In his book Peak Everything: Waking Up to the Century of Declines, Richard Heinberg lists these five "axioms of sustainability" (pages 88-95; all text here is quoted from that text):
Any society that continues to use critical resources
unsustainably will collapse.
Exception:
A society can avoid collapse by finding replacement resources.
Limit to the exception:
In a finite world, the number of possible replacements is
also finite.
Often, historically, collapse has meant a precipitous decline in population brought about by social chaos, warfare, disease, or famine. However, collapse can also occur more gradually over a period of many decades or even several centuries. There is also the theoretical possibility that a society could choose to "collapse" (i.e., reduce its complexity) in a controlled as well as gradual manner.
Population growth and/or growth in the rates of consumption of resources cannot be sustained.
The world has seen the human population grow for many decades and therefore this growth has obviously been sustained up to the present. How can we be sure that it cannot be sustained into the indefinite future? Simple arithmetic shows that even small rates of growth, if continued, add up to absurdly large – and plainly unsupportable – population sizes and rates of consumption.
To be sustainable, the use of renewable resources must proceed at a rate that is less than or equal to the rate of natural replenishment.
Renewable resources are exhaustible. Forests can be over-cut, resulting in barren landscapes and shortages of wood (as occurred in many parts of Europe in past centuries), and fish can be over-harvested, resulting in the extinction of near-extinction of many species (as is occurring today globally).
To be sustainable, the use of non-renewable resources
must proceed at a rate that is declining, and the rate of
decline must be greater than or equal to the rate of
depletion.
(The rate of depletion is defined as the amount being
extracted and used during a specified time interval, usually
a year, as a percentage of the amount left to extract.)
No continuous rate of use of any non-renewable resource is sustainable. However, if the rate of use is declining at a rate greater than or equal to the rate of depletion, this can be said to be a sustainable situation in that society's dependence on the resource will be reduced to insignificance before the resource is exhausted.
Sustainability requires that substances introduced into the environment from human activities be minimized and rendered harmless to biosphere functions.
In cases where pollution from the extraction and consumption of non-renewable resources that have proceeded at expanding rates for some time threatens the viability of ecosystems, reduction in the rates of extraction and consumption of those resources may need to occur at a rate greater than the rate of depletion.
These axioms are made available courtesy of:
*
Richard Heinberg
*
The Post Carbon Institute