I can't make a good decision about how to make my energy usage sustainable unless I know which activities are using the most energy. The chart presented here attempts to give an idea of the scales of energy I've been talking about in previous blog posts.
The total energy usage in the US per year (as noted in this blog post) is ~1x10^20J. For comparison, that is:
- ~1.8 million times the energy released by the atomic bomb dropped on Hiroshima and
- ~2600 times the energy that the largest atomic weapon in the US arsenal would release if detonated.
- ~ 47 times the energy released by all nuclear tests conducted... ever...
Increasing fuel efficiency or reducing miles driven by 20% would be the equivalent of reducing your home electricity usage by 100%. That's big leverage. Better than caulk or fluorescent light bulbs.
Flying is also pretty energy intensive. A single flight from SanFrancisco to Tokyo uses about the same energy as driving a car for a year** or ~3.5x the average annual electricity usage of a home. With about 4 flights per day 365 days/yr that is ~5100x the average annual electricity usage of a home per year of flights... and that's just one destination from one airport...
So shooting for 30% reductions in energy usage in the home may not be entirely where the leverage lies.
*assuming 15,000 mi/yr @ CAFE standard 27.5 mpg.
** assuming 5148 miles @ 5.29 mpg of kerosene.