“Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from
elsewhere to save us from ourselves.” Less than three decades after Carl Sagan penned this warning, the responsibility “to preserve and cherish . . . the only home we’ve ever known” is illuminated in stark and tragic fashion by the effects of a rapidly changing climate. Extreme weather events are more frequent and severe. A mass extinction is underway. Tens of millions face famine. A heightened risk of disease threatens the entire human population. The phrase “climate refugees” has entered the popular lexicon.