I stand on a small tributary of the Irrawaddy River. Across it is Myanmar—formerly Burma: I’m about as far west in the Chinese province of Yunnan as I can be. Borders between countries fascinate, for they illuminate different experiments in how we manage our natural world. Across the river, the land is going up in smoke. There’s a dense blue haze. At night, I see dozens of small fires, while overhead a satellite maps them from their thermal infrared radiation.