Study: Increased atmospheric Carbon Dioxide has increased U.S. forest health in recent decades

“Physiological and ecological factors influencing recent trends in United States forest health responses to climate change”



    • We review information on US forest health in response to climate change.• We found that trees are tolerant of rising temperatures and have responded to rising carbon dioxide.• No long-term trends in US drought have been found in the literature.• CO2 tends to inhibit forest pests and pathogens.• Projections of forest response to climate change are highly variable.

by Craig Loehle, Craig Idso, T. Bently Wigley (Forest Ecology and Management) (h/t to Poptech)

Abstract: The health of United States forests is of concern for biodiversity conservation, ecosystem services, forest commercial values, and other reasons. Climate change, rising concentrations of CO2 and some pollutants could plausibly have affected forest health and growth rates over the past 150 years and may affect forests in the future. Multiple factors must be considered when assessing present and future forest health. Factors undergoing change include temperature, precipitation (including flood and drought), CO 2 concentration, N deposition, and air pollutants. Secondary effects include alteration of pest and pathogen dynamics by climate change. We provide a review of these factors as they relate to forest health and climate change. We find that plants can shift their optimum temperature for photosynthesis, especially in the presence of elevated CO2 , which also increases plant productivity. No clear national trend to date has been reported for flood or drought or their effects on forests except for a current drought in the US Southwest. Additionally, elevated CO2 increases water use efficiency and protects plants from drought. Pollutants can reduce plant growth but concentrations of major pollutants such as ozone have declined modestly. Ozone damage in particular is lessened by rising CO2 . No clear trend has been reported for pathogen or insect damage but experiments suggest that in many cases rising CO2 enhances plant resistance to both agents. There is strong evidence from the United States and globally that forest growth has been increasing over recent decades to the past 100+ years. Future prospects for forests are not clear because different models produce divergent forecasts. However, forest growth models that incorporate more realistic physiological responses to rising CO2 are more likely to show future enhanced growth. Overall, our review suggests that United States forest health has improved over recent decades and is not likely to be impaired in at least the next few decades.

178 thoughts on “Study: Increased atmospheric Carbon Dioxide has increased U.S. forest health in recent decades

    • I don’t know anything about T. Bently Wigley, but Craig Loehle and Craig Idso outed themselves as competent honest scientists long ago, so they have nothing more to fear from alarmists than they have already risked.

      • Craig D. Idso is associated with Heartland and their anti” Anthropologic Whatever Will Extract Money From Taxpayers” effort. In short he is a “denier”. Or scientist. Honest researcher.
        Their point seems to be “things are normal but a bit better” with increased food for trees.
        The goofies should be applauding the increase in “biomass” resources. Wood is just juvenile coal. Their philosophy hates babies and the elderly. Big trees are sort of both. Good fuel. Natural. Pre-industrial.
        We can all live in the woods, running naked, eating bugs and lichens along with pine nuts (we will BE pine nuts).
        The science is that well fed trees ward of pests and diseases better, grow faster in both wet and dry conditions and are happier and better adjusted.

      • Actually coal was mostly lignin, found in bark.
        Back during the carboniferous period, trees had as much as ten times as much bark/lignin than now.

      • I wasn’t aware of their street cred in the skeptic world. They won’t be fired, they’ll be ignored as kooks.

    • Hmm? Humans take in biological matter and, among other things, expel CO2 in their breath. Ergo: Humans are bad CO2 polluters. Perhaps the alarmists should all hold their breath until they stop polluting. That would attain one of their unstated goals: fewer humans on the planet.

  1. Reblogged this on Climatism and commented:
    “Children just aren’t going to know what [CO2] is”.
    Especially as they’re taught by their schools, the climate crisis industry, and a disturbing amount of mainstream media that CO2 is “pollution”.

  2. Back in the 90s my first genuine realization that this issue had gone totally political was when otherwise intelligent friends of mine started dismissing or denying any positive benefit to increased CO2 and even increased warmth. I would say, “You know it really sucks that we’re getting bumper crops from farther north than anyone can remember” and they’d say, “Yeah, that’s scary.” And I would say, “No that’s not scary, that’s awesome!” and they’d call me a denier. Cognitive distortions like “Dismissing the Positive” and “Catastrophization” are symptomatic of a wide range of psychological problems, but one of the root causes of these self-distorting perceptions will not found in the DSM: “Politically motivated belief.”

  3. Funny how the wording changes when something pleasant is found. Would they say “Overall our review suggests that …” if they had found something supportive of warmism – that there wasn’t a Medieval Period for example? No, they woulld say it was “a coup de grace” “with great clarity of evidence”. []

    • Mike Jonas, I think that’s because the first quote you cite is from the paper itself. The second quote is from a blog article or press commentary.
      To be fair, even climate alarmists (or at least senior academic alarmists) restrict themselves to making their outrageous ‘headline’ claims in the general public media because they know they often can’t get away with it in the specialised journals.
      It happens in other fields too. Someone may publish a result of minor importance in cancer research, their university press office then bigs it up, and the media then describes it as a “breakthrough” when many specialists in the field simply yawn and look the other way. Climate science is just worse than all the others.

  4. This is in keeping with NASA’s finding that the planet on the whole is greening, notably in the Sahel south of the Sahara and fringing arid regions around the rest of the world. The oceans, too, are showing more biological activity because of carbon dioxide increase over a period of 13 years that the satellite was operating (up to 2010)
    No one in the literature seems to have bit the bullet and projected an exponential sequestration of carbon with this development. That is to say, if plants are growing around the fringes of arid areas were it was barren before, established forests are showing increased growth, and plankton are increasing in the ocean, then there should be an exponential absorption in these old and new carbon sinks. Anyone??

    • All feedbacks must have negative consequences. and/or lead to higher temps and/or the release of more GHG’s. It’s in the Ten Climastrological Commandments.

