Glossary entries, list 1

Carbon neutral:
Adding no new carbon dioxide emissions to the atmosphere; balancing the amount of carbon dioxide produced from activities like driving a car or producing electricity, with an equal amount offset by planting trees (which use CO2), supporting renewable energy from solar and wind

Emissions:
Gases and particles released into air and water from various sources, often associated with burning fossil fuels such as coal, gas and oil

Kilowatt-hour:
1 kWh = ten 100-watt bulbs all burning at the same time for one hour

Greenhouse gases:
Vapors such as water, ozone, carbon dioxide, carbon monoxide, methane and nitrous oxide that reflect solar radiation back to earth and are linked to global warming; Sources include forest fires, gasoline-fueled cars, coal-fired power plants and natural gas flares

LEED: Leadership in Energy and Environmental Design, a set of design standards for energy efficient and sustainable building practices established by the nonprofit U.S. Green Building Council; Existing and new buildings can earn certified, silver, gold or platinum ratings.

Therms: Unit of measure for natural gas and a heating value equivalent to 100,000 British Thermal Units (a BTU is the amount of heat needed to raise the temperature of one pound of water one degree Fahrenheit)