Lauren+Chadwick



The Paradoxical Impact They Have on Climate Change

// "Aerosols are naturally present microscopic airborne suspensions of liquid droplets or solid particles in a gas, usually air, which have tendencies to remain dispersed (floating) in the gas rather than to settle down." (Climate Change : In Context) //

 Lauren Chadwick and Hannah Kalichman

**Background on Aerosols: ** The maximum size of an [|aerosol] is 1 micrometer (10-6 of a meter). They can be larger, but these aerosols are extremely violent in nature. Artificially produced aerosols are extremely hazardous as well. These are the aerosols that cause the extreme change in climate. Examples of common aerosols (natural and artificial) include sulfate aerosols, asbestos, diesel fuel and [|silicon dioxide (silica)]. They can be entered into the atmosphere through deforestation, agriculture, industry, mining, transportation and volcanism.  -Hannah Kalichman

Aerosol particles can absorb/scatter solar radiation affecting the amount that hits the Earth’s surface (wide types especially). Aerosols are a common cause of the [|depletion of the ozone]. However, they also cause the affect of [|global dimming] or cooling of the Earth. This occurs when aerosols such as sulfate aerosols from volcanic eruptions reflect some of the sunlight that comes to Earth back into space. They create a blanket over our Earth, but [|NASA] has found through maps provided from the [|Total Ozone Mapping Spectrometer (TOMS)] that it is not doing enough to reverse the effects of global warming. Recently, TOMS has become a more advanced satellite called the [|Ozone Monitoring Instrument (OMI)] that is onboard the Earth Observing Satellite (EOS) to record aerosol particle activity.
 * How Aerosols Work: **

During volcanic eruptions, gases from the Earth’s center come up to the surface. These gases are propelled far into the atmosphere and it affects the distribution of light locally and sometimes even globally. A prime example of this occurred with [|Mount Pinatubo] in the Philippines. By spewing 20 million tons of sulfur dioxide into the atmosphere, it produced a temporary cooling of the Earth’s surface. The eruption, which occurred around June 12, 1991, caused global temperatures to drop about 1°F (0.5°C) between 1991 and 1993. This made the average global temperature in 1992 the coolest in 30 years. The mass shield of sulfate aerosols from the cataclysmic eruption of Pinatubo cooled Earth by reflecting sunlight away from its surface. In fact, since the eruption, some scientists have suggested that we produce the same affect artificially to reverse the effects of [|global warming]. However, the cooling of the Earth due to Volcanism only lasts several years at most. Realistically, it cannot reverse the affects of global warming. The [|Intergovernmental Panel of Climate Change (IPCC)] even ruled that human activities override global dimming. Sulfur Dioxide Above Mount Kilauea in 2008:
 * Volcanism: **

media type="youtube" key="GxACUqHKVb0" height="344" width="425"

 ** Volcanism and the Affect of Aerosols: ** Volcanism cools the Earth, but at the same time it is contributing to the depletion of the ozone layer. [|Sulfuric Acid] along with [|Chlorofluorocarbons (CFCs)] is converted into forms that assist this process of depletion. Volcanoes release millions of tons of sulfuric acid (H2SO4) into the atmosphere during eruptions. There are approximately 1,500 active volcanoes on the Earth in the present year, and though ash is too heavy to stay in the atmosphere, gases can stay as aerosols and move through the atmosphere with air currents.


 * Sulfate Aerosols: **

Sulfate Aerosols are sent into the atmosphere in numerous ways. They can create a haze in the [|troposphere], but they can also enter as emissions from fossil fuels, and mostly enter the stratosphere from severe volcanic eruptions such as Mount Pinatubo. Sulfur dioxide (SO2) enters the atmosphere first. It then bonds with oxygen to become sulfur trioxide (SO3). When sulfur trioxide bonds with water (H2O) it becomes sulfuric acid (H2SO4).

This creates a huge sulfate aerosol when it reacts with water vapor. This reduces solar radiation that could reach Earth's surface AKA global dimming. By reacting with ozone and chlorine from chlorofluorocarbons (CFCs), they assist in the depletion of the ozone layer. -Lauren Chadwick


 * The Chemistry: **

Aerosols that are released from volcanic eruptions, forest fires or even dust storms enter the atmosphere as gas or solid particles. When these particle are combined with water they stay suspended in the atmosphere both obsuring the ground from sunlight and trapping heat in the atomosphere.
 * SO2 + (O) [[image:http://mooni.fccj.org/~ethall/h2so4/arrow.gif width="32" height="19"]] SO3**
 * SO3 + H2O [[image:http://mooni.fccj.org/~ethall/h2so4/arrow.gif width="32" height="19"]] H2SO4 **



-Hannah Kalichman

** For More Information on the Acivity of Aerosols and their Impact on Climate Change: ** Dr. Jim Haywood, Aerosol Research Scientist: media type="youtube" key="Wq9Fa7AqGGQ" height="344" width="425"

Attributions:

Lauren Chadwick: Text, Research, Pictures/Captions, Videos, Title

Hannah Kalichman: Text, Pictures/Captions, Bibliography, Title Art

**__ Bibliography: __**

“Aerosols” National Institute for Occupational Safety and Health [|www.cdc.gov/niosh/topics/aerosols] “Total Ozone Mapping Spectrometer” [|www.toms.gsfc.nasa.gov]

“Welcome to AAAR” American Association for Aerosol Research [|www.aaar.org] “Aerosols and Climate Change” [] "NASA homepage and attributed links" []

Lerner, Brena Wilmoth and Lerner, K. Lee eds. __Climate Change: In Context__ Detroit MI, 2008 Vol 1 (16-20)

Lerner, Brena Wilmoth and Lerner, K. Lee eds. __Climate Change: In Context__ Detroit MI, 2008 Vol. 2 (822-825)

"The University of New South Wales School of Physices" [] "Aerosols, Cloud Nucleation and Global Dimming." __Windows to the Universe__. 23 Mar. 2009 .

"YouTube - Climate Change and Aerosols." __YouTube - Broadcast Yourself.__ 01 Mar. 2009 [].