lays out some pretty ambitious plans for citizen-based phenology observations and related activities. Their interactive “Observatory of Global Change” site (very much in development at this point) is here. They’re starting out as Europe-only, but would like to expand it planet-wide.

    Captcha: somewhere severe

  11. 61
    Ray Ladbury says:

    Keith Whelpdale, Merely “intorducing species” is almost always a bad idea unless you have a thorough understanding of the ecosystem. I do not believe we meet this criterion for even one ecosystem. Can you point to even one story of “assisted migration” that had a happy ending for the ecosystem into which the species migrated?

  12. 62
    James says:

    I would like to second Richard Pauli’s thanks to RC for publishing

    Re #14 Ken Boettger’s cogent rant.

    This comment from the Bush Fire posting
    “… The people actually living this hell – people like me, are going to aggressively get involved, because we are sick to the back teeth with what is happening to our climate and we want to go all out to stop climate change or stop it any further.”

    Both display enpassioned sincere opinion that unsafely attributes the event to Global Warming and naively assumes that we can stop climate change (now as opposed to 500 years time)

    If even interested parties do not get the fundamentals right then I fear we are doomed.
    In any event very interesting reading.

  13. 63
    John Mashey says:

    Greenfyre’s has a nice post, with good maps on soil types, including Why Farming the Canadian Shield might not really be a fun task. As a reminder, some good soil in the US came from Canada via the glaciers.

  14. 64
    Joe Hunkins says:

    Jim this is fascinating work – thanks to you and RC for this very relevant follow up to some of the questions raised in the “Bushfires!” post below.

    Although attributing an increase in tree mortality to AGW seems reasonable to me I’m still strugging with the notion that AGW could be considered more than a small contributing factor in specific events like the Bushfires or Katrina where other factors (land use, arson, natural variability) would (at least to me) seem to be more significant than an AGW causal component. I like the way the studies you cite attempt to isolate the AGW causal factors from others and hope we see more applications (and examinations) of that method.

  15. 65

    57 Aaron Lewis: Thank you. Yes, I am expecting hard times ahead. I hope there will be enough food to prevent a collapse of civilization, but I fear that the rain will not be there when you need it. If agriculture collapses, civilization collapses. It has happened dozens of times before due to very minor changes in climate. 99.99% of the people in the civilization die.

  16. 66
    dhogaza says:

    Can you point to even one story of “assisted migration” that had a happy ending for the ecosystem into which the species migrated?

    Hmm … one can think of neutral introductions, such as chukar in the western US.

    Of course, that success and neutrality is based on the fact that they co-evolved with cheatgrass, which was also established by the time they were introduced.

    Mostly, human efforts to muck with ecosystems have failed, but I’m probably not as negative as you. And in the “assisted migration” notion being presented, the “do no harm” mandate isn’t possible. We’re doing and have done harm, assisted migration would undoubtably tweak things, but the reality is that global warming is also tweaking things.

    It’s no longer a measurement of good vs. bad side effects of intervention. “bad” is a given, the only thing we can really consider is “less bad” or “more bad”.

    So maybe “assisted migration” has never had a happy ending for ecosystems, but surely sitting on our rear won’t either.

    It’s tough stuff. Conservation biologists can’t be bothered with the notion that maybe climate science is a worldwide communist conspiracy, they’re too busy looking at ecosystem effects (real, measured today) and possible paths out of this terrible trap we’ve set for ourselves.

  17. 67

    Carbon emissions are no doubt closely related to global warming .I was actively involved in a tour all over india, for creating climate awareness and found a organisation working on Carbon Positive Ecosystem
    This might interest you.

  18. 68

    Found a interesting organisation during IYCN climate awareness tour,in India who are into postive carbon emissions.
    this should interest you .

  19. 69
    Sekerob says:

    I’m all with Aaron Lewis in his observations. Got oranges, mandarin, lemon, apricot, cherry, plum, figs and none of the fruit is doing good. Typically, the oranges are half the weight… the apricots are bland, the figs fall off at half the size, the cherry tree was done mid may, not June… ah, and the olive orchard around the house… last harvest, first in 3 years, was in 4th week October. Had flowers all through the winter from various plants. The apricot is already budding since early Feb. Then the apple trees are not worth mentioning… cricket ball size. More atmospheric CO2 may have caused an imbalance between what the plants pull from the air versus what nutrients sit in the soil. Tipping point?

