https://www.nytimes.com/2018/03/03/opinion/sunday/species-conservation-extinction.html
The 8 Million Species We Don’t Know
The extinction of species by human activity continues to accelerate, fast enough to eliminate more than half of all species by the end of this century.
The worldwide extinction of species and natural ecosystems, however, is not reversible. Once species are gone, they’re gone forever. Even if the climate is stabilized, the extinction of species will remove Earth’s foundational, billion-year-old environmental support system.
Land and Marine areas currently protected by law(no where near
HALF EARTH status
A growing number of researchers, myself included, believe that the only way to reverse the extinction crisis is through a conservation moonshot: We have to enlarge the area of Earth devoted to the natural world enough to save the variety of life within it. The formula widely agreed upon by conservation scientists is to keep half the land and half the sea of the planet as wild and protected from human intervention or activity as possible. This conservation goal did not come out of the blue. Its conception, called the Half-Earth Project, is an initiative led by a group of biodiversity and conservation experts (I serve as one of the project’s lead scientists).
It builds on the theory of island biogeography, which I developed with the mathematician Robert MacArthur in the 1960s.Island biogeography takes into account the size of an island and its distance from the nearest island or mainland ecosystem to predict the number of species living there; the more isolated an ecosystem, the fewer species it supports. After much experimentation and a growing understanding of how this theory works, it is being applied to the planning of conservation areas.
So how do we know which places require protection under the definition of Half-Earth? In general, three overlapping criteria have been suggested by scientists. They are, first, areas judged best in number and rareness of species by experienced field biologists; second, “hot spots,” localities known to support a large number of species of a specific favored group such as birds and trees; and third, broad-brush areas delineated by geography and vegetation, called ecoregions.All three approaches are valuable, but applying them in too much haste can lead to fatal error. They need an important underlying component to work — a more thorough record of all of Earth’s existing species. Making decisions about land protection without this fundamental knowledge would lead to irreversible mistakes.
The most striking fact about the living environment may be how little we know about it. Even the number of living species can be only roughly calculated. A widely accepted estimate by scientists puts the number at about 10 million. In contrast, those formally described, classified and given two-part Latinized names (Homo sapiens for humans, for example) number slightly more than two million. With only about 20 percent of its species known and 80 percent undiscovered, it is fair to call Earth a little-known planet.
Paleontologists estimate that before the global spread of humankind the average rate of species extinction was one species per million in each one- to 10-million-year interval. Human activity has driven up the average global rate of extinction to 100 to 1,000 times that baseline rate. What ensues is a tragedy upon a tragedy: Most species still alive will disappear without ever having been recorded. To minimize this catastrophe, we must focus on which areas on land and in the sea collectively harbor the most species.
The worldwide extinction of species and natural ecosystems, however, is not reversible. Once species are gone, they’re gone forever. Even if the climate is stabilized, the extinction of species will remove Earth’s foundational, billion-year-old environmental support system.
Land and Marine areas currently protected by law(no where near
HALF EARTH status
A growing number of researchers, myself included, believe that the only way to reverse the extinction crisis is through a conservation moonshot: We have to enlarge the area of Earth devoted to the natural world enough to save the variety of life within it. The formula widely agreed upon by conservation scientists is to keep half the land and half the sea of the planet as wild and protected from human intervention or activity as possible. This conservation goal did not come out of the blue. Its conception, called the Half-Earth Project, is an initiative led by a group of biodiversity and conservation experts (I serve as one of the project’s lead scientists).
It builds on the theory of island biogeography, which I developed with the mathematician Robert MacArthur in the 1960s.Island biogeography takes into account the size of an island and its distance from the nearest island or mainland ecosystem to predict the number of species living there; the more isolated an ecosystem, the fewer species it supports. After much experimentation and a growing understanding of how this theory works, it is being applied to the planning of conservation areas.
So how do we know which places require protection under the definition of Half-Earth? In general, three overlapping criteria have been suggested by scientists. They are, first, areas judged best in number and rareness of species by experienced field biologists; second, “hot spots,” localities known to support a large number of species of a specific favored group such as birds and trees; and third, broad-brush areas delineated by geography and vegetation, called ecoregions.All three approaches are valuable, but applying them in too much haste can lead to fatal error. They need an important underlying component to work — a more thorough record of all of Earth’s existing species. Making decisions about land protection without this fundamental knowledge would lead to irreversible mistakes.
The most striking fact about the living environment may be how little we know about it. Even the number of living species can be only roughly calculated. A widely accepted estimate by scientists puts the number at about 10 million. In contrast, those formally described, classified and given two-part Latinized names (Homo sapiens for humans, for example) number slightly more than two million. With only about 20 percent of its species known and 80 percent undiscovered, it is fair to call Earth a little-known planet.
Paleontologists estimate that before the global spread of humankind the average rate of species extinction was one species per million in each one- to 10-million-year interval. Human activity has driven up the average global rate of extinction to 100 to 1,000 times that baseline rate. What ensues is a tragedy upon a tragedy: Most species still alive will disappear without ever having been recorded. To minimize this catastrophe, we must focus on which areas on land and in the sea collectively harbor the most species.
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