Thursday, June 27, 2013

Atmospheric aerosols may act to slow climate change

Aerosols are are tiny dust or liquid particles suspended in the atmosphere and air that can be both natural and man-made. Ranging from the ash of a volcano to the particles spewed by burning fossil fuels, numerous scientific studies have discovered that these aerosols actually slow global warming, contrary to prior belief.

It is important to distinguish between aerosols and the commonly referred to greenhouse gases, like carbon dioxide and methane. Greenhouse gases act as a sort of gaseous, one-way passage blanket that envelops the earth. Meanwhile, the liquid and solid aerosols suspended in the air act as both mirrors and "seeds for cloud formation", affecting global warming both directly and indirectly.

Aerosols can reflect and shoot the sun's radiation rays away from the Earth, and can also gather water in the atmosphere to create clouds. The bigger these clouds are in quantity and size (thickness), more light rays are scattered and less heat is absorbed by the earth.

Studies in and/or by Nature Geoscience, the UK Met Office, the Intergovernmental Panel on Climate Change, and other organizations have all asserted this as a very likely to be true observation.

"No question about it, they have a cooling effect" says Stephen Schwartz, an environmental senior scientist at the Brookhaven National Laboratory.

The brief explanation is this: Hurricanes are formed by the raw energy absorbed and released by the ocean. When a higher quantity of aerosols act to reflect much of the sun's rays, there is less heat by the ocean to be absorbed. Nevertheless, it is far too common to think that the number of hurricanes fluctuates based on climate change. Aerosols are simply predicted to decrease the intensity of these already heightened-intensity hurricanes.

This is not to say, however, that aerosols are 100% beneficial to the welfare of the human race by the diminishment of the hurricane's destructive power. During the last 2 to 3 decades, significant improvements in human health have been seen by the clean up and decrease in hazardous industrial aerosols.

For this reason, it is a difficult decision for me to label the presence or absence of aerosols as "better" than one another. This is because studies and observations are quite qualitative on both sides. For example, it is difficult to determine the quantifiable amount of human life loss due to human induced aerosol pollution. At the same time, environmental scientists maintain that while this relationship is a step forward, aerosols reducing global warming is a "perplexing variable" because of the lack of quantifiable data.

Nevertheless, this new discovery truly is a breakthrough. Further studies can hopefully uncover details and quantifiable aspects of this observation in the hopes of bettering planet Earth.

Image Credit: Colorado State University


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