Improved sustainability assessment of the G20’s supply chains of materials, fuels, and food

Abstract

Transparency in global value chains of materials, fuels, and food is critical for the implementation of sustainability policies. Such policies should be led by the G20, who represent more than 80% of global material, fuel, and food consumption. Multi-regional input-output (MRIO) analysis plays an important role for consumption-based assessment, including supply chains and their environmental impacts. However, previous accounting schemes were unable to fully assess the impacts of materials, fuels, and food. To close this gap, we provide an improved method to map key aspects of sustainability along value chains of materials, fuels, and food. The results show that the rise in global coal-related greenhouse gas (GHG) emissions between 1995 and 2015 was driven by the G20’s metals and construction materials industry. In 2015, the G20 accounted for 96% of global coal-related GHG emissions, of which almost half was from the extraction and processing of metals and construction materials in China and India. Major drivers include China’s rising infrastructure and exports of metals embodied in machinery, transport and electronics consumed by other G20 members. In 2015, the vast majority (70–95%) of the GHG emissions of metals consumed by the EU, USA, Canada, Australia, and other G20 members were emitted abroad, mostly in China. In contrast, hotspots in the impact displacement of water stress, land-use related biodiversity loss, and low-paid workforce involve the G20’s food imports from non-G20 members. Particularly high-income members have contributed to the G20’s rising environmental footprints by their increasing demand for materials, food and fuels extracted and processed in lower-income regions with less strict environmental policies, higher water stress and more biodiversity loss. Our results underline the G20’s importance of switching to renewable energy, substituting high-impact materials, improving supply chains, and using site-specific competitive advantages to reduce impacts on water and ecosystems.

Hotspots of Mining-Related Biodiversity Loss in Global Supply Chains and the Potential for Reduction through Renewable Electricity

“…Overall, more than half of global coal-mining related biodiversity loss is related to heat and electricity supply to manufacture metals (29%), cement (10%), chemicals (10%), and plastics (5%). This is in accordance to previous studies showing that many climate and particulate-matter related health impacts of coal combustion are induced in China and India 42,50 , with a rising fraction related to material production (mostly cement, steel and plastics for building their infrastructure and supplying the global market).…”

“…While Werner et al 41 found that mining quantity is a reasonable proxy for mining area (based on a mining dataset of 3'633 km 2 ), our results indicate that for most countries and mining products, neither quantity is suitable to predict mining area, nor is mining area appropriate to estimate biodiversity loss. Furthermore, our results show that hotspots of biodiversity loss differ from other environmental impacts of mining products, such as climate and particulate-matter related health impacts, dominated by China's steel and cement production 42 . This highlights the importance of considering local biodiversity loss of land use to promote sustainable practices in the mining and metals industry.…”

“…Overall, a quarter of global metals-related biodiversity loss is attributed to steel. This fraction is significantly lower than for climate impacts of metals, which are dominated by steel production (>80%), mostly because of coal combustion 42 .…”

Hotspots of Mining-Related Biodiversity Loss in Global Supply Chains and the Potential for Reduction through Renewable Electricity

“…36,49 Furthermore, our results show that hotspots of biodiversity loss differ from other environmental impacts of mining products, such as climate and particulate matter-related health impacts, dominated by China's steel and cement production. 50 This highlights the importance of taking the local biodiversity loss of land use into consideration to promote sustainable practices in the mining and metal industry.…”

“…This fraction is significantly lower than that for the climate impacts of metals, which are dominated by steel production (>80%), mostly because of coal combustion. 50 The link between metal mining and processing countries shows that most biodiversity loss is induced in a country other than where metals are further processed (Figure 4a,b). Similarly, most metals are processed in a country other than where they are finally consumed (Figure 4b,c).…”