The waters of Lake Chad sustain 70 million people in four countries. Beginning in the 1970s, the 25,000-square-kilometer lake began shrinking due to excessive drawdown for agriculture and mining. Now only 10 percent remains. The dwindling water supply devastated food production and fostered massive economic and political tensions. Many experts credit the worsening conditions for contributing to the rise of Boko Haram, an extremist group that has killed 20,000 people and forced 2.3 million more to flee.

Known as the “vitamins of industry,” rare earths refer to a cluster of minerals widely used in green technologies such as wind turbines, rechargeable batteries, and electric vehicles. Rare earth elements embedded in these products keep them light, efficient, and affordable. They’re essential to the decarbonization of the global economy envisioned in the Paris Climate Agreement, agreed to by 192 countries in 2015. And we may soon face a significant shortage, due in no small part to changes in China.

More than 40 years ago, the Soviet Union attempted to harness hydropower to modernize Afghanistan. Between 1960 and 1968, they poured money and technical knowledge into the 100-meter Naghlu gravity dam outside Kabul and a village for its workers called Sharnak. Although the town has been damaged and the boons of modernity remain elusive for many Afghans, the dam remains a crucial source of power for the capital and is the largest power plant in the country with an installed capacity of 100 megawatts.

As climate change threatens the stability of ecosystems around the world, the preservation of forests is seen as a “win-win” solution to curbing planet-warming emissions while producing value for developing country economies.

Ten years ago, amateur tilapia farmers in China were able to dig a pond, fill it with fish, add antibiotics and chemicals, and a few months later sell the fish to numerous unregulated processors. In those early days, fish farming created a great economic boom for first-time aquaculture farmers.

Revered for far more than its contribution to Indian civilization, the Ganges represents the goddess of salvation, Ganga. As a symbol of purity in Hindu mythology, the holy river is thought to cleanse believers both spiritually and physically with its waters.

Hans Rosling, the Swedish statistician, global health advocate, and “edutainer,” passed away this week in Uppsala, according to his foundation, Gapminder.