From the CO2Science archive: If you want to help ensure the survival of a rare tree, give it a magnificent umbrella-like shape and a cool name like Dragon’s Blood. Unfortunately for Croton urucurana that’s where the advantages end because it only grows in one place in the world, a single island off the coast of Yemen where a long civil war has led to deforestation and other ecological stresses. But CO2 knows no borders and neither does research. In 2012 there were two experiments showing that Dragon’s Blood Tree seedlings exposed to an extra 300 ppm CO2 grew on average 23.5% bigger. Whether or not that’s enough to save the species we can’t tell, but we are glad to do our part to help.