Dynamic assessment of ecological sustainability and the associated driving factors in Tibet and its cities.

With the general decline of the life support system on earth, it is of great value to carry out ecological sustainability research. This study used the improved ecological footprint (EF) model to calculate the EF of Tibet and its cities (prefecture-level administrative regions) from 2005 to 2017, quantified its ecological sustainability, and analyzed its driving factors using the logarithmic mean divisia index method. The study found that: (1) The EF of Tibet is steadily increasing, yet its distribution among cities is extremely uneven. The size of the internal sub-footprints is different and the distribution is extremely uneven in each city; (2) The ecology of Tibet and other cities is in a safe state, except for Lhasa that is in a completely unsafe state. The ecological footprint diversity index of Tibet, Lhasa, Qamdo, and Shannan showed a downward trend, while the other cities are the opposite. The coordination is deteriorating between the ecological and economic systems of Lhasa and Ngari, while the opposite is for Tibet and other cities; (3) The EF growth of Tibet and its cities is mainly driven by per unit of GDP, population size and footprint structure. The footprint intensity is a decisive factor in slowing down the growth of EF. This research is helpful for actors at all levels to identify the appropriate strength and type of policies to achieve ecologically sustainable development.