The partial pressure of carbon dioxide plays a major role in the transport of oxygen. In the alveoli, where there is high pO₂, low pCO₂, lesser H⁺ concentration and lower temperature, the factors are all favourable for the formation of oxyhaemoglobin, with the formation of oxyhaemoglobin the oxygen molecule is transported to the tissue whereas in the tissues, where low pO₂, high pCO₂, high H⁺ concentration and higher temperature exist, the conditions are favourable for dissociation of oxygen from the oxyhaemoglobin. Thus a decrease in the partial pressure of carbon dioxide helps in the oxygen transport.