Carbon reduction and water saving potentials for growing corrugated boxes for express delivery services in China.

Corrugated packaging for express grew by 90 times to 16.5 Mt y-1 in China, where 81% of recent global express delivery growth occurred. However, the environmental impacts of production, usage, disposal, and recycling of corrugated boxes under the entire supply chain remain unclear. Here, we estimate the magnitudes, drivers, and mitigation potentials of cradle-to-grave life-cycle carbon footprint (CF) and three colors of water footprints (WFs) for corrugated cardboard packaging in China. Over 2007 to 2021, CF, blue and gray WFs per unit package decreased by 45%, 60%, and 84%, respectively, while green WF increased by 23% with growing imports of virgin pulp and China's waste ban. National total CF and WFs were 21 to 102 folded with the scale effects. Only a combination of the supply chain reconstruction, lighter single-piece packaging, and increased recycling rate can possibly reduce the environmental footprints by 24 to 44% by 2035.

Tracking indirect water footprints, virtual water flows, and burden shifts related to inputs and supply chains for croplands: A case for maize in China.

Increasing crop yields to ensure an adequate food supply under water and land scarcity is dependent on intensive agricultural inputs (such as fertilizers, pesticides, agri-films, or energy) which consume water resources and generate water pollution. However, the burden shifting of water quantity and quality stress from producers to importer and consumers through agricultural input production, trade, and consumption have been largely overlooked. Here, taking maize in China as the study case, we mapped step-by-step indirect water footprint (IWF) of maize production, virtual water (VW) flows related to inputs driven by maize consumption, and the resulting burden shifting of water quantity and quality. Bottom-up WF accounting approach was applied. The maize consumption was intercepted into two stages: the crop production stage (CPS) from raw materials to the farm, and the crop trade stage (CTS) from farm to fork. Results show that the national average blue and grey IWF of maize production was 3.91 and 26.86 m3/t, respectively. In the CPS, the input-related VW flowed from the west and east coast to the north. In the CTS, the VW flows from the north to the south. Blue and grey VW flows in CTS caused by secondary flows of VW in CPS accounted for 48% and 18% of the total flows, respectively. In total VW flows along the maize supply chain, 63% of blue VW and 71% of grey VW net exports occurred in the north of severe water scarcity and water pollution levels. The analysis highlights the impact of the crop supply chain on water quantity and water quality in the consumption of agricultural inputs, the importance of step-by-step supply chain analysis for regional crop water conservation management, and the urgent need for integrated management of agricultural and industrial water resources.

Inputs for staple crop production in China drive burden shifting of water and carbon footprints transgressing part of provincial planetary boundaries.

Crop production is the biggest water user and key contributor to anthropogenic greenhouse gas emissions. Increasing crop yields to ensure adequate food supply under water and land scarcity is excessively dependents on intensive agricultural inputs (such as fertilizers, pesticides, agri-films, or energy), resulting in unintended environmental consequences. Supply chains bringing environmental-intensive inputs from their place of production to the croplands. However, most food-related environmental assessments ignore the environmental burden of agricultural input production, trade, and consumption. Here, we estimate spatially-detailed water (WF) and carbon footprints (CF) of wheat, maize, and rice production in China with extended system boundary from upstream raw material mining to the field. The agricultural inputs account for up to 24% and 89% of a crop's WF and CF, respectively, at the provincial level. The total local generated WF in Chinese northern provinces and CF in Shanxi and Inner Mongolia provinces for producing crops and agricultural inputs transgresses the corresponding downscaled blue water and carbon planetary boundaries. The study broadens the scope of traditional environmental impact assessments in agricultural production and sheds light on the significances to manage the linkages between the crop production and the agricultural inputs' upstream supply chains towards more efficient water use and less greenhouse gas emissions in food system.