Among the major factors contributing to the degradation of the environment are population pressures, particularly widespread poverty.  (Educating for a Sustainable Future, UNESCO) From 2.5 billion in 1950, world population is projected to reach more than eight billion by 2025.

The human population places the greatest stress on Earth's resources and natural processes.  The U.S. Geological Survey (USGS) estimates that the use of air, water, and other natural resources has increased by a factor of 10 in the past 200 years.  A cycle of consumption and overuse is perpetuated as areas are developed, resources exhausted, and populations relocate.  Excessive fishing, harvesting and grazing result from increased demand for food, goods, and services, which increases the demand for natural resources and land use.

The USGS report notes the serious effect this activity has had on the atmosphere, water cycle, and the climate, and how it has altered ecological systems.  It seems apparent that the delicate balance of natural nutrient cycles required to produce and balance elements essential to life are being disturbed and disrupted.  According to the report, "the challenge of sustainability involves…moving towards development which is environmentally sound."

Renewable and Finite Resources: While the fight to stop the exhaustion of non-renewable resources seems to be making headway, the rapid depletion of renewable resources is a continuing problem.  Improvements in monitoring techniques include water quality chemical analysis, satellite collection of data, and development of computerized systems such as the Geographic Information Systems (GIS).  These improved tools aid in data collection, organization, simulation, and modeling to enable scientists to observe and measure more effectively the effects of human activity on natural systems.

Increase in Detrimental Practices: Patterns of consumption and production in industrialized countries constitute the major causes of global environmental degradation.  Use patterns must be modified to adhere to methods of sustainability if the environment is to endure.  From the mid-nineteenth century until well into the second half of the twentieth, nearly 15 per cent of the Earth's forests were denuded.  Another six percent was denuded during the ten-year period from 1980 to 1990. 

A 1998 study in the environmental publication, World Watch, cites seven of ten biologists who expressed the fear that Earth is now in the midst of the fastest mass extinction of living things in the 4.5 billion-year history of the planet.  Seventy percent said they "…believe that during the next 30 years as many as one-fifth of all species alive today will become extinct, and a third of the respondents think as many as half the species on Earth will die out in this time."  The need for environmental awareness and action that leads to sustaining the Earth makes sustainability education crucial.