At ground level ozone is a dangerous pollutant, but at altitude it blocks the passage of harmful ultraviolet light.

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Example: In one of the most brazen chemophobic claims in the history of science and government, politicians around the world are now condemning carbon dioxide (the air that we breathe out and plants imbibe) as a dangerous pollutant.

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In 2009, the EPA declared their intention to regulate carbon dioxide (we exhale this dangerous gas) as a pollutant.

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