Aerosols?

     Aerosols can have a huge impact on both climate and climate change. Aerosols are often thought to be limited to aerosol spray cans or their dispersion, but the term is much broader. Aerosols are any particles suspended in the air; this can encompass clouds, sand, smoke, and many other particles both harmful and harmless. Aerosols in the atmosphere are the result of any number of activities, both natural and influenced by man, such as the stirring of soil dust, the evaporation of sea salt, or direct emissions from vehicles such as cars.

     Aerosols can greatly impact the world we live in, even affecting such trivial things as local weather and health. Because of their position in the atmosphere, aersols have two major purposes. One of these is the deflection of a portion of sunlight which, like ozone, helps to protect the Earth from its own form of overexposure. The other is ozone depletion, a complicated process in which aerosols form a type of cloud that breaks down ozone in colder temperatures. Aerosols can also have a significant influence on cardiovascular and respiratory diseases because of accidental breathing in of aerosol particles; major cases of this have resulted in wide-spread suffering such as in the London Smog Disaster.

Sources:

http://en.wikipedia.org/wiki/Aerosols

http://aerosol.ees.ufl.edu/atmos_aerosol/section01.html