Time to turn off more lights?

 

This is an image of Australia at night, created by Canadian scientist Felix Pharand-Deschênes:

 

 

According to The Climate Group, between 30 November - 6 December 2012 the combined greenhouse gas emissions of NSW, Vic, Qld, SA and Tas were 33 per cent above 1990 levels.

Electricity from coal this year to date produced 1.058 million tonnes CO2e in these five states.

How much of the light intensity in this picture would be reduced if Australian businesses turned off all those unnecessary, electrical advertising and architectural lights which blaze from their buildings each night?