Southwest forest trees will grow much slower in the 21st century

From Eurekalert

Public Release: 18-Dec-2018

Even forest trees growing in average conditions may decline in productivity as much as 75 percent

University of Arizona188916_web

A treasure trove of data about tree growth in the US West was found in these boxes, each of which contained 500 to 800 cores from individual forest trees. The cores are from the U.S. Forest Service Forest Inventory and Analysis program. Once measured and analyzed, the annual growth rings in these cores revealed that the growth rate of trees in Southwest forest may decline as much as 75 percent by 2100.Credit John D. Shaw, US Forest Service

Southwest forests may decline in productivity on average as much as 75 percent over the 21st century as climate warms, according to new research published on Dec. 17.

The new estimate is better than previous ones because it is based on a new database of information on the growth of trees under average conditions, according to the research team. Previous estimates were based on a database that included many trees growing in marginal conditions.

The finding is based on a treasure trove of about 20,000 unanalyzed tree cores discovered in a Utah laboratory about a decade ago. The annual growth rings visible in tree cores reflect each year’s climatic conditions.

The new tree-core samples are more representative of the forest as a whole than many of those collected and analyzed earlier, said first author Stefan Klesse, who conducted the analysis while a postdoctoral researcher at the UA Laboratory of Tree-Ring Research.

Senior author Margaret Evans said the spatial representation in the new data set from the U.S. Forest Service Forest Inventory and Analysis program is “unprecedented.” She calls the trees in the new data set that are living under average growing conditions “Joe Schmoe trees.”

“The Joe Schmoe trees will experience a 75 percent reduction in growth and the trees on the edge–according to our analysis–are pretty much doomed,” said Evans, an assistant professor in the UA Laboratory of Tree-Ring Research.

The database previously available to researchers is the International Tree-Ring Data Bank, or ITRDB, which included samples from many trees that were growing under marginal conditions — what Evans characterized as “on the edge.”

When the trees in the ITRDB were initially sampled, which was often decades ago, researchers chose trees living in marginal conditions because those trees were most sensitive to climate variation and thus best suited to reveal how climate varied over the past centuries.

Tree-ring researchers have long known the ITRDB samples might overestimate the effect of climate on average trees, but had no other data to use until now. And, even though the trees in the ITRDB may provide an overestimate of how the average forest tree will respond to the change in climate in the 21st century, that information is still valuable, Evans said.

“Those trees are the canaries in the coal mine — the edge of the forest is where we’re going to see the change first,” she said.

The research paper by Klesse, Evans and their co-authors, “Sampling bias overestimates climate change impacts on forest growth in the southwestern United States” was published in Nature Communications on Dec. 17. A list of co-authors is at the bottom of this release.

The U.S. Department of Agriculture, the U.S. Environmental Protection Agency and the Navajo Nation funded the research.

The new collection of Forest Inventory and Analysis tree cores turned up when scientists at the U.S. Forest Service Rocky Mountain Research Station in Ogden, Utah, were moving from one building to another. The researchers were surprised to find a bunch of dusty boxes filled with tree cores that had never been analyzed.

The cores had been systematically collected from trees throughout the eight interior states of the U.S. West during the 1980s and 1990s. The cores reflected the growth of individual trees going back to the 1920s and some even earlier.

Co-authors R. Justin DeRose and John Shaw of the U.S. Forest Service Rocky Mountain Research Station began the painstaking job of measuring annual growth rings from the approximately 20,000 cores, each from a specific tree. The two scientists enlisted Evans and sent her about 2,000 cores from Arizona trees. Her research team, which included eight UA undergraduates, began cataloging those cores and recording the data from them in 2015.

The researchers wondered what the new tree-ring records might reveal about how climate change would affect the growth of forest trees of the Southwest in the latter half of the 21st century. To figure that out, they focused on records from common pinyon pine, Douglas fir and ponderosa pine from Utah, Colorado, Arizona and New Mexico.

Klesse, who is now a postdoctoral researcher at the Swiss Federal Research Institute WSL in Zurich, compared information from the newly analyzed cores from “Joe Schmoe” trees, plus additional tree-ring growth records from 858 trees in Arizona and New Mexico, with the records in the ITRDB.