    2 summers ago worked out a water recycling solution. The air conditioners produce around 50-100 liters of water daily… the air is ~50%-60% humidity, but it barely rains. Captured via a tube system in barrels and used to water plants and trees. Water from the shower is caught in bucket until it’s warm enough to go in (the kid from Barcelona gave us the idea). Again to water the plants.

    No idea where global cooling is happening, but not here!

    Oh, bees and their decline: They lost the capacity of long distance scent. Studies showed that air pollution has caused smell reach to reduce to 300 meters.

  20. 70
    John A. Davison says:

    My responses as follows.

    #41 by Ray Ladbury.

    If evolution is not finshed, please provide me with a recent example with its immediate ancestor and the cytogenetic mechanism by which it was produced. So far no one has.

    #46 by Chris S.

    All my published and unpublished papers and essays are available at my website –

    I am not the same J.A. Davison of breast augmentation fame.

    #50 by Keith Wheldate.

    There are more unique niches being produced today than in any prior period due largely to the activities related to our technology. While it is true that prokaryotes have responded by metabolizing unique new chemicals, these responses are reversible, something evolution has never been. Similarly, the resistance to insecticides are also reversible and phasic, and accordingly do not reprsent creative evolutionary progress. Among eukaryotic organisms we observe only extinction without a single replacement organism having appeared in hisorical times. If I am wrong, it has yet to be established.

  21. 71

    Slightly OT, but what the heck — has been posting a lot of anti-AGW theory stuff; specifically, that the theory isn’t mathematical and therefore isn’t science. I joined and posted some equations and examples. Surprise, surprise, my post never showed up. I posted about that. That never showed up. Meanwhile, deniers continue to post. How interesting.

  22. 72
    christine says:

    Just curious…I lived in southern Colorado and used to walk the dogs daily on spring afternoons.I often watched the wind take the snowpack right off of the mountains. Is snowpack measured in a way that disappearance due to high wind is accounted for? And, does anyone know if there is increasing mountain wind in the western US in the spring when it would affect snowpack and drought?

  23. 73
    Mitch Lyle says:

    I can understand concern about ecosystem management, but it obscures the point that we have been ‘managing’ western forests for over a century now. There are large numbers of both deliberately introduced and invasive species (e.g. pheasant, cheat grass, chukar, catalpa along rivers). Timber harvest has both removed economic species and has opened up niches for other vegetation to take advantage of the way we harvest timber.

    The question is not whether we manage the system but how.

  24. 74
    Ray Ladbury says:

    Joeduck, So, do you attribute World War I entirely to the assassination of Archduke Ferdinand by Serbian anarchists? How about attributing the Civil War entirely to the election of a President with abolitionist leanings? The point is that the immediate causes of fire–be they dry lightning, arson or whatever–are common. It is only when they occur in an environment that is particularly susceptible to fire that the result is catastrophic. Climate change alters precipitation patterns and increases evaporation. In some places, this creates conditions that increase the fuel load. I grew up in Colorado. We usually didn’t worry about forest fire, but in August, we could count on smarting eyes and respiratory difficulty from smoke blowing over to the Front Range. It is very suggestive that we are seeing increased fire susceptibilty exactly where the IPCC reports predict we would.

  25. 75
    Ray Ladbury says:

    Dhogoza, As someone who has engaged in kudzu and multiflora rose eradication campaigns (and has the scars to prove it), and as a resident of the near-Chesapeake region, I’ve developed an axiomatic faith in the ability of humans to f*ck up the environment. This is particularly true when species are introduced to “help” the ecosystem. I don’t know of a single incident where this didn’t increase stress on native populations and accelerate their decline.

  26. 76
    Ray Ladbury says:

    Barton Paul Levenson: Answerbag, douchebag, what’s the difference?

