Potential impact of CO2 leakage from carbon capture and storage (CCS) systems on growth and yield in spring field bean

Anthropogenic carbon dioxide (CO2) emissions are a major factor contributing to rising global temperatures and climate change. Carbon capture and storage (CCS) is a potential mitigating measure which would allow industrial emissions to be captured and stored within deep geological sites. However, in view of possible subsequent leakage to the biosphere, this study examined the impact of elevated soil CO2 on root and shoot growth and crop yield in spring field bean (Vicia faba L.) under field conditions. The results revealed a strong inverse correlation between soil CO2 and O2 concentrations. An area containing plants exhibiting severe chlorosis, reduced growth and extensive mortality developed during the gassing period where soil [CO2] was greatest and [O2] was lowest. Root and shoot growth in surviving plants was significantly lower in gassed than in control plots when soil [CO2] exceeded 10%. Mean values for vegetative (shoot, stem and leaf dry weight plant−1, leaf area plant−1) and reproductive variables (pod and seed number plant−1 and seed dry weight plant−1 were reduced by 36–65% compared to control plants. The only variable which was positively affected by gassing was individual seed dry weight, which was increased by 18%. The results demonstrate the severity of damage to terrestrial vegetation that may be induced by CO2 leakage from CCS transport or storage facilities.

► Leakage from CO2 capture and storage (CCS) systems may damage surface vegetation. ► CO2 was injected into the soil under field bean crops to simulate leakage. ► Plants exposed to soil CO2 concentrations >50% did not survive. ► Root and shoot growth and seed yield of surviving plants were reduced by 36–65%. ► Leakage from CCS sites may greatly reduce the productivity of surface vegetation.