Now, planting certain trees is getting a second look, as scientists have found evidence of food-producing trees capable of turning CO 2 into limestone. The trees in question—three species of figs found in Kenya—could be well-suited for agro-forestry, as they’d provide both fruit and long-lasting carbon sequestration. After all, there’s a lot of carbon dioxide in the atmosphere, and trees store that carbon in their leaves and woody bark. This makes these fig trees particularly adept at storing carbon, because even after these trees die, some of that carbon remains in these calcium carbonate deposits. Well, the trees first convert CO 2 into calcium oxalate crystals, and then rely on specialized bacteria and fungi to transform it into calcium carbonate.