  27. 77
    dhogaza says:

    I don’t know of a single incident where this didn’t increase stress on native populations and accelerate their decline.

    Well, chukar studies haven’t found any such problems, and indeed might improve things slightly due to their fondness of cheatgrass (and certain other exotic weed) seed. Since they tend to hang out in a limited area, they don’t appear to be a vector for spreading cheatgrass, either.

    Of course, best would be to get rid of cheatgrass and other exotic weeds that chukar, unlike native species, dine on but unfortunately they’re here to stay. These plant species have caused immense harm to sage steppe habitat – with a big assist by another damaging introduced species, the cow.

    Also the moth introduced to attack tansy ragwort has been a rare but real biological control success story. The introduction of tansy ragwort itself was horribly negative here in the PNW, obviously.

  28. 78
    Hank Roberts says:

    re ‘Answerbag’ they’re certainly reticent about who owns the site; the question is posted there, and has mostly facetious answers. One answer says it’s owned by DemandMedia, which applies the “sell the readers to the advertisers” media model quite effectively, buying up social websites, and to own a vast number of domain names. Odd. Maybe DeSmog would know how to find out more. Sorry for the digression.

  29. 79
    Hank Roberts says:

    Oh, it looks like DemandMedia may be Google’s first true chance to do great evil profitably, if this story is true. You know all those websites Google finds that are nothing but advertising? That’s a very profitable business model invented by DM:

  30. 80
    Ike Solem says:

    Great post and comments. On the issue of ecological disruptions induced by climate change:

    Climate Change Opens New Avenue For Spread Of Invasive Plants, Nov 2008

    One way to mitigate this is to actively replant burned-out areas with appropriate mixes of native species – while keeping in mind that many of the plants are ecologically involved with plant and insect species whose range is also moving northwards:

    Birds seem to be heading farther north because of climate change, Feb 2009

    Over the 40 years covered by the Audubon study, the average January temperature in the United States climbed by about 5 degrees Fahrenheit. That warming was most pronounced in northern states, which have already recorded an influx of more southern species and could see some northern species retreat into Canada as ranges shift.

    Now, there are many proactive steps that could be taken to adapt to the new climate we are currently experiencing – but that requires that the public and government accept the reality of fossil fuel and deforestation-induced global warming.

    Take the expansion of the subtropical dry zones. Some scientists (i.e. Roger Pielke Jr.) have publicly claimed there is no science to back this up (in response to DOE Secretary Chu’s comments, Pielke said: “After 8 years of the Bush Administration’s cherry picking and selective reading of climate science it would be a shame to see the Obama Administration do exactly the same thing.”.

    What is the simplest, shortest explanation to counter that claim?

    1) Atmospheric CO2 is rising. The equation for atmospheric CO2 is here:

    Atmospheric increase = fossil fuel emissions + net emissions from land use changes – net oceanic uptake – “missing sink”.

    The split between fossil fuels and deforestation is about 70% – 30%. The “missing sink” is now generally thought to be terrestrial ecosystems, especially in the tropics. That simply closes the budget; tropical forests have thus kept atmospheric CO2 levels lower by billions of tons per year, and they cool the local surface temps via evapotranspiration as well. (By the way, traditional indigenous slash/burn farming was and is carbon neutral – it’s the conversion of tropical forest to charcoal for sale followed by cattle ranching and soy production that is most devastating).

    2) More CO2 leads to mid-atmospheric warming, the water vapor feedback, and surface warming.

    This paper and abstract lays it out succinctly:Fu et al Science May 2006, Enhanced Mid-Latitude Tropospheric Warming in Satellite Measurements

    The spatial distribution of tropospheric and stratospheric temperature trends for 1979 to 2005 was examined, based on radiances from satellite-borne microwave sounding units that were processed with state-of-the-art retrieval algorithms. We found that relative to the global-mean trends of the respective layers, both hemispheres have experienced enhanced tropospheric warming and stratospheric cooling in the 15 to 45° latitude belt, which is a pattern indicative of a widening of the tropical circulation and a poleward shift of the tropospheric jet streams and their associated subtropical dry zones. This distinctive spatial pattern in the trends appears to be a robust feature of this 27-year record.

