2. Looming Tragedy

Ecologists have applied the concept of “carrying capacity”, the population of a species that an ecosystem can support, to human populations. Ecological limits to growth in population and the economy dominated environmental concern in the 1970s and beyond. More recently they have been supplanted by the idea of planetary boundaries, based on the stresses that the earth system is capable of absorbing, several of which (including biosphere integrity and climate change) have already been transgressed, suggesting the system is in grave peril. This chapter also considers the points of critics of the idea that there can be limits, then analyzes the political implications of limits and boundaries, from the authoritarianism associated with some 1970s thinkers to the need for cooperative global action to the more democratic possibilities that could be associated with degrowth and planetary boundaries.