<![CDATA[Grist - Comment Feed for High CO2 crops could be low on nutrition]]> Grist Comment Feed en Comment #1 by justlou http://www.grist.org/article/global-warming-and-empty-calories/ Tue, 14 Aug 2007 23:40:41 -0700 http://www.grist.org/article/global-warming-and-empty-calories/1 Don't count on the quantity either

I would not advise counting on the quantity of food continuing to rise and match population growth. Collapses have been associated with  declining quantities and qualities of food sources, both of which affect health, disease and political stability.  

An interesting article on Peak Phosphorus and the relationship between phosphorus production, peak oil, agricultural production and population growth:
http://www.energybulletin.net/33164.html
"Phosphorus may be the real bottleneck of agriculture."

]]> Don't count on the quantity either

I would not advise counting on the quantity of food continuing to rise and match population growth. Collapses have been associated with  declining quantities and qualities of food sources, both of which affect health, disease and political stability.  

An interesting article on Peak Phosphorus and the relationship between phosphorus production, peak oil, agricultural production and population growth:
http://www.energybulletin.net/33164.html
"Phosphorus may be the real bottleneck of agriculture."

]]> Comment #2 by Biodiversivist http://www.grist.org/article/global-warming-and-empty-calories/ Wed, 15 Aug 2007 00:57:59 -0700 http://www.grist.org/article/global-warming-and-empty-calories/2 Common sense would suggest

that plants evolved to grow in a given CO2 environment will be compromised when that environment changes. The plants will eventually evolve and adjust to the new levels but that will take stable levels and a few centuries.

In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world

]]> Common sense would suggest

that plants evolved to grow in a given CO2 environment will be compromised when that environment changes. The plants will eventually evolve and adjust to the new levels but that will take stable levels and a few centuries.

In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world

]]> Comment #3 by sindark http://www.grist.org/article/global-warming-and-empty-calories/ Wed, 15 Aug 2007 01:17:22 -0700 http://www.grist.org/article/global-warming-and-empty-calories/3 Temperature and crops

Another major consideration is the increase in both maximum and minimum temperatures.

Higher maximum temperatures increase the chances of crop failure, especially among plants that use C3 photosynthesis. Higher minimum temperatures in winter can assist the spread of pests, as the current situation in British Columbia's pine forests amply demonstrates.

]]> Temperature and crops

Another major consideration is the increase in both maximum and minimum temperatures.

Higher maximum temperatures increase the chances of crop failure, especially among plants that use C3 photosynthesis. Higher minimum temperatures in winter can assist the spread of pests, as the current situation in British Columbia's pine forests amply demonstrates.

]]> Comment #4 by justlou http://www.grist.org/article/global-warming-and-empty-calories/ Wed, 15 Aug 2007 02:02:16 -0700 http://www.grist.org/article/global-warming-and-empty-calories/4 Other Factors

Many of the crop experiments testing the influence of higher carbon dioxide levels on photosynthesis and yield were conducted in very controlled, growth chamber like environments.  In the real world production will be affected by many environmental factors that are not controllable.  Higher temperatures during grain fill will reduce the number of days that grains are being filled, decreasing yield potential.  Higher night temperatures will increase respiration rates, decreasing grain fill.  Plus warming will be associated with extremes of drought and flooding which can reduce production.  Other biological factors affected by temperature and CO2 include weed, disease and insect pests also enter into the equation.  

Can the gene jockeys keep ratcheting up the biotechnology to compensate for all the potential negatives associated with warming and higher CO2?  Very unlikely.  

Food vs. energy production is also a key determinant.  As is our continuing destruction of prime farmland in the US.

]]> Other Factors

Many of the crop experiments testing the influence of higher carbon dioxide levels on photosynthesis and yield were conducted in very controlled, growth chamber like environments.  In the real world production will be affected by many environmental factors that are not controllable.  Higher temperatures during grain fill will reduce the number of days that grains are being filled, decreasing yield potential.  Higher night temperatures will increase respiration rates, decreasing grain fill.  Plus warming will be associated with extremes of drought and flooding which can reduce production.  Other biological factors affected by temperature and CO2 include weed, disease and insect pests also enter into the equation.  

Can the gene jockeys keep ratcheting up the biotechnology to compensate for all the potential negatives associated with warming and higher CO2?  Very unlikely.  

Food vs. energy production is also a key determinant.  As is our continuing destruction of prime farmland in the US.

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