I personally think AN is more authoritative than Stanferd, but that's just me...
Source: Stanford University
Posted: December 6, 2002
Climate Change Surprise: High Carbon Dioxide Levels Can Retard Plant Growth, Study Reveals
The prevailing view among scientists is that global climate change may prove beneficial to many farmers and foresters at least in the short term. The logic is straightforward: Plants need atmospheric carbon dioxide to produce food, and by emitting more CO2 into the air, our cars and factories create new sources of plant nutrition that will cause some crops and trees to grow bigger and faster. But an unprecedented three-year experiment conducted at Stanford University is raising questions about that long-held assumption. Writing in the journal Science, researchers concluded that elevated atmospheric CO2 actually reduces plant growth when combined with other likely consequences of climate change namely, higher temperatures, increased precipitation or increased nitrogen deposits in the soil.
sciencedaily.com
but we have the axe 
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INCREASED CO2 LEVELS ARE MIXED BLESSING FOR AGRICULTURE
COLUMBUS, Ohio – A new study suggests that rising levels of carbon dioxide in the atmosphere could be a boon for agricultural crops, as this greenhouse gas helps crop plants grow and reproduce more.
Peter Curtis
But that boon comes with a price, said Peter Curtis, a professor of evolution, ecology and organismal biology at Ohio State University. Greater growth and reproduction may hurt the nutritional value of crops.
“If you’re looking for a positive spin on rising CO2 levels, it’s that agricultural production in some areas is bound to increase,” Curtis said. “Crops have higher yields when more CO2 is available, even if growing conditions aren’t perfect.
“But there’s a tradeoff between quantity and quality. While crops may be more productive, the resulting produce will be of lower nutritional quality.”
researchnews.osu.edu |
