Irrigation of biomass plantations may globally increase water stress more than climate change

Bioenergy with carbon capture and storage (BECCS) is considered an important negative emissions (NEs) technology, but might involve substantial irrigation on biomass plantations. Potential water stress resulting from the additional withdrawals warrants evaluation against the avoided climate change impact. This study quantitatively assesses potential side effects of BECCS with respect to water stress by disentangling the associated drivers (irrigated biomass plantations, climate, land use patterns) using comprehensive global model simulations. Results suggest that widespread use of irrigated biomass plantations, while limiting global warming to 1.5 °C by the end of the 21st century, could double the global area and population under severe water stress, exceeding even the impact of climate change alone. Sustainable water management is crucial to mitigate this.

Fabian Stenzel, Peter Greve, Wolfgang Lucht, Sylvia Tramberend, Yoshihide Wada, Dieter Gerten