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Some trees are growing like crazy

  1. Dec 7, 2009 #1

    Xnn

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    This is basically a good news story. Aspen trees (I call them populars) are doing just about
    everything they can to soak up as much CO2 as a tree can. While CO2 levels
    have risen about 19% over the last 50 years, Aspen trees have accelerated their growth
    rate even more so; 53%! That is astounding as it is more than proportional. Aspens already
    grown fairly fast and since global warming is also predicted to result in elevated precipitation
    levels, Aspens have been shown to grow like crazy. This has not been observed in Pine or
    Oak and I can't speculate on why that may be.

    Anyhow, it seems a good reason to quit mowing the lawn and plant some trees instead.

    http://www3.interscience.wiley.com/journal/122659631/abstract


    http://www.eurekalert.org/pub_releases/2009-12/uow-ggc120109.php

     
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  3. Dec 8, 2009 #2

    Integral

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    Very interesting

    Seems we need to start planting lots of Aspen!

    The problem is that we dare not burn the resulting wood. It should be buried, how good a form of sequestration is this?.

    This is the type of response discussed in the Gaia Hypothesis. Essentially, it is earths lifeforms that not only control the composition of the atmosphere, they determine it.
     
  4. Dec 9, 2009 #3
    Or at least the timber be used to make some nice furniture that will be used for a large period of time.
     
  5. Dec 9, 2009 #4

    vanesch

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    There's another way of looking at this: one has always emphasised the catastrophic side of increased CO2 levels. Maybe this is one of the advantages. If this works out for crops too, that would simply be fantastic.
     
  6. Dec 9, 2009 #5
    My guess would be risky.

    Buried in a peat swamp might lead to long term sequestration of most of it. But you'd run out of peat swamps fairly smartly.

    Just sticking it in a hole would lend itself to breaking down anaerobically, which would eventually release methane, which would be worse that the CO2 that you started with in the small number of centuries time-scale.

    As far as I can see the only reliable geosequestration would be to leave the coal and oil underground in the first place. I call it presequestration. It's yet to catch on at ExxonMobil.
     
  7. Dec 9, 2009 #6
    There's probably a limit to how many tables we can use.

    If we have released 329 billion tonnes of carbon into the atmosphere, and wood is about 50% carbon by weight, and there's 6.8 billion of us, we need about 100 tonnes of wood furniture each, to bring us to pre-industrial levels.

    Or, if we are prepared to accept 350ppm, and there are 380 ppm, and the oceans would resupply about 1:1 then we need to use about 60ppm by volume in the atmosphere. Which is about 90ppm by weight. If the atmosphere weighs about 5.2 quadrillion tonnes, that's about 468 billion tonnes of CO2, or about 127 billion tonnes of carbon or about 254 billion tonnes of wood.

    Which is only about 36.7 tonnes each. Of course last year we released about 8.6 billion tonnes of carbon more, so at current rates (which look to be conservative) we'd have to add about 2 tonnes of wooden furniture each year each from now on ... less natural sequestration. Probably around 1700 kilograms. Give or take a couple of hundred.

    Many people in Ethiopia can't afford their share of the furniture so we might have to buy it for them and ship it over. (Perhaps in heavy wooden boats).

    Or look at lower fossil fuel use.
     
  8. Dec 9, 2009 #7
    Yeah, I thought carbon fertilization was one of the biggest things people talked about on the "it's not really a problem" side of the issue. Remember that book, "The Greening of Earth" or something like that? But I thought that was pretty much debunked, and it had been determined that relatively few species are as overjoyed by the climate changes as this kind of tree, and therefore the overall positive effect was tiny compared to other effects being discussed. Disclaimer: I have no citation for this and am probably somewhat of a moron. :tongue2:
     
  9. Dec 9, 2009 #8
    I think that that's right.

    There are parts of the world where primary production is limited by CO2, but there are also ground nutrients, sunlight and water limiting growth.

    There is a missing Carbon sink that is fairly significant. (See the right hand column in http://lgmacweb.env.uea.ac.uk/lequere/co2/carbon_budget.htm"). And I personally attribute this to increased primary production in the terrestrial biosphere of phytoplankton.

    But increased primary production is not always a good thing:
    • Parasitic vines tend to show more increased growth than woody species under increased CO2 concentrations. This suggests more risks for biodiversity. (And other unforeseeable consequences like http://www.msnbc.msn.com/id/13046200/").
    • Many plants respond to the increased CO2 with reduced stomata, either in number or size or both. This increases the plants resistance to drought, but is expected to have a devastating effect on the climate of the west Amazon basin where nearly all the rainfall is from repeated transpiration. (The weather systems move generally from west to east, and the Andes mean that most moisture falls as orographical rainfall.) This contributes to the modelled collapse of the Amazon rainforest after about 3 degrees of warming.
    • Plants that have increased production under CO2 fertilisation often have reduced nutritional value. This is bad for grazing plants and insects, but also for humans and transport costs.
     
    Last edited by a moderator: May 4, 2017
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