Environmental Engineering Reference
In-Depth Information
Sources: BP, Statistical Review of World Energy 2013, Historical data workbook; World Bank, World Development In-
dicators (WDI) Online Data, April 2014
Note that as recently as 1990, under half the world had “improved sanitation facilities.” The increase to
two thirds in only a few decades is a wonderful accomplishment, but a lot more development is necessary
to make sure everyone has a decent, sanitary environment.
Part of the way we have solved sanitation problems is through the industrialized world's ability to thor-
oughly sanitize any water human beings might consume using high-energy machines. Just as important,
we have created entirely separate water systems to deal with sewage. Historically, a person's sewer tended
to be connected, at least in part, to his drinking water. This was rarely intentional, and early civilizations
did construct sewer systems to isolate human waste, but natural, unrestricted water flows usually lead to
a certain amount of mixing between the human waste and the nearest freshwater source—particularly as
more and more people group together.
Today, sewage is not only kept separate from clean water sources, but it is also extensively treated to
render its most dangerous elements harmless so that it can be disposed of safely, in some cases used as a
fertilizer or even, thanks to the latest technology, turned into drinking water.
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The technology of sewage
treatment is another advance made possible by industrialization, and it is yet another energy-intensive pro-
cess for transforming our environment.
Want a more sanitary environment for people around the globe? We need more cheap, reliable energy
from fossil fuels.
CLEANING THE AIR
