Documents population growth 32 results

"Estimée à 7,4 milliards de personnes par les Nations unies, la population mondiale n'a jamais été aussi nombreuse qu'aujourd'hui. Va-t-elle continuer à croître ou connaître un palier dans les prochaines décennies ? Alain Parant, s'appuyant sur sa contribution au Rapport Vigie 2016, actualisée pour tenir compte de la révision 2015 des perspectives de la population mondiale établies par les Nations unies, fait ici le point sur les grandes tendances démographiques à venir. Comme il le souligne, si la croissance de la population mondiale est aujourd'hui moins vive que par le passé, elle demeure une tendance lourde, tirée par les pays en développement, et résultant notamment de l'allongement de la durée de vie moyenne et d'une fécondité globalement supérieure au niveau de remplacement des générations. Outre la poursuite de cette croissance démographique, le monde devrait être aussi marqué par un vieillissement général de la population (plus aigu dans les pays les plus développés). Enfin, un continent se démarque des autres en matière démographique : l'Afrique, dont la croissance démographique connaît un rythme nettement plus rapide qu'ailleurs et devrait continuer sur cette lancée, avec pour conséquences une population nettement plus jeune que dans le reste du monde et, surtout, un volume de population à venir tel qu'il semble compliqué — sinon impossible — pour le continent de l'assumer seul dans des conditions correctes. Au vu de ces tendances, la question migratoire devrait donc, dans les décennies à venir, se poser de manière de plus en plus vive et occuper une place centrale dans les relations internationales."

"The first decade of the 21st century witnessed an historic reduction in global poverty and a near doubling of the number of people who could be considered middle income. But the emergence of a truly global middle class is still more promise than reality. In 2011, a majority of the world's population (56%) continued to live a low-income existence, compared with just 13% that could be considered middle income. And though there was growth in the middle-income population from 2001 to 2011, the rise in prosperity was concentrated in certain regions of the globe, namely China, South America and Eastern Europe. The middle class barely expanded in India and Southeast Asia, Africa, and Central America."

"The world economy is affecting ecosystems in a way that puts future living standards at risk. Important issues include global warming, fading resource stocks, scarce water supplies, and decreasing biodiversity. It is broadly ac-accepted that the future of our planet should be one of our major concerns. But when it comes to concrete policies, most clearly those related to climate change, grave difficulties arise. This may come as a surprise. In fact, it should not be surprising. Forward-looking and green policies have always proved to be demanding and controversial. At the global scale, national policy difficulties are only compounded. There is not sufficient consensus across the different countries. World society is not very dynamic in problem solving. Rather, it is graying and inertial, cultivating conservative views and institutions. Economic interests and political perceptions diverge widely across countries. While the potentials offered by green technologies are huge, institutions have not yet adapted to meet the challenges. The political debate lacks sufficient focus; it includes very diverse opinions and notions on admittedly complex issues. It is true that the most prominent sustainability policy, climate policy, combines the most difficult and complex conditions for policy making in a single subject. Correction of a big market failure, international consensus building, long-run planning, major uncertainties, huge equity concerns, and very heterogeneous country interests are ingredients that would bedevil any political decision. On the bright side, concepts such as “green economy” and “sustainable development” have prominently entered the political debate, documenting the rising number of bridges between economy and ecology. Re-source-efficient technologies are increasingly being developed and applied. Yet, while everyone would highly welcome political solutions to the climate problem, accepting their consequences is much less widely embraced. These include significant reductions in natural resource use, especially with fossil fuels. They also entail acknowledging responsibility for past emissions and obligations to other countries and future generations. Consistent sustainability policies require a framework and an institutional setting that has yet to be built and globally implemented. Such a framework would end-able policymakers exploiting the huge potentials for greening the economy. Many scientific and applied contributions on sustainability have al-ready been published. But the majority of the advocated policies have not been implemented; major problems such as global warming have not yet been properly addressed. It appears that sustainability policies are not attracting sufficient political support. By pointing to the profound problems inherent in policy making in this area, this book explains why this is the case. It also provides the elements needed to increase general understanding and to find political consensus. Compared to the much broader scientific contributions on sustainability, some authored by large numbers of international researchers in different disciplines, the present book takes a more modest approach. It draws on selected research results to explain the most important sustainability is-sues from the point of view of economics. The book points at central underlying problems and misperceptions with the aim of increasing ambitions and rationality in political decision making. It reflects the high complexity of reaching sustainable development, which will require the contribution of social sciences involving many different perspectives. The book uses neither formal models nor mathematical equations. These can be found in the underlying original academic works cited in the references. The approach follows that of the famous economist Alfred Mar-shall, who advised using formal analysis until the results were fully de-rived but then to “burn” the mathematics, translate the conclusions into normal language, and illustrate them by “examples that are important in real life.” In following this procedure, this book aims to make the economic approach to sustainability attractive for a broader audience and a useful input to policy making."

"This paper examines the impact of population growth on global climate change. The author employs the Global Change Assessment Model (GCAM) to estimate the effects of population growth on the global average temperature by 2100. Observing that a larger population supports a larger economy, which translates in close proportion into additional releases of carbon dioxide (CO2), the paper notes that global temperature should in any year be nearly linear in relation to the rate of growth when the rate of population growth is constant.

The paper finds that an additional 1 percentage point of population growth through the end of the century would coincide with about an additional 2 degrees Fahrenheit in average global temperatures. Over time, the temperature change is greater and becomes increasingly sensitive to population growth."