Interesting read. I once wondered what would be the contribution to atmospheric heat of the combustion of cigarettes, and waved it as probably insignificant. A quick googling suggests burning a cigarette releases 7.8 J/mg of tobacco[1], that a cigarette weighs around 1 g, and that about 5 trillions (5e12) cigarettes are smoked annually [2]. This amounts to 3.9e16 J, or, averaged over one year, 1.2e9 W; corresponding to the total US energy consumption around 1730, according to the figure in parent's link.

Insignificant today, but not a few centuries back.

[1] https://www.researchgate.net/publication/307705601_Heat_Emis... [2] https://www.vitalstrategies.org/tobacco-atlas-global-tobacco...