Lighting plays a fundamental role in our lives, says this feature on the website of the World Watch Institute. "We use lights to illuminate most of our daily activities and to create a safe, comfortable environment." But each kilowatt-hour of electricity releases over two pounds (nearly 1 kilo) of carbon dioxide (CO2). "The buildup of CO2 and other “greenhouse gases” in the atmosphere is contributing to global climate change, which is predicted to result in more frequent and severe storms and droughts, the rapid spread of infectious diseases, rising sea levels, and other adverse effects that could harm humans and other life on Earth."