The Phase 1 environmental statement estimates that 5.8–6.2 million tons of carbon dioxide equivalent emissions will be involved in the construction of that section of the line, with operation of the line estimated to be carbon negative thereafter; operational emissions, modal shift, and other environmental mitigations—such as tree planting and decarbonisation of the electrical grid—are expected to provide a saving of 3 million tons of CO2-equivalent emissions over sixty years of operation. The carbon dioxide emissions per passenger-kilometre in 2030 are estimated to be 8 grams for high-speed rail, as opposed to 22 grams for conventional intercity rail, 67 grams for private car transport, and 170 grams for domestic aviation.