The main threat to the planet’s biodiversity, and therefore a threat to human well-being, is the combination of population growth and the resources utilized by that population. Human populations require resources to survive and thrive, and many of these resources are being extracted from the environment in an unsustainable way.
The top three immediate threats to biodiversity are habitat loss, overexploitation, and the introduction of exotic species. Two direct result of ‘s population growth and resource usage. The third comes from the increase in mobility and exchanges. A fourth major cause of the extinction, is anthropogenic (man-made) climate change, as a consequence of the energy needs of the human population and the use of fossil fuels to meet those needs.
People depend on technology to change their environment and make it habitable. Consider Sumatra’s outstanding biodiversity: it is home to an orangutan species, an endangered species of elephant, and the Sumatran tiger, but half of Sumatra’s forest already does not exist . The island of Borneo is home to other orangutan species, has lost a similar forested area.
Forest loss happens even in protected areas forests will be cleared for logging and Palm oil is used in products including food, cosmetics, and biodiesel in Europe. Much of the loss (2.4%) occurred in the tropics, where forest loss is mainly due to the harvesting of timber. These losses certainly also represent the extinction of unique species in these areas.
The market for illegally harvested tropical timber is huge, and timber products can often be found at hardware stores in the United States. In 2006, this amounted to US$3.6 billion in timber products. Most illegal products are imported from countries that act as middlemen and are not the origin of the wood.
The Forest Stewardship Council (FSC) certifies sustainably harvested forest products. There are other certifications besides the FSC, but they are managed by logging companies.
While it would be great if there was a list of legal and illegal timber, it’s not that simple. Laws on logging and forest management vary from country to country; What is illegal in one country may be legal in another. Where and how a product is sourced and whether the forest it comes from is sustainably managed are factors that influence whether a wood product is FSC certified.
It’s always a good idea to ask questions about the provenance of a wood product and how the supplier knows it was legally harvested.
Dam building of rivers affects flow and access to habitats. Changing a river regime can reduce or eliminate populations adapted to seasonal river changes. Many fish species in the United States, particularly rare or restricted-range species, have experienced declines caused by damming of rivers and loss of habitats. Research has confirmed that amphibian species that must complete parts of their life cycles in and on terrestrial habitats are at increased risk of population decline and extinction due to the increased likelihood of losing one of their habitats or access between them,
Overexploitation is a serious threat to many species. While it was an extremely productive fishery for, 400 years, the modern industrial trawlers in the 1980s and pressure on fishing have made it unsustainable. The causes of the fishery collapse are both economic and political. Most fisheries are managed as a common resource available to all those interested in fishing, even if the fishery area is within the territory of a country.
Coral reefs are extremely diverse marine ecosystems threatened by different processes, such as ocean acidification, pollution, tourism, etc.
Bushmeat is the generic term for wildlife slaughtered for food. Hunting is practiced around the world, but hunting practices, particularly in equatorial Africa and parts of Asia, are thought to be threatening several species with extinction.
Traditionally, bushmeat was hunted in Africa to feed families directly. However, the recent commercialization of this practice has meant that bushmeat is now readily available in grocery stores, which has pushed harvest rates to unsustainable levels. In addition, the growth of the human population has increased the need for protein foods that agriculture cannot meet.
The introduction of exotic species often experiences dramatic population increases in their new habitat and re-adapts to the area’s ecological conditions. Invasive species may threaten other species through competition for resources, predators, or disease.
Lakes and islands are particularly vulnerable to the threat of extinction from introduced species.In, Lake Victoria was responsible for the extinction of around 200 cichlid species through the deliberate introduction of the Nile perch. The islands do not account for much of the world’s land area, but they are home to a disproportionate number of endemic species due to their isolation from mainland ancestors.
Many marine and freshwater species have been introduced when ships discharge ballast water from a port of origin into the waters of a port of destination. The water is pumped from the home port onto an empty cargo ship. The water is taken from the ocean or the port estuary and typically contains living organisms such as plant parts, microorganisms, eggs, larvae, or aquatic animals.
Pioneering The European green crab, Carcinus maenas, was probably introduced into San Francisco Bay in the late 1990s, possibly in ship ballast water, and has spread north along the coast to Washington. Crabs have been found to dramatically reduce the abundance of native mussels and crabs, resulting in an increase in the prey species of these native invasive alien species can also be pathogenic organisms.
Climate change will also alter the gradual melting and subsequent refreezing of the poles, glaciers, and higher mountains, a cycle that has provided freshwater to the environment for centuries. This could lead to an abundance of saltwater and a shortage of freshwater.