Biodiversity is an elementary requirement for the long term sustainability of the environment, continuity of life on the earth and the maintenance of it integrity. It is ultimately linked with the survival of human beings. Biodiversity is the source of most of human needs and ironically human life on the earth depends only upon few narrow spectrums of those species of plants life which provides our entire food. We have not yet explored those millions of species which nature have erected. A number of them are getting extinct even before we came to know about them. Future of our food and medicines vitally depends upon the gene pool of the wild relatives of modern crop and medicinal plants which are found in tropical forests. Except for climate change the loss of biodiversity is the most pressing global environmental problem caused by human activities. Its main driver is land-use change. Biodiversity, a global public good, is threatened by ignorance of both its positive externalities, i.e. third-party ramifications, and its private benefits. In order to halt its loss we need instruments and measures that conserve biodiversity and allow for these externalities.