    There has also been a recent update on water vapor feedback:

    The water-vapor feedback implied by these observations is strongly positive, with an average magnitude of λ q = 2.04 W/m2/K, similar to that simulated by climate models. The magnitude is similar to that obtained if the atmosphere maintained constant RH everywhere.

    So, can we say that increased fequency drought and wildfires globally are caused by the new atmospheric composition? Can we say that a giant storms in 1997-1998 were more frequent due to El Nino? Yes, we just have to talk about the frequency of events, and not focus on any particular event. If you do that, the pattern is obvious across a wide spectrum of data.

    The pattern is modulated by the natural climate fluctuations, such as the changes in ocean-atmosphere heat and water vapor exchange during a major El Nino, and some very wet years are likely in store over the next decade – but the general trend is not reversible over the next 50 years, so we have no choice but to take steps to prepare for it – while not forgetting that the only long-term solution is the elimination of fossil fuel combustion.

  31. 81
    Rick Brown says:

    Re: Steve #44- 20 February 2009 at 11:08 AM “I disagree with the portrayal of forest conservation as the best mitigation strategy given by #15 (Doug).”

    There is room for debate about the roles of forests and wood products in mitigation strategies, but that quickly leads to assumptions, often unrealistic, even fanciful, about demand, product substitution and the like (OT here). However the science is quite clear that the combined carbon stored in a managed forest and wood products will be less than in the same forest landscape left alone.

    Some representative quotes from papers that start with the premise that managing for wood products will be a good thing:

    Heath and Birdsey 1993:
    “We originally hypothesized that harvesting trees and manufacturing wood products would eventually lead to larger C pools in the forest and products than the C pool in the forest from no harvesting. This does not occur within the [90-year] time frame of this study. . . . the no harvesting scenario features a larger C pool.”

    Kurz et al. 1998:
    “The transition from a natural to a managed disturbance regime in forested landscapes generally results in a reduction in C pools . . . The increase in forest product pools off-sets some of the landscape-level ecosystem C losses.”

    Perez-Garcia et al. 2005:
    “One can observe that over time, the most carbon was accumulated under the no action [i.e., no logging] scenario, followed by the scenario that allowed a clear-cut harvest to occur every 120 years, then the 80-year harvest scenario, and finally the 45-year harvest scenario.”

    For a fuller discussion with more citations, I’ll direct those interested to my paper “The implications of climate change for conservation, restoration and management of national forest lands,” available at (the pertinent section starts on p. 13)

    Heath, L. S. and R. A. Birdsey (1993). “Carbon trends of productive temperate forests of the coterminous United States.” Water, Air and Soil Pollution 70: 279-293.

    Kurz, W. A., S. J. Beukema, et al. (1998). “Carbon budget implications of the transition from natural to managed disturbance regimes in forest landscapes.” Mitig Adapt Strat Glob Change 2: 405-421.

    Perez-Garcia, J., B. Lippke, et al. (2005). “An assessment of carbon pools, storage, and wood products market substitution using life-cycle analysis results.” Wood and Fiber Science 37 (CORRIM Special Issue): 140 – 148.

  32. 82
    Rod B says:

    Aaron (24), Kevin (43), et al: You all are (and, alas, will likely continue to) mix up climate and weather, though you blast skeptics when they (incorrectly) do the same thing. The vast majority of climate scientists and the moderators of RC say changes in local current weather conditions, which might be as long as many decades, are not proof of climate change. This thread’s commentary says the same thing and explains pretty well why. That changes in weather might indicate a connection to climatic change is correct; that it might also point to some attribution (like this commentary), sometimes even a suspiciously significant attribution (ala the Arctic), is correct; that it ought to motivate scientists (and others) to watch it very closely, suspiciously and carefully is correct. But proof? or a “resounding yes”? — all because your hummingbirds showed up a few days early, for example? Clearly NOT.

  33. 83
    tamino says:

    Re: #14 (Ken Boettger)

    Scientists look closely at temperature data all the time. But just so you don’t feel that Ellensburg is neglected:

  34. 84
    SecularAnimist says:

    Human beings do not have the capacity to “manage ecosystems”, which are quite capable of “managing” themselves anyway.