      • “All feedbacks must have negative consequences”.
        My favorite “news” story in that category actually is CO2 fertilization story. My path to climate skepticism over the CO2 fertilization issue.
        My original training was as a biochemist, and way back in the early 90s, very soon after “global warming” became an alarmist issue, it occurred to me to wonder why the indisputable and hugely beneficial effects of CO2 fertilization were not being acknowledged in the media. Year after year I wondered and waited for an acknowledgment that never came.
        About 10 years on (about 2007) I FINALLY saw a CO2 fertilization story. However, as impossible as it seems, they actually did find a way to put a negative spin on CO2 fertlization. They realized that there is a plant that everybody hates. You guessed it: Poison Ivy! That was the “news” story. Here is a recent NYTimes recap of the 2006 results.
        According to solemn deep thinkers from the NYTimes, burning fossil fuels is bad because POISON IVY is going to grow faster! Amazing. For me that was the breaking point. If you can look at CO2 fertilization and notice only that Poison Ivy is growing faster, out of 200,000 plant species which are pretty much ALL growing faster, you are definitely not interested in anything resembling the truth.

      • Tom, I read an article in the mid to late 90’s that warned that weeds in general, but not crops or desirable plants or trees, would grow faster, basically choking farms in weeds.
        (BTW I also studied chemisry, but only after finding out that my first major and original degree goal, climatology, was not a natural science degrees, but a social science one. So all of the science and math classes I had taken were basically useless except as electives, and I would have to take a whole bunch of social science core classes. Then after they ended the interdisciplinary natural science degree program, I switched to the subject that I had the most classes in.)
        I already knew the global warming scare was BS the first time I heard it, as it contradicted nearly everything I had ever learned and studied about Earth history, physical chemistry, and meteorology. I was aware that the CO2 warming hypothesis had long been considered and rejected, that warm period s were the good times in human civilization, and that we were very likely in the final stages of the interglacial besides for everything else. So even if it was true, it was GOOD news, not bad.

  5. Wait! What if one of the oh-so-soon-to-be-frequent monster storms blows down all the newly enriched trees full of sequestered carbon? Don’t we have a Godzilla El Nino in progress and more surely on the way? I can easily picture a cataclysmic thunder storm following on its heels and igniting million acre tracts of dead blown down wood that send columns of dense, warm smoke swirling toward the North Pole. Polar bears will be doomed. Their decomposing corpses will produce giga tons of methane and the sighs of relief from all those seals and their oh-so-cute babies will surely increase the already deadly concentration of CO2. This is not good news. We’re doomed! How’s that for feedback?

      • Hmm, when you get that grant money I can do the modeling for you. Let me know what outcome you’re after so I can get started.

      • Yeah, he likely would get that grant Roy… but then all of us here in the reality blogosphere will have to shoot down the final writeup for ignoring that stronger trees and healthier forests have stronger and more “robust” root systems.

  6. Wow, trees are resilient and adaptable, who knew? Maybe that’s why they grow to be very tall and hundreds of years old, and, in the absence of chainsaws, can take over miles upon miles of the landscape.

  7. That’s really good news, but hardly surprising. It is consistent with my belief that the climate system must benefit from the equivalent of homeostasis to a large degree, otherwise we wouldn’t be here to worry about climate change.

  8. More good news for increasing CO2. What’s not to like about increased plant growth and increased plant tolerance of drought, a true greening of the earth?
    And maybe if we are very lucky, we will have longer growing seasons and a delay of the next glacial period. I’d much rather have a little warming if we can get it as opposed to catastrophic global cooling with the next glacial period that appears highly likely based on lots of paleo climate evidence. It’s just a matter of time.
    I wonder if anyone has determined how much warming might be added by albedo effects from the greening of the earth from more CO2? Plants absorb a lot more sunlight than deserts. In my view, a little warmer is better.

    • You would think that the UN would be on board with something that increases global agricultural productivity to help the feed the world, yet has no demonstrable adverse side effects. Isn’t this enough ‘transfer of wealth’? After all, we had to pay for the fossil fuels that put all this beneficial CO2 into the atmosphere.

      • Isn’t this enough ‘transfer of wealth’?
        The UN doesn’t count it as a transfer unless it is transferred by the UN. They will of course have to skim some of it….er, uhm, charge a commission….er, uhm, apply an administrative fee…. er, uhm….do all three. And a few more I didn’t think of. And if they get caught, they will promptly and in great detail, investigate themselves and exonerate the themselves.
        (Lest anyone mistake the above for sarcasm, it is not. It is barely contained anger and derision)

      • dbstealey
        January 18, 2016 at 6:51 pm
        Don’t you mean ‘transferred through the UN’?
        I think both work, but I think the UN are angling for the “by the UN” route. It would be a compulsory transfer at gunpoint once their “world government by unelected bureaucrats” comes to fruition.

    • The net effect from increased plant biomass is probably cooling, not warming. While plants absorb solar energy, a significant fraction is consumed to construct the biomass out of atmospheric CO2 and water. Deserts reflect more, but forests exhibit a much larger evaporative cooling effect from plant transpiration and surface water evaporation.
      The ground surface of a desert can get hot enough to fry an egg, but neither a forest canopy or the ground beneath it will ever get this warm. If it did, the plants would die.

      • “Pine forest vapors form small aerosol particles that may significantly cool the climate by reflecting the sun’s energy back into space, …” link

      • commieBob, you are correct…
        That is why the southernmost Appalachian Mountains have been called the “Smokies” (or the equivalent) since long before Columbus “discovered” the new world.

      • Another net effect of healthier trees which resist disease and insects more better, should be somewhat faster growth, even above that given by CO 2 fertilization alone. Faster growth, wider tree rings, mistaken dendroclimastrology conclusions…Oy!
        It is less worserer than we thunk.

  9. This will produce more biomass to power a converted Drax plant in the UK. I wonder why the Big Oil financed this study?

  10. Wow, this is an incredible paper. They systematically go through the major global warming bogeymen and without histrionics, eviscerate them one by one.

  11. But I thought the increase in CO2 – a trace gas already – cannot have an effect. You keep reporting that changing CO2 cannot have any affect on temperature. Weird!

    • You keep reporting that changing CO2 cannot have any affect on temperature.
      Sergei, can’t help wondering who you’re talking to here. The indentation indicates that you are addressing the author of the post, which would be Mr. Watts. I don’t recall that Anthony has ever made such a report; perhaps you could give a citation.

