Population

A Long History of Linkage between Climate and Populations

Population geography has acknowledged for many years the role played by climatic factors in explaining the history of population and the emergence of cities. Thus, for mankind, the passage across the Bering Strait to America 13,000 years ago was possible due to the low sea levels of the Ice Age, while the Medieval Climate Optimum which lasted between the 8th and 13th centuries stimulated the population of Polynesia by making navigation relatively easy, thanks to regular winds and clear skies. The desertification of the Sahara and the Arabian Peninsula also played an important part in the densification of the population on the banks of the Nile and consequently contributed to the birth of ancient Egyptian civilization.

More recently, the droughts of the 1930s in the plains of the American Dust Bowl (parts of Kansas, Oklahoma, Texas, New Mexico, and Colorado) forced thousands of migrants toward California, and those that struck the Sahel between 1969 and 1974 displaced millions of African farmers and nomads.

Notwithstanding the present media focus on global warming, the amount of systematic research on climate and populations remains limited. There is much vagueness surrounding the concepts employed, the underlying mechanisms involved, the number of persons affected, and the geographical zones concerned. Climatic factors are rarely the sole cause of migration, and the economic, social, and political situation of the zone under threat can, depending on the case, increase or decrease the flow of migrants.

The use by numerous authors of the term “climate refugee” has also led to confusion, because it evokes the juridical status recognized by the UN Convention of 1951 to political refugees. The High Commissioner for Refugees, aware of a risk of confusion between political and nonpolitical refugees, has always treated with the utmost prudence the idea of including environmental motivations in the international definition of refugees, even if this category of the population is deemed a part of the protective mandate toward displaced persons.

The Consequences of Global Warming

Alarming predictions of greater resource scarcity, desertification, risks of droughts and floods, and rising sea levels that could drive many millions of people to migrate appeared in the review on the economic consequences of global warming delivered to the British government by Sir Nicholas Stern at the end of November 2006. While it is extremely difficult to elaborate scientific predictions by combining climate and migration models, the expected consequences of climate change can be compared to past experiences so as to establish a list of the populations most at risk and the possible resulting emigration flows. Three consequences of climate warming forecast in the latest report of the Intergovernmental Panel on Climate Change (IPCC) for the end of the 21st century appear to be the most threatening potential causes of

...