For projections of the region’s precipitation and temperature in the 21st century, he used climate projections from one of the most current climate models, CMIP5 (Coupled Model Intercomparison Project Phase 5).

His analysis revealed that growth of the ordinary forest trees would not be reduced as much under climate change as the trees whose records are included in the ITRDB.

Even so, he said, “As the climate warms, tree growth will decline.”

Evans said, “The trees have to take whatever they get in terms of climate conditions. When the temperatures rise they have to cope with it — or not.”

She and Klesse are expanding their research to include data from 30,000 cores collected from Douglas fir trees spanning the continent from Mexico to Canada.

###

Other co-authors are Christopher Guiterman of the UA; Ann Lynch of the U.S. Forest Service and the UA; and Christopher O’Connor of the U.S. Forest Service Rocky Mountain Research Station in Missoula, Montana.

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87 thoughts on “Southwest forest trees will grow much slower in the 21st century

  1. finding is based on a treasure trove of about 20,000 unanalyzed tree cores discovered in a Utah laboratory about a decade ago None of which reflect the growing benefits of the now higher CO2 levels. I missed the explanation of the root cause of the dire future growing conditions. It can’t be temperature since we’re cooler than the Holocene Optimum, which was far beyond the scope of this ‘study’.

    • It is well known that trees possess an “intelligence” telling them in advance whether to expect a warm winter or a dry summer. We just never discovered that it applies to decades, not just the next year. It is good to know that trees are more intelligent that many researchers.

    • “I missed the explanation of the root cause of the dire future growing conditions.”

      I missed it, too, and I read the whole thing. Something about climate change, which doesn’t really convey much information.

      I know tropical species of trees have a hard time in colder climates, but I would think species used to a colder climates would do better in a warmer climate not worse. I suppose there are some who couldn’t adapt.

      Of course, that’s assuming CAGW is real, but we haven’t had any evidence for that yet, so all these studies based on CAGW being real are just pure speculation, just like CAGW.

      • Depends: Yellowstone forests suffer worse pest attacks in summer if winters are not cold enough to kill off enough pests. Apple trees also fruit better in summer with goodly doses of winter frost, which is more relevant in maritime UK than it would in the interior of the US.

        Some seeds also germinate best after periods of cold, just as some cones only release seeds from cones in response to fire/extreme heat.

        Nature does not always have linear graphs.

      • All plants have an optimum temperature at which they grow the best.
        Above or below that temperature, and growth slows.

        • Mark, and that is further varied by such factors as CO2 levels, rainfall and cloud cover before you get to soil nutrients, insects and disease eta.

        • Mark, forgot to mention the various published studies which found that trees are able to control their leaf temperature to optimise photosynthesis.

    • Those future growing conditions were based on ….

      “For projections of the region’s precipitation and temperature in the 21st century, he used climate projections from one of the most current climate models, CMIP5”

      Once again, nothing but climate gaming.

        • Isn’t this research just more fruit from a poisoned tree where the poisoned tree is the climate model temperature projection?

    • Why can’t it be temperature, even if it’s cooler now than in the past? And why do you put “study” in quotation marks?

      High temperature and low precipitation could easily stunt tree growth.

      The CO2 levels have been increasing for many decades, not just in the past 10 years. Looks like it didn’t offset growth, though. Gee, hard to fathom – the idea that CO2 is good for all vegetation and therefore for the world might have limited application. Can’t be right – that would support the research! I mean, gee, if they are called greenhouse gases, plants must behave like they’re grown in a greenhouse!

    • This is the same decline in growth rate which caused Mann et al so much trouble. Mann’s problem signaled that there was something wrong with their interpretation of tree rings and this is probably what is behind the present finding. Whatever the cause, it almost certainly isn’t global warming.

    • All roads lead to doomsday. All change is bad. 97% of all doomsayers agree, so they can’t possibly be wrong.

