due to its poor efficiency. My 62" projection computer monitor/TV is on 12 hours or more per day and consumes less then 21" CRT, i.e.195W, while any plasma of this size dissipates ~550W. 

And new LED powered projection monitors have even up to twice better efficiency, <100W consumption. Global warming could appear as one more scientific chimera, but not $200-300 of savings in your pocket per year.