carbon dioxide

Talk about a Eureka moment. Scientists at Sandia National Labs, seeking a means to create cheap and abundant hydrogen to power a hydrogen economy, realized they could use the same technology to "reverse-combust" CO₂ back into fuel. Researchers still have to improve the efficiency of the system, but they recently demonstrated a working prototype of their "Sunshine to Petrol" machine that converts waste CO₂ to carbon monoxide, and then syngas, consuming nothing but solar energy.