Emissions have plummeted as the pandemic slowed the world. It could be a mere blip—but it is an unprecedented opportunity for a greener, more sustainable economy. Serving in America’s armed forces is a long-established path to citizenship, but that path is narrowing. And we ask how sport will emerge from the pandemic, even if the stands stay empty. For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/radiooffer