Suppose that the co2 concentration in theatmosphere
increased 100-fold. how would this affect the ability ofhb to
deliver o2 and why?

Ability to deliver increases.

Explanation:

Carbon dioxide is transported by the blood in the dissolved form. carbonic anhydrase is the enzyme which is a metalloenzyme having zinc at active site converts carbon dioxide into carbonic acid which dissolves in the blood.

Thus,  

H₂O (l) + CO₂ (g) ⇔ H⁺(aq) + HCO₃²⁻(aq)

If the concentration of the carbon dioxide is increases, then there is increase in the concentration of the hydrogen ions and thus decrease in the pH which results in the hemoglobin proteins releasing the uptake load of the oxygen. (Bohr effect)