The capture of CO₂ from smokestacks could make an important contribution to limiting climate change, but there are two obstacles. One is that you have to store that CO₂ somewhere (like underground reservoirs). The other is that the capture process requires energy, so your power plant ends up producing less electricity per unit of fuel. That comes with a financial cost.

There are efforts afoot to overcome both of those hurdles, but there are also other possible approaches. One that sounds obvious and attractive is to turn that CO₂ into something useful and valuable, rather than just reservoir filler. The sticky wicket here is chemistry. Carbon dioxide is pretty stable, and turning it into something else can require a large energy input.