Everything ASHRAE does is focused on how to use energy more wisely in order to create built environments that are healthy, productive, safe and well for the occupants. Most of the time those occupants are people. Energy efficiency is a priority within that context.
Putting a price on emissions and comparing that to the benefits of efficiency is not an area ASHRAE has explored up to this point. ASHRAE is focused on finding solutions on the energy side. That's not to say ASHRAE won't take that up, but at this point it's not an area that ASHRAE has investigated yet.