Environmental Biology Essays 2008
On the one hand it needs to be factual and scientific, a clear statement of a specific “destination”.
The simple definition "sustainability is improving the quality of human life while living within the carrying capacity of supporting eco-systems", is applied not only to human sustainability on Earth, but to many situations and contexts over many scales of space and time, from small local ones to the global balance of production and consumption.
This formulation attempts to explain human consumption in terms of three components: population numbers, levels of consumption (which it terms "affluence", although the usage is different), and impact per unit of resource use (which is termed "technology", because this impact depends on the technology used).
Most of the increase will be in developing countries whose population is projected to rise from 5.6 billion in 2009 to 7.9 billion in 2050.
This increase will be distributed among the population aged 15–59 (1.2 billion) and 60 or over (1.1 billion) because the number of children under age 15 in developing countries will decrease.
In short, it can entail the full compass of biological and human activity or any part of it.
The overall driver of human impact on Earth systems is the destruction of biophysical resources, and especially, the Earth's ecosystems.