Civil Engineering Reference
In-Depth Information
Figure 11.4
Full world
al
Energy
Energy
Growing
Economic
Subsystem
Resources
Wastes
Recycled
matter
Source:
Adapted from Goodland, Daly and El Serafy (1992)
Key Points 11.1
❍
The economic system and the environmental system are inextricably
integrated, since goods and services can not be produced or consumed
without the environment providing resources at the beginning of a
product's life cycle and absorbing waste at the end of the cycle.
❍
The mass balance model focuses on energy used and wasted by economic
activity. It highlights the resource intensive nature of construction and
prompts a contrast between the 'empty world' of the past and the 'full
world' of today.
❍
There are two contrasting approaches to achieving sustainable
development: one based on technology, in which decreases in natural
capital are substituted by man-made assets; and another which places far
greater emphasis on the critical nature of natural capital.
