In artifical conditions in laboratory there is a significant effect, up to 20% when doubling pre-industrial CO2 concentration.
But, in practice for wild plants nitrogen quickly becomes the bottleneck, so the real gains are much smaller.
And even for farming plants (which have fertilizer providing additional nitrogen) the real gains diminish, and are more in 5-10% range. For some crops CO2 has very little effect at all (for example corn).
Additionally - crops grew with raised CO2 levels have less proteins and useful nutrients.
And then you have to factor in the harmful effects from global warming on crops (heat damage, dry soil, less farmland available) and the overall effect is likely negative.
In artifical conditions in laboratory there is a significant effect, up to 20% when doubling pre-industrial CO2 concentration.
But, in practice for wild plants nitrogen quickly becomes the bottleneck, so the real gains are much smaller.
And even for farming plants (which have fertilizer providing additional nitrogen) the real gains diminish, and are more in 5-10% range. For some crops CO2 has very little effect at all (for example corn).
Additionally - crops grew with raised CO2 levels have less proteins and useful nutrients.
And then you have to factor in the harmful effects from global warming on crops (heat damage, dry soil, less farmland available) and the overall effect is likely negative.
https://www.scientificamerican.com/article/ask-the-experts-d...