The Western Sahel region—a cluster of arid, low-income countries stretching from Senegal, on Africa’s Atlantic coast, inland to Mauritania, Burkina Faso, Mali, Niger, and Chad—is home to the world’s most youthful populations. According to current UN Population Division estimates, about 57 percent of this six-country region’s population is 19 years old or younger. As security conditions deteriorate across the rural Sahel, governments in Europe and North Africa are taking notice of these countries’ demographic status—and for good reasons. Sustained population youthfulness (often called a “youth bulge”) contributes to low levels of educational attainment, joblessness and social immobility, and ultimately to rapid population growth, which tends to drive declines in per-capita availability of freshwater and other critical natural resources: factors that are associated with the risk of persistent violent conflict and represent powerful push factors for migration.

As Syria has collapsed, spasming into civil war over the last five years, the effects have rippled far beyond its borders. Most notably, a surge of refugees added to already swelling ranks of people fleeing instability in Afghanistan, Iraq, Pakistan, and sub-Saharan Africa, leading to the highest number of displaced people since the Second World War. At the same time, scientists have noted record-breaking temperatures, a melting Arctic, extreme droughts, and other signs of climate change. For some, an obvious question is: what does one have to do with the other?