A study in the United Kingdom found that

producing food requires nearly five times as much

energy as is contained in the food. This chart shows

how much energy is used for each 1000 Calories

(4.184 megajoules) of food consumed.

Food supply

9.74 MJ

Packaging

2.12 MJ

Home storage

and cooking 5.96 MJ

Transportation

and retailing

Based on data from “What it takes to make that meal” Science, vol. 237, p. 809, 12 February 2010. 1.55 MJ

2

Sustainability

and Human

Values

A SUSTAINABILITY ETHIC

I

n 1962, Rachel Carson’s book Silent Spring

questioned the wisdom of the rapidly increasing

applications of pesticides and fertilizers on the world’s

crops. She envisioned a world in which incautious

application of chemicals to increase crop yields in

the short term would undermine Earth’s capacity to

provide resources essential to human well-being—clean

air, fresh water, and fertile soil. Carson’s compelling

description of the environment as a network of complex

and interrelated systems is credited as a foundation of

the modern environmental movement.

Carson’s idea that we need to consider trade-offs

between short-term gains and long-term sustainability

continues to resonate as we face the challenge

of feeding a human population that exceeds

7 billion and continues to grow. Humans

consume an increasing fraction of the world’s

land and ocean food resources, and rely on

technology-intensive methods to do so. In

addition to chemical inputs, diets in developed

countries use great amounts of energy (see

inset). For example, the photograph shows an

entire shoal of tuna caught in a purse seine and

surrounded by a towing cage that will take them

to a tuna farm for fattening and harvest.

Making effective decisions about energy,

chemicals, food, and the environment requires

that we account for ethics and values, the

subjects of this chapter. As you read, keep in

mind these words from the Earth Charter, formulated

in 1992 by representatives from 178 countries: “Let

ours be a time remembered for the awakening of a

new reverence for life, the firm resolve to achieve

sustainability, the quickening of the struggle for justice

and peace, and the joyful celebration of life.”