Questions Concerning "Plant Life in a CO2-Rich World"

1. It has been argued by some that human-caused increases of the earth’s atmospheric CO₂ is beneficial to the environment (= global ecosystems) because it will enhance photosynthesis, increasing productivity, and thus help feed the world. Do you agree or disagree? Why?
2. Guard cells in stomatal complexes of leaves act as mutisensory regulatory valves. What are the implications of guard cell response to global elevations in CO_2?
3. Often, in the real world, environmental changes do not occur in isolation, that is a change in one component is linked to a second component and so on. Thus, as humans cause an elevation in atmospheric CO₂, a second component is also changed, for example global warming. How will the combined effects of elevated CO₂ and an attendant increase in temperature affect the cultivation and harvest of corn (C₄ plant) in Nebraska?
4. Why do "short-term gains" in photosynthesis under elevated CO₂ not necessarily translate into "long-term gains" in photosynthesis?
5. Why are C₄ plants at a disadvantage relative to C₃ plants with the predicted increase in global CO₂?
6. Do stomata tend to close or open in response to elevated CO₂?
7. When stomata close, which is impacted more, CO_{2 uptake} or water loss? Why?
8. Is CO₂ the most limiting factor to luxurious plant growth or are nutrients and water also a factor? Which are the most limiting?
9. How will the following respond to an increase in atmospheric CO₂? Plant biodiversity; Plant extinction; Plant community structure; Weedy plant species ; Nitrogen content of leaves; Insect consumption of leaves; Predators of insects
10. Will increased plant growths in response to elevated CO₂compensate for the CO₂ increase? That is, will the increased growth, enhance photosynthesis resulting in an increased carbon sink to balance the source (burning of fossil fuels and deforestation.)?
11. How will an increase in CO₂ plus and increase in temperature in tundra potentially aggravate the rise of atmospheric CO₂? (Hint: consider the permafrost and decomposition rates in tundra ecosystems).