More CO2 helps us grow food (that’s a good thing)

Climate-caused food disaster? Balderdash.

The FAO just revised (increased) its forecast for global cereal production. The 2017/18 season is heading for an all-time record of 3.3 million tonnes, while stocks have built up to a record reserve of over 720 million tonnes.

The graph on the right also shows utilization. I think that means consumption, though it’s an odd word to describe it.

The world stocks-to-use ratio of cereals is projected at 27.3 percent, which I think means we have a buffer of about three months’ worth of global consumption. So nobody should go hungry in the short term. There’s an excellent analysis of these figures and an account of climate change over the last few hundred years by Vijay Jayaraj. A brief quote:

The global food production index — an index of crops considered edible and nutritious — has risen steadily in the past six decades. Doubling from 1983 to 2008, it grew more than twice as fast as population and has continued to rise. … Yet climate alarmist scientists, politicians, and mainstream media claim that climate change would hinder global agricultural production. There are two key reasons their claims are false — exaggeration of climate change and misconceptions regarding the biological impact of carbon dioxide.

I like his conclusion:

If anything, the Modern Warm Period, with its high carbon dioxide concentration, has given us reason to celebrate this winter, not to fear.

The recent history of grain production is breathtaking. The next graph shows production since 1960, with the changing area of land used. The combined effects of technological improvements and increasing carbon dioxide have so increased production that the loss of land hasn’t stopped a miraculous increase in output.

While the area of cultivated land has fluctuated, and 15 years ago plummeted, food production rose steadily—we can thank climate change.

Forecasts of widespread starvation from climate change have come to nothing. Since 1960, there have been few famines (or perhaps none, but I’d need more time) caused by failed production. Most have had political causes or were exacerbated by politics, including mismanagement, ethnic conflict and war, and numbers of deaths have substantially declined over recent centuries. One of the worst famines was North Korea in 1996, where up to 3.5 million were estimated to have died. The world’s population has never been better fed, and there is every reason for optimism.

15 Thoughts on “More CO2 helps us grow food (that’s a good thing)

  1. Increases in crop production is primarily due to genetic improvement. The CO2 fertilisation effect is real, but only up to the point of the greatest limiting factor. Plant physiologists talk about the C/N ratio; if more carbon is available, then there has to be a corresponding increase in nitrogen to take advantage of it.
    Crop locations are shifting because of changes in climate. I would also suggest that the reduced temperature differential between equator and pole is causing a wavier jet stream with weather systems locked in one place, leading to more prolonged droughts and flooding. Attribution is difficult but there are plenty of examples in 2017.

  2. Richard Treadgold on December 18, 2017 at 12:11 pm said:

    You imply that nitrogen won’t be available, but it always is, otherwise constant elevated CO2 levels in a greenhouse would at some point stop boosting productivity.

    Anyway, you should start answering a few of my questions. Don’t you recognise a question mark or are you deaf?

  3. Richard Treadgold on December 18, 2017 at 12:14 pm said:

    Simon, please give a reference for the reduced temperature differential. Given no substantial temperature increase for 20 years, I don’t believe the differential could have changed more than a smidgeon, so prove it. Then explain the air/water radiative warming, you’ll find it easy, apparently.

  4. Plants source nitrogen from the soil, which is why farmers apply fertiliser 😉
    You can not use twenty years to determine a trend, but even if did you would still see a warming trend for all temperature series:
    Please reopen your sixth form physics text book and read the discussion on conduction, convection, and radiation.

  5. Barry Brill on December 18, 2017 at 7:42 pm said:

    Oh dear, Simon

    1. Plants source nitrogen from the atmosphere as well as the solid. See “fixation” in your sixth form bio text

    2. You can use 20 years to determine a trend, or even 10 years if the signal is strong enough to overcome the noise,

    3. “the reduced temperature differential between equator and pole is causing a wavier jet stream”. The equator/pole temp gradient determines the energy in the hemispheric climate systems. Because that gradient steadily reduced during the 20th century, the frequency and strength of “extreme weather events” has subsided in recent times. Do you believe the energy loss has also caused more slow-moving systems?

  6. 1. Bacteria does the fixation, not the plant. The bacteria is in the soil.
    2. The irony is that a warming trend is statistically significant even when the start-point is cherry-picked on the 1998 El Nino.
    3. The reduced temperature differential probably has reduced wind-speeds in the northern hemisphere but systems are more likely to get stuck in one place (e.g. droughts in California, our November lazy high). Conversely, there is potentially more heat and moisture available for weather systems to feed off (e.g. Houston). As I said before, attribution is difficult but a lot of people will claim that weather patterns are changing.

  7. “…..a lot of people will claim that weather patterns are changing”
    Yes, Simon, I find the new weather to be much more exciting than the old weather….which, let’s face it, had become frankly boring.

  8. Gary Kerkin on December 21, 2017 at 10:19 am said:

    It seems to me that Simon is the one “cherry picking” information. Below are three points that are very useful. One is anecdotal, one is a practice common among commercial growers. The third is a physical, chemical fact.
    1. The anecdotal comment came from a dairy farming friend of mine in Southland. He thinks he would really enjoy a couple of degrees higher temperature and double the amount of carbon dioxide. So would his cows!
    2. It is common practice among glass house growers to increase the partial pressure of CO2 in the buildings to increase growth rates and yield. And of course, it is warmer inside the glass houses. The green house effect, don’t you know!
    3. The Arrhenius equation in chemistry dictates that the rate of reaction is positively related to temperature. In addition the chemical equation which describes photosynthesis (CO2, water, sunlight, … -> plant matter) will move to the right as the partial pressure of CO2 is increased.

