Sublime

Between now and midcentury the population of the world is expected to rise by somewhere between a third and a half of what it is today—i.e., by about two Chinas, or by six or seven United States of Americas—and

Japan is the world’s most rapidly-aging nation. To cite just one of many extraordinary data points, in 2012 its citizens bought more diapers for adults than for children.

Most of the world’s 28 low-income countries are in Africa, along with war-torn Syria and Yemen and the broken state of North Korea. In total, they are home to around 700 million people. The 54 nations that qualify as lower-middle income have a combined population of 3.4 billion, of which more than a third lives in India. Together, these two groups

It is a question of when—not if—large and growing areas of countries become uninhabitable owing to prolonged freshwater shortages, extreme heat, widespread flooding, and frequent, costly storms. Bangladesh may well be the first country with a substantial population to face this problem on a large scale. The amount of land able to support human exis