The day I first set foot in a tropical rainforest, in Malaysia in the early 1980s, I experienced something profound. From the echoes of gibbons calling from the canopy in the early morning mist to the iridescent flash of a bird in a beam of sunlight, rainforests are a sensory delight as well as a marvel to anyone’s scientific curiosity. As I subsequently watched these forests dwindle and, in some cases, vanish, I have felt an equally profound sense of loss and a nagging guilt that I was somehow part of the story, because I had done little to remedy the situation.