Bicarbonate and H+ ions are formed when carbonic acid dissociates. Carbonic acid, on the other hand, is formed when carbon dioxide dissolved in water – in this case, carbon dioxide is produced by tissues after cellular respiration which dissolves in blood plasma (rate catalyzed by carbonic anhydrase enzyme). Because Fred has chronic emphysema, he is unable to effectively expel excess carbon dioxide in the blood hence the bicarbonate ions and H+ accumulate in the blood.
Urinalysis would show low pH in the urine meaning that the kidneys are not excreting excess bicarbonate ions (also the reason for high bicarbonate in the blood)