Trees dying faster as climate warms

From the Washington Post:

The death rates of trees in Western U.S. forests have doubled over the past two to three decades, according to a new study spearheaded by the U.S. Geological Survey, driven in large part by higher temperatures and water scarcity linked to climate change

Nathan L. Stephenson, one of the lead authors, said summers are getting longer and hotter in the West, subjecting trees to greater stress from droughts and attacks by insect infestations, factors that contribute to tree die-offs.

“It’s very likely that mortality rates will continue to rise,” said Stephenson, a scientist at the Geological Survey’s Western Ecological Research Center, adding that the death of older trees is rapidly exceeding the growth of new ones, akin to a town where the deaths of old people are outpacing the number of babies being born. “If you saw that going on in your home town, you’d be concerned.”

The recent warming in the West “has contributed to widespread hydrologic changes, such as a declining fraction of precipitation falling as snow, declining water snow pack content, earlier spring snowmelt and runoff, and a consequent lengthening of the summer drought,” they wrote.

The scientists said it was hard to predict how the changes would transform the Western landscape, although they anticipated that in the future the West will boast sparser forests that cannot store as much carbon as they do now, which could contribute to further warming.

This is yet another symptom where subtle climate shifts damage the natural negative feedback in the carbon cycle, which further accelerates the climate changes. There has recently been a whole spate of reports about how the ocean’s ability to absorb carbon is beginning to decline as it becomes saturated, cleaning up after mankind’s profligate use of fossil fuels. But that’s for another post.  An article appears in today’s Sunday Star Times regarding the tree deaths, but is not available online.

28 Comments Posted

  1. It was a casual joke actually. Just have friends in Canada who are complaining bitterly about the cold weather. Just gone back from visiting NZ so noticing it more than usual I suppose.

  2. Oh, and by the way Owen, if you read the Wikipedia article, you’ll see that preliminary results suggest the previous (not the current) cold winter was less successful than predicted at killing the beetle.

  3. And last winter too, and the one before that – should we be expanding the equation? Imho warming is going on a regional basis (eg the ozone hole) – even more ground for research…the loss of the earth’s ice may well be unrelated, may well be a man-made phenomena. But those researchers have lately gone from talking about a 15foot sea-level rise to a 60foot one – whoopsie!
    Then people keep leaving the jet-engine aside when discussing warming patterns – and in terms of tree loss – seen a photo of our humble globe from space lately?
    The burning off of central America looks like the planet has been hit by a giant phosphorus bomb – tree loss is a massive understatement.

  4. In Canada, the mountain pine beetle has been destroying pine forests in British Columbia. By 2008 50% of the lodgepole pine forests are estimated to be dead, and this is predicted to rise to 80% dead by 2013.

    There are two causes for the spread of the beetle: 1) forest fires have been suppressed, leading to old weak trees surviving, which are susceptible to attack, and 2) winter temperatures have not been getting cold enough to kill the beetle.

    You can read about it here:

  5. lol good point, i guess if i had heard that global warming had lead to monsoon-like rains & some kind of mass die-off among insect populations i wouldn’t have been any more surprised

  6. Actually there’s another interesting Solar link. I don’t think either of these jokers actually has a decent theory to explain WHY this sort of stuff could be true, but the statistics are interesting….

    Not explicable by any known physical mechanism.

    We are as ignorant of the universe as we are negligible to it.


    It is not however, anything like a reason to reject AGW as a theory.

    AGW isn’t a theory of everything either though ( good list 🙂 ). The popular press is doing a marvelous job of obfuscating truth and promoting panic and confusion.

    The science is a lot less equivocal. The statements more limited. For predicting weather, use what works.

    I would be surprised if AGW models back-cast drought properly. The forcing doesn’t give anything like specific timing to results, one of many.

    I would NOT be surprised to find a rising frequency/intensity of droughts with the solar rhythms superimposed on them and if I were NIWA I’d be looking seriously at integrated methods.


  7. Nandor,
    That’s fine. As I wrote this I knew it would be difficult to tease out the two issues because Global Warming (Climate Change) is such a catch-all topic on which most people have made up their minds and accept no challenge.

