Environmental Engineering Reference
In-Depth Information
is used globally for agriculture to produce food. Future possible shortage
of freshwater is already speculated to spark off conflicts in arid regions of
Africa. Evidence of global warming is mounting, there is growing urban air
pollution where most live, and the oceans are clearly increasing in acidity
due to CO
2
absorption. Phytoplankton and marine biota are particularly
sensitive to changes in the pH of seawater (Riebesell et al., 2000), and both
the ocean productivity as well as its carbon-sink function might be seriously
compromised by acidification. Some have suggested this is in fact the next
mass extinction since the dinosaurs' die-off, poised to wipe out the species
sustainable mode of living to save itself from extinction in time before the
geological life of the planet ends?
A driving force behind human success as a species is innovation. Starting
with Bronze Age toolmaking, humans have steadily advanced their skills
to achieve engineering in outer space, building supercomputers and now
have arrived at the frontier of human cloning. Human innovative zest has
grown exponentially and is now at an all-time high based on the number
of patents filed worldwide. Recent inventions such as the incandescent light
bulb, printing press, internal combustion engine, antibiotics, stem-cell
manipulation, and the microchip have radically redefined human lifestyle.
A singularly important development in recent years is the invention of the
ubiquitous plastic material. It was about 60 years back when science yielded
the first commodity thermoplastic material. It was an immediate and
astounding successwithincreasing quantities ofplasticsmanufactured each
subsequent year to meet the demands of an expanding base of practical
applications. There is no argument that plastics have made our lives
interesting, convenient, and safe. But like any other material or technology,
the use of plastics comes with a very definite price tag.
Mining anything out of the earth creates enormous amounts of waste; about
30% of waste produced globally is in fact attributed to mining for materials.
In 2008, 43% of the toxic material released to the environment was due
to mining (US Environmental Protection Agency, 2009). For instance, the
mining waste generated in producing a ton of aluminum metal is about
10 metric tons (MT) of rock and about 3 MT of highly polluted mud. The
gold in a single wedding band generates about 18 MT of such waste ore left
over after cyanide leaching (Earthworks, 2004)! The complex global engine
of human social and economic progress relies on a continuing supply of
