Featured Research

from universities, journals, and other organizations

A model predicts that the world's populations will stop growing in 2050

Date:
April 4, 2013
Source:
Plataforma SINC
Summary:
Global population data spanning the years from 1900 to 2010 have enabled a research team to predict that the number of people on Earth will stabilize around the middle of the century.

Estimated and projected world population according to different variants, 1950-2100 (billions, 2010 Revision). The model matches with the low fertility variant.
Credit: Credit: UN

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.

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 Félix F. Muñoz, 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," Muñoz 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," Muñoz 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.


Story Source:

The above story is based on materials provided by Plataforma SINC. Note: Materials may be edited for content and length.


Cite This Page:

Plataforma SINC. "A model predicts that the world's populations will stop growing in 2050." ScienceDaily. ScienceDaily, 4 April 2013. <www.sciencedaily.com/releases/2013/04/130404072923.htm>.
Plataforma SINC. (2013, April 4). A model predicts that the world's populations will stop growing in 2050. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2013/04/130404072923.htm
Plataforma SINC. "A model predicts that the world's populations will stop growing in 2050." ScienceDaily. www.sciencedaily.com/releases/2013/04/130404072923.htm (accessed April 19, 2014).

Share This



More Health & Medicine News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) — In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) — A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) — The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) — President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins