Medieval brainbox William of Ockam (Surrey, England) said:
Entia non sunt multiplicanda praeter necessitatem.
More things should not be used than are necessary.
When applied to philosophy or science: the simpler the explanation the better.
Applied to living on a crowded planet where mankind is breaching nature’s limits, the rule becomes:
Use the simplest technology possible consistent with your lasting well-being.
This is the Bustard’s fourth rule. Application of this rule to low-carbon living would surely put a pin in the balloon of unbridled techno-optimism.