Geir Ólafsson.
Earth & Energy

Cleaner Air: Atmospheric Acidity Has Returned to Pre-Industrial Levels

Acid levels in the air are nearly as low as they were before the 1930s.

The Good News

The rise of industrialist culture that began in the 1930s heralded the degradation of air quality. This trend would persist for decades, as increasing emissions coincided with the growth in numbers of factories and vehicle ownership. One indicator of such degradation is atmospheric acidity, an increase in which is caused by gaseous and particulate pollutants.

Researchers from the University of Copenhagen’s Niels Bohr Institute (NBI) have found that in recent years, atmospheric acidity is back down to the pre-industrial levels. Using a modified version of Continuous Flow Analysis, they were able to determine the fluctuations in air acidity from year to year.

What’s better, is that the new method is able to distinguish between the effects of man-made emissions from those caused by natural phenomena, say volcanic eruptions.

Helle Astrid Kjær, NBI
Image credit: Helle Astrid Kjær, NBI

Making Progress

Lead author Helle Astrid Kjær attributes this decline to the commitment of nations to put a stop to air pollution. She says, “In the 1970s, both Europe and the United States adopted the Clean Air Act Amendments, which required filters in factories, thus reducing acid emissions and this is what we can now see the results of.”

Aside from yielding a better method for measuring atmospheric acidity, this brings to light the success of pollutant regulation.

Of course this is not an end of worry over air pollution. Though this represents the significant headway we are making in the fight against climate change, it should also serve to reassert that we have a long way to go. Dr. William R. Stockwell, a professor of chemistry at Howard University told the Huffington Post that it would be “a stretch… [to] conclude that atmospheric acid production has returned to preindustrial levels everywhere.” Even so, Stockwell is “surprised” at the results.

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