Biodiversity loss refers to the decline or disappearance of biological diversity, which is the variety of living things that inhabit the planet, its different levels of biological organization, and their respective genetic variability, as well as the natural patterns present in ecosystems. Biodiversity loss can lead to a breakdown in the functioning of the ecosystem where the decline has happened. The following are some of the causes of biodiversity loss:

• Changes in land use, such as deforestation, intensive mono-culture, and urbanization
• Loss, degradation, and fragmentation of habitats, which is principally caused by the increasing encroachment of industrial activities and farming, fueled by demand from high-consumption lifestyles in wealthy countries and rising consumption in low- and middle-income countries
• Overfishing and overhunting, which are emptying the oceans and tropical forests of animals, especially the large species, and disrupting ecosystem functioning
• Transport for trade and tourism, which are driving the spread of invasive alien species, which threaten the integrity of the ecosystems they invade
• Growing demand for exotic species as food, pets, and medicine, which is driving the illegal or unsustainable trade in many species

Biodiversity loss not only results in species extinction, but it also affects humans by depriving humanity of accessing services that natural ecosystems provide, such as the wealth of oxygen that we breathe or the benefits of pollination provided by animals in ensuring global food security. It is estimated that over a quarter of Earths land surface has already exceeded the safe limit of a 10% drop in biodiversitys contribution to ecosystem services. The consequences of mass extinctions for humans are unknown, but it is clear that biodiversity loss is just as catastrophic as climate change, and the solutions are linked.