The use of the word "entirely" is not reasonable at all.

The term "fossil fuel" applies to coal, but not oil. I was an organic chem major for a while, and, though there is disagreemnt among scientists, many recognise oil as the product of heat and pressure deep in the Earth.

Corbon dioxide is not a pollutant. In the early days of life on Earth, oxygen was the pollutant and CO2 was necessary for life.

Actually, I am not sure what is meant by "pollution". Burning wood in most parts of the world is the natural thing to do. Forests were burning away for millions of years before Man figured he had to put fires out. Wood fires may be wrong in the Los Angeles basin, but not here in the vast expanses of the Great Basin.