solar energy

Ever wonder what does Sustainability mean? Care to see the harnessing of water and solar power at Arizona’s earliest hydroelectric plant and Tempe’s modern solar array? How does a city turn its effluent water into a riparian preserve? Ever wonder how does river restoration work in the desert?

The greenhouse gas effect functions by trapping in the atmosphere heat from the Sun’s radiation. The greenhouse gases can be thought of as creating a one-way mirror—they allow the short wavelength energy emitted by the Sun to pass through the atmosphere and warm the Earth’s surface, but they do not allow all the longer wavelength energy radiated by the Earth back to space.

An idealized model of the natural greenhouse gas effect.

Estimate of the Earth’s annual and global mean energy balance. Over the long term, the amount of incoming solar radiation absorbed by the Earth and atmosphere is balanced by the Earth and atmosphere releasing the same amount of outgoing longwave radiation.

The amount of aerosols in the air has direct effect on the amount of solar radiation hitting the Earth's surface. Aerosols may have significant local or regional impact on temperature. Water vapour is a greenhouse gas, but at the same time the upper white surface of clouds reflects solar radiation back into space.

Posted by Stephen Miller | on August 29, 2008
Reducing a city’s carbon footprint requires more than switching to energy-saving light bulbs, and leaders across the Southwest are finding more and more creative ways to meet the challenge.

Posted by Chelsey Killebrew | on August 27, 2008
Roger Angel designs telescopes and has been in the astronomy field for more than 30 years. Now, he directs light on a different area of research—solar energy.

Posted by Chelsey Killebrew | on August 18, 2008
With its energy-efficient buildings, climate-controlled houses, and the dry desert landscape, a neighborhood in Tucson, Ariz., has created community-standard codes to reduce greenhouse gas emissions and water use to protect the environment.