How do ecomyths start? And why do they persist long past their due date? Well here is an article that gives some answers to both these questions.
Ecomyths prey on people's fears, their guilt and their lack of general knowledge. They utilise slick graphics. sound bites, spin and 'cleverly executed' pieces of propaganda to parse doublespeak into dogma that can be peddled by anyone with a loud and/or authoritative voice.
But ecomyths are easily uncovered. Just ask the advocate of the latest myth a simple question: 'why would you say that?' Listen quietly to their reply and then ask again: 'why would you say that?' All too often the response will encompass the phrase 'well, as you know...' or 'well, as everyone knows'. Which is the vocal advocate's way of stating that they don't know, they are merely reciting what they believe to be axiomatic: so much that is commonly understood that they have no need to account for it.
Good ideas are robust. They withstand scrutiny and embrace sound principles. Ecomyths hide behind dogma and a few well chosen 'whys?' will unravel them and reveal them for the morally authoritative constructs they are. Then you can deconstruct them, because the science is a just mask for the morality that drives the central belief.