Afforesting arid land with renewable electricity and desalination to mitigate climate change

Afforestation can effectively remove CO2 but is constrained by the availability of suitable land and water resources. This study shows the large potential of afforestation for CO2 sequestration in arid areas globally, using renewable electricity, particularly from solar photovoltaics, to power desalination plants. Afforestation is one of the most practised carbon dioxide removal methods but is constrained by the availability of suitable land and sufficient water resources. In this research, existing concepts of low-cost renewable electricity (RE) and seawater desalination are built upon to identify the global CO2 sequestration potential if RE-powered desalination plants were used to irrigate forests on arid land over the period 2030-2100. Results indicate a cumulative CO2 sequestration potential of 730 GtCO(2) during the period. Global average cost is estimated to be euro457 per tCO(2) in 2030 but decrease to euro100 per tCO(2) by 2100, driven by the decreasing cost of RE and increasing CO2 sequestration rates of the forests. Regions closer to the coast with abundant solar resources and cooler climate experience the least costs, with costs as low as euro50 per tCO(2) by 2070. The results suggest a key role for afforestation projects irrigated with RE-based desalination within the climate change mitigation portfolio, which is currently based on bioenergy carbon capture and storage, and direct air carbon capture and storage plants.

Automated summary

This study demonstrates the potential of using renewable electricity, particularly from solar photovoltaics, to power desalination plants and facilitate afforestation for CO2 sequestration in arid areas worldwide. The results indicate a cumulative CO2 sequestration potential of 730 GtCO(2) during the period from 2030 to 2100. The average global cost is estimated to decrease from euro457 per tCO(2) in 2030 to euro100 per tCO(2) by 2100.