    • Dipchip,

      Well, you can be certain if they did, they’d burn all evidence of it. Erase their emails, throw their computers in a river, and cut out the tongues of the researchers. We all know that the truth can’t come out. It’s science, after all, a swamp infested by corruption, fraud and global conspiracy. Because of all the scientists who rake in billions by fooling people that is’ going to get warmer. Disgusting seeing them in their Porsches and 10,000 sq ft houses, professors swaggering around in Armani suits with 20 karat diamond cuff links.

  2. That is contrary to everything observed in the explosive encroachment of pinon pine and western juniper on southwest deserts over the last 40 years. Trees are c3 plants and they benefit greatly from increases in atmospheric CO2. If you want to look at a real scientific study of growth ring variability being positively affected by increased atmospheric CO2 – check this out:

    http://libres.uncg.edu/ir/uncg/f/P_Knapp_Post_2001.pdf

    • It would seem to me that if one was interested in determining the effects of seasonal changes on the trees surviving in the fringes of the “habitable zones” one merely needs aerial photographic evidence on the size of these marginal forests and compare them for acreage changes.

    • The trees that are now there are growing more slowly than the trees that weren’t there before! It’s easy once you put on your Green goggles and bang your head on a tree a few times.
      Somehow I just know that this is about 100% offside with the entire bullshit career of Mikey Mann and his tree rings.

    • William Abbott,

      C3 plants benefit from increased CO2 sometimes. Depends on what’s limiting growth.

      A “real” scientific study, huh? Maybe, but that doesn’t mean if refutes the main article. Nor does an observation of the encroachment of pines in deserts.

      This was in Oregon, not in the Southwest.

      One has to wonder where they got there precipitation data for these sites, beginning in 1896.

      There is no control for other factors besides CO2 levels. The recovery could be based on something else – temperature, stand density, herbivory… anything that is different between the two time periods.

      ” Beginning and ending CO2 levels were 295/306 ppm for 1896-1930, and
      319.5/366.7 ppm for 1964-1998 ”

      So, the change in CO2 of the first time period was much less than the second, and there was only 13.5 ppm difference between the two. However, there doesn’t seem to be a pattern of greater recovery late in the second period.

      Sorry, this isn’t a good argument against the paper in the post.

  3. Can one prove causation because of climate changes or is it simply correlation that can be explained by other factors?

    • I suppose this question must firstly answer: “What constitutes climate change?”
      Big variations that remain year after year?
      Minor fluctuation in seasonal temperatures or precipitation?

    • What correlation can we posit about a thing that hasn’t happened yet? I am also willing to bet it won’t!

    • Michael,

      “Proof” is for mathematicians. Science is about probabilities.

      With the proper statistical methods, one can sometimes demonstrate a high likelihood that climate change has a causative role. It’s rarely a simple correlation. Climate is not one variable, nor are the causes of climate change, so other statistics are more appropriate.

      • Careful Kristi, you’re starting to make sense.
        If you keep this up people will start calling you a denier.

  4. “A treasure trove of data about tree growth in the US West was found in these boxes, each of which contained 500 to 800 cores from individual forest trees.” ?

    This sounds an awful lot like the way Democrats always find “extra” ballot boxes after the polls close… lol

  5. Tree rings are used to estimate past temperatures: tree rings estimate how trees respond to temperatures: tree ring analysis predicts future climate change: tree ring analysis tells us how trees will respond to climate change – does this all seem a bit circular?

    • …and incorrect.
      Tree rings correspond to growth. Growth is effected by growing conditions. Climate is only one part of the growing conditions. There are numerous factors which affect tree’s growth. If it was shaded by adjacent vegetation, exposed to fire, or even if irrigation gets altered by changes in forest geography are just a few factors.
      All that can be determined by tree ring data is that the tree had different growth from year to year. Any conjecture as to what actually caused the growth difference is unproven speculation.

      • Rocketscientist,

        Well, if you’re only looking at one tree that may be true. But if you’re looking at thousands of trees, you know the climate parameters they are sensitive to, and you run a multiple regression to test for how much variance each of those factors explains, it is no longer speculation.

