Biodiversity as an asset. The Earth's biological resources are vital to humanity's economic and social development. As a result, there is a growing recognition that biological diversity is a global asset of tremendous value to present and future generations. At the same time, the threat to species and ecosystems has never been so great as it is today. Species extinction caused by human activities continues at an alarming rate.
Definition of biodiversity. The term "biological diversity" is commonly used to describe the number and variety of living organisms on the planet. It is defined in terms of genes, species, and ecosystems which are the outcome of over 3,000 million years of evolution. The human species depends on biological diversity for its own survival. Thus, the term can be considered a synonym for "life on Earth". To date, an estimated 1.7 million species have been identified. The exact number of the Earth's existing species, however, is still unknown. Estimates vary from a low of 5 million to a high of 100 million.
The extinction of species. Species extinction is a natural part of the evolutionary process. Due to human activities, however, species and ecosystems are more threatened today than ever before in recorded history. The losses are taking place in tropical forests -- where 50 - 90 per cent of identified species live -- as well as in rivers and lakes, deserts and temperate forests, and on mountains and islands. The most recent estimates predict that, at current rates of deforestation, some two to eight per cent of the Earth's species will disappear over the next 25 years.
Human dependence on other species. While these extinctions are an environmental tragedy, they also have profound implications for economic and social development. At least 40 per cent of the world's economy and 80 per cent of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic development, and adaptive responses to such new challenges as climate change. The variety of life is our insurance policy. Our own lives and livelihood depend on it.
Source: Documents of the Clearing-House Mechanism, UNCBD