Alternative for "more"?

In discussions related to conserving environment, some participants say "Give me alternative for Energy, sea-food, etc..."

Let us dig deeper in to this 'alternative' in an abstract way. Assume scientists come up with an alternative to fuel for 1 million cars and a sustainable method to feed 6 billion people. As soon as the alternative is in horizon, human's would rise their requirement to 2 million cars and 8 billion people. Our requirement has been a moving target so before anything, first we need an alternative for the attitude called "more".