text: Among other things, Pardos et al . report that seedling relative growth rate rose 2.2-fold when going from the lowest to the highest combined light-water treatment in the elevated CO 2 environment, but only 1.6-fold when doing so in the ambient CO 2 environment. In addition, they say that "cork oak showed particularly large increases in biomass in response to elevated CO 2 under low-watered and high-illuminated conditions." What it means