Human activity places pressure on many aspects of the environment. For instance, deforestation results in the invasion of weed species,
habitat displacement, and, when undertaken on a large scale, adversely affects air quality and
carbon dioxide sequestration. Examples of pressures under the Pressure-State-Response ("PSR") framework include: pollutants discharged from factories, or draining into a river from the land; it could be the removal of forest from the land or
over-harvesting by fishermen or hunters. In this framework, only pressures introduced by human interaction with the environment are considered. Natural pressures such as extreme weather are only considered in the context of human-induced
climate change (i.e.
global warming). A "state" is the condition of the environment at a particular time. This is assessed by measuring various aspects of the atmosphere, air, water, land and organisms. == State of the Environment reporting ==