According to a recent report by the International Council on Clean Transportation (ICCT), the shipbuilding industry consumed 33.2 million tonnes of steel in 2021 and 2022, primarily from China, South Korea, and Japan.
This consumption led to an estimated 72.2 million tonnes of embodied GHG emissions. By targeting the steel supply chain through measures like increasing scrap-based steel production and adopting hydrogen-based technologies, the sector can play a critical role in achieving international climate goals.
As the steel sector strives to decarbonize to meet international climate goals, tracing demand through the shipbuilding supply chain reveals opportunities to reduce greenhouse gas (GHG) emissions from both sectors through enhanced collaboration.
The analysis informed several policy and strategy recommendations to reduce these emissions, including improving energy efficiency, increasing the use of scrap-based electric arc furnace steel production, adopting hydrogen direct-reduced iron processes, and enhancing cross-industry collaboration.
Shipbuilding requires a substantial amount of steel. It is typically 75%–85% of a ship’s weight (Sustainable Shipping Initiative, 2023). The deadweight tonnage of the global ship fleet has grown over 200% since the 1980s (United Nations Conference on Trade and Development, 2023b), and further global fleet growth will increase both the demand for steel for shipbuilding and the GHG emissions associated with meeting that demand. Decarbonizing the full life cycle of a ship also requires decarbonizing the steel industry.
As informed, steel is typically produced via the blast furnace-basic oxygen furnace (BF-BOF) process using coal and iron ore, or via the electric arc furnace (EAF) process using electricity and scrap or direct-reduced iron (DRI). In the BF-BOF process, coke (coal) reacts with sinter/pellets (agglomerated iron ore) in the blast furnace to form molten iron, which decarburizes in the BOF via high-purity oxygen to produce crude steel (Koolen & Vidovic, 2022). The primary sources of GHGs in the BF-BOF process are sintering/pelletizing, coking, and molten iron production from the use of coking coal as the reductant.
