The concept of ecological footprinting has been challenged on several grounds. First, many factors of the calculations are based on crude estimates and it is questioned whether the numbers are applicable to other places (the method is biased to Northern Hemisphere lifestyles). Second, the model generally does not count multiple uses of land: a forest is a carbon sink and the same area is not counted for food production. Third, at the household level, the model is biased in favor of households with more children and against, for instance, sin ...
Ethically, the number of Earths "consumed" alludes to the categorical imperative, which requires everyone to behave in such a way that they can consistently advise all others to behave. How to move footprint thinking from abstract thinking or teaching to action is one of the method's challenges.
One of the less-publicized but most powerful insights of ecological footprint methods is that, contrary to many people's assumptions, it is human use of renewable resources, not of non-renewable ones, that poses the real sustainability crisis. ...
