No one, not even the cartographers of Google, can tell you exactly how many islands there are on earth, for to count an island, you must first define it. Is Australia a continent, an island, or both? Its tectonic grandeur implies one answer. Its improbable marsupial wildlife, having evolved over epochs of biogeographic isolation, implies another.
Several years ago, a pair of fastidious geographers attempted to conduct a census of islands, putting the global total at 5,675, if by island one means a body of land, larger than ten square kilometers but smaller than a continent, encircled by water. This figure, as the fastidious geographers fastidiously note, excludes the additional 8.8 million islets (smaller than ten square kilometers) and 7 billion nano-islets (as small as one square foot, “just enough…