I define conservation as the maintaining of what you already have. Therefore, conversation does not require a cease of economic growth.
I think I understand what this question is trying to override.
"It was once suggested that all economic growth will cost conservation. "
This theory is incorrect, because there are more variables to the situation than stated above. You can increase economic prosperity while maintaining conversation.
This is a general assumption*
For instance, you can sustain economic growth while sustaining conservation at an equal rate; if you move one variable, then you will not expect the other to move. Simply, because their is no relationship that exists in the first place.