One of the consequences that I find more fascinating with the increased CO2 problem is the changes that affect specific components of the environment. One example that I like is the effect on poison ivy. Researchers at Duke University (Mohan et al., 2006), as part of their Free-Air CO2 Enrichment (FACE) experiment, reported a large change in poison ivy activity when they added CO2. They claim:
"...elevated atmospheric CO2 in an intact forest ecosystem increases photosynthesis, water use efficiency, growth, and population biomass of poison ivy."
For more information on the experiment and the many results they have obtained from it, check here. They have more than 250 publications on the findings of the experiment.
So now, on top of all the other changes, we have to put up with poison ivy on steroids.
However, it is important to keep in mind that
... species that respond strongly to elevated Carbon in [nonresource-limited] experiments are unlikely to also be the most responsive in resource-limited field conditions... [so] we cannot directly extrapolate ... which species will be most responsive to elevated Carbon in the long term.
(Ali et al., 2013)
The rise in [CO2] will probably alter the prevalence of invasive species, but the nature of this change is difficult to predict. Whereas alien species may benefit from higher[CO2] in some regions, native species may benefit in others. Plants with certain CO2-responsive traits are likely to benefit from the rise in [CO2], especially if they are growing in ecosystems where those traits are rare. For instance, C3 species growing in C4-dominated ecosystems are likely to benefit from the rise in [CO2] (but under some circumstances may not). Invasiveness and CO2-responsiveness are not clearly linked.