I firmly believe that the risks that we face in common from the mounting dangers to the environmental natural resource and life support systems of our planet are far greater as we move into the 21st century than the risks we face or have faced in our conflicts with each other. And these risks can only accelerate as the levels of population and human activity continue to grow in the period ahead. All people and nations have, in the past, been willing to accord highest priority to the measures required for their own security. We must now give the same kind of priority to ensuring the security and sustainability of the life-support systems of our earth.

　

　 Before moving on to the specific environmental learning programs, this Section explicates a broader picture pertaining to the relationship between Earth's ecological system and the human orientation toward it. It sheds light on both the natural and human realities that collectively point to the immediate need to promote participatory and experiential environmental learning at this beginning stage of the 21st Century.

　 Various indications point out that we are living at a truly unique and crucial stage in the history of humanity. The pace of change in the human life-style has been accelerating enormously: while we were hunter-gatherers for some 50,000 years, until the advent of the agricultural revolution over 5,000 years ago, we are already evolving out of the industrial era in less than three centuries as we rush through this turn of century into the new Millennium (Gardner 2001, 191 ; Milbrath, 1996, 116).

　 Unfortunately, the rapidity of change in the pattern of human subsistence has been matched by the speedy deterioration in Earth's ecology, including its "terrestrial, aquatic, polar, ocean, and coastal" sub-systems (Brown and others 2000, 389). This development is directly attributable to such diverse yet causally related human-induced phenomena as deforestation, desertification, pollution of air, freshwater and oceans, climate change, etc. Most striking is the rapidness of the deterioration. On the land, the world's tropical forest has been shrinking by 10 percent per decade; in the oceans, the percentage of severely damaged coral reefs grew from 10% to 27% during the final eight years of the 20th Century. It is estimated that, whereas the rate of species extinction used to be only one per four years during the 17th-19th centuries, as many as 40,000 species disappeared annually during the last two decades of the 20th Century―a rate that is predicted to continue, if not escalate (Hiramatsu 2001, 22, 28; Mastny 2001, 92).

　 As for a prediction of the near future, Maffi (2001) noted that "experts consider it a strong possibility that 20 percent of the world's existing species will be lost over the next thirty years" (underline mine. 4). The cost of this drastic destruction of Earth's biological diversity is multifaceted and substantial. It represents the permanent loss of numerous lineages that could potentially be invaluable sources for medical and economic uses, for stabilizing Earth's ecosystems, and for the inquiry into the process thorough which Humanity and all other forms of Life on Earth reached the current status (Mishler 2001, 75-76).

　 Like the case of treating human illness, the time allowed for us to make effective adjustments is finite. Indeed, even if we stabilize the greenhouse gases today, the "temperature increases and especially sea-level rise would continue for many decades thereafter"; even if we reverse the rapidly proceeding process of switching from deforestation to that of forestation, "it would take many generations to replace the lost forests"; and recovering the lost top soil for agriculture, the principal foundation for our foodstuff, may take "centuries or even millennia" (Trenberth 2001 , 19; United Nations Environment Programme l999, 362). Moreover, some scholars point out that we are approaching dangerously close to the points that would "trigger irreversible collapse of ecosystems" (Brown and others 2000, 389). It thus seems inevitable that, without immediate and spirited efforts to reverse this destructive trend, our offspring (including those who are already born) will enjoy much less natural blessings than we and our ancestors have done.