Right now we are in the Goldilocks Zone, but we will not stay there because we are changing the physical and chemical conditions of our planet. If only we heeded the warning from ancient Rome. It is true that pandemic eruptions in ancient Rome were associated with cold, not heat. But a new study shows that even relatively mild climate changes can affect human health, let alone the extreme changes we're facing. Research on climate change and pandemic outbreaks in ancient Rome was presented last month by Karin Zonneveld of the University of Bremen and colleagues in Science Advances, based on an analysis of climate conditions in southern Italy over eight centuries: from about 200 BC to 600 BC. (Ruth Schuster)