Earth is seeing an unprecedented loss of species, which ecologists are calling a sixth mass extinction. Almost all past extinctions have occurred by natural processes, but today human activities are overwhelmingly the main cause of extinction.
There is no doubt that biodiversity loss, together with climate change, are some of the biggest challenges faced by humanity. Along with human-driven habitat destruction, the effects of climate change are expected to be particularly severe on biodiversity. Current estimates of extinctions are, without a doubt, gross underestimates.
Trends documented by the the World Bank and Worldwatch Institute, and reported to the Rio+5 conference in 1997, estimated 150 to 200 species of life become extinct every 24 hours.
In May 2019, a United Nations report warned that 1 million species are threatened by extinction. More recently, 571 plant species were declared extinct. Some plants have been going extinct up to 350 times faster than the historical average – with devastating consequences for unique species. Based purely on numbers, biodiversity hotspots, like Madagascar, are expected to lose more species to extinction than coldspots, like the UK; however, coldspots stand to lose more uniqueness than hotspots, for example, seven coldspot extinctions led to the disappearance of seven genera, and in one instance, even a whole plant family.
Botanists at an International meeting in St Louis, USA in 1998 warned that two thirds of all species of mammals, birds, butterflies and plants will disappear by the end of the next century due to the destructive habits of man. They claim that the current rate is similar to the mass extinctions that wiped out the dinosaurs 65 million years ago. The destruction is piecemeal as humans encroach on the natural environment and fragment it, leaving little room for other species to survive.
Key areas of concern are: wild relatives of domesticated species which are essential to maintain the genetic variety of the domesticated breeds; harvested species and the threat to them through unsustainable rates of harvesting, leading to their biological extinction; totemic species, namely those held to be of special socio-cultural value to particular peoples; species of special importance to science; animal species that are sufficiently important and endangered to warrant captive breeding (especially in the light of the limited facilities for such breeding); wide-ranging species that move between non-contiguous ecosystems, because of their ecological value and because an exclusively ecosystem-oriented approach will not conserve them; and indicator species because of their role in indicating the effectiveness of ecosystem maintenance.