Sarah Kaplan, Washington Post, June 3 2017
COEUR d’ALENE, Idaho — Jakob Namson peered up at the towering ponderosa pine before him. He looked at his notebook, which was full of calculations scribbled in pencil. Then he looked back at the pine. If his math was right — and it nearly always is — then he would need to plant 36 trees just like this one to offset the 831 pounds of carbon dioxide that his drive to school emits each year.