  6. Here is a nice compilation of 30 natural systems in which global warming exerts both an effect and the opposite of that effect

    It was first posted by Jimbo then re-posted by Pierre Gosselin at NoTricksZone, with links to papers:

    http://notrickszone.com/2011/03/30/robust-science-more-than-30-contradictory-pairs-of-peer-reviewed-papers/

    Here they are as a text list:

    Amazon dry season greener
    Amazon dry season browner

    Avalanches may increase
    Avalanches may decrease – wet snow more though [?]

    Bird migrations longer
    Bird migrations shorter
    Bird migrations out of fashion

    Boreal forest fires may increase
    Boreal forest fires may continue decreasing

    Chinese locusts swarm when warmer
    Chinese locusts swarm when cooler

    Columbia spotted frogs decline
    Columbia spotted frogs thrive in warming world

    Coral island atolls to sink [?]
    Coral island atolls to rise [? – ?]

    Earth’s rotation to slow down
    Earth’s rotation to speed up

    East Africa to get less rain
    East Africa to get more rain – pdf

    Great Lakes less snow
    Great Lakes more snow

    Gulf stream slows down (and it causes warming)
    Gulf stream speeds up a little (and it also causes warming)

    Indian monsoons to be drier
    Indian monsoons to be wetter

    Indian rice yields to decrease – full paper
    Indian rice yields to increase

    Latin American forests may decline
    Latin American forests have thrived in warmer world with more co2!

    Leaf area index reduced [1990s]
    Leaf area index increased [1981-2006]

    Malaria may increase
    Malaria may continue decreasing

    Malaria in Burundi to increase
    Malaria in Burundi to decrease [?]

    North Atlantic cod to decline
    North Atlantic cod to thrive

    North Atlantic cyclone frequency to increase
    North Atlantic cyclone frequency to decrease – full pdf

    North Atlantic Ocean less salty
    North Atlantic Ocean more salty

    Northern Hemisphere ice sheets to decline [? – ? – ?]
    Northern Hemisphere ice sheets to grow [?]

    Plant methane emissions significant
    Plant methane emissions insignificant

    Plants move uphill
    Plants move downhill [?]

    Sahel to get less rain
    Sahel to get more rain
    Sahel may get more or less rain

    San Francisco less foggy
    San Francisco more foggy

    Sea level rise accelerated
    Sea level rise decelerated – full pdf

    Soil moisture less
    Soil moisture more

    Squids get smaller
    Squids get larger

    Stone age hunters may have triggered past warming [?]
    Stone age hunters may have triggered past cooling

    Swiss mountain debris flow may increase
    Swiss mountain debris flow may decrease
    Swiss mountain debris flow may decrease then increase in volume

    UK may get more droughts
    UK may get more rain

    Wind speed to go up [?]
    Wind speed slows down [?]
    Wind speed to speed up then slow down

    Winters maybe warmer [? – ?]
    Winters maybe colder ;O)

  7. I may not be a dendrologist but I am not stupid. This study would lead you to believe that temperature is the controlling factor of whether trees survive or die. Rubbish! How were other factors like water, nutrients, CO2, sunshine, and disease accounted for? This study would lead one to think that the Little Ice Age is the most productive period for these trees.

    One question for these folks. Did the climate model provide localized rainfall projections that were used in their analysis? If not, then they missed a big factor in tree ring growth. I smell biased results. I suspect increased rainfall (more evaporation from higher temperatures) along with higher CO2 levels and higher temperatures might have changed their results.

    • Jim, you started you comment with, “I may not be a dendrologist but I am not stupid.”

      You also have common sense, which appears to be lacking in members of the climate science industry.

      Cheers and Happy Holidays,
      Bob

      • How can common sense possibly help? We’re in the post-1960 era, where unknown, yet known to be anthropogenic effects happen to control tree growth. Everyone knows that.

  8. Headline: Southwest forest trees will grow much slower in the 21st century

    From the article: Southwest forests may decline in productivity on average as much as 75 percent over the 21st century as climate warms, according to new research published on Dec. 17.

    MAY decline.

    Charles, with all due respect, headline should not portray a speculative opinion, based on a single study, as fact.

  9. His analysis revealed that growth of the ordinary forest trees would not be reduced as much under climate change as the trees whose records are included in the ITRDB.

