Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Population trends: Another influence on climate change

12.10.2010
Changes in population growth and composition, including aging and urbanization, could significantly affect global emissions of carbon dioxide over the next 40 years, according to a new study out next week.

The research, appearing in Proceedings of the National Academy of Sciences (PNAS), was conducted by an international team of scientists from the National Center for Atmospheric Research (NCAR), the International Institute for Applied Systems Analysis (IIASA), and the National Oceanographic and Atmospheric Administration. It was funded by a European Young Investigator's Award, the Hewlett Foundation, and the National Science Foundation, which is NCAR's sponsor.

By mid-century it is estimated that global population could rise by more than three billion people, with most of that increase occurring in urban areas. The study showed that a slowing of population growth, following one of the slower growth paths considered plausible by demographers at the United Nations, could contribute to significantly reducing greenhouse gas emissions. The researchers found that such slow growth paths by 2050 could account for 16 to 29 percent of the emissions reductions thought necessary to keep global temperatures from causing serious impacts. The effect of slower population growth on greenhouse gas emissions would be even larger by the end of the century.

"If global population growth slows down, it is not going to solve the climate problem, but it can make a contribution, especially in the long term," says the study's lead author, Brian O'Neill, an NCAR scientist.

O'Neill's co-author, IIASA scientist Shonali Pachauri, says that slower population growth will have different influences, depending on where it occurs.

"A slowing of population growth in developing countries today will have a large impact on future global population size. However, slower population growth in developed countries will matter to emissions, too, because of higher per capita energy use," says Pachauri.

Scientists have long known that changes in population will have some effect on greenhouse gas emissions, but there has been debate on how large that effect might be.

Urbanization and aging

The researchers sought to quantify how demographic changes influence emissions over time, and in which regions of the world. They also went beyond changes in population size to examine the links between aging, urbanization, and emissions.

The team found that growth in urban populations could lead to as much as a 25 percent rise in projected carbon dioxide emissions in some developing countries. The increased economic growth associated with city dwellers was directly correlated with increased emissions, largely due to the higher productivity and consumption preferences of an urban labor force.

In contrast, aging can reduce emissions levels by up to 20 percent in some industrialized countries. This is because older populations are associated with lower labor force participation, and the resulting lower productivity leads to lower economic growth.

"Demography will matter to greenhouse gas emissions over the next 40 years," says O'Neill. "Urbanization will be particularly important in many developing countries, especially China and India, and aging will be important in industrialized countries."

The researchers worked with projections showing that population aging will occur in all regions of the world, a result of people living longer and declines in fertility.

Future scenarios of human behavior

The authors developed a set of economic growth, energy use, and emissions scenarios, using a new computer model (the Population-Environment-Technology model, or PET). To capture the effects of future demographic change, they distinguished between household types, looking at age, size, and urban vs. rural location.

In addition, they drew on data from national surveys covering 34 countries and representative of 61 percent of the global population to estimate key economic characteristics of household types over time, including labor supply and demand for consumer goods.

"Households can affect emissions either directly, through their consumption patterns, or indirectly, through their effects on economic growth," O'Neill explains.

The authors also suggest that developers of future emissions scenarios give greater consideration to the implications of urbanization and aging, particularly in the United States, European Union, China, and India.

"Further analysis of these trends would improve our understanding of the potential range of future energy demand and emissions," says O'Neill.

The researchers caution that their findings do not imply that policies affecting aging or urbanization should be implemented as a response to climate change, but rather that better understanding of these trends would help anticipate future changes.

The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation. Any opinions, findings and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Scientific contacts:

Brian O'Neill, NCAR Scientist
303-497-8118
boneill@ucar.edu
Shonali Pachauri, IIASA Scientist
+ 43 (0) 2236 807 475
pachauri@iiasa.ac.at

Rachael Drummond | EurekAlert!
Further information:
http://www.ucar.edu

More articles from Studies and Analyses:

nachricht Obstructing the ‘inner eye’
07.07.2017 | Friedrich-Schiller-Universität Jena

nachricht Drone vs. truck deliveries: Which create less carbon pollution?
31.05.2017 | University of Washington

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>