    • I and most of the other commenters believe the science which says doubling CO2 will raise the temperature .14 degrees Celsius or Kelvin. If our calculations are wrong then doubling CO2 would lead to a .55C increase. With the obvious feedbacks pretty close to bupkis.
      Here in 61108 we are at about 1C or 274.3K. Here we sorta WANT warmer winter nights.
      We like plants too. Within a short distance neighbors plant crops. Crops grow better with more CO2. CO2 increases drought resistance, greater pest tolerance and better disease resistance while raising growth rates .
      We like wealthy neighbors who spend money with us.

      • In 2014, Craig Loehle, one of the authors of the paper in this article, estimated the climate sensitivity as around 1.99°C, far more than the 0.14° or 0.55° you believe. The 2014 article was published by the Cato institute, hardly a global warming shill. The first climate sensitivity estimate ever (Arrhenius, 1896, well before anthropogenic climate change was a meme) was 4°C, also far higher than your estimates. So I wonder on what you base your extremely low climate sensitivity estimates?
        I live on the 60th parallel. A 2°C global warming amounts to 4-6°C regional warming in my area. Our national weather service already had to revise the definition of meteorological seasons to deal with years in which autumn otherwise never ends. What is now a comfortable snowy day will be a miserable rainy day. A December at this latitude without snow or ice is unbelievably dark and depressing.
        Plants growing better if they get more CO2 is but a silver lining in a very dark cloud.

    • Sergei,
      The paper claims that increased CO2 causes plants to grow better, and that higher temperatures do the same, but nothing about CO2 causing changes in temperature, or not that I can see.

    • Of course it does sergeiMK. That is why the UN should institute a global war on CO2 and sequester every gram of it in the ground. 20 ppm or bust!!!

    • 1) Only a few people here have ever claimed that CO2 can have no impact on temperature.
      2) The article above says nothing about CO2 and temperature, it talks about CO2 and plant growth.
      3) Are you really as dumb as you make yourself sound?

    • I think it is. Slowly. But it’s turning. The problem is the huge piles of taxpayer loot available to scientists who promote the ‘dangerous man-made global warming’ hoax.
      More than $1 billion is shoveled out in federal grants every year to ‘study climate change’. The U.S. alone has handed out more than $100 BILLION so far. Scientists skeptical of the scare don’t get those grants. And if they work for a university there is immense pressure to do whatever is necessary to secure part of that funding.
      See the article on Climatism to understand what’s behind this scam.

      • “Scientists skeptical of the scare don’t get those grants.”
        Yet we read of Idso that “the latter of which [urban CO2 concentrations] he investigated via a National Science Foundation grant as a faculty researcher in the Office of Climatology at Arizona State University.”
        It seems they do get the grants after all!

      • The last year this was properly accounted for (2013) the direct federal climate R&D was $2.4 billion, not $1. That does not include renewables subsidies, renewable R&D, …

      • Wow, one scientist, and that proves that there is no discrimination based on belief.
        You really don’t know how to think, do you.

      • Mark w. “You don’t know how to think, do you?” If you disgree with what I have said, why must you insult my thinking ability? That would be better justified if you had actually made a logical point, but you have not. I did not claim there was no discrimination based on belief. I proved that some scientists that do not subscribe to the global warming “alarmism” do get grants. This contradicts the claim that “Scientists skeptical of the scare don’t get those grants.”
        You could have said that this one case does not prove there is no discrimination based on beliefs, and I would have agreed with you. But no, you felt your point was so good it demonstrated that I cannot think.
        You, who accuse me of not being able to think, have just pointed out that my evidence does not show something I never claimed it to show. It is pretty clear that this does not demonstrate that I have a thinking problem.

      • seaice, since my post contains the answer to your question, I must conclude that your inability to think, (and read apparently) has been proven.

      • “seaice, since my post contains the answer to your question, I must conclude that your inability to think, (and read apparently) has been proven.”
        There was no question in my original post. The only question in my reply was asking why you insulted my thinking ability instead of pointing out any error you thought I had made. Since your responses do not answer this question you reply makes no sense. You merely said my evidence does not prove something I never said it did. The thinking problem appears to be yours.
        Please tell me which question and how your responses answer it.

  12. So you can’t understand how something might be good for trees and growth of plants without that thing changing temperatures? That must be difficult sergei.

  13. See the 1990s videos (1992,1998) The Greening of Planet Earth and the sequel, The Greening of
    Planet Earth continues. Both videos were inspired and based on Sherwood Idso’s work.
    who is Craig’s father.

  14. Are you kidding me? Every tree in Bew Jersey and the surrounding states is either dead or dying!! We receive pictures from people all over the country and the world of the dying trees! What kind of nonsense are you putting out here?
    [Bew Jersey? Did that blue wind blew new yew trees too? 8<) .mod]

      • @J. Philip
        It is, in fact, more densely populated than India. Something that I’m sure drives the Ehrlich crowd nuts, since “overpopulation” must lead to poverty in their view. New Jersey is #3 in median household income in the US, behind Maryland (overpaid bureaucrats) and Alaska (oil royalties).

    • Every tree in Bew Jersey …

      Bew Jersey is so tiny that it doesn’t appear on most maps. It doesn’t have much of a tree population.

    • Sharon LePere,
      If you read this site for a while you’ll see the other side of the story. It’s a fact that the U.S. has much more forest now than it did a century ago, and agricultural productivity is rising in lockstep with the rise in harmless, beneficial CO2.
      It’s clear you’re a victim of climate alarmism. This site is the remedy. There is always another side to issues like this. You just haven’t heard it yet.

    • Sharon,
      Ogden Nash is a great poet, but you mustn’t take him so seriously:
      I doubt if ever I shall see
      A billboard lovely as a tree.
      In fact, unless some billboards fall
      I’ll never see a tree at all.

    • Logging was so severe in New Hampshire that it led to an energy shortage. After “The Year without a Summer” and the “resolution” to the Indian problem, many people moved from our hardscrabble farms to the midwest.
      Today, New Hampshire is the second most forested state by percentage (Maine is #1) and the only signs of the deforestation are stone walls that used to divide pastures now run through the woods and some bare mountain tops where the soil was destroyed in fires in logging slash.
      Except for a pathogen affecting beech trees and the Woolly Adelgid, I haven’t seen many pictures from around here of dying trees. Well, not counting forestry and access roads for wind turbines….

    • No one suggested that CO2 makes trees immortal. Trees will always die, some sooner than others. What you are offering is anecdotal evidence to counter an overall study.
      I help manage 250 acres of ancient woodland (continuously wooded since before 1600) and renewal is a continuous cycle. The biggest damage in the last few years is the soil water content which makes alder, willow and poplar more viable than birch is some areas.

    • It is called winter Sharon. You must be from the south. Not to worry, the days grow longer even now, and when the rains of March give way to the warm breezes of April, all will be well in the forest, yet again.
      So it is written, so it shall be!

      • But in the meantime, bring in the kitten and break out your mittens…snows are a-comin’!
        Yepper, put on your flannels and turn on the weather channel, chills winds be brewin’.
        Fold up the linens and…oh, never mind…you get the idea.

    • Every single tree???? When you decide to exaggerate, you don’t hold back, do you.
      Let me see if I have this straight. People send you pictures of dying trees, and this proves that all trees are either dead or dying?
      No wonder you fall for the CO2 nonsense.

  15. Ed Begley Jr. advises us to only pay attention to peer reviewed articles by people with Phd after their name. Well, this paper by Drs. Loehle, Idso and Wigley would seem to qualify. Guessing Ed never reads it, though.

  16. Here I go again.
    I’m sure I have more in common with Craigs 1&2 than with sergei, but I don’t get this deification of CO2.
    It’s true that there’d be no life without it and Champagne would just be a geographic region, but I get the feeling that my fellow skeptics are all into homeopathy and think that there’s nothing that 2 ppm CO2 can’t do.
    Folks love to declare that greenhouse growers employ enhanced CO2, and that is true, to some extent, but they don’t just raise the level 60 ppm, which is 3 decades worth of natural increase. No, they try to get to 1500 ppm, which is around 400% of ambient, not 15%. More often than not, however, growers are just able to compensate for the depletion that occurs in an environment that is sealed off from the outside in order to minimize heat loss, money loss and profit loss. Most of the world’s hot-houses don’t attempt to supplement CO2 because it’s a minor consideration next to heat and moisture control.
    In a controlled environment with 3 or 4-fold enhancement of CO2 you can expect an increased yield of 15%. And I’m supposed to believe that we can isolate the contribution of (modestly) increased CO2 over “recent decades” to forest health and “greening” of deserts?

    • CO2 because it’s a minor consideration next to heat and moisture control”
      NO, CO2 is the MAJOR building block of ALL life on Earth. Get used to that FACT
      Plants grow far better at 1000ppm than at 400ppm, 220ppm they stop completely.

      • It is possible for both statements to be true. CO2 modification may be a minor consideration for commercial greenhouses, AND CO2 may be the major building block of all life on Earth (which of course it is). Getting used to your fact does nothing to contradict what mebbe said.

    • Since plants basically stop growing at 220ppm, this should be considered the baseline.
      A growth from 300ppm to 400ppm is MORE THAN DOUBLING the AVAILABLE CO2.

    • There was a study done somewhere on CO2 over a field on a calm day.
      iirc, CO2 started around 600ppm in the morning and once the sun hit, this was rapidly depleted to around 200ppm at midday, then growth stopped for the day.
      Photosynthesis is CO2 + H2O, + energy from sun or similar. All three are needed, and on this planet, CO2 has been the limiting factor in those places where water is available.
      Yes, the biosphere is expanding in response to increased CO2, and the planet can THANK humans for some small part of that.

    • mebbe-
      “but I don’t get this deification of CO2.” “but I get the feeling that my fellow skeptics are all into homeopathy and think that there’s nothing that 2 ppm CO2 can’t do.”
      Extremely assume much? 🙂

      • I’ve seen that before and I don’t find it convincing.
        About 60ppm increase in CO2 purportedly gives an 11% increase in foliage coverage if you believe that.
        However, it didn’t suddenly increase from 240ppm to 400, it happened incrementally, 2ppm per year, so you can either contrast two points in time or come up with a series of observations that progress and correlate. They, of course, used a computer model.

    • Mebbe, it isn’t deification of CO2 that’s the problem, it’s demonization.
      May I suggest that you check out and also that you note this quote:
      “For the majority of greenhouse crops, net photosynthesis increases as CO2 levels increase from 340–1,000 ppm (parts per million). Most crops show that for any given level of photosynthetically active radiation (PAR), increasing the CO2 level to 1,000 ppm will increase the photosynthesis by about 50% over ambient CO2 levels. For some crops the economics may not warrant supplementing to 1,000 ppm CO2 at low light levels. For others such as tulips, and Easter lilies, no response has been observed.”

      • Monna Manhas,
        I agree that demonization of CO2 is the BIG problem and deification is not even its little sister but I still find the claims made for small increases in CO2 extravagant.
        Trees are particularly difficult to evaluate as they have lifespans longer than humans and just keep on growing year by year at all real concentrations of CO2. Mann and Briffa think all variability is because of warmth.

    • mebbe,
      “In a controlled environment with 3 or 4-fold enhancement of CO2 you can expect an increased yield of 15%. And I’m supposed to believe that we can isolate the contribution of (modestly) increased CO2 over “recent decades” to forest health and “greening” of deserts?”
      No, you’re just supposed to stop telling yourself it’s impossible, long enough to do some wondering about how it might be true, it seems to me.
      For one thing, it may be that CO2 is a limiting factor in a forest setting because all those trees in a forest are extracting it, and the actual availability is not nearly at 400ppm much of time while the light is suitable for efficient photosynthesis. .The trees might be starving for CO2 at times, and so growi8ng below their potential optimum, and we are simply seeing the results of alleviating that intermittent starvation to some degree.

      • JohnKnight January 19, 2016 at 2:20 pm
        I’m not sure why you conclude that I’ve given this no consideration, but you have, however, that’s not an unfamiliar assumption.
        As far as your hypothetical situation goes, I would say that, even if it were the case, then it would also have been the case at 340ppm. Unless, of course, some tipping point had been reached in the interim, but that would warrant a great deal of fanfare.
        I have lived and worked in the forests of BC for decades and do not think at all that the steady increase in CO2 is anything but beneficial to all plants, in as much as growth is concerned. When it comes to this nebulous “forest health” (for which there is no SI unit) I am less than convinced. I do not, for example, think it likely that the forests of today are somehow “healthier” than in 1902 simply because there’s more CO2.

      • mebe,
        “I’m not sure why you conclude that I’ve given this no consideration, but you have, however, that’s not an unfamiliar assumption.”
        I conclude no such thing, I merely responded to what you said/asked;
        “And I’m supposed to believe that we can isolate the contribution of (modestly) increased CO2 over “recent decades” to forest health and “greening” of deserts?”
        Not “expected to believe”, I don’t think, but to consider . . Get it?
        “As far as your hypothetical situation goes, I would say that, even if it were the case, then it would also have been the case at 340ppm.”
        Right, and might still be the case at 450ppm . . it’s a matter of the CO2 being a limiting factor to a whole bunch of plants competing for it, basically. More CO2, more/bigger plants using it up . .

  17. Can someone point me to the “health” of the trees being sent to the UK for Drax wood fired power station.
    I really CANNOT UNDERSTAND how the Greenies in the USA could possibly let that happen !!!!
    Is there a vast amount of money, or something, being paid to them to ignore this ?

    • Andy, like all pagan religions they don’t mind if the high priests making sacrifices to their gods. Just don’t let them catch you doing it.

    • Andy,
      The eastern provinces of Canada import oil from holes in the desert thousands of miles away.
      Your steak dinner did not come from your backyard, and neither did the avocado in your guacamole.
      When you flush, it doesn’t all wind up on your lawn.
      The world is a complicated place.

      • And seriously, how do you keep coming up with such a load of incoherent rubbish.
        If you can’t see the idiocy and utter HYPOCRISY of cutting down forests in the USA to ship to burn in UK power stations, you have some serious rationality and common sense issues.
        But we have all noticed that, many times.

      • Can you explain the hypocrisy please? I can see problems with all biofuels competing with food production, but I don’t see hypocrisy in using crops for energy in principle.

      • Actually, as I am way out in the country on a septic tank and drain field, it does all end up on my front (side actually at my place) yard. The grass is quite green from all the extra fertilizer too.
        Of course in the long view of the water cycle you could say the water winds up back in the oceans since it evaporated through the grass’ transpiration and is whisked away on the winds (or at least the water part).

    • “I really CANNOT UNDERSTAND how the Greenies in the USA could possibly let that happen !!!!”
      Because shipping them “coal” would be evil? LOLOL 🙂

    • As long as they are using plantation trees and not old growth, there is nothing wrong with this in principle. These trees are planted specifically for fast growth so they can be cut down and used, just like any other crop. There is not much difference between paper pulp or burning from an ecological perspective. There are lots of factors to consider, but the principle is fine with me.

      • They are not using plantation trees (usually SYP) grown for pulp, saw timber, and peeler blocks. They are clearcutting swampy hardwood bottomlands and pelletizing the whole tree rather than just the slash/crowns. Google images. Disaster for wildlife, and will take a hundred years to recover.

      • Not what they say. They claim “Drax and its suppliers use trees from thinnings, tree tops, limbs and other low grade wood together with sawmill residues to make pellets.” There are some whole trees that cannot be used for higher value products such as structural timber.
        This is interesting as it is the “eco groups” that claim there is ecological harm and “big power” that says it is not. What is pretty clear is that pellets are low value compared to timber, so there is no incentive for forresters to divert good wood to pellet production. Trees that can be used for high value purposes will not be used for pellets.

      • I live in British Columbia and we cut down a lot of trees, process them and send them across the world.
        Many of them are used as building materials and many are used for newsprint and other ephemeral applications.
        I find it astonishing that the Drax conversion happened and I don’t think for a minute that it would have without the AGW hysteria, but I burn wood for heat and so do my neighbours. Our woodlands are ‘managed forests’, not plantations per se, and we typically clear-cut many acres at a go. It all has an effect on wildlife. So do cities, mines, agriculture, highways etc.

      • The processing and shipping must bite into the net energy produced by the pellets. Shipping from the forest to the mills, then to a port, then across 3600 mile ocean, thenfrom port to DRAX.
        Sounds ridiculous to this kid.
        If burning pellets is such s good dealio, why not burn them here? Maybe to power the mills?

      • Menicholas,
        Every sawmill in this province, large or small, had a distinctive bee-hive burner for the waste but they were outlawed years ago. Regulations compelled chipping slabs and edgings and selling for pulp.
        Pulpmills often are powered, at least in part, by hog fuel. I don’t know the economics of pelletizing; pellets are certainly amenable to automated feeds.
        Quite a bit of the waste wood energy most be lost driving out the moisture, but it’s still worthwhile if it’s local.

  18. Denser forests due to CO2 increase atmospheric H2O, the most potent GHG, and also kill Spotted Owls that can no longer fly effectively through the forests to catch ground dwelling rodents. How ironic, the decrease in Spotted Owls is due to CO2. LOL

    • “Denser forests due to CO2 increase atmospheric H2O, the most potent GHG, and also kill Spotted Owls that can no longer fly effectively through the forests to catch ground dwelling rodents. How ironic, the decrease in Spotted Owls is due to CO2. LOL”
      I’m calling bullcrap on this one. Sorry. 🙂 It has nothing to do with increased CO2 nor do denser forests kill spotted owls.
      Spotted Owls love old growth forests. The tree cover is higher (for flying) and the fallen logs and plants provide ample places for mice and snakes and other critters to breed-which they eat. Those old growth forests are being destroyed “due to agriculture, industrial development, urban sprawl. These are all factors that have contributed to the extensive loss and fragmentation of prime wildlife habitat”

      • Which leads to the rise of the bar owl which is a genetically identical pattern shift of the spotted owl to hunt the open places from the cuts. Turns out the spotted owl also likes the suburban environment where nesting in billboards and hunting in yards is a good alternative.