    Andrew, you should know that everything is consistent with global warming theory – even including global cooling. For many people it is now “irrefutable” because it is no longer subject to refutation.
    Anyhow the list of “perils” is at

    Hilarious. It begins:
    Acne, agricultural land increase, Afghan poppies destroyed, Africa devastated, Africa in conflict, African aid threatened, African summer frost, aggressive weeds, air pressure changes, airport malaria, Agulhas current, Alaska reshaped, moves, allergy season longer, Alps melting, Amazon a desert, American dream end, amphibians breeding earlier (or not), anaphylactic reactions to bee stings, ancient forests dramatically changed, animals head for the hills, animals shrink, Antarctic grass flourishes, Antarctic ice grows, Antarctic ice shrinks, Antarctic sea life at risk, anxiety treatment,
    and so on and so forth. (They are all linked to the source.)

  8. we’re not told the trees are dying because of high temperatures.
    we’re told they are dying because of droughts & insect infestations, conditions which are consistent with global warming theory.

  9. RE: the dying trees.
    What I don’t get is that we are told these trees are dying because of global warming.
    The warming last century is about 1 degree C. OR even 2 degrees if you chose different data sets.
    THe microclimate across a typical farm varies by more than two degrees – ask any grape grower. So how can trees be dying from a change in temperature which is within the site wide variation within a typical forest and certainly well within year to year variations? Why did they not die in 1934 or 1998 – the hottest years on record?

  10. My post above is not about AGW but about conflicting theories about how best to make long range forecasts of floods and droughts.
    These long range forecasts are hugely important to New Zealand, both for our rural towns and our agricultural sector.
    There is a conflict between the preferred means of making these forecasts.
    One group of research (in the southern hemisphere) finds that the oscillations in the solar magnetic field fit remarkably with historical records of flood and drought and are already proving useful forecasting models. On the other hand NIWA is using modified IPCC models which assume a steady increase in extreme weather events as CO2 concentrations rise. The IPCC models do not backcast floods and droughts at all well while the Magnetic field theory does.
    This is too important to be left to an academic debate. We should compare the backcasting and forecasting records of the two theories and see which proves the most accurate.
    And frogblog you are quite irresponsible (not to say insulting) to describe the observations by these highly reputable organisations as a mash up of skeptic myths. The South American floods were no myth and now was the Australian drought and all those before. The African studies are official and reliable. What is about these research findings that you can describe as a myth? This stands aside from whether the globe is warming and its cause. These people are trying to develop long range forecasting techniques for floods and droughts.
    Why would you want to reject their findings out of hand – unless they are presenting inconvenient truths?

  11. Interesting post Frog. I was encouraged to think that we might see more leadership from the USA at the Copenhagen climate change negotiations, by Obama’s talk of rolling back climate change in his inaugural speech. Even so I think that it is only when rich nations like the USA start to feel it for themselves that they will give up the kinds of games we saw at Posnan.

    Owen, also a very interesting post. You say “This is further evidence that the science of the New Zealand climate is by no means ’settled’” and this seems to me to be true. I had understood climate science as enormously complex, and far from being totally understood. I guess that uncertainty is why climate change predictions generally range from the conservative (like the IPCC) to the truly alarming (though not necessarily alarmist). I regularly read articles about research opening new understanding of the effects of some agent on climate. The research authors usually also point out that this doesn’t negate global warming theory.

    So I am not sure why you describe the research on the effects of solar activity and global warming science, as “conflicting theories…”. I don’t think the IPCC or any other authoritative source sees atmospheric CO2 or other GHG’s as the ONLY things acting on climate. Why would it be an either / or kind of thing?

  12. Nice mash up Owen, of all the usual sceptic myths. Yes, of course solar and magnetic cycles affect the weather. This has been known for quite a long time and factored into the models. So has water vapour, to the extent that they can, and the myth that the IPCC ignores vapour continues to fog your posts.

    You are correct about one thing though – the observed data does not often fit the model’s predictions. They have been consistently shown to be far too conservative in their estimates, as scientists are naturally conservative and don’t want to be alarmist. The only significant failures we have so far in the models is their under-predictions of the anthropogenic component of global warming above the natural cyclical changes that you love to say are new discoveries.

  13. Why do we think things should remain static?
    Species come & species go, the only thing that is constant is change.

    We run about like headless chickens trying to stem the tide of nature.

    The stuff that can grow we try to eradicate, for the stuff that can’t, we spend a fortune controlling the habitat that is already extinct in nature

    Adapt or perish is nature’s message.

  14. wat dabney seems to offer the proposition that we should reject observed data because they do not fit a theory…
    i’m more inclined to do the opposite

  15. “Alarmists” Owen? Like the new US President huh…suppose it’s better than declaring war on people you can’t find, and prosecuting (attempting to, unsuccessfully) people you paid others to turn in by race.
    I pledge $50 towards your airfare to Marble Bar in Australia – apart from the obvious benefits – I will look forward to hearing your views re global warming upon returning.

