The U.S. Environmental Protection Agency recently filed a report stating carbon dioxide and other greenhouse gases pose a danger to human health. The EPA refused to categorize carbon dioxide as a health hazard under the Bush Administration, even after a 2007 Supreme Court decision demanded action. The EPA’s new "endangerment finding" could pave the way for federal regulations on carbon dioxide and other climate-warming gases.

Currently, the only limits on carbon dioxide are set by individual states. The Obama Administration and democrats in Congress have shown interest in a market-based cap and trade system for regulating carbon dioxide.

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