They worry that both the manufacturing processes of the lights and the electricity needed to power them will generate lots of carbon dioxide (CO2) emissions. They worry that the lights are manufactured in China and thus the amount of CO2 emissions generated during their construction is effectively unknowable.
The average house with Christmas lights uses a fair amount of electricity– equal to about 22.8 days of 
the average household’s electricity consumption. Green groups claim that an “extravagant light display” can generate 881 pounds of CO2 throughout the holiday season. This is roughly equal to the CO2 emissions of a single car driving 958 miles, according to the Environmental Protection Agency
