The cost of establishing a private wildlife sanctuary is extremely high, namely because of the cost of land. Governments invariably own large tracts of unused land that can be conserved. The reason to establish such areas is to conserve the biodiversity of the environment. The biodiversity is critical for future generations as we still do not fully know what potential future value exists in the conserved fauna and flora. In addition conserved areas act as lungs for the earth. The large tracts of conserved forests generate oxygen and affect the climate. Large areas of grassland act as water sponges to supply fresh water to rivers. There are many more reasons but time does not allow me to expand further.