Half-Earth
by Edward O Wilson
Half of the Earth’s surface and seas must be dedicated to
the conservation of nature, or humanity will have no future..
Unstanched haemorrhaging has only one end in all biological
systems: death for an organism, extinction for a species. Researchers who study
the trajectory of biodiversity loss are alarmed that, within the century, an
exponentially rising extinction rate might easily wipe out most of the species
still surviving at the present time.
The crucial factor in the life and death of species is the
amount of suitable habitat left to them. When, for example, 90 per cent of the
area is removed, the number that can persist sustainably will descend to about
a half. Such is the actual condition of many of the most species-rich
localities around the world, including Madagascar, the Mediterranean perimeter,
parts of continental southwestern Asia, Polynesia, and many of the islands of
the Philippines and the West Indies. If 10 per cent of the remaining natural
habitat were then also removed – a team of lumbermen might do it in a month –
most or all of the surviving resident species would disappear.
Today, every sovereign nation in the world has a
protected-area system of some kind. All together the reserves number about
161,000 on land and 6,500 over marine waters. According to the World Database
on Protected Areas, a joint project of the United Nations Environmental Program
and the International Union for Conservation of Nature, they occupied by 2015 a
little less than 15 per cent of Earth’s land area and 2.8 per cent of Earth’s
ocean area. The coverage is increasing gradually. This trend is encouraging. To
have reached the existing level is a tribute to those who have led and
participated in the global conservation effort.
But is the level enough to halt the acceleration of species
extinction? Unfortunately, it is in fact nowhere close to enough. The declining
world of biodiversity cannot be saved by the piecemeal operations in current
use alone. The extinction rate our behaviour is now imposing on the rest of
life, and seems destined to continue, is more correctly viewed as the
equivalent of a Chicxulub-sized asteroid strike played out over several human
generations.
The only hope for the species still living is a human effort
commensurate with the magnitude of the problem. The ongoing mass extinction of
species, and with it the extinction of genes and ecosystems, ranks with
pandemics, world war, and climate change as among the deadliest threats that
humanity has imposed on itself. To those who feel content to let the
Anthropocene evolve toward whatever destiny it mindlessly drifts, I say please
take time to reconsider. To those who are steering the growth of reserves
worldwide, let me make an earnest request: don’t stop, just aim a lot higher.
I see just one way to make this 11th-hour save: committing
half of the planet’s surface to nature to save the immensity of life-forms that
compose it. Why one-half? Why not one-quarter or one-third? Because large
plots, whether they already stand or can be created from corridors connecting
smaller plots, harbour many more ecosystems and the species composing them at a
sustainable level. As reserves grow in size, the diversity of life surviving
within them also grows. As reserves are reduced in area, the diversity within
them declines to a mathematically predictable degree swiftly – often
immediately and, for a large fraction, forever. A biogeographic scan of Earth’s
principal habitats shows that a full representation of its ecosystems and the vast
majority of its species can be saved within half the planet’s surface. At
one-half and above, life on Earth enters the safe zone. Within half, existing
calculations from existing ecosystems indicate that more than 80 per cent of
the species would be stabilised.
There is a second, psychological argument for protecting
half of Earth. The current conservation movement has not been able to go the
distance because it is a process. It targets the most endangered habitats and
species and works forward from there. Knowing that the conservation window is
closing fast, it strives to add increasing amounts of protected space, faster
and faster, saving as much as time and opportunity will allow.
The key is the ecological footprint, defined as the amount
of space required to meet the needs of an average person
Half-Earth is different. It is a goal. People understand and
prefer goals. They need a victory, not just news that progress is being made.
It is human nature to yearn for finality, something achieved by which their
anxieties and fears are put to rest.
The Half-Earth solution does not mean dividing the planet
into hemispheric halves or any other large pieces the size of continents or
nation-states. Nor does it require changing ownership of any of the pieces, but
instead only the stipulation that they be allowed to exist unharmed. It does,
on the other hand, mean setting aside the largest reserves possible for nature,
hence for the millions of other species still alive.