  16. Owen

    The reason it doesn’t is because the greenhouse growers are working to provide OPTIMUM levels of water and CO2… and keep the vermin away… and aren’t growing trees.

    Yes the plants may need marginally less water, but apparently they still need more than they are currently getting at those temperatures… and heat stress is a real problem for the trees where they are. If given sufficient time the species will find itself cooler and wetter environments…

    My point was that the researchers observing the trees were observing that the trees were dying, not thriving, in the altered conditions, and no amount of spin can change that.


  17. While many things limit plant growth and health the relationship between CO2 and water seems to be the opposite to what alarmists claim.
    Any NZ horticulturist operating a greenhouse will tell you that pumping CO2 into the greenhouse raises productivity by up to 40%. CO2 is definitely a fertizer and not a polluter of plants.
    But more importantly for this debate the increased CO2 also reduces the demand for water because the stomata do not need to be as open so as to pick up C02 from the normal concentrations in the air.
    So more CO2 means higher productivity with lower demand for water.
    May attribute part of the Green Revolution (and the Greening of the West Coast US deserts) to this effect.
    If this applies in the greenhouse why not in the open air? And greenhouses are warmer too as I know having just watered the tomatoes in my regular polyhouse.

  18. Good topic frog – thank you – the msm continues it’s “disconnect”, and their owners may well wonder why they are losin big money…
    Germany’s formerly famous ‘Black Forest’ was effectively lost to acid rain some 30 years ago.
    Then almost all of France’s ancient forests (over 80 million trees) were lost to hurricanes only a few years ago – including the historic ancient forests of Versailles.
    Global Warming is only one of the problems.
    As I lived in a native forest for 4 years I noted how they were the most sensitive of environments/ecosystems. The most rewarding lessons are lost before most humans arrive.

  19. I know you’re trying to be annoying, bb, but this is really not up to your normal trolling standards at all. What’s your obsession with Obama? I don’t remember posters here being overly enamored; most have been rather skeptical about what he will likely do, so this particular attempt is hardly likely to get up anyone’s nose. If you insist on posting crap, we’d like at least to be entertained, please.

  20. the death of older trees is rapidly exceeding the growth of new ones,

    What you say about their survival may be true overall, but is clearly not true in the region studied. As to what survived and what did not, the answer can only be that we do not know.

    The false optimism of the CO2 as a fertilizer argument can also be misleading. It is a fertilizer… but there are limits to how much it can help. Growth is subject to a number of limiting factors, CO2 is only one of them.

    Give your plants 3x the CO2 and what will happen? If they are up against a limit based on water or nitrates in the soil or something else, NOTHING will happen. Drought is the other problem the western US forests are experiencing.


  21. There could be another explanation which deserves to be checked out. Mind you it may well be that the southern hemisphere is beating to a different drum.

    Regional and District Plans are supposed to manage the effects of natural hazards and of course we all have an interest in guarding ourselves against the ravages of floods and drought. Indeed the ability to be prepared for floods and droughts is vital to our agricultural economy. Hence the significance of this announcement which is causing some robust discussion among meteorologists and climate scientists.

    “Sun’s Magnetic Field May Impact Weather And Climate: Sun Cycle Can Predict Rainfall Fluctuation.” (See summary from Science Daily below)
    According to Professor Baker, the author of this paper published in Geographical Research, the droughts in Australia are related to the solar magnetic phases and not the greenhouse effect. He says “This discovery could substantially advance forecasting from months to decades. It should result in much better management of agricultural production and water resources in areas where rainfall is correlated to Southern OsciIlation Index and El Nino (ENSO) events.”
    This Australian study, which uses data from 1876 to the present, is significant because it confirms the claims of other scientists such as Will Alexander, a hydrologist who has been studying the correlation between river flows, flooding and droughts and solar activity in South Africa and in much of the rest of the African Continent. Colonial records go back over 100 years. Similar work in South America (Solar Forcing of the Stream Flow of a Continental Scale South American River” by Pablo Mauas et al; Physical Review Letters, 17 October 2008) has drawn similar conclusions.
    While the Australian study focuses on floods the South American study concludes:
    “On the multidecadal time scale, we found a strong correlation with solar activity, as expressed by the sunspot number, and therefore probably with solar ir-radiance, with higher activity coincident with larger discharges; on the yearly time scale, the dominant correlation is with El Niño. These correlations can be used for flood prediction: (Equations which follow here deleted for brevity show 99% signiicance)
    Early flood prediction, in fact, has large social and economic impacts: During the last flood, in 1997, 180 000 km2 of land were covered with water, 125 000 people had to be evacuated, and 25 people died. In all, the three largest floods of the Parana´ during the 20th century caused economic losses of five billion dollars. ”

    Dr Willem de Lange of the University of Waikato reports:
    “We found a similar pattern for Northland based on the Schwab & Hale cycles more than a decade ago – but we didn’t have enough data to try the Gleisberg cycle.”

