Aerosols Good or Bad? There is a wide misconception that aerosols are bad for the environment and contribute to the depletion of the ozone. Aerosol (derived more or less from “air-solid”) is technically just the suspension of fine particles, such as solids or liquid droplets, in a gas. As such, clouds, smog, smoke, air born dust, etc. are all aerosols. About 90% of all aerosols are naturally produced . They can either be directly emitted into the atmosphere (primary aerosol like dust, sea salt and black carbon), or they can be formed in the atmosphere by condensation (secondary inorganic aerosol such as sulfates, nitrates and ammonium). Aerosols are argued to be cooling the surface of the earth. This is relevant because the effects of aerosols may have beneficial or possibly dire consequences. Aerosols play a large role in cooling the surface of the earth, counteracting global warming, medicine, and therefore nothing should be done to eliminate them. Many types of aerosols have a cooling effect on the Earth, such as the aerosols produced from the burning of fossil fuels. The aerosols produced from this are known to partially counteract global warming caused by various greenhouse gases. In order to say that aerosols cool the earth, we have to explore the different theories on how they are said to do so. According to Jeffrey T. Kiehl in "Solving the Aerosol Puzzle" the burning of fossil fuels and biomass (in natural and man-made fires) leads to the production of substantial amounts of aerosols in the atmosphere. These particles increase the reflection of sunlight back to space directly. This effect reduces the amount of solar energy available to the climate system, a phenomenon called negative climate forcing (that is, a cooling of the atmosphere) (Kiehl 1). This means that the more reflective property of the clouds, prevents sunlight from entering the earth's atmosphere, causing cooling. This research done by Kiehl is also backed up by Daniel Rosenfield who states that because pollution aerosols act as cloud condensation nuclei, clouds forming in a more polluted atmosphere contain a larger number of smaller drops that are slower to merge and fall as precipitation. As a result, the clouds are brighter, thicker, longer-lived, and more extensive, thus reflecting more sunlight back into space and partially mitigating global warming (Rosenfield 1). Aerosols also cool the earth indirectly by increasing the brightness of clouds. According to Maria the carbonyl groups associated with organic molecules in aerosols, exert influence on cloud properties, affecting cloud formation and causing cooling (Maria 1924). Aerosols serve as nuclei for liquid and solid cloud droplets, modifying cloud optical properties, this is another form of indirect aerosol cooling. In Glen Lesins' article he mentions how the anthropogenic indirect aerosol effects of modifying cloud albedo and cloud lifetime cannot be deduced from observations alone but require a modeling component. After the model is put under indirect aerosol test, he concludes that the simulated clouds are more susceptible to aerosols than observed clouds, meaning indirect aerosol effect does not cool the earth quite as much as previously stated. Lesins does however say that there is a significant cooling occurring. Many geoscientists argue that these thick clouds formed by aerosols trap heat and light on the earth surface. This is completely plausible, however since the clouds reflects light there is higher cooling taking place on the surface of the earth than heating. In "Organic Aerosol Growth Mechanisms and Their Climate-Forcing Implications" the writer states the direct effects of carbonaceous aerosol cause cooling by light scattering and warming by absorption, both of which increase nearly proportionally with the aerosol burden (Maria 1924). Therefore we see how aerosols in fact help the environment rather than harm it. Due to the cooling caused by aerosols, we see how it counteracts the effects of global warming. As the aerosols cool the surface and the greenhouse gases heat the earth, the temperature stays relatively constant. In "Is Thinning Haze Unveiling the Real Global Warming?" the writer talks about how the aerosol cloud which significantly cools the earth is now thinning. This is relevant because as this cloud thins the effects of global warming will be dire (Kerr 1480). Concluded by Kerr in "The sunlight-reflecting haze that cools much of the planet seems to have thinned over the past decade or