The key to saving one-half of the planet is the ecological
footprint, defined as the amount of space required to meet all of the needs of
an average person. It comprises the land used for habitation, fresh water, food
production and delivery, personal transportation, communication, governance,
other public functions, medical support, burial, and entertainment. In the same
way the ecological footprint is scattered in pieces around the world, so are
Earth’s surviving wildlands on the land and in the sea. The pieces range in
size from the major desert and forest wildernesses to pockets of restored
habitats as small as a few hectares.
But, you may ask, doesn’t a rising population and per-capita
consumption doom the Half-Earth prospect? In this aspect of its biology,
humanity appears to have won a throw of the demographic dice. Its population
growth has begun to decelerate autonomously, without pressure one way or the
other from law or custom. In every country where women have gained some degree
of social and financial independence, their average fertility has dropped by a
corresponding amount through individual personal choice.
There won’t be an immediate drop in the total world
population. An overshoot still exists due to the longevity of the more numerous
offspring of earlier, more fertile generations. There also remain
high-fertility countries, with an average of more than three surviving children
born to each woman, thus higher than the 2.1 children per woman that yields
zero population growth. Even as it decelerates toward zero growth, population
will reach between 9.6 billion and 12.3 billion, up from the 7.2 billion
existing in 2014. That is a heavy burden for an already overpopulated planet to
bear, but unless women worldwide switch back from the negative population trend
of fewer than 2.1 children per woman, a turn downward in the early 22nd century
is inevitable.
And what of per-capita consumption? The footprint will
evolve, not to claim more and more space, as you might at first suppose, but
less. The reason lies in the evolution of the free market system, and the way
it is increasingly shaped by high technology. The products that win are those
that cost less to manufacture and advertise, need less frequent repair and
replacement, and give highest performance with a minimum amount of energy. Just
as natural selection drives organic evolution by competition among genes to
produce more copies of themselves per unit cost in the next generation, raising
benefit-to-cost of production drives the evolution of the economy.
Teleconferencing, online purchase and trade, ebook personal libraries, access
on the Internet to all literature and scientific data, online diagnosis and
medical practice, food production per hectare sharply raised by indoor vertical
gardens with LED lighting, genetically engineered crops and microorganisms,
long-distance business conferences and social visits by life-sized images, and
not least the best available education in the world free online to anyone,
anytime, and anywhere. All of these amenities will yield more and better
results with less per-capita material and energy, and thereby will reduce the
size of the ecological footprint.
In viewing the future this way, I wish to suggest a means to
achieve almost free enjoyment of the world’s best places in the biosphere that
I and my fellow naturalists have identified. The cost-benefit ratio would be
extremely small. It requires only a thousand or so high-resolution cameras that
broadcast live around the clock from sites within reserves. People would still
visit any reserve in the world physically, but they could also travel there
virtually and in continuing real time with no more than a few keystrokes in
their homes, schools, and lecture halls. Perhaps a Serengeti water hole at
dawn? Or a teeming Amazon canopy? There would also be available streaming video
of summer daytime on the coast in the shallow offshore waters of Antarctica,
and cameras that continuously travel through the great coral triangle of
Indonesia and New Guinea. With species identifications and brief expert
commentaries unobtrusively added, the adventure would be forever changing, and
safe.
The spearhead of this intensive economic evolution, with its
hope for biodiversity, is contained in the linkage of biology, nanotechnology,
and robotics. Two ongoing enterprises within it, the creation of artificial
life and artificial minds, seem destined to preoccupy a large part of science
and high technology for the rest of the present century.
The creation of artificial life forms is already a reality.
On 20 May 2010, a team of researchers at the J Craig Venter Institute in
California announced the second genesis of life, this time by human rather than
divine command. They had built live cells from the ground up. With simple
chemical reagents off the shelf, they assembled the entire genetic code of a
bacterial species, Mycoplasma mycoides, a double helix of 1.08 million DNA base
pairs. During the process they modified the code sequence slightly, implanting
a statement made by the late theoretical physicist Richard Feynman, ‘What I
cannot create, I do not understand,’ in order to detect daughters of the
altered mother cells in future tests.
If our minds are to break free and dwell in the far more
interesting universe of reason triumphant over superstition, it will be through
advances in biology…
Read more here:
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