    What we need to do is not to “manage ecosystems” but to manage our own behavior so that we do not damage and degrade ecosystems.

    The dualistic idea that the world — the Earth’s biosphere — consists of (1) human beings and (2) “resources” to be used, consumed and discarded by human beings is the root of all of our problems.

  35. 85
    Hugh Laue says:

    #67,68 Regarding terminology “carbon POSITIVE emissions” means (should mean) MORE CO2 emitted (to atmosphere) than sequestered (through e.g. photosynthesis) whereas “carbon NEGATIVE emissions” means less. Presumably as applied to any cradle to grave process. Thus, regarding global warming impact, “carbon positive” is negative and “carbon negative” is positive. :)

    captcha so- hopeful

  36. 86
    Steve Bloom says:

    Re #81: Ike, don’t confuse Pielke Jr. with any sort of climate scientist. He’s a *political* scientist. His activities are best understood if they’re seen as an effort to maximize his own profile. My advice is to keep away from the briar patch; i.e. ignore him.

  37. 87
    Harmen says:

    Phenology has a long tradition in the Netherlands.

    The data is gathered via a popular radio show and thousands of volunteers.

    This site is in Dutch but contains a lot of data about the earliest blooming dates of plants, the earliest date of spotted travelling birds, the earliest appearance dates of several insects..etc…

  38. 88
    thefordprefect says:

    OT but thought you might be interested in this:

    An absolute howler in itself!!!!!!!! Couldn’t do better if one tried. What a joke of an authority on global warming.

    This scientific howler provoked much amusement and derision on expert US blogs, such as Anthony Watts’s Watts Up With That – since “negative feedback” would lower temperatures rather than raise them. The BBC soon pulled its video.

    NEGATIVE FEEDBACK LOWERS TEMPERATURE!!!! (for heavens sake get it right – it stabilises temperature!)

    How long before this howler gets corrected/pulled

  39. 89
    Bernie says:

    You should really listen to Gavin on not focusing on a single location. A quick look at Google indicates that any increase in temperature in and around Ellensburg needs to take into account that the population has grown by 36% since 1990. Moreover the data at NASA suggests that the temperature has certainly not chnaged at the rate that your post would suggest. Try here for temperature and here for temperature

  40. 90
    Lawrence McLean says:

    Re #82 Rod B.
    Many times I have noted that you disparage biological observations that confirm Global warming.

    In reality biological trends are the best proof for global warming. The point raised by Aaron Lewis in #56 illustrates my point. A single measurement or recording will miss the significant change of the time spent at the measured value. Biology however is “recording” all the time. Have you ever realized that Climate of a region controls the sort of biology that exists there.

    When it is observed that hummingbirds are coming earlier, and that it is a persistent trend, it is NOT “clearly NOT” proof of global warming.

    Honest anecdotal observations must never be disparaged. When you see black smoke billowing from all the windows in your house, but you can’t see the flames, does that mean you have no proof that your house is on fire?

  41. 91
    James says:

    Rod B Says (21 February 2009 at 12:43 PM)

    “That changes in weather might indicate a connection to climatic change is correct; that it might also point to some attribution (like this commentary), sometimes even a suspiciously significant attribution (ala the Arctic), is correct; that it ought to motivate scientists (and others) to watch it very closely, suspiciously and carefully is correct. But proof? or a “resounding yes”? — all because your hummingbirds showed up a few days early, for example? Clearly NOT.”

    If it is just one area experiencing a change, then it could easily be just long-term weather. But if you have very many sites distributed around the world, and most if not all of them show similar evidence of warming… Well, the statisticians here can better speak to the odds that it’s just chance: I’ll stick with “three times is enemy action” :-)

    I also think it rather strengthens the argument when the warming is predicted, and the causal physics described, well in advance of the effects being noticed.