  19. Tom Bombadil reports that the trees are thriving in his beloved valley of the Withywindle. He says “”Hey dol! merry dol! ring a dong dillo! Ring a dong! hop along! fal lal the willow! Tom Bom, jolly Tom, Tom Bombadillo!”
    Tom reports that the Ents are also thriving.
    All is well in Middle Earth.

    • Many of the younger readers here wouldn’t know who Tom Bombadil was, as he was written out of the movies 🙂

      • You take that back tobyglyn and wash your mouth out with soap! (or your hands off with acid…lol) ALL of my young readers” read the book(s) too. Don’t assume that ANY of the readers here base their knowledge of Tolkien only on stuff that has the name “Jackson” attached to it. Dishonor on you and your family! 🙂

  20. From the paper: ” No clear trend has been reported for pathogen or insect damage but experiments suggest that in many cases rising CO2 enhances plant resistance to both agents.”
    Hmmm, I guess pine beetles didn’t get the memo. They’ve devastated tens of millions of acres of pine trees across the US and Canada. In British Columbia alone, 44 millions acres have been affected, an area the size of Missouri.

    • “Hmmm, I guess pine beetles didn’t get the memo.”
      But the conclusions shouldn’t be that CO2 is not a help to them, but rather that some other agent has counter-acted it, like too little precipitation, which makes it hard for trees to produce enoungh insect-killing sap.

      • Higher CO2 means lower nighttime temperatures, and in winter this is important as it takes very cold temps to keep the populations in check. Increased drought, due to a mixture of AGW and natural causes, weakens the trees. And lack of forest fires which have wiped out the beetles in burn areas is also a factor. It is a combination of all of these.

      • There is no trend to more droughtiness in the US. In fact, the opposite is the case, as documented by Tony Heller on his blog.
        And as far as I know, data shows a slight increase in night temps over time, but who can say if this is real or due to adjustments.
        And there is no trend towards less cold weather anywhere.
        The citrus industry in Florida, and agricultural interest in many other states, means that a very long and detailed history of cold weather in the south has been kept.
        Last year was about the coldest on record in the Eastern US, and in other years in the recent past there have been intrusions of Arctic air far to the south in the Western States…including this year.
        Even if one takes it as true that the data sets which show the most warming, the amount is tiny…less than a degree C.
        So, what lack of cold air and/or increases in drought might be being referred to here?

    • Pine beetles are a problem wherever pine forest density is allowed to get to high. The fact that undergrowth management and thinning operations have not occurred in our forests is leading to two major things: rampant spread of pathogens and wildfires growing huge and out of control at the drop of a thunderstorm. This is a forest management problem not a CO2 problem.

    • Pine beetles are a natural part of the forest. The rampant infestation of a decade ago was the result of decades of fire suppression and the utter refusal of environmentalists to allow controlled burns or selective falling of trees in “old growth” forests. “Old growth” forests are dying forests, and the beetles just love them.
      Best forest management practices include allowing the forest to burn as long as it doesn’t endanger people or their property. But many environmentalists live in large cities and have no idea of what the real world is like.

    • Perhaps the damage would be even worse if not for the CO2 fertilization and concurrent increased resistance to attack.
      I try to eat healthfully and stay fit, but that does not prevent mosquitos from biting me, an occasional wasp sting, a very occasional cold, or any other ailment gonibg around. But I think it helps me keep those things from laying me low.

    • Chris
      Any idea when and why this beetle evolved to eat pine trees?
      At what point did humans involve themselves in this evolutionary track?
      Why is it, in some areas, after the beetle attack, only 10% of trees are affected?

  21. The United Nations International Panel on Plant Growth (UNIPPG) is soliciting proposals to determine:
    1. whether man has influenced that growth
    2. has there been a fair distribution of that growth
    3. have native species been given priority preference for that growth.
    If the proposers have early evidence, the design committee is welcoming precautionary principle suggestions for how to ameliorate the above problem and asks the applicants to consider a sliding scale, cost weighted approach considering the average GDP per nation.

  22. It keeps the foamy head on top of a pint of good beer and makes trees grow bigger, stronger and healthier.
    What’s not to like?

  23. Authors of papers: Loehle, Idso, and Wigley; they (probably) are have been too “cautious” conclusions.
    These are similar, but more clear – evident:
    … eg for U.S.:
    “The total carbon sequestration by the LULUCF sector has increased by about 14% since 1990…”
    … tropic:
    “A new NASA-led study shows that tropical forests may be absorbing far more carbon dioxide than many scientists thought, in response to rising atmospheric levels of the greenhouse gas.”
    … Sahel:
    “Over the past decades the Sahel has often been portrayed as a region undergoing desertification; thus as a region plagued by recurring droughts and widespread land degradation, with severe famine as the outcome. Recent analysis of satellite data suggests, however, that this view of the Sahel may not be accurate. I n contrast, and to the surprise of many scientists and policy-makers, these studies reveal that large areas of the Sahel have in fact become increasingly green over the past 20 years.”
    Dardel et al., 2014., Re-greening Sahel: 30 years of remote sensing data … : “Trends are found positive and statistically significant almost everywhere in Sahel over the 1981–2011 period.”

  24. Since continental land masses are not evenly distributed throughout the globe won’t those extra, and extra large, growing trees add enough extra mass to disrupt the delicate balancing of our planet as it spins and wobbles its way around the sun? Won’t CO2 turn those trees into demonic menaces, disrupting the day/night cycles, the seasons,

