What does Alexander von Humboldt, who died more than 150 years ago, have to do with climate change and sustainability? The naturalist and polymath, after whom countless streets, plants, and even a sea on the moon are named, has shaped our understanding of nature as a living whole, as a cosmos in which everything, from the smallest to the largest, is interconnected and of which we are an inseparable part, like no other scientist. Historian Andrea Wulf places this understanding at the center of her exploration of Humboldt's life and work in her award-winning book "Humboldt's Invention of Nature," which she rethought radically. She follows the traces of the gifted networker and shows that our current knowledge of the Earth's vulnerability is rooted in Humboldt's beliefs. Encountering him again today serves as a reminder.