More green plants?
http://www.climatecentral.org/news/study-finds-plant-growth-surges-as-co2-levels-rise-16094
FTA
Trees are likely to invade grasslands in the drier regions, and their deep roots are better equipped to tap groundwater and at the same time stabilize the soils.
“Even if nothing else in the climate changes as global CO2 levels rise, we will still see significant environmental changes because of the CO2 fertilization effect,” says Dr. Donohue
So we are coming out of an ice age, still not proof of harm by man, and still not even close to the temps of the Medieval optimum!