  China aims for net-zero carbon emissions by 2060, and an emissions peak
before 2030. This will reduce its consumption of coal for power generation and
steel making. Simultaneously, China aims for improved energy security,
primarily with expanded domestic coal production and transport infrastructure.
Here, we analyze effects of both these pressures on seaborne coal imports, with
a purpose-built model of China's coal production, transport, and consumption
system with installation-level geospatial and technical detail. This represents
a 1000-fold increase in granularity versus earlier models, allowing
representation of aspects that have previously been obscured. We find that
reduced Chinese coal consumption affects seaborne imports much more strongly
than domestic supply. Recent expansions of rail and port capacity, which reduce
costs of getting domestic coal to Southern coastal provinces, will further
reduce demand for seaborne thermal coal and amplify the effect of
decarbonisation on coal imports. Seaborne coking coal imports are also likely
to fall, because of expanded supply of cheap and high quality coking coal from
neighbouring Mongolia.
