Women in Madagascar are scrambling to access contraception—while they still can. By the end of this year, one of the most prominent organizations that provides family planning services in the country will have shut down 21 of its 22 mobile contraception clinics, an important service in a country where transportation and roads are in poor shape.

Over the past 25 years, economic and political demographers have documented how declines in fertility rates have preceded improvements in state capacity, income, and political stability in much of East Asia, Latin America, and, most recently, in the Maghreb region of North Africa (Tunisia, Morocco, Algeria). Nonetheless, social scientists still debate over where and when this “demographic dividend” will occur in the youthful, low-income countries of sub-Saharan Africa.  Elizabeth Leahy Madsen of the Population Reference Bureau and I find that, for most youthful countries—like those in sub-Saharan Africa—changes in population age structure provide a means to gauge the timing of their future development.

Six years of brutal warfare have destroyed basic infrastructure in Yemen, Libya, and Syria.  While U.S. and European governments have been largely preoccupied with providing immediate assistance and dealing with refugees, international humanitarian organizations—such as the International Committee of the Red Cross and Doctors without Borders—are focusing on how to repair, maintain, and safeguard the facilities that provide essential services like clean water, sanitation, and electricity.  Yet these efforts are hindered by lack of resources, protracted violence, and—most insidiously—by the warring parties’ intentional targeting of humanitarian actors and environmental infrastructure. Just as the extensive damage from hurricanes in the Caribbean and southeastern United States has underscored the need for more resilient infrastructure, the wars of the Middle East show that protecting infrastructure is key to protecting civilians caught up in conflict.

With air pollution causing more than one million deaths in 2015 and reducing the lifespan of citizens in northern China by three years, clean energy has become a top priority for China’s leaders. China tops the world in wind and solar power installations and the government plans to invest more than $360 billion through 2020 on renewable energy. But the green energy transition needs more than renewable power generation: Long-distance electricity transmission could play a key role in cleaning up China’s brown skies. Our recent study estimated that transmitting a hybrid of renewable and coal power through 12 new high-voltage transmission lines could prevent 16,000 deaths from air pollution exposure, and avoid 340 million tons of CO₂ emissions in China.

A threat looms on the sun-splashed horizon of the Republic of the Marshall Islands. The specter of climate change wraps its fingers around the islands, raising sea levels, salinizing soils, and sapping freshwater resources. These changes will make it even harder to sustain crops, which could push the population to even greater reliance on  processed foods, which has already spurred a diabetes epidemic on the islands. The major role played by the United States in the history of the Marshalls, where nuclear bombs were famously tested during the Cold War, may continue, as the impacts of another existential threat—climate change—continue to increase.

While attention in the United States is focused on the disasters in Puerto Rico and the Caribbean, a crisis across the Atlantic is rapidly becoming one of the worst humanitarian disasters since World War II. In the Lake Chad basin of West Africa, about 17 million people are affected by the emergency, struggling with food insecurity, widespread violence, involuntary displacement, and the consequences of environmental degradation. An estimated 800,000 children suffer from acute malnutrition; and although international donors pledged $672 million in February, the famine and humanitarian misery continues unabated. Suicide bombings and attacks by Boko Haram, which have killed at least 381 civilians since April 2017, have forced many people to leave their homes and farmers to leave their lands, interrupting livelihoods and reducing food supplies.

In 2011, a group of Hong Kong water activists and researchers traveled the length of the Dongjiang (East) River, which stretches from northeast Guangdong Province into Hong Kong’s New Territories, to investigate the challenges facing the watershed. The Dongjiang basin, which provides nearly 80 percent of Hong Kong’s water supply, has suffered water shortages due to the region’s increasing urbanization and industrialization. They found unchecked wastewater discharges—from agriculture, poultry farms, chemical plants, tanneries, and even an open-air quartz quarry—were dangerously degrading  water quality.

Girls and women bear the brunt of climate change impacts. Natural disasters kill more women than men: an estimated 90 percent of those killed in some weather-related disasters were female. The effects of climate change on natural resources can also further exacerbate existing gender inequalities.  Girls may be kept out of school to fetch water, as droughts drive them to walk farther and farther to find it. Seeking to stretch scarce household resources, families may marry off their daughters before the legal age and they may become more vulnerable to human trafficking after natural disasters.