Thursday, July 25, 2013

Review finds increased CO2 will lead to increased crop yields, even if warming resumes

A new review paper from SPPI & CO2 Science finds "future increases in the atmosphere's CO2 concentration will likely lead to increased crop growth and yield production, even in areas where reduced soil moisture availability produces significant plant water stress."

[Illustrations, footnotes and references available in PDF version]

As the air's CO2 content continues to rise, nearly all of earth's plants will exhibit increases in photosynthesis and biomass production; but climate alarmists periodically claim that elevated concentrations of atmospheric CO2 will lead to more droughty conditions in many parts of the world and thereby significantly reduce or totally negate these CO2-induced benefits. Therefore, to help determine to what degree this claim has any validity, we here review and summarize the results of numerous CO2-enrichment studies that were designed and conducted in such a way as to reveal the various means by which atmospheric CO2 enrichment may actually help a number of important food crops to successfully cope with this potential problem of more frequent periods of less-than-optimal water availability.
If atmospheric CO2 enrichment allows plants to maintain a better water status during times of water stress, it is only logical to expect that they should exhibit greater rates of photosynthesis than plants growing in similarly-water-deficient soil in non-CO2-enriched air.
Where water availability is a prime limiting economic resource, it can be distributed more effectively under higher CO2 conditions
Average wheat yields are likely to increase by 1.2 to 2 t/ha (15-23%) by the 2050s because of a CO2-related increase in radiation use efficiency.

To briefly summarize the findings of this review of the effects of water insufficiency on the productivity of the world's major agricultural crops, the earlier optimistic conclusions of Idso and Idso (1994) are found to be well supported by the recent peer-reviewed scientific literature, which indicates that the ongoing rise in the air's CO2 content will likely lead to substantial increases in the photosynthetic rates and biomass production of the world's major agricultural crops, even in the face of the stressful conditions imposed by less-than-optimum soil moisture conditions. Therefore, future increases in the atmosphere's CO2 concentration will likely lead to increased crop growth and yield production, even in areas where reduced soil moisture availability produces significant plant water stress.


  1. golly, gosh!

    what *great* news to learn we'll have more food to feed the starving billions whose homes and businesses were permanently flooded by rising sea water levels induced by melting polar caps caused by warmer global average temperatures.

    Can I now ignore all the other "features" of environmental destruction caused by rising co2 levels in particular, and fossil fuel proeuction and consumption in general?

    1. You're going to have to wait a long time before sea levels flood your home, around 60,000 years at the current rate, but unfortunately another ice age will intervene well before then.

      To answer your 2nd Q: yes, because there isn't any environmental destruction caused by CO2

  2. If the globe is really warming, won't that just shift the different crop producing regions to the north. For example the corn-belt may push into southern Canada.

    1. Possible but unlikely...

      Globe has warmed only 0.7C over past 150 years since the Little Ice Age- which hasn't caused any noticeable shift in crop producing areas, and could well be that the total area suitable for crop production will simply expand with 1-2C warming, if it occurs.

  3. You say that it will be 60,000 years before ANONYMOUS has his home flooded. Doesn't it depend on where someone lives? I mean, some island communities in India have already seen there homes disappear as entire islands are now underwater...

    1. Global sea levels are rising < 7 inches per century, with no acceleration past 203 years. That means it is natural, not man-made. In some areas such as you mention, the ground is sinking from subsidence, but this has nothing to do with CO2.