Also, in some countries the daylight lasts longer, so there is no need anyways. Where nights are shorter, so you don't keep them on for long.
Secondly, people should plug off the TV and other electrics, before going to sleep, teacher told it uses total of 20% of unwanted energy, also saves money as said above.
There are lots and lots of people in UK and US (especially), that are said to be "obese", and 60% and apart from that 80% of the people do not keep themselves fit, so they should walk more instead of driving cars for place you can get in 5 mins by walking.
change in economic conditions > change in lifestyle > global warming