The novel sorbents for capturing acid and greenhouse gases converts red mud into a sorbent material that can be used to remove acid and greenhouse gases, utilizing a series of chemical reactions. The first set of reactions entail sorption of the acid/greenhouse gases and subsequent neutralization by the alkali content of the red mud. The salts generated by the neutralization reactions decompose to release the acid gases which are immediately converted to environmentally benign elemental products (N2, O2, S) by thermo-catalytic reactions. In a different set of reactions, the alkaline earth oxides (CaO and MgO) present in the sorbent capture the acid/greenhouse gases and convert them to nitrate, nitrite, carbonate and sulfite salts. The salts (beside carbonate) decompose to yield the acid gases which are converted to elemental products by thermo-catalytic reactions. The loaded sorbents are thermally regenerated to the oxide forms for re-capturing the gases.