claim: U.S. Sen. Ron Johnson led the fight to let polluters release unlimited amounts of carbon pollution and took nearly $225,000 from polluters.
evidence: The international community began the long process towards building effective international and domestic measures to tackle GHG emissions ( carbon dioxide, methane, nitrous oxide, hydroflurocarbons, perfluorocarbons, sulphur hexafluoride ) in response to the increasing assertions that global warming is happening due to man-made emissions and the uncertainty over its likely consequences.