Given the liberals' past behavior on such issues, my guess is one that specifically requires that us peons cut back on our lifestyles (i.e. go live in caves) in the name of saving the planet while they continue to live their "high carbon" lifestyles because they are simply "too important" to be subject to the same laws as we are.
...which is why they are forever exempting themselves (and their families) from the same draconian rules and regulations the rest of us plebians are forced to live by. Some pigs are just more equal than others.