Civil Engineering Reference
In-Depth Information
Special enzymes in the mould release carbohydrates which enter the earth, stim-
ulating bacterial growth, which in its turn attacks the molecular structure of the
cellulose and releases soluble constituents of nitrogen. The end product is
humus, which forms a foundation for different plant organisms, providing nutri-
ents for the growth of new cellulose fibres.
In this way global recycling is based almost entirely on closed cycles, which
means that there is hardly any waste in nature. These methods can also be con-
sidered a more sensible way of depositing a material compared with ordinary
recycling or energy recovery.
Raw materials in a world context
The term 'under-developed country' is a totally misleading description when
considered in an ecological light. In many cases the ecological cycles work much
better in the so-called under-developed countries. Here we characterize coun-
tries by their degree of industrialization: high industrialization, medium indus-
trialization, and low industrialization.
Most of today's global consumption of materials takes place in the northern
temperate zone. But that does not mean that most of the raw materials are found
in this part of the globe - it seems that the consequence of increased industrial-
ization is an increased dependence on imported raw basic materials. Western
Europe imports about 80 per cent of its minerals and 60 per cent of its energy. The
suppliers are usually countries with low industrialization.
Looking at the accessibility of raw materials, it is quite clear that increased
consumption and industry in countries with low or medium industrialization
must lead to a de-industrializing of the northern part of the globe. Many west-
ern European concerns have exported all or part of their work operations to
guarantee future development. Initially it looks as though they often choose a
manufacturing process that has difficulty achieving Western environmental
standards.
Energy resources
On current projections, there are sufficient gas and oil resources for another
40-60 years. Coal reserves will last for another 1000 years, but with the problem
of related acid rain and carbon dioxide emission. Environmentalists predict a
quick and violent ecological crisis if we use coal as an alternative energy
resource. This means we have to keep to nuclear power in breeder-reactors, using
uranium and thorium, or renewable energy resources such as the sun, wind, heat
exchangers and water power. The conclusions are quite clear: nuclear power has