    PS: And for those following the Sierra snowpack, the forecast for Sunday & Monday is rain up to the 8000 ft level :-(

  42. 92

    John A. Davison writes:

    Among eukaryotic organisms we observe only extinction without a single replacement organism having appeared in hisorical [sic] times

    Speciation normally takes hundreds of thousands of years. But since there are so many species… surprise! We have, in fact, seen speciation in historical times! Check here:

  43. 93
    dhogaza says:

    If it is just one area experiencing a change

    Or one species in one ecosystem …

    Rod B has to explain away why the phenomena is occurring worldwide. Phenology in The Netherlands was mentioned above, the English are a bit nuts about it too. And records show changes in species arrivals, first blooms of garden plants, even the first date upon which one’s lawn needs mowing all consistent with warming (i.e. earlier in spring). Horticultural zones in the Eastern US have moved northwards. Farmers are seeing changes. Birders are seeing changes. Biologists are seeing changes. The list is long and exhaustive.

    Unless someone really has been sneaking LSD into the world’s water supply and we’re all imagining thngs, the biological evidence is that it’s warming.

    Rod B will, though, find some way to explain it away to his own satisfaction.

  44. 94
    pat neuman says:

    What’s happening to conifers now has likely happened before (though at a much slower rate). In some global warming events in Earth’s past, it seems likely that global albedo decreased before CO2 peaked, thus contributing to events when global temperature peaked before CO2 peaked.

    Western U.S. Forests Suffer Death by Degrees by Elizabeth Pennisi
    Mortality rates in seemingly healthy conifer stands have doubled in the past several decades, and often, new trees aren’t replacing dying ones, forest ecologists report on page 521 of this issue of Science. Warmer temperatures and subsequent water shortfalls are the likely cause of the trees’ increased death rate, they say.
    Science 23 January 2009

  45. 95
    xyz says:

    There was an interesting piece on the BBC programme called “Countryfile” today – 11am on 22 February 2009. The programme can be watched on the BBC website

    The programme visited Kew Gardens and had botanical experts discussing the impacts of climate change on trees and other plant life. From the BBC website blurb: “Kew is one of the best places to see the effects of the changing climate, and thanks to more than 50 years of detailed observations from one of Kew’s botanists, scientists are now noticing some tell tale changes in our native flora.”

    Some interesting points were made. Since the 1950′s the flowering of daffodils has crept forward by 41 days. One tree expert made the comment that the effect on native tress in the temperate regions was disastrous. Such trees need to have a rest season (winter) before they wake up in the spring and because the seasons were merging into one the trees were becoming susceptible to attack by various agents.

    Apparently, as mentioned in the programme, there is a substantial database available for access to the plant observations over the decades. The climate change impacts on plant life are observable and it is through the efforts of the myriad observers who have participated that those impacts can be readily discerned.

  46. 96
    thefordprefect says:

    I see the use of negative feedback to mean negative forcing continues on
    This does not inspire confidence in their conclusions!

    A few weeks ago I plotted central england temp (and Nantes) ahainst pinot noir grape harvest times. There is a pretty good correspondance as shown in this plot:

    The grape harvest can the be extended back to 1300s.

    It is a pity that the harvest date data has not been updated to the present
    some refs:

  47. 97
    Chuck Booth says:

    Re # 70 John A. Davison, and BPL’s response (#92)

    Davison is presenting the same old arguments we’ve been hearing from the creationist and ID camps for decades. BPL’s response is on target, but merits some clarification:

    Jerry A. Coyne, a highly respected evolutionary biologist at the Univ. of Chicago has a new book out, Why Evolution is True (Viking Press), in which he addresses (in Chpt 7) the evidence for speciation past and present. From fossil and molecular evidence, he estimates that it takes between 100,0000 and five million years for a given species to diverge into two reproductively isolated populations, the defining characteristic of speciation according to Ernst Mayr’s Biological Species Concept. Consistent with this estimation, Coyne points out that the estimated 100 million extant species on this planet could have evolved from a single prokaryote ancestor living 3.5 billion years ago (the estimated time when the first cells appeared) if ancestral species split into two species once every 2 million years. At BPL notes in his response (#92), given such a slow rate of speciation, we shouldn’t expect to see species, let alone genera, form before our eyes.

