Aerosols influence global climate by scattering incoming solar radiation, causing a cooling effect. Much of this effect results from organic aerosols, which are classified as “primary” or “secondary.”

Incoming visible solar radiation heats the surface of terrestrial planets; infrared photons emitted by the surface are absorbed in the low atmosphere by greenhouse gases.

A recent statistical analysis strengthens evidence that human activities are causing world temperatures to rise. Most climate change scientists model Earth systems from the ground up, attempting to account for all climate driving forces. Unfortunately, small changes in the models can lead to a broad range of outcomes, inviting debate over the actual causes of climate change.

University of Colorado at Boulder researchers will scan Venus during a spacecraft flyby this week using an $8.7 million instrument they designed and built for NASA's MESSENGER Mission, launched in 2004 and speeding toward Mercury.

Monsoons, the life-giving, torrential rains of Asia and Africa, have an ancient, unsuspected connection to previous Ice Age climate cycles, according to scientists at the University of California, Santa Barbara, and at Kiel University in Germany.