"Scarcity" -- not enough food or water or land and so on -- does not explain what it says it explains. Hunger, for example, is rarely the result of no food at all, but of not enough food in a certain place for certain people because those with more power deny them access to it. This may be conceded, but the claim that there will not be enough food in future because of future population growth still seems plausible. Future resources crises, however, will caused by the same imbalances of power as they are today.
