>This process has several advantages when compared to other methods of converting CO2 into fuel. The reaction uses common materials like copper and carbon, and it converts the CO2 into ethanol, which is already widely used as a fuel.

>Perhaps most importantly, it works at room temperature, which means that it can be started and stopped easily and with little energy cost. This means that this conversion process could be used as temporary energy storage during a lull in renewable energy generation, smoothing out fluctuations in a renewable energy grid.

Is it too much to ask that a science journal report on science in, like, quantitative terms to support a headline? Specifically: What's the efficiency (or how much energy is required per mole)? Estimated overall costs compared to batteries or grain ethanol? Other available chemical processes for capturing CO2, and their efficiency? Not reported. I have no idea what their arbitrary cut-off for "efficient" is, but if they say they want to make it more efficient, it obviously isn't efficient enough. Actual numbers might help to judge.