Energy
Although hard to calculate, energy has the aspects of health, ecology and ethics on its production, storage, transportation and usage. Every fuel has an ecological footprint and there is no true clean fuel. Therefore, when multiple energy sources are available, each must be analysed for their practicality, scalability and ecological footprint, and chosen sensibly.
The thumb rule of energy in natural living is to adopt a lifestyle that uses lesser energy until you will reach a saturation point that serves basic needs for survival. This point may be subjective by a consensus can be reached on what consitutute basic needs given a particular environment.
Habits rooted in pragmatism like using grid energy only when required, supplementing it with locally installed renewable energy, using locally sourced carbon based fuel for household applications and offsetting that carbon footprint and opting for public transportation whenever feasible must be cultivated. A lifestyle relying less and less on electricity — like sleeping as it gets dark and being an early bird — will serve two purposes — it reduces energy usage and contributes to a healthy lifestyle.