Regarding encouraging plant growth, that is a direct CO2 effect. Interestingly, I just learned that it is killing koalas. You see, CO2 fertilized plants put more of their energy into structure. Eucalyptus leaves become harder for present day koalas to digest because they are more fibrous.
The person I heard this from (a world renowned ecologist) suspects that many food plants may become more fibrous and harder to digest. So the CO2 fertilization effect is not obviously a win for us fauna.
In general, rapid change in the environment is bad for niche species and good for pests. That is why the concept of "degraded ecosystem" makes sense.
Now picture ever increasing disruption everywhere...
Image: New Zealand Herald, at the first link above.
The only thing we can be sure of about the future is that it will be absolutely fantastic. So if what I say now seems to you to be very reasonable, then I have failed completely. Only if what I tell you appears absolutely unbelievable, have we any chance of visualizing the future as it really will happen.
- Arthur C. Clarke (h/t Brin)