    Where the heck does the 75% figure come from?!? This is more science by press release, as nowhere in the body of the report is this claim put forward. Morons!

    • OK, poor reading comprehension on my part. That statement was made, but does not seem to have any foundation in the analysis. Except for the usual CMIP 5 models, and the investigators incapacity to wonder why the actual record shows periodic variability but nevertheless project linear decline while the data are in an apparent trough (see Figure 5).

      https://www.nature.com/articles/s41467-018-07800-y

  10. I own a few acres of forested land along the shore of a lake. In the 50s a dam was built on the lake outlet to increase, and maintain lake level. This, along with increased power boat wave action, caused the shore line to encroach on the forest, is some cases as much as 50 feet. The trees along this area fell into the lake. This does not make for very useful shoreline, to me, at least.

    For several years I have been pulling these trees from the lake. Several oaks had as many as 100 rings. The tree rings are interesting. They start out nearly round. About the time of the dam, the lakeside of the rings start getting closer and closer together. As the tree died, they got too close together to distinguish individual rings.

    Note that this tree ring distortion coincides nearly exactly with accelerated CO2 content in the air. Clearly, Mann made global warming is proved with these tree rings.

    • Tom

      The tree rings are interesting. They start out nearly round. About the time of the dam, the lakeside of the rings start getting closer and closer together. As the tree died, they got too close together to distinguish individual rings.

      Note that this tree ring distortion coincides nearly exactly with accelerated CO2 content in the air.

      Odd, isn’t it? Exactly OPPOSITE of what every “conventional wisdom” would have established about your tree rings! More water over long periods of time (ground is saturated in fact), better sunshine (as mature trees fall around them), more CO2, higher temperatures, nearby water to reduce great temperature fluctuations, even no fires around the trees. EVERY “fact” should indicate that your trees should have been growing so fast they would merge together into one huge round bush!

      But they didn’t. Every tree died. Thus verifying Mann’s greatest fear: That of being proved wrong.

    • Note that this tree ring distortion coincides nearly exactly with accelerated CO2 content in the air.

      It also coincides with the saturation of the soil surrounding the roots according to your account, much more likely to be the cause of the trees dying.

  11. On the face of it, the conclusion that Douglas Fir trees will stop growing or suffer a dramatic drop in growth due to an increase in temperature of 1 or so degrees C in the presence of a significantly higher CO2 concentration is unbelievable.

    Increasing the CO2 concentration conserves moisture in the tree. This leads to additional growth.
    Increasing the CO2 concentration increases the growing efficiency.
    Increasing the temperature increases the length of the growing season.

    What, exactly, is counteracting all these positives for growth that the result is a 75% reduction in growth? The answer is an RCP8.5 climate model.

    ‘Nuff said.

    Why does any well-informed tree researcher believe that the growing conditions 1920-1990 represent “normal” growing conditions? There was nothing “normal” about the 20th century conditions. The temperature and rainfall were all over the place. See Tony Heller’s recent paid of videos on the topic of the US Climate report recently released. Point to the years where growing conditions were “normal”.

    • There is a bright side.
      As these tree have a dramatic drop in growth, the availability of trees for firewood will decrease and CO2 emissions will drop. QED the world is saved

      the proof is left to the student

  12. First of all any “science” that uses MAY in it’s introduction is crap!
    Second what exactly do these people think the climate is going to do? It’s either going to get hotter or it’s going to get colder- $#%^ all Al Gore can do about it, and yes that will affect things as it has for eternity!
    Tired of this lunacy!

  13. So the whole point of the paper is that looking at ordinary tree rings instead of itrdb tree rings substantially decreases the temperature impacts. Naturally, the press release puts the most alarmist spin on it — even “average conditions” will reduce productivity by up to 75%.

    How can 75% reduction be a significant *decrease* in impacts? Because the original figure in this particular case the reduction in growth rate is 75% *instead of 106%*. How can the “growth rate” decline by 106%? I have to admit that isn’t obvious to me at first glance, I wouldn’t think you could get below no growth at all.

