Turning carbon dioxide into fuel. Our present dependence on fossil fuels means that, as our demand for energy inevitably increases, so do emissions of greenhouse gases, most notably carbon dioxide CO2. To avoid the obvious consequences on climate change, the concentration of such greenhouse gases in the atmosphere must be stabilized. Researchers have developed a new system that could potentially be used for converting power plant emissions of carbon dioxide into useful fuels for cars, trucks, and planes, as well as into chemical feedstocks for a wide variety of products, using H2O, CO2 and solar energy.