Should solo Hummer drivers be allowed the HOV lane if they're carbon neutral?

California bill SB 1374, if passed and signed into a law, would allow any car to join the HOV sticker program as long as that vehicle is carbon neutral. This would mean someone driving alone in a Hummer could legally be allowed into the HOV lane, if the Hummer's emissions were offset. Senator Jim Battin officially proposed the legislation but his press release - which includes lines like "every owner of a polluting, flashy, fuel sucking car" - makes me think he is not serious. The law is starting to grow on me anyway. Why shouldn't a carbon neutral car - even a Hummer - be allowed in the HOV lane?
[Source: LAist]