Taking all these factors into account, the math suggests you’d need somewhere around 50 acres’ worth of trees, planted in tropical areas, to absorb the emissions produced by an average American in her lifetime. Multiply that by the population of the United States, and you get more than 16 billion acres, or 25 million square miles, roughly half the landmass of the world. Those trees would have to be maintained forever. And that’s just for the United States—we haven’t accounted for any other country’s emissions.
