An estimated 1.8 billion people today are between the ages of 10 and 24 and 85 percent of them live in developing economies and/or fragile states. Such youthful age structures can lead to a number of challenges, including increased potential for instability, and countries with large numbers of young people must find ways to address their unique needs.

As presidents, prime ministers, and other policymakers from across the continent gather in Washington, DC, this week for the first-ever U.S.-Africa Leaders Summit, what are the issues to watch?

World Population Day began in 1987 after public imagination was sparked by the idea that there could be 5 billion people on Earth. Today, we’re well past 7 billion and according to the latest UN projections, headed north of 9 billion by mid-century.

“You can look into the future a couple decades and get a very good idea about where countries are going,” said Richard Cincotta during a presentation at the National Defense University last summer – at least when it comes to demography.

When Pakistan makes the news, more often than not it’s for one of two things: violent extremism or drone strikes. Adil Najam, a Pakistan expert and a lead author for the UN’s Intergovernmental Panel on Climate Change, says those headlines distract from a far more pressing security concern for the country: climate change.

The latest report by the United Nations Intergovernmental Panel on Climate Change (IPCC) brings new evidence to bear on the real and potential impacts of climate change, emphasizing the need to manage risks and build resilience. In a dramatic, slickly produced video accompanying the much-anticipated Working Group II contribution to the report, released on March 30, several of the working group’s dozens of authors discuss key issues addressed in their section, which covers “impacts, adaptation, and vulnerability.”

Blue Ventures has become a leader in the population, health, and environment (PHE) community through its work with the remote, semi-nomadic Vezo people living along Madagascar’s southwestern coast. In a new short documentary, The Freedom to Choose: Empowering Communities to Live With the Sea, Blue Ventures describes how their approach has helped the Vezo respond to the combined challenges of resource scarcity, poor reproductive health, and unsustainable livelihoods.

In southwestern China, three parallel rivers – the Nu, Lancang, and Jinsha (also known as the Upper Mekong, Salween, and Yangtze, respectively) – form a series of corridors that connect the tropical rainforests of Southeast Asia to the Tibetan Plateau. These areas are some of the most biodiverse in the world, and scientists argue they have value as “climate refugia” – places worth preserving in order to allow species to retreat to cooler, more suitable climates as temperatures rise. A cascade of dams, however, has been planned for the region, threatening to submerge habitats, reduce the flow of tributary rivers, and make the area less suitable for many plant and animal species.