Environmental Engineering Reference
In-Depth Information
2
The daily minimum energy an adult human needs to live is approximately 1,000
kilocalories (1 million calories). A person who consumes less than this amount of
energy will lose weight and may eventually die. World War II prisoners in concen-
tration camps received less than 1,000 kcal/day. An adult engaged in normal activ-
ities needs about 2,000 kcal/day, which is the amount of energy contained in a cup
of petroleum. For a person performing heavy manual work, 4,000 kcal/day are ne-
cessary.
Table 2.1
shows the energy needs for a number of human tasks.
To satisfy the growing needs of human beings in modern societies, a considerable
increase in energy consumption is necessary.
Looking through history, one can clearly see that, as human beings have ad-
vanced technologically, their energy needs have also increased.
Figure 2.1
shows
the relationship between human development and energy needs across four cat-
egories: food, home and commerce, industry and agriculture, and transportation.
Table 2.1 Energy needs for different activities