  25. 4. CO2 is the feedstock for carbon-based life on Earth, and Earth’s atmosphere and oceans are clearly CO2-deficient. CO2 abatement and sequestration schemes are nonsense.
    Observations and Conclusions:
    1. Temperature, among other factors, drives atmospheric CO2 much more than CO2 drives temperature. The rate of change dCO2/dt is closely correlated with temperature and thus atmospheric CO2 LAGS temperature by ~9 months in the modern data record
    2. CO2 also lags temperature by ~~800 years in the ice core record, on a longer time scale.
    3. Atmospheric CO2 lags temperature at all measured time scales.
    4. CO2 is the feedstock for carbon-based life on Earth, and Earth’s atmosphere and oceans are clearly CO2-deficient. CO2 abatement and sequestration schemes are nonsense.
    5. Based on the evidence, Earth’s climate is insensitive to increased atmospheric CO2 – there is no global warming crisis.
    6. Recent global warming was natural and irregularly cyclical – the next climate phase following the ~20 year pause will probably be global cooling, starting by ~2020 or sooner.
    7. Adaptation is clearly the best approach to deal with the moderate global warming and cooling experienced in recent centuries.
    8. Cool and cold weather kills many more people than warm or hot weather, even in warm climates. There are about 100,000 Excess Winter Deaths every year in the USA and about 10,000 in Canada.
    9. Green energy schemes have needlessly driven up energy costs, reduced electrical grid reliability and contributed to increased winter mortality, which especially targets the elderly and the poor.
    10. Cheap, abundant, reliable energy is the lifeblood of modern society. When politicians fool with energy systems, real people suffer and die. That is the tragic legacy of false global warming alarmism.
    Allan MacRae, Calgary, June 12, 2015

    • “3. Atmospheric CO2 lags temperature at all measured time scales.”
      Wrong. CO2atm/ppm goes down in Summer and increases in Winter. You know that and you know why. That phenomenon could as easily be said that CO2 leads temps. Both statements by themselves are equally wrong.

      • Marcus, what does that have to do with CO2/temp relationship on an annual time scale? Read what I said.

      • My statement should have read: …”Northern Hemisphere” Summer… and Winter. PIMF. Perhaps that caused confusion.
        There is a clear correlation between CO2 on an annual basis and the action of the NH biosphere.
        @ Original Mike: Do you disagree?
        Ps I’d be happier if people stopped using “Ummm…” It’s too cutesy by at least, an order of magnitude.

      • Alan Robertson wrote January 19, 2016 at 4:07 am
        “3. Atmospheric CO2 lags temperature at all measured time scales.”
        Wrong. CO2atm/ppm goes down in Summer and increases in Winter. You know that and you know why. That phenomenon could as easily be said that CO2 leads temps. Both statements by themselves are equally wrong.
        Allan MacRae says:
        Nonsense Alan R. See my 2008 paper on icecap or this plot:
        BTW, the seasonal CO2 “sawtooth” that you reference also lags NH temperature and is driven by it.
        Regards, Allan

      • Alan Robertson:
        You assert

        CO2atm/ppm goes down in Summer and increases in Winter. You know that and you know why. That phenomenon could as easily be said that CO2 leads temps. Both statements by themselves are equally wrong.

        Sorry, but changes to atmospheric CO2 concentration follow changes to global temperature by months. This was first determined by Kuo et al. in 1990, and several subsequent studies have confirmed it while revealing that the length of the lag increases with distance from the equator.
        The seminal paper was Kuo C, Lindberg C & Thomson CJ, ‘Coherence established between atmospheric carbon dioxide and global temperature’, Nature 343, 709 – 714 (1990). It analysed Mauna Loa CO2 time series and its Abstract says

        The hypothesis that the increase in atmospheric carbon dioxide is related to observable changes in the climate is tested using modern methods of time-series analysis. The results confirm that average global temperature is increasing, and that temperature and atmospheric carbon dioxide are significantly correlated over the past thirty years. Changes in carbon dioxide content lag those in temperature by five months.


  26. Thoughts from 2009… …seem to be gaining popularity.
    Best to all, Allan
    (Plant) Food for Thought (apologies – written too late at night)
    1. “As CO2 is a critical component of growth, plants in environments with inadequate CO2 levels – below 200 ppm – will cease to grow or produce.”'s_atmosphere
    2. “The longest ice core record comes from East Antarctica, where ice has been sampled to an age of 800 kyr BP (Before Present). During this time, the atmospheric carbon dioxide concentration has varied by volume between 180 – 210 ppm during ice ages, increasing to 280 – 300 ppm during warmer interglacials…
    … On longer timescales, various proxy measurements have been used to attempt to determine atmospheric carbon dioxide levels millions of years in the past. These include boron and carbon isotope ratios in certain types of marine sediments, and the number of stomata observed on fossil plant leaves. While these measurements give much less precise estimates of carbon dioxide concentration than ice cores, there is evidence for very high CO2 volume concentrations between 200 and 150 myr BP of over 3,000 ppm and between 600 and 400 myr BP of over 6,000 ppm.”
    Questions and meanderings:
    According to para.1 above:
    During Ice ages, does almost all plant life die out as a result of some combination of lower temperatures and CO2 levels that fell below 200ppm (para. 2 above)? If not, why not?
    Does this (possible) loss of plant life have anything to do with rebounding of atmospheric CO2 levels as the world exits the Ice Age (in combination with other factors such as ocean exsolution)? Could this contribute to the observed asymmetry?
    When all life on Earth comes to an end, will it be because CO2 permanently falls below 200ppm as it is permanently sequestered in carbonate rocks, hydrocarbons, coals, etc.?
    Since life on Earth is likely to end due to a lack of CO2, should we be paying energy companies to burn fossil fuels to increase atmospheric CO2, instead of fining them due to the false belief that they cause global warming?
    Could T.S. Eliot have been thinking about CO2 starvation when he wrote:
    “This is the way the world ends
    Not with a bang but a whimper.”
    Regards, Allan 🙂

