Feeding the World - A Load of Rubbish

Dear Editor,

                     Gwynne Dyer ( Worldwatch 12/01/11) makes his usual sense – nonsense, that is !

There are indeed projections that show the population growing by 35% to 9 Billion and beyond – these being one basis for the IPCC’s dire climate change predictions. Other estimates show a downturn after 2050.

However, as the population grows so does humankind’s generation of CO₂ – with estimates of a doubling by century’s end; but this requires that every scrap of the world’s energy-store be burned (oil, gas, coal, wood, cow-dung ….)

Over 600 studies (bracketed figures) have been published on the effect of increasing CO₂ on food plant yields :-

-       Wheat yields (235) increase by 32.1 ± 1.8 %

-       Rice (182) by 34.4 ± 1.8 %

-       Soybean (179) by 46.5 ± 2.8 %

-       Maize (20) by 21.3 ± 4.9 %

These are the four biggest crops in calorific terms, and will obviously keep pace with population growth, entirely due to CO₂ emission increase (which is why commercial greenhouses often use CO₂-enriched air at 900-1000 ppm.).

In addition, such improved yields require appreciably less water as plants don’t have to open as many stomata. Not that this poses a problem as the prophesized global warming inevitably brings more rain …..

Dave Finney, Matua