As you approach Greece from the air, smog covers the land like a curtain – a thick grey line separating the deep blue Mediterranean sky from the Pindos mountains that run the length of the country north to south. There isn’t a major fire along the aircraft route, but with more than five hundred active wildfires across the country, the smoke is everywhere. Greece is facing its worst heatwave in four decades. With every passing year, the country sees more extremely hot days in the summer months. Wildfires are a feature of its ecosystem at the best of times. Now the threat is existential.