He raises his hand and says, louder than he meant: "But don't you know that broken wind turbines are buried in the earth? And that solar panels are largely non-recyclable when they are written off? And that electric car batteries are often a burden on the environment, even more so than the exhaust fumes from petrol cars?"

The whole class suddenly seems awake and looks at him dubiously. Only after a few seconds, which for Kashmir seems like hours, Esmée says, "Where did you get that from, Kashmir?" And Xander continues: "If this is really true, then how sustainable are these renewable energy sources really?" He looks at his teacher questioningly and the class follows his gaze. Mrs Kohls remains silent for a moment and smiles. "That is such an appropriate critical question. To be honest, I don't know the answer either, but we can find out together. Before we find out the sources and their reliability, I'd like to think about what Kashmir's comments triggered in all of you. I'm very curious about that. Kashmir, would you like to start?"