Sahara Desert Greening Due to Climate Change?

Desertification, drought, and despair—that’s what global warming has in store for much of Africa or so we hear.

Emerging evidence is painting a very different scenario, one in which rising temperatures could benefit millions of Africans in the driest parts of the continent.

Scientists are now seeing signals that the Sahara desert and surrounding regions are greening due to increasing rainfall.

If sustained, these rains could revitalize drought-ravaged regions, reclaiming them for farming communities.

This desert-shrinking trend is supported by climate models, which predict a return to conditions that turned the Sahara into a lush savanna some 12,000 years ago.

Green Shoots

The green shoots of recovery are showing up on satellite images of regions including the Sahel, a semi-desert zone bordering the Sahara to the south that stretches some 2,400 miles (3,860 kilometers).

Images taken between 1982 and 2002 revealed extensive regreening throughout the Sahel, according to a new study in the journal Biogeosciences.

The study suggests huge increases in vegetation in areas including central Chad and western Sudan.

The transition may be occurring because hotter air has more capacity to hold moisture, which in turn creates more rain, said Martin Claussen of the Max Planck Institute for Meteorology in Hamburg, Germany, who was not involved in the new study.

“The water-holding capacity of the air is the main driving force,” Claussen said.

While satellite images can’t distinguish temporary plants like grasses that come and go with the rains, ground surveys suggest recent vegetation change is firmly rooted.

In the eastern Sahara area of southwestern Egypt and northern Sudan, new trees—such as acacias—are flourishing, according to Stefan Kröpelin, a climate scientist at the University of Cologne’s Africa Research Unit in Germany.

“Shrubs are coming up and growing into big shrubs. This is completely different from having a bit more tiny grass,” said Kröpelin, who has studied the region for two decades.

In 2008 Kröpelin—not involved in the new satellite research—visited Western Sahara, a disputed territory controlled by Morocco. “The nomads there told me there was never as much rainfall as in the past few years,” Kröpelin said. “They have never seen so much grazing land.”

“Before, there was not a single scorpion, not a single blade of grass,” he said. “Now you have people grazing their camels in areas which may not have been used for hundreds or even thousands of years. You see birds, ostriches, gazelles coming back, even sorts of amphibians coming back,” he said. “The trend has continued for more than 20 years. It is indisputable.”

Uncertain Future

An explosion in plant growth has been predicted by some climate models. For instance, in 2005 a team led by Reindert Haarsma of the Royal Netherlands Meteorological Institute in De Bilt, the Netherlands, forecast significantly more future rainfall in the Sahel. The study in Geophysical Research Letters predicted that rainfall in the July to September wet season would rise by up to two millimeters a day by 2080. Satellite data shows “that indeed during the last decade, the Sahel is becoming greener,” Haarsma said. Even so, climate scientists don’t agree on how future climate change will affect the Sahel: Some studies simulate a decrease in rainfall. “This issue is still rather uncertain,” Haarsma said.

Max Planck’s Claussen said North Africa is the area of greatest disagreement among climate change modelers.

Forecasting how global warming will affect the region is complicated by its vast size and the unpredictable influence of high-altitude winds that disperse monsoon rains, Claussen added. “Half the models follow a wetter trend, and half a drier trend.”

The Ageing of the World’s Population

The Ageing of the World’s Population

Over the past few years, the world’s population has continued on its remarkable transition path from a state of high birth and death rates to one characterized by low birth and death rates. At the heart of that transition has been the growth in the number and proportion of older persons. Such a rapid, large and ubiquitous growth has never been seen in the history of civilization.

The current demographic revolution is predicted to continue well into the coming centuries. Its major features include the following:

