In the context of a peaceful sustainable society "overconsumption has two distinctly different destructive roles.
      1) a civilization's total consumption exceeds the delivery of good and services
            that can or will be produced by the environment using a given technology
      2) one individual's consumption takes the supporting resources
            of a second person.

Let me expand the meaning of these two types of overconsumption.

The first overconsumption refers a group if individuals each consuming the same quantity of supporting resources, Like rabbits on an island eating the grass. Each rabbit is a consumer but by him or her self cannot be an over-consumer. The overconsumption is a property of the rabbit's group relative to a level of production. And the penalty for overconsumption is paid by everyone starving with the weakest starving to death.

There are several mechanisms that lead to this first type of overconsumption conditions; births exceed deaths, weather or blight decreases grass production. But all the mechanisms create the same condition -- too many rabbits for the available grass.

The second kind of overconsumption is defined by the creation of inequity. Rabbits don't have this problem because each rabbit cannot over eat. But humans can. One human can consume what could keep 1000 other humans happy. Actually this inequality is not an overconsumption until the consumption of one person actually suppresses the wellbeing of a second person.

Then overconsumption leads to conflict. Conflict consumes (wastes) the whole group's resources, and reduces total group's wellbeing.