Increased oxygen delivery to tissues in reponse to increased CO2 is -

A shift of the oxygen-hemoglobin dissociation curve to the right in response to increases in blood carbon dioxide and hydrogen ions has a significant effect by enhancing the release of oxygen from the blood in the tissues and enhancing oxygenation of the blood in the lungs. This is called the Bohr effect, Deoxyhemoglobin binds more H+ than oxyhemoglobin does and forms carbamino compounds more readily, binding of O2, to hemoglobin reduces its affinity for CO2 (Haldane effect).