All those who think humans can engineer their way out of global warming should like this one.

Reddit comment / question:

A big issue is where you put it. The reason the CO2 is there is because we use ~10TW of fossil fuel energy to power our society. That energy is released because CO2 is a much higher entropy state than complex hydrocarbons. Turning CO2 back into carbon and storing it requires energy, and defeats the purpose of burning hydrocarbons in the first place. Storing it as a gas is extremely challenging, because it also requires energy to compress a gas into a smaller space.

If we had some clean safe power source for all of our energy needs, such as nuclear power that the general population trusted, we could potentially convert all that CO2 back into solid carbon and store it as bricks somewhere. I don't know about how it would be collected.

My first XC90 had one of those on the front/radiator.  It was/is suppose to make the car exhaust neutral in that the air pushing the pollutants through the filter would separate it, thus taking it out of the environment.

http://europe.autonews.com/article/19980622/ANE/806220837/volvo-installs-smog-eating-radiator

At ground level ozone causes smog, a health hazard. The combination of sunlight and unburned hydrocarbons from vehicle exhaust is one cause of ozone.

So... is there a good solution?

The demo is impressive:

The video above is from 2012, and while since that time no carbon-extracting mega-walls have been erected, Carbon Engineering has made serious headway on an equally impressive engineering feat: A carbon extracting “demo” plant, located in Squamish, British Colombia. Although neither modular, nor boundlessly deployable, as the company’s proposed capture filter system is, the demo plant is designed to demonstrate the technology’s large-scale viability, and pave the way for a subsequent commercial plant.