Between the Sahara to the north and savanna to the south lies the semi-arid Sahel, a region stretching from Senegal to Sudan that has experienced desperate poverty, climate change, malnutrition, and violence. While every context is different, the Sahelian countries share some common challenges, including a pattern of recurring crises and fluid borders. Boko Haram’s reign of terror in northern Nigeria and Mali’s coup have both had cross-border components. [Video Below]

A pair of recently launched data sources offers visualizations to help people understand two hot-button issues in demography: the demographic dividend and changing fertility rates.

In a commencement speech at the U.S. Coast Guard Academy today, President Obama said “climate change constitutes a serious threat to global security, an immediate risk to our national security, and, make no mistake, it will impact how our military defends our country.”

Sub-Saharan Africa is often characterized as an outlier in terms of population dynamics and reproductive health. While women are having fewer children around the world, even prompting some places to begin worrying about aging populations, the demographic transition is proceeding more slowly in Africa. Fertility rates in North and Southern Africa have declined to around three children per woman, but the three other sub-regions of the continent – East, Central, and West Africa – retain much higher fertility, between five and six children per woman. Whether, and how quickly, fertility rates decline in these regions over the next few decades will in large part determine the peak of world population. These regions’ demographic trajectories also have important implications for health, governance, food security, economic development, land use, climate vulnerability, and even security.

Expectations for the upcoming UN climate change summit in Paris are higher than they’ve been in years. Experts expect it will be the best chance to achieve a binding, universal agreement to limit carbon emissions. But the conference is still not getting the attention it deserves from policymakers and the public, given the stakes – and not just for the environment but for the international system writ large, said Nick Mabey, founding director and chief executive of the UK-based environmental NGO E3G at the Wilson Center on February 12.

“Nigeria’s population is only two percent of the world population, but we contribute about 10 percent of the maternal mortality,” said Oladosu Ojengbede, professor and director of the University of Ibadan’s Center for Population and Reproductive Health. [Video Below]

Population projections undergird many important policy decisions, from the U.S. government’s Feed the Future program to the Sustainable Development Goals. But they’re not as straightforward as they appear. Demographers often base their estimates on complicated assumptions that aren’t obvious to the end user.