    So according to experts in Australia, South Africa, South America and New Zealand there is now strong evidence that droughts and floods in the southern hemisphere are driven by solar activity (in particular the sun’s magnetic field) and that the level of carbon dioxide in the atmosphere is largely irrelevant.
    This is not a new idea and indeed researchers have been discussing these correlations since at least 1992. Part of the problem has been the focus on temperature while essentially ignoring precipitation. Two most likely reasons for this bias are- IPCC followers didn’t want to look at water vapor as the most important greenhouse gas, and the IPCC computer models’ inability to deal with clouds.
    This creates something of a dilemma for Government and our weather forecasting services. Government has been turning to NIWA as the authority on extreme weather events and of course NIWA is committed to the theory of Anthropogenic Global Warming as the key driver of climate in New Zealand including extreme weather events such as floods and droughts. Their standard approach seems to be to apply the outputs of the models to New Zealand and base their long range forecasting on these models and their scenarios. For example NIWA spokesmen on Television typically say things like “A warmer atmosphere holds more water than a cool one and hence as global temperatures rise rain storms are more severe and more floods are the result.”
    This reflects the Government’s official current position that the IPCC models are reliable and that Greenhouse gas concentrations in the atmosphere, including methane from agricultural production, will cause increased flooding in future.
    But these studies from the Southern Hemisphere are saying something quite different. Professor Baker is telling us that Solar Activity Cycles are able to make ten year forecasts of drought conditions while Will Alexander’s work and the research by Pablo Mauas et al in South Amercia says the same but for flood conditions as well.
    Surely this is where the weather rubber hits the economic road.
    The Ministry of Agriculture and Federated Farmers must insist that these conflicting theories are put to the test. Our farmers need to know when we are entering periods of drought and flood and they need to know that forecasts are based on the most appropriate scientific theories. Many of our Mayors would like to have access to the best forecasting tools as well.

    This is further evidence that the science of the New Zealand climate is by no means ‘settled’, and this body of research is another scientific topic which should be debated before the Select Committee.

    Once again, models are telling us one thing and observations are telling us something completely different.

    It’s time to test these conflicting theories in our own back yards. The stakes are too high to ignore.

    A Summary of Baker’s Paper.
    ScienceDaily (Dec. 3, 2008) — The sun’s magnetic field may have a significant impact on weather and climatic parameters in Australia and other countries in the northern and southern hemispheres. According to a study in Geographical Research, the droughts are related to the solar magnetic phases and not the greenhouse effect.
    The study uses data from 1876 to the present to examine the correlation between solar cycles and the extreme rainfall in Australia.
    It finds that the Southern Oscillation Index (SOI) – the basic tool for forecasting variations in global and oceanic patterns – and rainfall fluctuations recorded over the last decade are similar to those in 1914 -1924.
    Author, Professor Robert G. V. Baker from the School of Environmental Studies, University of New England, Australia, says, “The interaction between the directionality in the Sun’s and Earth’s magnetic fields, the incidence of ultraviolet radiation over the tropical Pacific, and changes in sea surface temperatures with cloud cover – could all contribute to an explanation of substantial changes in the SOI from solar cycle fluctuations. If solar cycles continue to show relational values to climate patterns, there is the potential for more accurate forecasting through to 2010 and possibly beyond.”
    The SOI-solar association has been investigated recently due to increasing interest in the relationship between the sun’s cycles and the climate. The solar application offers the potential for the long-range prediction of SOI behavior and associated rainfall variations, since quasi-periodicity in solar activity results in an expected cycle of situations and phases that are not random events.
    Professor Baker adds, “This discovery could substantially advance forecasting from months to decades. It should result in much better long-term management of agricultural production and water resources, in areas where rainfall is correlated to SOI and El Niño (ENSO) events.”

  22. Conditions now are comparable to the previous natural warming event – the Medieval Warm Period. Forests obviously coped back then, so there is no reason for concern now.
    Indeed, since CO2 is a fertiliser, they will benefit from any increase in atmospheric levels.

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