DURBAN, South Africa — Arguably the most elegant aspect of an inelegant subject is how this city of 3.2 million residents, South Africa’s second largest, is solving monumental water and waste challenges in its jammed informal settlements.

In December 2015, Beijing issued its first-ever “red alert” for smog, its highest air pollution warning, which closed schools and restricted the number of cars on the road. Less than two weeks later, it issued its second.

The government of El Salvador took a truly extraordinary step in an attempt to control the rapidly spreading Zika virus last week by asking its citizens to avoid getting pregnant from now until 2018. Yes, you read that right.

This fall, the National Intelligence Council released an intelligence community assessment of the extent to which factors such as climate change, severe weather, conflict, resource scarcity, disease, poor governance, and environmental degradation will impact peoples’ purchasing power and food availability over the next decade. They found “the overall risk of food insecurity in many countries of strategic importance to the United States will increase.”

Venezuela seems suspended at a critical juncture. Following national elections in December, the opposition Democratic Unity Roundtable was set to occupy two thirds of the 167-seat National Assembly, an upset that would reduce the late Hugo Chávez’s United Socialist Party to a distant second place for the first time and given opposition legislators the power to enact sweeping political changes.