Biodiversity is a fragile thing, susceptible to all sorts of threats. Even as it supports all life on Earth it is constantly facing threats and damage that is almost impossible for our multiple ecosystems to recover from. Threats to biodiversity come from many sources, most human but some natural.
Largest among the threats to biodiversity looms human greed. Historically, humans have always taken what they needed from the earth itself, and from its plant and animal species, with no regard as to whether the resources being consumed were finite or not. It has only been since the middle of the 1980s, as species started becoming extinct at a record rate of speed, that threats to biodiversity became recognized as a major concern.
Deforestation left acres of former forests bare, and inhospitable to the animals and plants that depended on them for food and sustenance. Some bodies of water, such as the Aral Sea, have had their saline levels change so radically that they are uninhabitable by the marine life that used to be plentiful.
These and other threats to biodiversity, again mostly caused by humans, have created situations where support for the human life of some regions is imperiled by the changes to the area. For example, when a body of water is no longer habitable, the fish become extinct or migrate elsewhere, contributing to hunger of the local land species that used to feed on them.
Engineering projects such as dams and irrigation channels which change the flow of water to a region, and can create either flood basins or deserts, depending on which project is placed in a region are among the biggest man-made threats to biodiversity. They render vast amounts of land unusable for growing food, although to be fair an irrigation project is usually carry outed to bring water to land that is more either arid or far more populous than the land used for the project.
Humans have used all the fossil fuels they can get their hands on in fact have fought wars over these resources with no thought that someday we might run out of them. And, whole national economies have been based on the production of and selling of those same fossil fuels.
Threats to biodiversity are almost as numerous as the regions that are threatened. While, given the differences between the regions, there is no one, uniform solution, there are things that can be done in all them, such as careful planning, identification and preservation of threatened species, and learning that all natural resources are finite, that can clearly help us learn how to minimize the threats to biodiversity, which are, ultimately threats to our own well-being.