    • Updating to 2015: See points 9 to 12 below:
      This is the dCO2/dt vs. temperature relationship I was referring to above. See my 2008 paper at:
      or this plot:
      There are several observations about this striking dCO2/dt vs. temperature relationship:
      1. The dCO2/dt vs. temperature correlation is remarkably strong for a natural global phenomenon.
      2. The integral (of dCO2/dt) is atmospheric CO2, and it LAGS temperature by about 9 months in the modern data record. CO2 also LAGS temperature by about 800 years in the ice core record. Thus CO2 LAGS temperature at all measured time scales. Thus the global warming hypothesis assumes that the future is causing the past. Thus the CAGW hypothesis fails.
      3. This close dCO2/dt vs temperature relationship indicates that temperature drives CO2 much more than CO2 drives temperature.
      4. The dCO2/dt vs. temperature correlation is the only detailed signal I have found in the data – there is NO evidence that CO2 LEADS temperature or that increasing atmospheric CO2 significantly increases global temperature.
      5. Furthermore, global temperature declined from ~1940-1975, increased from ~1975-2000, and has stayed flat (or cooled slightly) since ~2000, all while atmospheric CO2 increased; so the correlation of temperature to increasing atmospheric CO2 has been NEGATIVE, Positive, and Near-Zero. I suggest Near-Zero is the correct estimate of the sensitivity (ECS) of global temperature to increasing atmospheric CO2. There is and never had been a manmade global warming crisis – there is no credible evidence to support this failed hypothesis.
      6. With few exceptions including some on this blog, nobody (especially the global warming alarmists) wants to acknowledge the LAG of CO2 after temperature – apparently this LAG of CO2 after temperature contradicts deeply-held beliefs about global warming dogma.
      7. While basic physics may suggest that CO2 is a greenhouse gas, the overwhelming observational evidence indicates that the impact of increasing CO2 on global temperature is so small as to be insignificant.
      8. In summary, observational evidence strongly indicates that the manmade global warming crisis does not exist.
      9. Finally, atmospheric CO2 is not alarmingly high; in fact, it is dangerously low for the survival of terrestrial carbon-based life on Earth. Plants evolved with about 2000ppm CO2 in the atmosphere, or about 5 times current CO2 concentrations.
      10. In one of the next global Ice Ages, atmospheric CO2 will approach about 150ppm, a concentration at which terrestrial photosynthesis will slow and cease – and that will be the extinction event for all terrestrial life on this planet.
      11. More atmospheric CO2 is highly beneficial to all carbon-based life on Earth. Therefore, CO2 abatement and sequestrations schemes are nonsense.
      12. As a devoted fan of carbon-based life on this planet, I feel the duty to advocate on our behalf. I should point out that I am not prejudiced against other life forms. They might be very nice, but I do not know any of them well enough to form an opinion. 🙂
      Regards to all, Merry Christmas, Happy Holidays!
      – Allan

      • Thanks Allan, I have long thought that we came pretty close to going out during last glacial. Before we had even evolved. As the glacials seem to get colder and lower in C02 each time, I guess the next one will be the end. I read a comment in a paper yesterday. It was “we should all die now and give the earth a chance.” How many years has it taken to get to this level of intelligence?

      • Hi Eve,
        The problem is that ALL terrestrial carbon-based life will end when atmospheric CO2 drops below about 150ppm. Not just the human species – but all terrestrial species.
        Every kingdom, phylum, class, order, family, genus, and species on Earth, with the exception of freshwater and sea creatures.
        Maybe not during this next ice age, but one after that – in any case, the blink of an eye in geologic time.
        Unless, of course, we get a lot smarter and recognize that the problem is not too much atmospheric CO2 but too little, and decide to do something about it. And what are the odds of that, with the crop of leaders we have now?
        So we will give the Earth to non-carbon based species – I understand there are some out there, but they are likely to take billions of years to evolve into someone you can converse with – if ever.
        If that is “giving Mother Earth a chance”, she might prefer carbon-based life forms after all.
        My best to you and Adam, Allan 🙂

  27. Hold on there just a second. We all know that CO2 is a pollutant. Therefore, these trees are polluted trees! Let’s chop’em all down.

  28. Most of the USA’s virgin forest was gone before 1920.
    Before coal became widely used we had clear cut vast areas of hardwood forest such as in Pennsylvania.
    Johnsonburg PA in 1895 versus now
    I keep saying over and over – switching from wood to coal as fuel, (and from wood to steel and/or concrete for large structures) is what saved our forests! Now it is additionally clear that burning coal is also good for our forests.

    • Agree Mike – all good points.
      We can lend you some forest of you feel the need – we have over 300 million hectares (750 million acres) of boreal forest in Canada. That is about 1000 km north-south and about 6000 km east-west. But it appears you have some left in Maine and a lot more in the US Northwest and Alaska – a total of about one billion acres of forest between Canada and the USA. 🙂
      What amazes me is the cutting and pelletizing of forests in the USA and Canada to fuel power plants in Europe. Apparently it replaces coal. This is enviro-lunacy – the result when scoundrels and imbeciles take over government policy.
      Best, Allan
      Worldwide, the boreal zone covers:
      •1.9 billion hectares
      •14% of Earth’s land
      •33% of Earth’s forested area
      Canada has:
      •28% of the world’s boreal zone – that’s 552 million hectares
      •75% of all of its forests and woodlands in the boreal zone – that’s 307 million hectares in total

  29. “Future prospects for forests are not clear because DIFFERENT MODELS PRODUCE DIVERGENT FORECASTS.”
    So they’ve noticed that too, eh?

  30. Ristvan @7:06AM
    Your number is incorrect.
    Federal Climate Change Expenditures Report To Congress August 2013.
    20,408,000,000. This includes tax provisions and payments in lieu of tax provisions.

  31. CO2 is very good for trees and all vegetation. It makes vegetation less reliant on water and grow faster. CO2 inhibits forest pests and pathogens. Good vegetation is good for us too.
    The idea that CO2 is a danger or a pollutant is inverse nonsense. Rising temperature cause more CO2 not the other way around. Slowly the fog of deception is dispersing.

  32. As a consulting forester in my own business I help private landowners manage their forest land. Most forest land needs improvement cuttings – removing trees with poor stem quality and/or wispy live crowns which produce little diameter growth while retaining those trees with good stem quality and superior live crowns which can produce good diameter growth. Good forestry can double the growth rate of the more desirable trees by increasing the spacing between crop trees.
    Many studies have shown the increase in CO2 has had a significant positive impact on the growth rates of our forests, but most of them always claim other greater negative effects like an increase in droughts which has never been proven. The real threat to our forests is not climate change but non-native insects such as the hemlock wooly adelgid, the emerald ash borer, and the Asian longhorned beetle and non-native invasive plants such as oriental bittersweet, Japanese barberry, and multiflora rose. It would be far better for the environment if funds and subsidies from the many climate studies and renewable energy schemes like wind & solar were instead directed to eradicating these real threats to our forests.

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