Final answer:
The Bohr effect describes how a lower blood pH, caused by increased carbon dioxide, reduces hemoglobin's oxygen affinity, making oxygen release more readily to tissues.
Step-by-step explanation:
With the Bohr effect, hemoglobin more readily releases the oxygen it carries because of a lower, more acidic pH in the blood. This effect occurs because an increase in carbon dioxide in the blood leads to more hydrogen ions and a subsequent decrease in pH, thereby reducing hemoglobin's affinity for oxygen. As the pH decreases, the oxygen dissociation curve shifts to the right, meaning that oxygen is released more easily from hemoglobin at the tissue site, facilitating oxygen delivery to cells.