Effect of ecological restoration projects on carbon footprint in a grassland ecosystem on the Qinghai-Tibet Plateau

Abstract

Investigating the cost-effective and low-carbon pathways for grassland ecological restoration projects is vital to achieving carbon neutrality and Sustainable Development Goals. To fill the gap of incorporating ecological and socioeconomic systems of ecological restoration projects, this study established a cost-benefit evaluation framework that integrated the carbon footprint based on life cycle assessment and a carbon price measurement model based on the Slack-Based Measure-Data Envelopment Analysis model. Taking a ‘Returning Grazing Land to Grassland Project’ on the Qinghai-Tibet Plateau as a case, this study quantified the carbon footprint of three different ecological measurements, including fences construction (released 107 kgCO2-eq·hm−2 and absorbed 322 kgCO2-eq·hm−2), degenerated grassland improvement (released 1080 kgCO2-eq·hm−2 and absorbed 580 kgCO2-eq·hm−2) and artificial grassland planting (released 2540 kgCO2-eq·hm−2 and absorbed 6540 kgCO2-eq·hm−2). Raw material production was the largest emitter. In addition, we calculated the carbon price in the grassland ecosystem by the carbon price measurement model, at 1.06 yuan·kgCO2-eq−1 on average during 2011–2018. In the cost-benefit analysis, the total carbon sequestration benefits (8.90 × 106 yuan) outweighed the total carbon emission costs (4.26 × 106 yuan). Optimizing the usage and transportation of building materials and the application of fertilizer can benefit carbon emission mitigation and enhancement of carbon sequestration capacity in grassland. This study provided a theoretical basis for ecological restoration projects and grassland carbon pricing mechanisms aiming for sustainable management.