As president of the Environmental Defense Fund, Fred Krupp helped establish a market-based cap-and-trade system to limit acid rain pollution in the late 1980s.

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"In fact, when you burn coal, you emit more acid rain pollution, more air pollution, more smog and more global warming pollution which threatens the entire planet, " said Becker, global warming program director for the Sierra Club.

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Amphibians can act as an early warning sign of pollution such as acid rain due to their porous, absorbent skin.

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But the government is becoming increasingly concerned about the problems that pollution brings, such as sickness from filthy air and arid soil from acid rain, which has made it keen to boost the use of renewables and increase energy efficiency.

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