In recent years, extensive wildfires, characterized by dark plumes of smoke that often stretch across national borders, have captured international headlines. So far, 2023 has proven particularly severe, with fires blazing across the Amazon basin, Canada, and Europe. These fires profoundly impact people's lives, endanger ecosystems, and release large amounts of greenhouse gases. Worryingly, their frequency and intensity are increasing. Here we answer four basic questions related to their causes and solutions, and the role different actors can play.