It is increasingly easy to comprehend the tightening connectivity among all of us on the Planet. We can more easily see that what we consume has an effect on people elsewhere.
There is an increasingly direct connection, in an era of globalization, between our energy use and global hunger. If we use ethanol converted from grain (in order to overcome our dependence on foreign sources of petroleum), it drives grain prices--read food prices--upward for the Planet. (And so will the upward pressure on grain prices caused by China as it urbanizes and decreases its grain production.) Middle-class Americans can adjust, as can middle-class people everywhere, to rising food prices by delaying purchases, such as the next pair of $100 athletic shoes. But for approx. one-third of the Planet--those who already spend a high proportion of their income on food, sometimes as much as 80+%--any incremental rise in food prices can have deleterious effects on their nutritional standing. It will soon be the case that our diet/energy use will have profound effects on the wellbeing of real people, although hidden to us, around the globe. What we drive and what we consume do matter.
I have my students calculate their "ecological footprint" on the Planet. They (as was I) are shocked to learn that on average it takes four or more planets to sustain their (our) lifestyle of (over)consumption. At least I am planting within them the concept that each of us has an impact on the Planet. (I believe many people have never considered they have an "impact" on the life support systems of Spaceship Earth.) I also mention that our family companion dogs have a higher nutritional status--with their greater intake of vitamins, minerals, essential fatty acids, and amino acids--than approx. 2 billion people on Earth.
When I lived in the bush in Jamaica, those people around me spent most of their income on food. There was little margin for error and little discretionary spending on anything other than food. If their food prices were to increase by a small amount, they would have little else to draw from to make up the difference.
Increasing hunger is in the offing, due to rising energy prices. So, what we consume is crucial in a connected, globalized world.