    And what conditions are these stunning declines by 2100 based on? Regional temperature and precipitation from 15 CMIP5 models with (you guessed it) RCP 8.5 emissions. So a scenario that won’t happen is combined with something the models show no skill at, and Bad Things Happen. Go figure. Since the effects are based on reaction to temperature and precipitation variance alone, I see no room for fertilization from the massive CO2 influx required by RCP 8.5.

    So what’s the historical variation? The ring-width index (figure 5) shows very large annual fluctuations (though the FIA is noticeably smaller than the ITRDB), by the running mean rises dramatically from 1900 to the teens, drops dramatically into the 50s, increases again into the 80s, then declines again on pretty much the same slope as earlier in the century — projections are that *this* decline will just keep going and going and going.

    Figure 4 explains why the heading is all about Southwest forest trees. There’s a lot of samples from the northern rockies in Montana and northern Idaho, but the analysis only explains variance on the samples from the southern rockies in Arizona/Utah/Colorado. It makes me curious what the same analysis performed on the same species in the Canadian Rockies would show. Looking at range maps, it seems the Rocky Mountain Douglas Fir has limited range in the southwest, the Common Pinyon is all in the southwest, and Ponderosa pine looks well represented (with different subspecies in the two regions).

    What’s the significance to the lumber industry as a whole? The Rocky Mountain states have less timber production than the pacific or north or south, pretty much because it has virtually no private timber production and in the other regions wood from private forests is much larger than from public land. Well, and there’s less trees, what with the whole desert thing. Within the context of the southwest, I found a report that the 4-corners state was 43% Ponderosa Pine, 26% Lodgepole Pine, 12% Douglas Fir, and 7% Aspen. So the studied species are a little over half (Pinyon must be less than 7%) of southwest timber. I’m immediately curious how the lodgepole samples reacted — and looking back at figure 4A and 4C I have the impression that the far more important Ponderosa Pine has less of the big bright red circles than the triangles (fir) and squares (pinyon). It’d be interesting to see the effect broken down by species, I think.

    • So what’s the historical variation? The ring-width index (figure 5) shows very large annual fluctuations (though the FIA is noticeably smaller than the ITRDB), by the running mean rises dramatically from 1900 to the teens, drops dramatically into the 50s, increases again into the 80s, then declines again on pretty much the same slope as earlier in the century

      It’s interesting that this variation in tree ring widths is inverse to temperature, but tracks SW US 4-corners area preciptation closely.

      The Boulder/Hoover Dam is infamous in dam construction history for its water rights being allocated in 1925-1930 political water negotiations for over-allocating water to the cities and states who funded the Hoover Dam. (The 1925-1930 water rights are about 15% greater than the long-term actual annual water flowing into Lake Meade behind the dam!)

      But the water was “sold” by politicians based on the water flow surveys taken back in 1915-1916 in the canyon itself – thus proving that regional Colorado River runoff was higher in the 1913-1918 “teens” than in the 1890’s (which had higher Global Average Temperatures) or 1940’s (also high GAT) and 1990-2010 (today’s high GAT). And each of the three “high GAT” periods was characterized by alarmingly low Colorado River flow!

      Foreign readers note: The “4 corners area” is a very dry region with cold winters and hot summers where 4 very large state “corners” touch. Though the region is a desert, the Colorado River water comes from higher mountain snow runoff in the Rockies a bit further north and west. So a very large river runs through a desert, but up to 5000 feet below the desert itself down in the bottom of a series of huge canyons, one of which is the well-known Grand Canyon. The geology and geography are “interesting” in an area larger than France or Poland.

    • There’s some limber pine mostly found in Utah, NM, and Colorado in the southwest area. Not familiar with pinyon pine timber used for construction.

  14. For Mike Mann, bristle cone pines from the southwest were very important in his temperature reconstruction. For him the overriding variable for tree ring growth was temperature. The trees were thermometers. In his model, wider rings meant warmer temperatures. Is this correct? For these people wider rings mean cooler temperatures. Is that correct? Interesting that some trees are positive thermometers, and some are negative. I guess some trees have a break point for change in temperature response. Very complex. It would seem, as many have noted, that the models control for all the other variables, and the data about each variable is available at each site to use in the model. This is an accomplishment of heroic proportions.

