Enhanced rock weathering supply chain lifecycle sustainability

Climate change caused by anthropogenic greenhouse gas (GHG) has been widely reported as one of the negative human induced impacts with the scientific evidence suggesting that climate change presents overwhelming global risks to economies, the environment and livelihood and so it demands urgent global response in mitigation and adaptation. In view of this, there is growing research into potential CO2 sequestration methods that can be implemented as climate mitigation strategies. One such option, which has been reported as a credible mechanism is Enhanced Rock Weathering (ERW); a form of global carbon sequestration which involves the spreading of crushed silicate rocks on lands to speed up
the removal of atmospheric carbon dioxide. Despite the potential of ERW, there is limited understanding of the Triple Bottom Line (TBL) supply chain sustainability implications of ERW which encompasses economic, environmental, and social impacts and these remain an important but underexplored research area. Consequently, providing a robust theoretical base and developing a quantitative supply chain modelling framework for analysing and understanding the TBL implications of ERW have become timely and important.

To address the aforementioned issues, this research adopts a quantitative research approach based on the methodological principle of supply chain TBL (economic, environmental, and social) impact assessments to address the pertinent questions surrounding ERW sustainability. For the environmental quantitative analysis, environmentally extended input-output and process life cycle analyses are used separately for estimating impacts across a range of comprehensive and integrated indicators. The economic assessment of ERW is done by way of performing macro-level lifecycle costing of silicate production using economic input-output model. Social implications of the ERW process such as labour rights and human
rights issues are assessed using a socially extended input-output method based on the social hotspot database (SHDB).

The research findings suggest that improvements in TBL sustainability associated with ERW implementation is dependent on improvements in environmental and social impacts. Based on a comparative lifecycle assessment, the study also highlights that embodied environmental impacts of basalt fertiliser is less when compared to industrial fertilisers and artificial silicate sources.