Stepped Energy Descent Pathways Linking the Scenarios
As previously mentioned, energy descent may not be a continuous gradual process. Instead it could be characterised by an initial crisis that sets the conditions for a new order that is stable for some time before another crisis leads to further descent. The growth of energy and resultant technological complexity over the last two hundred years has involved varying rates of change, plateaus and even regressions during wars and depressions, but energy descent is likely to be much more variable than energy ascent. This is consistent with our common sense understanding that growth is a more consistent process than decline.
Natural ecosystems tend to maintain homeostasis under stress through the allocation of stored resources. If the conditions continue to deteriorate, then further stress can fracture the homeostasis. If the stress involves a reduction in energy availability, the system may collapse. But total collapse and system disintegration is rare, at least in the short term. More typically a re-stabilisation at a lower level of energy processing and organisational complexity occurs. The new homeostasis will typically be stable for some time before declining energy availability precipitates another crisis. This may also be a model for how human societies respond to the crisis of resource and energy decline. It also makes sense that natural disasters, or a crisis such as war, rarely continue for very long but they shape the new state that emerges in their aftermath. If crisis does persist at an intense level for years then psychosocial systems reorganise around the crisis as the new normality.
The following conceptual graph shows these two pathways from Hubbert’s Peak of Oil (and net energy production). The discontinuities are periods of extreme crisis, conflict and/or breakdown. Each scenario represents a homeostasis that tends to be self-maintaining until further stress precipitates a further unravelling.

The red pathway is more extreme after continued growth leads to a precipitous drop through natural disasters, economic depression and/or war. Brown Tech emerges as the new world order allowing recovery and modest growth before further natural disasters/climate change and oil depletion precipitate another discontinuity leading to a Lifeboat world. The green pathway is less extreme with a lower peak and a gentler decline through the first discontinuity to the Green Tech scenario while the descent to Earth Steward is even more continuous driven by on-going depletion and decay of infrastructure from the Hubbert’s Peak and Green Tech worlds.
The chart also shows the relative levels of net energy availability per capita. This is much more speculative than the general concept of the stepwise descent or the relationships between the scenarios, because it depends on many variables. I’ve shown the Brown Tech and Lifeboat scenarios as processing more net energy per capita than the Green Tech and Earth Steward scenarios respectively. A range of factors contribute to this speculative maths, and hide some harsh realities. Depending on how net energy is understood and evaluated, a higher total energy base in Brown Tech may maintain greater organisational and technological complexity but Green Tech may be more energetically efficient at providing real human services.A harsher discontinuity leading to Brown Tech may produce a higher death rate in the more urbanised populations while more severe controls on births may further reduce populations. The numbers of people the energy base needs to support strongly affects the per capita level so a higher per capita figure may reflect lower birth rates and/or higher death rates rather than a more energy rich society. Alternatively the lower death rate during the gentler
discontinuity leading to Green Tech combined with a higher birth rate to tap the more distributed rural resources of the Green Tech world may result in overall higher populations. Although net energy per capita is lower, life may on average be better than in the Brown Tech scenario.
Similarly in the second discontinuity crisis, the death rate increases but more so in the red pathway to the Lifeboat. The lack of community capacity in the midst of massive material salvage opportunities, combine with the lower population, to deliver relatively high net energy per capita even though life is very harsh. The more abundant distributed renewable resources of the Earth Steward scenario leads to a higher birth rate (to tap those resources). Combined with the lower death rate, the higher overall population gives a very low net energy per capita. Efficient communitarian economies and a spiritual rather than material culture may make for higher wellbeing despite limited resources per person.