ABC's Catalyst: increased CO2 is bad for plants

Cassava, soon to be cyanide if we keep driving SUVs

Another week, another “climate” scare story from Catalyst. The ETS is dead and nobody’s interested in reducing CO2 to “tackle climate change” any more, so the ABC goes looking for another reason to cripple Western economies and send our standards of living back to the Dark Ages.

And they find a corker. You thought increasing CO2 in the atmosphere would be good for plants? Wrong. It’s bad, and the ABC’s “science” programme jumps on this research without pausing for breath. Brilliant. Forget global warming, forget how the majority of plants would benefit from increased CO2, forget how we are actually living in a CO2 starved atmosphere. Now it’s “food security” that everyone’s worrying about, thanks to reduced nutrition and increased toxins:

Dr Graham Phillips
The next big food issue could be how rising levels of carbon dioxide are affecting our fruit and vegies. Now we know that plants love CO2 so rising levels of it will affect their metabolisms and it seems almost certain that for many foods the levels of nutrition will go down and for some toxin levels will go up. Both serious issues when you are trying to feed a world with an increasing population.

Dr Ros Gleadow
We’re tracking worst case scenario with carbon dioxide at the moment [what? – Ed] and we need to predict what sort of things are going to happen in the future.

Maybe they could predict the future with some dodgy second-hand climate models bought off the back of a truck from Michael Mann. That should do the trick. Or Madame Za Za’s crystal ball, perhaps? Just like last week: more scary music, more alarmism. And they’ve found a plant, cassava, that links rising CO2 levels with increased levels of cyanide. Almost a Holy Grail for the ABC’s alarmism department – cut CO2 or you’ll die of cyanide poisoning:

Back in the lab Ros’s group have been looking at how rising CO2 will affect the cyanide levels of cassava.

Dr Ros Gleadow
We grew cassava at three different concentrations of carbon dioxide. Today’s air, one and a half times the amount of carbon dioxide and twice the carbon dioxide of today. And we found that cyanogen concentration in the leaves increased.

Dr Graham Phillips
So as we get more Carbon Dioxide in the atmosphere these will contain more cyanide?

Emeritus Prof. Howard Bradbury
More cyanide yes. The yield from the roots which is the main thing, will go down. So that is the most worrying aspect.

And the last word to Dr Gleadow:

Dr Ros Gleadow
I don’t want to be a gloom and doom person. I want to think okay clover’s going to become more toxic, let’s develop other cultivars. If cassava’s going to become more toxic, let’s look at some other cultivars. Let’s look at other ways we can deal with this problem.

Don’t say that! It’ll spoil the story!

Read/watch it here.


  1. So… do people eat the cassava leaves, or some other part of the plant? *looks it up* oh right!

    Typical of these total jackAsses to leave out the most pertinent fact of the matter.

    We did have a similar thing in Sudbury, Ontario. Heavy-duty metals mining and smelting up there for over 100 years. People were concerned that blueberries might contain various heavy metals…. it turns out those metals are absorbed into the leaves, leaving the fruit quite edible and safe.

    These same scientists would be screaming to high heaven that blueberries would be poisonous. And they get PAID to be that STUPID.

  2. Actually, people do eat the parts of Cassava that contain the cyanogens, it’s just that they prepare it in a manner to remove them. What the study fails to mention is whether this process is affected at all.

    Never mind the fact that Cassava produces cyanogens no matter the level of CO2, ie the plant is only doing what it does naturally, only *better* with increased CO2 levels, ie it’s a *good* thing for this plant, and for plants overall.

    Of course, if you’re always looking to make bad things out of good like alarmists do, this kind of story comes as no surprise.

  3. Since plants , and therefore all life including scaremongers , are more than 90% CO2 combined with H2O by sunlight , I would ask how much larger and faster the Cassava grew – as it undoubtedly did .

  4. John Marshall says:

    How do these clowns equate this ‘research’ to UK practice of increasing CO2 levels to over 1500ppmv in greenhouses to increase crop production. I do not see people dying in the streets here from eating tomatoes so grown.

  5. No problem – it’s easy to get rid of the cyanide: mix the flour with water and roll it out:

    “The method involves taking the dry flour and then you add an equal amount of water and then mix it up. The flour all swells up, they then take the wet flour and put it on a basket in a thin layer not more than a centimetre thick and the enzyme can then attack the cyanide compound and break it down and gradually liberate hydrogen cyanide, which is a gas.

    Dr Graham Phillips
    Gee it’s a pretty simple method for detoxifying?

    Emeritus Prof. Howard Bradbury
    Very simple, yeah.”

    Get over it.

  6. Charles HIgley says:

    They pointedly do NOT mention what toxic levels are regarding cyanide. It’s a threshold thing – are the levels still lower than the threshold? If higher, then how much cassava is too much. Obviously, it would not be one bite per kill. Remember, these plants have mitochondria, also, and cyanide would likely poison them, too!

    Eat too much of virtually any one veggie or fruit and there will be toxic consequences. That’s true today and NOT dependent on CO2. Just like the natural levels of mercury in tuna and swordfish, it’s a matter of quantity eaten and thresholds.

    Their quick conclusion that nutrient levels will go down is also highly suspect. If what they are looking for is to get in the news, their data fits, but is their data worth the electrons used to transmit it? I think not.

    Around the world, plants have been benefitting from higher CO2 – not a problem.

    As CO2 partitions between the oceans and air at 50/1, we would have to put 50 times more CO2 into the air than needed as the oceans would fight us and soak it up. Using all available fossil fuels today, the best we could do is to raise the current CO2 in the atmosphere by 20%.

    Studies of doubling of atmospheric CO2 are cute, but worthless. Horticulturists standardly raise the CO2 in their greenhouses to 1000 ppm and the plants love it. That’s way more than doubling CO2, by the way.

    So, we have narrow-minded and narrow-viewed scientists trying to 1) raise their profile, 2) breath life into the dying global warming scam by shifting the scare, and/or 3) probably hoping to attract more grant funding.

    TIme to either start doing real science or go find another job, guys. This one isn’t going very well. People are laughing . . .

  7. william says:

    oh blimey, we have been pumping the co2 levels up to 1000ppm in our green houses, sorry everyone,

    plants seem happy though.

  8. Bruce A. Kershaw says:

    Please go to
    Thank you

  9. A good round of details, Bruce, thank you, bookmarked!

  10. John Marshall says:

    If you look at the Cassava description in Wikipedia is states that the plant contains cyanide and care must be taken in preparation. Improved cultivars, whether through CO2 increase or any othe rreason, will increase the chemicals in the plant because the plant will grow bigger. No mystery there then.


  1. […] Oh noes, plants contribute to global warming.  And they will rise up to poison us all. […]

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