Klaus Lackner, a professor at Columbia University who is developing the tree, met with U.S. Energy Secretary Steven Chu last month to talk about the concept. In an interview with CNN, Lackner said the synthetic tree is "several hundred times better at collecting CO2" than windmill generators. Lackner says that for every 1,000 kilograms of carbon dioxide collected, the tree emits just 200 kilograms. This ratio is more than enough to warrant the relatively high cost of building the trees (about the same as a new automobile) or retrofitting coal plants.