Energy’s lying all about the ground. Tress, bushes, shrubs, roots all have some either to burn or eat. Broad estimates for ecosystems abound. The boreal ecosystem generates about 17000 joules per square metre per day captured net primary productivity (see Appendix C). The human body needs about 17 000 000 joules a day. Therefore a person needs 1000 square metres of forest to live. However, the efficiency of the energy conversion process is at best 10% so really a person would need 100 000. But of course people don’t live alone. A family of four needs 400 000 square metres. If all this was taken from one area, all the vegetation would be gone and nothing remain for future years. By browsing through ten times this amount, i.e. 4 000 000 square metres, the family may survive. All of this assumes the energy is all directly convertible from vegetation to human needs. For anyone who’s eaten pine needles, they know this isn’t necessarily so.

Energy transfer works best in temperate climates. Water aids in the transfer. This is the reason for estuaries at mid-latitudes of Earth having the greatest net primary productivity, as well as the greatest variety and quantity of life. This location is also where humans have constructed many of their great cities; to the loss of the net primary productivity.

Without fossil fuels, people will naturally migrate to temperate climates with easy living conditions and most abundant quantities of energy/food. However, this region is already near to full with people. How will any new comers fit? What will happen to the indigenous flora and fauna when they arrive?