so" aerosols counteract part of the warming effects of greenhouse gases, mostly by increasing the amount of sunlight reflected back to space. The continuous injection of sulfur into the stratosphere has been suggested as a “geo-engineering” scheme to counteract global warming, but this is a proven method to reverse the effects global warming. In "Aerosols, Clouds, and Climate" they say how because of aerosols "the clouds are brighter, thicker, longer-lived, and more extensive, thus reflecting more sunlight back into space and partially mitigating global warming" (Rosenfield 1). Since more nations are becoming aware of the health problems caused by aerosol, there are going to be many limitations on the amounts emitted. The decreased amount of aerosols being released into the atmosphere will decrease aerosol cooling, rapidly increasing the rate at which the earth warms. Many scientists are in favor of aerosol control because they claim that it causes respiratory problems in people, however asthma sufferers require a fine mist that can deeply penetrate their bronchial area therefore aerosol sprays are used to deliver medicine into the lungs of asthma patients. Aerosols are a key part of medicine, to deliver certain drugs into the human body through the pulmonary. "Over the past 60 years, significant inhalation products have been developed not only for the treatment of asthma, but also for other pulmonary diseases, such as chronic obstruction pulmonary diseases (COPD), cystic fibrosis, pneumonia, to name a few"(Wang 1). Via aerosol products, disinfectants (antimicrobials) are thoroughly and easily applied throughout surfaces in hospitals, the home or at school, eliminating bacteria and reducing the threat of disease. Aerosols therefore help prevent us from getting seriously ill. Insect repellents are more thoroughly applied to cover the entire body, protecting users from insect-borne diseases such as Malaria or the West Nile Virus. Cuts and scrapes can be disinfected with a targeted aerosol spray that does not require direct contact with the wound, decreasing discomfort and delivering a highly effective amount of untainted disinfectant. As we can see aerosols have many applications in medicine, making it an essential. Considering the research, we can conclude that aerosols are a essential part of the world and that the regulation of aerosols will do more harm then good. Although burning fossil fuels emit greenhouse gases, it also emits aerosols, which we learned cool the surface of the earth and in turn counteracts the heating of global warming. As country's start to impose for limitations on the emission of aerosols There will be a direct effect on the rate of global warming. Most scientists predict it will rapidly increase. Aerosols also have many roles in the medical field. Therefore we can conclude that aerosols play a large role in cooling the surface of the earth, counteracting global warming, medicine, and therefore nothing should be done to eliminate them. This research is critical because by decreasing the use of aerosols we could be doing more damage to the environment.
Works cited
Anderson, Theodore L., et al. "Climate Forcing By Aerosols -- A Hazy Picture." Science 300.5622 (2003): 1103-1104. Science & Technology Collection. Web. 12 Apr. 2014.
Kerr, Richard A. "Is A Thinning Haze Unveiling The Real Global Warming?." Science 315.5818 (2007): 1480. Science & Technology Collection. Web. 12 Apr. 2014.
Kiehl, Jeffrey T. "Solving The Aerosol Puzzle." Science 283.5406 (1999): 1273-1275. Science & Technology Collection. Web. 12 Apr. 2014.
Lohmann, Ulrike, and Glen Lesins. "Stronger Constraints On The Anthropogenic Indirect Aerosol Effect." Science 298.5595 (2002): 1012-1015. Science & Technology Collection. Web. 12 Apr. 2014.
Maria, Steven F., et al. "Organic Aerosol Growth Mechanisms And Their Climate-Forcing Implications." Science 306.5703 (2004): 1921-1924. Science & Technology Collection. Web. 12 Apr. 2014
Paeth, Heiko, and Johann Feichter. "Greenhouse-Gas Versus Aerosol Forcing and African Climate Response." Climate Dynamics 26.1 (2006): 35-54. Academic Search Complete. Web. 3 June 2013
Rosenfeld, Daniel, et al. "Climate Effects Of Aerosol-Cloud Interactions." Science 343.6169 (2014): 379-380. Science & Technology Collection. Web. 12 Apr. 2014.
Wang, Yi-Bo, et al. "The Impact Of Pulmonary Diseases On The Fate Of Inhaled Medicines—A Review." International Journal Of Pharmaceutics 461.1/2 (2014): 112-128. Academic Search Complete. Web. 3 May 2014.