Of course this all presumes that the established trends maintain
themselves as all unique populations transition into modernism. The
take home is that we will have an expanded population that sustains
at close to ten billion people.
My own opinion here is that we will actually transition into a
sustainable lifeway that naturally demands and employs a high density
steady state base population and that this could easily approach one
hundred billion before we are finished.
With extended life times typically approaching 300 years and global
reproduction at maintenance, our society will be quite different.
Yet that is were we are going and actual capability is imminent.
I also observe that this projection is limited solely to the surface
of the earth were we will be fully engaged in its terraforming. It
makes no allowance to deep habitats, also internally sustainable, or
for space habitats that are also likely feasible. Adding in those
options, human population is potentially unlimited, at least in
comparison to the numbers we can integrate to the Earth's surface.
The population projections in this item presuppose that we never do
get our global act together and that is becoming progressively less
likely.
Model predicts that
the world's populations will stop growing in 2050
Posted by
TANNBreakingnews, Ecosystems, Environment11:00 AM
Global population data
spanning the years from 1900 to 2010 have enabled a research team
from the Autonomous University of Madrid to predict that the number
of people on Earth will stabilise around the middle of the century.
The results, obtained with a model used by physicists, coincide with
the UN's downward forecasts.
According to United
Nations' estimates, the world population in 2100 will be within a
range between 15.8 billion people according to the highest estimates
-high fertility variant- and 6.2 billion according to the lowest --
low fertility variant-, a figure that stands below the current 7
billion.
A mathematical model developed by a team from the Autonomous University of Madrid (UAM) and the CEU-San Pablo University, both from Spain, seems to confirm the lower estimate, in addition to a standstill and even a slight drop in the number of people on Earth by the mid-21st century.
A mathematical model developed by a team from the Autonomous University of Madrid (UAM) and the CEU-San Pablo University, both from Spain, seems to confirm the lower estimate, in addition to a standstill and even a slight drop in the number of people on Earth by the mid-21st century.
The population prospects between 1950 and 2100 provided by the UN were used to conduct the study, published in the journal 'Simulation'. Mathematical equations which are used in scientific fields, such as condensed matter physics, were then applied to this data.
"This is a model that describes the evolution of a two-level system in which there is a probability of passing from one level to another," as explained by Felix F. Munoz, UAM researcher and co-author of the project.
The team considered Earth as a closed and finite system where the migration of people within the system has no impact and where the fundamental principle of the conservation of mass -biomass in this case- and energy is fulfilled.
"Within this
general principle, the variables that limit the upper and lower zone
of the system's two levels are the birth and mortality rates,"
Munoz pointed out and recalled the change that occurred in the ratio
between the two variables throughout the last century.
"We started with a general situation where both the birth rate and mortality rate were high, with slow growth favouring the former," he added, "but the mortality rate fell sharply in the second half of the 20th century as a result of advances in healthcare and increased life expectancy and it seemed that the population would grow a lot. However, the past three decades have also seen a steep drop-off in the number of children being born worldwide."
The model's S-shaped sigmoid curve reflects this situation with an inflection point in the mid-1980s when the speed at which the population is growing starts to slow down until it stabilises around 2050.
The data also reflect the downward trend in the UN's series of prospects. "Overpopulation was a spectre in the 1960s and 70s but historically the UN's low fertility variant forecasts have been fulfilled," Munoz highlighted.
As recently as 1992 it was predicted that there would be 7.17 billion people on Earth by 2010 instead of the actual 6.8 billion. In fact, the fertility rate has fallen by more than 40% since 1950.
"This work is another aspect to be taken into consideration in the debate, although we do not deal with the significant economic, demographic and political consequences that the stabilisation and aging of the world population could entail," the researcher concluded.
Source: Plataforma SINC [April 04, 2013]
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