According to an IPCC scenario, the concentration of ground-level or tropospheric ozone (O3) may reach 70 ppb in 2050. Then, more than 30% of global cereal acreage could be exposed to significant ozone pollution, which in turn would lead to significantly lower crop yields.
Ground-level or tropospheric ozone (O3) is ingested by plants through their stomata (pores in the epidermis of plants) and has a growth-inhibiting effect: O3 leads to a reduced rate of photosynthesis, increased respiration and accelerated ageing of leaves. O3 also increases the plants’ susceptibility to diseases and other stress factors. O3 is also thought to alter the concentration of nitrogen, carbohydrates and phenols in the leaf and grain.