Didn't look for bakery data but found this for breweries
in this document:
"The EPA Mandatory GHG accounting rule applies to facilities from specific industries that directly emit 25,000 metric tonnes of carbon dioxide equivalent or more per year. Assuming an average thermal requirement of 1.5 therms per barrel of production and an emission factor of 5.29 kg CO2 emitted per therm, an average brewery would produce roughly 125 barrels of beer per metric ton of CO2 emitted. It is unlikely that craft brewers under approximately 3 million barrels of annual production would be susceptible to this rule based on their size and operations. Naturally this threshold would change if the EPA accounting rule limit changed. "
Interesting. Nice find.
I didn't read the whole article in detail, only skimmed it. But it clearly shows beer producers are thinking about how to manage energy costs. As one of those costs, the article mentioned capture & recovery of CO2 made during fermentation, and other phases of producing beer, instead of venting to the atmosphere. (Begins on page 16.) Many of those process seemed to involve CO2 as a by product of heating or refrigeration, not as a direct product of yeast during fermentation.
I searched for the word yeast, and on page 46, it mentions the efforts of the Sierra Nevada Brewing Co. at recovering and recycling the CO2 produced by yeast during fermentation. The brewery recycles the recovered CO2 back into the plant for various uses after the beer is produced, including sanitizing, moving product, and purging & pressurizing tanks.
This brings the discussion back to the question of governments regulating or taxing the production of CO2. This document, produced by the Brewer's Association, shows brewing companies' the best and latest practices at managing costs. If CO2 production became a cost item similar to energy use, the brewers would respond to that just as they are already trying to manage energy use to keep costs down. This article demonstrates that it makes sense to the brewery industry, and it would make similar sense to other industries as well.
For the life of me, I cannot understand why some politicians (GOP politicians) refuse to consider this approach. Are they being paid by energy producers' lobbies to block such laws?
@highfigh – If this is what you meant when you first mentioned brewing and baking as sources of CO2, then I previously got what you meant all wrong. It could be considered as a good way to proceed.