Today approximately 44 percent of the world’s 7.2 billion people are under 24 years old – and 26 percent are under 14. Of those 7.2 billion people, a staggering 82 percent live in less developed regions of the world – primarily sub-Saharan Africa and Asia. Currently, the global median age is 29.2 years old, a sharp contrast to Europe, for example, where the median age is 41.

It is difficult to find a country feeling the negative impacts of climate change more severely than Bangladesh. Name any alarming, seemingly far off effect of a warming world being discussed in the halls of Washington or the summits of Copenhagen, and there is a good chance Bangladesh is experiencing it today. Flooding, drought, sea level rise, mass migration, and crushing poverty are exacerbated by a growing population and rapid urbanization. This perfect storm of climactic and demographic trends presents a looming crisis for Bangladesh, no more so than when it comes to food security.

As world leaders gathered at the UN for a special event on achieving the Millennium Development Goals (MDGs) last month, there was much to celebrate. Some of the MDG targets – on poverty reduction and safe drinking water, for example – have been reached ahead of the 2015 deadline. But on MDG 5, which addresses maternal mortality and reproductive health, progress lags shamefully behind.

Sub-Saharan Africa is not only the fastest growing region of the world demographically but is also one of the most vulnerable to climate changes, according to many measures, and already facing natural resource scarcity in many areas. These factors combine with existing development challenges to create security threats that African governments and the United States should be concerned with, says ECSP Director Roger-Mark De Souza in a presentation for the Africa Center for Strategic Studies’ introductory course on demography and the environment at the National Defense University.

For a country that once made headlines for famine, poverty, and war, Ethiopia is gaining a reputation as a development leader on the African continent. In just over 10 years, the country has slashed child mortality rates by half, rising in global rank from 146 in 2000 to 68 in 2012. More money is being spent on health care, poverty levels and fertility rates are down, and twice as many children are in school.

Population aging and decline are frequently described as a threat to countries’ economic development and social stability. Evocative language, such as “demographic winter” and “graying of the great powers,” portrays the serious consequences that many observers envision as fertility and growth rates decline and the elderly comprise a greater percentage of the population. These concerns reach around the globe, including in Africa, which has the lowest percentage of elderly among the world’s major regions.