    However, there is evidence that speciation can occur much faster than Coyne estimates. For example, cichlid fish occupying Lake Victoria and neighboring lakes are thought, based on DNA evidence, to have undergone a rapid period of speciation over a period of approximately 40,000 years, between 132,000 and 98,000 years ago, leading to the 500 or so endemic species that, until recently, called Lake Victoria home (Verheyen et al, Science, 11 April 2003:
Vol. 300. no. 5617, pp. 325 – 329;

    Coyne’s clear explanations of the evidence for biological evolution, including mechanisms, are reviewed in more detail in several articles in the February 6, 2009 issue of Science:
    The Red Queen and the Court Jester: Species Diversity and the Role of Biotic and Abiotic Factors Through Time
    Michael J. Benton
    Science 6 February 2009: 728-732.

    Adaptive Radiation: Contrasting Theory with Data
    Sergey Gavrilets and Jonathan B. Losos
    Science 6 February 2009: 732-737.

    Evidence for Ecological Speciation and Its Alternative
    Dolph Schluter
    Science 6 February 2009: 737-741.

    Finally, the following article (on the plant, Arabidopsis) describes a genetic mechanism that can be observed in real time and can account for reproductive isolation in plants and animals that can lead to speciation (within two generations, in some cases):
    Divergent Evolution of Duplicate Genes Leads to Genetic Incompatibilities Within A. thaliana
    David Bikard, Dhaval Patel, Claire Le Metté, Veronica Giorgi, Christine Camilleri, Malcolm J. Bennett, and Olivier Loudet
    Science 30 January 2009: 623-626;

    Gene duplication and mutations in the extra copies of the genes may explain the reproductive isolation seen in closely-related species of fruit fly, Drosophila:
    Speciation in progress? A continuum of reproductive isolation in Drosophila bipectinata.
    Kopp A, Frank AK
    Genetica. 2005 Sep;125(1):55-68

    Gene, or genome, duplication may also be responsible for the great diversity in teleost fish:
    Genome Duplication, a Trait Shared by 22,000 Species of Ray-Finned Fish
    Taylor, J. S. et al
    Genome Res. March 1, 2003 13:382-390;

    Are humans evolving? Coyne (Chpt 8 in his new book) points out that it is difficult to know. Because humans form essentally one worldwide, interbreeding population, and the key selective forces that shaped our evolution in the past have likely been eliminated by our culture and technology, it is unlikely that a new species of Homo will form by reproductive isolation and divergence. However, humans do show changes in gene frequencies over time, and it is not implausible to assume that the entire human population will change over time such that a few hundred thousand years in the future a paleontologist will look at the relicts of Homo sapiens from the year 2000 and declare those specimens a different species from him-/herself.

    Back on topic:

    Response to Rod B (#82):

    Do a Google (or better yet, Google Scholar) search for the key words “climate change range expansion” and “climate change migration” and you’ll find many recent peer-reviewed research papers documenting the north ward range expansions of more southerly species, the northward withdrawal of more northerly species, and the early arrival of migrating birds returning to the north. The anecdotal observations you dismiss should not be taken as scientific evidence in and of themselves, but they are consistent with the scientific evidence based on many studies and many species of animals and plants.

  48. 98
    Jim P says:

    93 dhogaza

    “all consistent with warming”

    or all consistent with species continuously extending their geographic ranges?

    Don’t use garden plants as an example. The reason we have widespread Fuchsia in Irish hedgerows and Rhodedendron in Scotland is nothing to do with warming. Pyracantha everywhere is giving birds early nesting opportunities well before the beech hedges have budded.

  49. 99
    Pat Neuman says:

    Correction, #94 – Should have said … seems likely that albedo INCREASED globally as conifer died-off, which may explain why global temperature peaked before CO2 peaked for some global warming events in Earth’s past.

  50. 100
    Hank Roberts says:

    > species continuously extending their geographic ranges?
    Not while the total number is dropping off rapidly. Think.
    Some move north, some move uphill; movement toward cooler temperatures.
    Look at the population numbers and habitat fragmentation.

    Making stuff up and challenging scientists to disprove it is a tactic.
    A familiar one. But it’s not science.

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