    As to changing weather patterns it is worth noting the quote by Mark Twain which the NZ Climate Science Coalition has on its web site header, “Climate is what we expect, weather is what we get.” The problem with most people “claiming the weather patterns are changing” is that they either do not have sufficient knowledge of history, or they have forgotten what has happened before. For example in the autumn of 1963 the Met Office posted a press release in which they showed a a huge low pressure area in the Southern Ocean south of Australia from which almost continuous lows peeled off heading across the South Island. The Press (Christchurch) published it under the headline “Now They Tell Us”—the summer of 1962-63 was lousy, as I recall. Pretty much what happened this last winter! Ok, different season, I know, but the pattern is similar. The hyperbole used by the media whenever a tropical cyclone heads in our direction ignores the fact that it is not unique. Recently we were regaled with a story that an area had suffered the biggest event (dry period, warm temperature, sorry, I can’t remember the details—old age, you know) in 63 years with the not so hidden implication that it was a result of climate change. Pardon? I thought the real implication was that something close to the event happened 63 years ago.

    I find weather “patterns” (how can they be patterns when weather has chaotic elements) fascinating. For example, if I were to say that tomorrow will be much the same as today I would be correct 70%-80% of the time.

    Incidentally, very nearly 43 years ago my family and I held our collective breath as the eye of a category 5 cyclone passed over us.

  9. Dennis N Horne on December 21, 2017 at 12:45 pm said:

    Our civilisations have developed during a abnormal time in Earth’s climate. It would have been nice to keep it going a bit longer.

    On the other hand it’s an exciting experiment fucking up a whole planet. We can do it only once.

    The staples like wheat, maize, rice won’t adapt as fast as the climate is changing, particularly to less water.
    Not sure they like wild fires much either…

    But hey, what do 30,000 climate scientists know? Or the Royal Society, National Academy of Sciences, American Association for the Advancement of Science, American Physical Society, American Chemical Society, American Statistical Association etc etc etc?

  10. Dennis N Horne on December 21, 2017 at 12:54 pm said:

    Plenty of stuff showing you can’t extrapolate from glasshouse to field. Here’s one comment:

    Increasing CO2 threatens human nutrition – Samuel S. Myers et al, Nature 510, 139–142 (05 June 2014)
    “Here we report that C3 grains and legumes have lower concentrations of zinc and iron when grown under field conditions at the elevated atmospheric CO2 concentration predicted for the middle of this century. C3 crops other than legumes also have lower concentrations of protein, whereas C4 crops seem to be less affected. Differences between cultivars of a single crop suggest that breeding for decreased sensitivity to atmospheric CO2 concentration could partly address these new challenges to global health.”

    “A new CSIRO study, led by Dr Zvi Hochman, has found that Australia’s average yields from wheat-growing more than tripled been 1900 and 1990 thanks to advances in technology, but have stalled in the years since then.The study found that, since 1990, our wheat-growing zone had experienced an average rainfall decline of 2.8 millimetres, or 28 per cent per cropping season, and a maximum daily temperature increase of about 1 degree.
    Australia’s “yield potential” – determined by climate and soil type – which is always much higher than farmers’ actual yields, has fallen by 27 per cent since 1990.”

    Never argue with idiots, they drag you down to their level and beat you with experience.

  11. Ian Cooper on December 21, 2017 at 1:26 pm said:

    No points for guessing where you were 43 years ago Gary Kerkin. I knew someone who was shut up in a padded VW Combi van on the day. He described getting out of the van to stretch and purvey the damage to Darwin while the eye was passing over. Then back in the van for round 2! I asked him why he came to Palmerston North after that? He said for more benign weather patterns. I didn’t have the heart to tell him that our old ‘Palmy Town,’ had suffered at the hands of New Zealand’s most destructive ex-tropical cyclone of the 20th century nearly 40 years earlier! So the two ‘Palmerstons’ had that much in common.

    This La Nina is strong enough that we should be mindful of the sting in her tail, the propensity for ex-tropo cyclones to drop in on us at the end of the season! This can then lead to a flourishing of ‘Human-blamers,’ so be alert for them.

  12. Gidday Ian,
    I know what you mean by wind in Palmerston North, having lived there a couple of years, 1960, ’61.
    Apparently the southerlies blow up the West Coast and are funneled by the Farewell Spit straight into Foxton beach. Palmerston North city itself is sat down a little bit in the Rangitiki river valley, but if you take a left just after the Fitzherbert Ave bridge heading south, you get up on the plains, and boy does it perpetually blow up there.
    But then we have loons like Dennis who still believe in “climate change”, and thinks we’re affecting all this.
    He says…”Plenty of stuff showing you can’t extrapolate from glasshouse to field”
    Well Dennis, you had better explain this to your heroes, Arrhenius, Tyndall, etc, who simply and directly extapolated from the inside of glass and metal tubes, to the Earth’s atmosphere.

  13. Gary Kerkin on December 24, 2017 at 10:51 am said:

    Not in Darwin, Ian, it was in Dampier two months later. We were in a company flat (ground floor of 3 levels) designed for 135mph winds. Cyclone Trixie was a category 5 storm when it hit Dampier and the airport registered something like 155mph winds. The accommodation buildings all had to be strengthened. Incidentally, Cyclone Tracey was at category 2 when it flattened Darwin.

    The present El Niña is certainly having an interesting effect if, as I understand, it is responsible for the pressure conditions over the Tasman that have been dictating our weather. My wife commented this morning that it must be a long time since Wellington enjoyed the warmest daytime temperature in NZ. Well, in terms of the temperatures reported in news bulletins. Our temperatures in Upper Hutt have been up to 4º warmer than Wellington.

    Merry Christmas to all.

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