Create an account
gas that absorbs ultraviolet solar radiation, found in the stratosphere, a zone between 15 and 50 kilometers (9 to 30 miles) above Earth's surface.
Passive Solar Energy Systems
Solar energy that collects energy without the use of mechanical devices.
An atmospheric condition formed through a combination of weather conditions and pollution, especially from motor vehicle emissions.
Solar energy cells, usually made from silicon, that collect solar rays to generate electricity.
Maintenance of a resource in its present condition, with as little human impact as possible.
Particles from a nuclear reaction that emit radiation; contact with such particles may be harmful or lethal to people and must therefore be safely stored for thousands of years.
The process of collecting used materials that would otherwise be thrown away and turning them into raw materials for new uses.
A substance in the environment that is useful to people, is economically and technologically feasible to access, and is socially acceptable to use.
A place to deposit solid waste, where a layer of earth is bulldozed over garbage each day to reduce emissions of gases and odors from the decaying trash, to minimize fires, and to discourage vermin.
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together