Changes

They generally propose that the plant material accumulated in swamps<ref name="ACF" />

They generally propose that the plant material accumulated in swamps<ref name="ACF" />

== Environmental and societal Impact==

== Environmental and Societal Impact==

The burning of coal has lead to serious environmental consequences, such as the increase of coal-originating [[mercury]] in ocean fish such as tuna, or the release of chemicals that lead to acid rain. Acid rain is caused by the release of sulfur dioxide from fossil fuels, which dissolves to form sulfuric acid in rain clouds.<ref>http://www.foxnews.com/story/0,2933,210660,00.html</ref> Acid rain can have serious impacts on local ecosystems, agriculture, and many structures, as the acid can eat away at building materials sensitive to acid, such as limestone.

The burning of coal has lead to serious environmental consequences, such as the increase of coal-originating [[mercury]] in ocean fish such as tuna, or the release of chemicals that lead to acid rain. Acid rain is caused by the release of sulfur dioxide from fossil fuels, which dissolves to form sulfuric acid in rain clouds.<ref>http://www.foxnews.com/story/0,2933,210660,00.html</ref> Acid rain can have serious impacts on local ecosystems, agriculture, and many structures, as the acid can eat away at building materials sensitive to acid, such as limestone.