Flying over the Indonesian half of the island of New Guinea, rainforest stretches like a sea of green, broken only by rugged mountain ranges and winding rivers. The verdant canopy shows little sign of human influence. But as you near Jayapura, the provincial capital of Papua, the tree cover becomes patchier — a sign of logging — and red scars from mining appear before giving way to the monotonous dark green of oil palm plantations and, finally, grasslands and urban areas.