The study investigates the environmental effects associated
with economic activities in four categories: energy consumption,
air emission, freshwater consumption, and water pollutant discharge.
Energy use and energy structure affects urban carbon
footprint and other air pollutions [53]. As Xiamen depends upon
imports for most of its energy use, energy conservation and
emission reduction are crucial for sustainable development [54].
Air emissions, such as Greenhouse Gases (GHGs), sulfur dioxide
(SO
2
), and nitrogen oxide (NO
), contribute to climate change, acid
rain, ocean acidification, and water pollution through atmospheric
deposition. In Xiamen's Western Sea and Tong’an Bay, atmospheric
deposition accounts for 10.05% of the nitrogen loading from nonpoint
sources [27]. Water scarcity has been a long-term problem in
Xiamen city. Its per capita water availability is far below the
X
internationally recognized alarm level [55]. Currently, over 80% of
the water supply relies on a trans-regional water diversion
program [56]. Historically, water pollution in the Xiamen Bay are
measured in terms of chemical oxygen demand (COD), total
nitrogen (TN) and total phosphorous (TP) [27]. In the study, data
on the above external effects per unit of output by industry sector
(r
i
) are compiled from recent studies on the China's economy and
environment: energy consumption and air emission coefficients