What is sustainability?

Sustainability does not have a rigid definition but for the purposes of discussing energy concerns sustainability means: taking the long-term view of how our actions effect future generations and making sure we don't deplete resources or cause pollution at rates faster than the earth is able to renew them.

Why should we think about energy?

We need to think about energy because it has become somewhat of a necessity in our world.  We mindlessly use it every day as if there are infinite ways to supply it.  Unfortunately that's not the case so as engineers we must think of new, permanent ways to conserve energy without compromising our quality of life.