What uses CO as fuel? If that was so why is there 50% more CO in the atmosphere now ? I clearly do not understand why prying the oxygen off the carbon dioxide --and using energy to do it--makes any sense at all.

"What uses CO as fuel? If that was so why is there 50% more CO in the atmosphere now ? I clearly do not understand why prying the oxygen off the carbon dioxide --and using energy to do it--makes any sense at all."

As is says in the article, CO is feedstock to industrial processes. In the air we have excess CO2 that is the most oxidized form of carbon.