Extract

Virtually all of the materials and all of the energy that enters the economic system is disposed of as waste. When the disposal of wastes exceeds the capacity of the biosphere to absorb them the consequences can be bad for humans and other species. The ‘sinks’ overflow and the ‘services’ that nature provides diminish. The conversion of land for agriculture and settlements can exacerbate these problems especially when habitat is destroyed, which is a major cause of the ‘sixth extinction’. At the global level the concept of planetary boundaries has been introduced to help humanity avoid crossing thresholds that would cause irreversible damage to the environment. The data shows that as economies grow, many of these problems increase. Examples are provided covering climate change, CFCs and lead, nuclear wastes, forests, oceans and fresh water.