    • Ashby Lynch – I noticed that too. Michael Mann and others use tree rings as temperature proxies: higher growth implies higher temperatures. Now they say the opposite. The obvious conclusion to be drawn is that all tree ring temperature proxies are useless and must be discarded.

  15. Evans said, “The trees have to take whatever they get in terms of climate conditions. When the temperatures rise they have to cope with it — or not.”

    How did they survive the pre-Columbian mega droughts? How did they survive the Eemian? Ditto for polar bears, coral reefs, etc. But as someone stated earlier in the comments, all roads lead to doomsday with the warmists.

  16. Some of these, ponderosa pine, even aspen, are left isolated in the high Chisos Mountains in
    Big Bend National Park and other such outliers in West Texas at latitudes up to 3 degrees farther south than sampled. When statements like this appear– “The geographic trend in R2 was weak but significant…..” among others, it suggests reducing the rhetoric and paying more attention to empirical data.

  17. Let me get this right. Taxpayers paid the USFS to produce 20000 tree cores across 8 western states over two decades. But nothing was done with them for another two decades. Somebody needs to be fired.

    • Taking the core samples was probably just the first step in a multi-year study of some sort. I would guess that somewhere along the line money for continuing the study dried up so the samples just sat on the shelf. It’s probably pure luck that they didn’t get tossed because someone wanted to store a couple of extra cases of copy paper.

      • I think you guessed correctly regarding the funding issue, but since this was a governmental contract it would be considered destruction of government property if the cores had been tossed out. We, in my industry, end up storing a great bit of unused government property and they pay us to store it.
        It is usually a major contract faux pas to omit clauses regarding disposal and disposition of equipment and hardware from expired programs.

  18. Any study that claims that increasing CO2 levels from 300 ppm to 400 ppm to 500 ppm will reduce any kind of plant growth deserves to be thrown out with prejudice. These people are photosynthesis deniers. Don’t they know that 97+% of all biologists believe photosynthesis is a plant growth process with sunlight, H2O and CO2 an inputs? These people are anti-science.

  19. What limits a tree’s growth depends on where that tree is located. For a tree located in a dry region it will be precipitation and it doesn’t matter whether the region is hot or cold. In a region with reasonable precipitation the temperature will be a factor as will drought and flood, the combinations are limitless and can be limited to a small physical area.

  20. Except the basic theory of dendrochronology is that tree growth is more or less directly proportional to temperature. Sorry, but this is nonsensical. By what mechanism do they propose such a small change in temperature will effectively kill the trees? Have they corrected for the fact that recorded heat waves are often correlated with (and due to) drought, which a planetary warming will not only not be, but will typically increase rainfall?

  21. As usual we see the word “MAY”. Reminds me of the old TV show wit Sgt. Friday, “Give me the facts Mad’m”

    Is it possible in todays world to do proper research without using computers. ?

    Seems to me that “Modelling”” “is just another word for GIGO.

    MJE

  22. Rubbish. With more CO2 the trees will grow faster and use less water than a tree with 100ppm less CO2.

    Seems to me that the “Climate Scientists” have acquired a set of data that they will gatekeep access to and conjure up any set of conclusions they wish to produce….. as per usual.

  23. The growth rate of individual trees must be correlated with tree density. More trees in a given area are all competing for a finite amount of nutrients, (apart from CO2). In managed forests thinning is carried out in order to maximise growth of individual trees.
    Any study must consider the amount of growth per land area in order to be meaningful.

  24. MODERATE / CTM: Headlines describing warmist claims like this should be preceded by “Claim:”—as was the case until recently.

  25. ‘The new estimate is better than previous ones because it is based on a new database of information on the growth of trees under average conditions, according to the research team.’

    “Our last estimate was crap, but you can believe this new one.”

  26. For projections of the region’s precipitation and temperature in the 21st century, he used climate projections from one of the most current climate models, CMIP5 (Coupled Model Intercomparison Project Phase 5).

    And they knew everything.

    The spiderwebs bevore their eyes no more blocked vision.

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