The joy of extra CO2

Sit up class!

Straight backs. Face the front.

Davidson stop reading comics under the desk. Will the big lout at the back put the stock market report away. Do your trading at playtime.

Take out your copy of Climate Change: The Facts 2017.

No not the 2014 one Lizzie. Stop making faces at her Gab. It’s not her fault that she’s slow.

Turn to page 189. Chapter 14. Carbon Dioxide and Plant Growth by Dr Craig D Idso, the founder, former president and current chairman of the board of the Centre for the Study of Carbon Dioxide and Global Change.

This is an amazing paper and it falls right into my original ballpark – Agronomy, the integrating part of Agricultural Science that I studied in Hobart and then at the Waite Ag Research Institute in Adelaide. The Institute is a centre of excellence located next to the CSIRO Soils Division and the Wine Research Institute. Wine was not the big deal that it is these days, we were still taking it from glass flagons and beer was still overwhelmingly the drink of preference.

No I am not going to tell you about my research again, I told you about that when we did the neutralisation of the oceans and the barrier reef.

You all know that the level of CO2 is seriously sub-optimal for plant growth and a revelation in this paper is that the temperature is arguably sub-optimal as well.

The trend in CO2, from a preindustrial baseline a bit under 300 ppm we are now about 400 and we could reach 800 by the end of the century under the “business as usual” scenario.

Productivity. He cites figures for the extra growth of plants with 300ppm extra CO2 (not sure about the baseline). Average for herbaceous plants is 33% extra biomass. Especially strong performers are fruit of all kinds including grapes and also carrots and turnips near 70% extra.

Trees do even better, woody plants average 50% more biomass with the extra CO2.

Many aquatic plants do better as well, although there has been less study of them.

Yes Johanna I know he’s still reading comics. You don’t need to be a tittle tattle.

Enhanced water efficiency

This is a doozey because water is a limiting factor many places especially for broad acre farming and grazing where irritation is not an option.

You don’t need to laugh Bruce, you know I meant irrigation.

Higher CO2 reduces the opening of the stomata (pores) in the leaves which give out water vapour (the main loss of water from the plant). They also produce less stomata. One might expect this to reduce the intake of CO2 but apparently with higher concentrations that is not an issue.

Enhanced water efficiency enables plants to expand into drier areas. This is already being observed to reduce soil erosion as a collateral benefit.

More organic matter. More growth means more food and fibre. It also means more organic matter returning to the soil to build up soil structure and fertility and the population of earthworms, another collateral benefit with positive feedback effects.

Amelioration of environmental stresses

Tomorrow the class will cover the additional benefits of CO2 including the major biosphere impacts and the possibility that CO2 enhanced crops will do so much better with slightly higher temperatures that the nett benefits of warming will exceed the most optimistic calculations based on the impact of CO2 alone.

That’s it class, it is playtime and I’m dying for a fag, I mean a smoke. See you tomorrow and Lizzie, do bring Climate Change: The Facts 2017.

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19 Responses to The joy of extra CO2

  1. John Constantine

    The trials into plant growth in high concentrations of co2 [ by the simple method of running plastic lines down the rows of growing plants in the paddock, and continually releasing co2 as they grew] has been halted at the Horsham trial site, as the results [ co2 is an effective fertiliser for field crops] made the wrong people enraged.

    ” THE removal of a 45,000 litre gas cylinder from Agriculture Victoria’s Plant Breeding Centre at Horsham has marked the end of 11 years of field trails.”

    “It was the only facility of its kind in the world, having been built specifically to study the impact of elevated CO2 on field crops grown in semi-arid conditions.”

    They not only had to halt it, but they had to destroy the supporting infrastructure so it could never restart. Sound familiar?.


  2. Herodotus

    Patrick Moore approves this message.

  3. Bruce of Newcastle

    Furthermore if you have energy you have water.

    Three quarters of the Earth is covered by water. All it takes is desalination (energy) and punping (energy) through pipes (energy) and you have water anywhere to grow things with.

    The people who think the current 7.3 billion homo sapienses is too many don’t have the imagination to see what can be done to grow the pie. I suspect we could manage 30 billion easily.

    It’s not unlinked that Greens hate energy and hate population too.

  4. Boambee John

    Bruce of N

    It’s not unlinked that Greens hate energy and hate population too.

