Negatives from more C02:
- The added heat cancels out any short termed positive effect for some of the plants. A 20 years study of crops grown under enhanced CO2 finds that there is an upper limit to C3 enhancement from CO2, while C4 plants, after a sufficient length of time, adapt to high CO2 by improving their uptake of nitrogen. So: Increased CO2 ultimately depresses C3 growth, while C4 plants, which include numerous pest varieties, will become more vigorous. The net result is depressed food production.
- Weeds benefits faster from more C02
- Biodiversity is already affected by GW
- Insects and their habitats are already affected by pollutions and CC
- Oxygen producing phytoplankton in the oceans are already effected by global warming.
- Farmers world wide are hit hard by floods and drougts. Natural Disasters Are Costing Farming Billions of Dollars a Year
- Greening the earth adds to the land albedo effect and is amplifying global warming
- Increased carbon dioxide levels in air restrict plants' ability to absorb nutrients
- Plant quality declines as CO2 levels rise
- Climate change happening 'too fast' for plant and animal species to adapt
- CO2 enhanced plants will need extra water both to maintain their larger growth as well as to compensate for greater moisture evaporation as the heat increases. Where will it come from? In many places rainwater is not sufficient for current agriculture and the aquifers they rely on are running dry throughout the Earth.
Greening the earth adds to the land albedo effect;
As the land warms up, trees and forests migrate north. White snow that reflects sunlight back to space is covered with dark green leaves or dark brown tree trunks and branches, which absorb sunlight and convert it to heat, with the same effect of amplifying global warming.
Darkening the earth's albedo is a very bad idea right now.
Crop failure and bankruptcy threaten farmers as drought grips Europe
The "C02 is good for plants" argument debunked:
Two major groups of plants have shown a surprising reversal of fortunes in the face of rising levels of carbon dioxide in the atmosphere.
During a 20-year field experiment in Minnesota, a widespread group of plants that initially grew faster when fed more CO2 stopped doing so after 12 years, researchers report in the April 20 Science.
A 16-year study found that we’re at a point where more CO2 won’t keep increasing plant production, but higher temperatures will decrease it
IPCC report warns of future climate change risks, but is spun by contrarians | Dana Nuccitelli
Warming rivals habitat loss and land degradation as a threat to global wildlife
Worrying the Facts Versus Challenging the (Hidden) Premise
The CO2-Is-Plant-Food argument, at least as used by conservative climate skeptics, has two parts. The first is the “scientific” claim that CO2 is good for plants. The second is the policy implication: therefore, CO2 should not be regulated so as to slow or reverse its increase. But the implication only seems to follow from the claim. To actually get to this policy, one must also assume a broader rule or premise: things that are good for plants are not regulated.