The impact of importing on the CO₂ intensity of the global and national construction industries

CO₂ intensity is a valuable indicator for investigating the amount of CO₂ emissions prevented by importing relative to the economic costs the importer pays for international trade; this plays a significant role in mitigating climate change and promoting environmental sustainability. This study explores the effect of importing on the CO₂ intensity of the construction industry by establishing an analytical framework that divides the total CO₂ intensity into aggregate CO₂ intensity in imported products (AII) and aggregate CO₂ intensity in domestic products (AID), and targets the gap between AII and AID to reveal the effects of importing. A multi-regional input-output model was adopted to evaluate the AII and AID of the construction industries in 15 economies for 2014 and then the LMDI method was used to decompose the gap between AII and AID from the perspective of the source industry. The results indicated that importing showed an increased effect of 3.11 ton/USD on the CO₂ intensity of the construction industry globally. At a national scale, importing increased the CO₂ intensity of the construction industries in most countries (13/15). In terms of decomposition analysis, the aggregate CO₂ intensity effect decreased AII by 23.15 ton/USD and the aggregate structure effect increased AII by 151.51 ton/USD. For most economies, the aggregate structure effect, especially when sourcing from the electricity industry and the mining industry, mainly caused AII to be higher than AID and resulted in a pulling effect of importing on the CO₂ intensity of the construction industry. On this basis, adjusting industrial source weights in importing is significant for achieving the CO₂ intensity mitigation targets of the global and national construction industries.