    The Greens of the 1980s and 90s hated population growth – think of Australians for an Ecologically Sustainable Population, Australians Against Further Immigration, Zero Population Growth and similar groups.

    The Greens of today are adamant supporters of Third World unassimilable immigration.

  5. Megan

    Thanks for the giggle, Rafe. Your class would give the miscreants in”Yes, What?” a run for their money.

  6. Nerblnob

    John Constantine
    #2765947, posted on July 17, 2018 at 8:14 pm


    It doesn’t say anything at all about how or why the plug was pulled.

  7. RobK

    Thanks Rafe,
    I read your paper last week when you included a link. Very interesting.
    The other advantage of lower leaf transpiration is that the humidity of the air is buffered for longer as the plants and soil don’t dry so quickly….moderating sensible heat. Greening Australia with coal.

  8. Hairy-handed gent

    There is likely something in this. One of the accepted advances in grain production (in Aussie at least) has been that productivity has been growing around 3% pa for some years, at least from around 1990- 2010. Of this about 1% was thought due to improved genetics (i.e. breeding better varieties) and around 1.5%, or perhaps 2% is due to better management (i.e. agronomy).

    Now there has been recently some acknowledgement that something else might be operating here too, and it is possible that increased levels of CO2 has also been playing a role, probably not obvious, for some time, and may be providing improved crop yields with existing varieties.

    The same possibly applies to the observed improved water use efficiency of crop production – where it is assumed it is all due to better practices by growers, when it is possible that some of this is due to increased CO2 meaning that plants require less water in exchange for CO2 to grow in a higher CO2 atmosphere.

    All in all I reckon a higher level of CO2 coupled with a slightly warmer temperature will be a net gain for all.


  9. Nato

    This is how I imagine Terry McCrann thinks he writes, dgressing to a relevant sidelight, but this doesn’t leave a fact hanging in the air on its own.

    Sure the content was good, but right here, right now I really enjoyed it as a bedtime story, too.

    Good night.

  10. Tom

    10/10 for presentation, Champion. (But you’re such a dobber).

  11. MichelLasouris

    A little off topic I suppose, but I burn all the plastic and paper I accumulate; the only rubbish in my garbage is glass and tin…food scraps go to the chooks. Ok, so I’m ostensibly adding to the CO2 load, the results of which are highly questionable as all here agree. But what I DO know for certain is that no nanoparticles of plastic waste from our house will end up in the food chain, and that is 100% beneficial to the planet. I found some old “free” plastic bags that somehow got slightly buried in the yard. They had decomposed to the point that they adhered to my skin exactly like grey paint, and washed off as a sort of slurry. No wonder people are worried about plastic……..

  12. Iampeter

    This is all good points but the best point is that CO2 doesn’t warm anything and is used in greenhouses precisely BECAUSE its plant food.

  13. No wonder people are worried about plastic…

    Yes. Because they are complete idiots.
    Repeat after me: carbon and hydrogen are nothing to worry about.

    And polypropylene may be dangerous if you put your head inside the bag.

  14. Mark M

    Arrhenius never saw CO2 as an earth scorching gas of the climate doomsday.
    Quite the opposite …
    “These showed that if six parts of CO2 are added to the atmosphere, five will be absorbed by the oceans.
    Arrhenius saw nothing adverse in such a development.
    It will “allow our descendants,” he said, “even if they only be those of a distant future, to live under a warmer sky and in a less harsh environment than we were granted” (l1).
    Such a view is consonant with the ideology of “optimistic evolutionism”embraced by Arrhenius and many of his contemporaries(22).” (page 11)

  15. Os

    Was Sinc reading “Charley’s War”?

  16. P

    Bit off topic but interesting link:
    Rejecting Carbon Colonialism
    African Development Bank breaks with anti-fossil fuel banks to fund coal power, prosperity.

  17. Motelier

    Sorry I’m late today and missed yesterday’s lesson, here is my absent note.

    Nice article and good responses.

    Any-one with a lawn to mow will tell you that les fertilizer and water is needed today.

  18. Tim Neilson

    Greening Australia with coal.

    We’ve got our election slogan.

  19. Spring is coming

    Greening Australia with coal.

    Or Green Coal

Comments are closed.