• One out of every ten persons is now 60 years or above; by 2050, one out of five will be 60 years or older; and by 2150, one out of three persons will be 60 years or older.
• The older population itself is ageing. The oldest old (80 years or older) is the fastest growing segment of the older population. They currently make up 11 percent of the 60+ age group and will grow to 19 percent by 2050. The number of centenarians (aged 100 years or older) is projected to increase 15-fold from approximately 145,000 in 1999 to 2.2 million by 2050.
• The majority of older persons (55 percent) are women. Among the oldest old, 65 percent are women.
• Striking differences exist between regions. One out of five Europeans, but one out of twenty Africans, is 60 years or older.
• In some developed countries today, the proportion of older persons is close to one in five. During the first half of the 21st century that proportion will reach one in four and in some countries one in two.
• As the tempo of ageing in developing countries is more rapid than in developed countries, developing countries will have less time than the developed countries to adapt to the consequences of population ageing.
• The majority of the world’s older persons (51 percent) live in urban areas. By 2025 this is expected to climb to 62 percent of older persons, although large differences exist between more and less developed regions. In developed regions, 74 percent of older persons are urban dwellers, while in less developed regions, which remain predominantly rural, 37 percent of older persons reside in urban areas.
• Over the last half of the 20th century, 20 years were added to the average lifespan, bringing global life expectancy to its current level of 66 years. Large differences exist between countries, however. In the least developed regions, men reaching age 60 can expect only 14 more years of life and women, 16 more, while in the more developed regions, life expectancy at age 60 is 18 years for men and 22 years for women.
• The impact of population ageing is increasingly evident in the old-age dependency ratio, the number of working age persons (age 15 – 64 years) per older person (65 years or older) that is used as an indicator of the ‘dependency burden’ on potential workers. Between 2000 and 2050, the old-age dependency ratio will double in more developed regions and triple in less developed regions. The potential socioeconomic impact on society that may result from an increasing old-age dependency ratio is an area of growing research and public debate.

Source: Population Division, Department of Economic and Social Affairs, United Nations Secretariat

Meanings and Images in an Ageing Society
Images of ageing are rooted in culture and cut right to the marrow of the society in which we live. However, the understanding of one’s language and culture can very often contrast with the meanings and images given it by others. This paradox also mimics ageing in advanced societies, where, with the accumulation of years and experience, roles diminish, and images play a part.

Mass media, the machine of image-making, is also a link in the globalization chain, and can have profound effects on the developing world, and particularly on the older women who live there. For its part, the flow and interchange of ideas and information through new technologies is as much an extraordinary achievement as it is an ordinary fact of life. The positive impact that is gained from other ideas, learning about other populations, areas of expertise, and alternative ways of life is boundless. But knowledge and images are often mutual passengers in the information voyage and the image landscape conveyed by the western media weighs heavily on the side of glorifying youth, while either omitting older persons or depicting them in stereotypes. This has a particular impact on the lives of older women, as they tend to suffer greater political, social, and economic exclusion than do older men.

As society ages however, it also changes in ways that relate to age. Perceptions of the transitions that mark the boundaries of age are being altered as family, kinship and community structures change. In many parts of the world it is not uncommon today to be part of a four-generation family, where the chronological rules for assuming the roles of grandparents or grandchildren are increasingly blurred. At the same time, more individuals are growing older outside of traditional family networks and are simulating family life through communities or primary groups. The rhythm of the life cycle continues to develop through these different dynamics and, consequently, is not as tightly bound by chronological age or stages as it once may have been.

The same can be said for images that surround the idea of change. While change often arouses anxiety, challenges that stem from new orders of complexity should be met with inquiry rather than reproach. Situations or choices that once seemed incompatible, work or retirement, strength or vulnerability, can be approached and accommodated within the same creative mix that occupies the vastness and diversity of life in the human community.

The new architecture of ageing requires policies that remove obstacles and facilitate contributions. It also requires seminal thinking and images that reflect reality and potential, not stereotypes and myths. So relative are the experiences of ageing in different parts of the world, and so complex and multiple their roles, that the world can no longer accept images of ageing as a panorama of near homogeneity.

Policy Considerations
Old age policies were designed, for most of the 20th century, with a youthful society in mind. From this point onward, policies for older persons, younger persons and those in between, must be designed with an ageing society in mind, society where soon, every third individual will be over the age of 60. International, national and local communities must begin now to adjust and design their infrastructures, policies, plans and resources.
Policy interventions that include social and human, as well as economic investments, can prevent unnecessary dependencies from arising whether in late life for individuals or downstream in ageing societies. When judicious investments are made in advance, experts suggest that ageing can be changed from a drain on resources to build-up of humane social, economic and environmental capital. This requires investing in the phases of life, fostering enabling societies, and creating flexible but vibrant collaborations in the process, through which the future building of a society for all ages can take hold in the present.

Finally, recognition of the uniqueness that unfolds throughout one’s life is core to igniting society’s embrace of the contributions of its older citizens. The “package” of knowledge, wisdom and experience that so often comes with age is part of an inner awareness that cannot be traded, sold or stolen. It should, however, be activated, amplified and utilized in all the crossroads, fields and storefronts of society, and in the windows of our creative imaginations.