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Inego_de_Loyola
Guest
I think I covered this somewhere in this thread. The issue is more like it’s the amount that makes the food or poison. Here’s an excerpt from a paper I wrote on Food Rights & CC:
What might global warming and its effects mean for food and food production? First we need to address the argument that elevated carbon dioxide levels increase crop production.** Aside from this being disingenuous because the CO2 is also causing warming and other effects that could be harmful to crops,** there is evidence that increasing CO2 will not help crops as much as expected, and may even harm some crops and sea life, never mind the warming (Cline 2007: 23-26). While earlier enclosed studies showed increased growth with added CO2, recent open field studies show less increase and even a decline of some crops (Long, et al. 2006, Cruz, et al. 2007: 480). Furthermore, crops were found to be less nutritious (Högy, et al. 2009), and had greater pest damage (Hunter 2001). In the real world, crop growth is affected by many factors beyond CO2, including other nutrients, water supply, climate, extreme weather events, soil moisture, toxins expected to increase with global warming, and soil acidification from CO2 (Oh and Richter 2004). So while CO2 may moderately enhance crops up to a point, these other factors are expected to limit the potential enhancement and even lead to eventual declines. When the impact of warming is considered, a nonlinear relationship regarding crop productivity has been found for mid and high latitudes – the U.S., Canada, Europe, Russia, Japan and Northern China – with increased yields projected up to around 2050, after which the warming causes sharp decrease (Schlenker and Roberts 2009). A more recent study has found that climate change has already reduced some crops globally, despite CO2 fertilization and improved technology (Lobell, et al. 2011). As for sea life, an important human food supply, CO2-caused ocean acidification is having negative impacts on zooplankton (at the base of the food chain), shellfish, fish, and coral reefs, home to one-fourth of sealife (Rogers and Laffoley 2011; Doney, et al. 2009; Hoegh-Guldberg, et al. 2007; Munday, et al. 2010).
BZZZZT I’m sorry, but warming is good for most plants; would you like to take another guess.