According to the Energy Star program, if every American home replaced just one light bulb with one certified LED or a CFL bulb, it would prevent 6 billion pounds of greenhouse gas emissions per year, equivalent to the emissions from about 550,000 cars.
The impact of nighttime light pollution on the the night environment, wildlife and human sleep cycles and health are often minimized. But we shouldn't. See: International Dark-Sky Association.
It's really impressive.
We should not forget that artificial lighting accounts for a very significant amount of residential power use: 9%, on average, in the US.
Hence the importance of renovating old lighting systems and installing new LED (and CFL) lighting systems, and new energy efficient lighting fixtures.
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