Porous carbons provide a low-cost route to a highly stable material for the adsorption of various gases. In particular, activated carbons (ACs) and zeolite templated carbons (ZTCs) show promise in their ability to capture and store environmentally relevant small molecules such as hydrogen, carbon dioxide and methane. Indeed biogas upgrading and methane storage are already partially commercialised. While ZTCs offer precise control over porosity, ACs have the advantage of being easy to synthesise from a wide range of sources. This review examines state-of-the-art techniques to control the porosity of both ACs and ZTCs in order to fine-tune their ability towards the capture and storage of various gases under different pressure and temperature applications.