Be parsimonious

Consume what you need, not necessarily what you want.  Reduce your family’s ecological footprint.  Resist consumerism.  Share what you have with those in need if they are not freeloaders^[1].  Find pleasure and self-worth in what you do and know and in the company you keep, rather than in what you own and consume.  Encourage and support others to be parsimonious. 

On a spaceship hurtling through the Galaxy in search of a life-sustaining but as yet unidentified planet; a spaceship with a closed life-support system that until now has been regenerating but about whose longevity there are growing doubts; a spaceship whose voyage will be measured not in years but in generations; on such a spaceship with such a mission, the occupants may be expected to be parsimonious. 

The occupants will ration their non-renewable supplies to the absolute minimum required to sustain life on board.  They will adopt a lifestyle that places the least stress possible on the spaceship's internal biosphere.  The space-travellers will be effective, doing only those things that contribute toward their goals; and they will be efficient, using as few inputs as possible to produce the outputs required. 

That spaceship is Our planet Earth, and we are its occupants.

Parsimony is another of our critical success factors.   

Taken to an extreme it would make us a dull lot indeed - Calvinists in suspended animation.  There is lot to be said for wanton and conspicuous consumption and frivolity.  To Hell with tomorrow!  Life without hope is no life^[2], but neither is life without pleasure^[3], life without generosity^[4], or even life without risk^[5]. 

However, the principle of parsimony should be our default state-of-mind.  When in doubt, conserve and share!  When a gaggle of lobby groups presents conflicting arguments^[6] and evidence on whether or not a particular activity is damaging to the biosphere, the benefit of the doubt ought always to go to the conservationist, and certainly against the party that stands to make a pecuniary gain from the contentious activity.  You do not gamble with the biosphere.