What role does yeast play in sourdough?

The yeasts cause the dough to rise by creating carbon dioxide bubbles, while the lactic acid bacteria provide the sour flavor (in the form of acetic acid and lactic acid) and preserve the bread by lowering its pH, which prevents the growth of food borne pathogens.

answer: because

explanation: idk

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.