Remember when Obama pledged that the US would lead the global fight against trace amounts of natural atmospheric gas?

New UN Climate Chief Urges US To Approach Climate Talks In Meaningful Way

The new head of the U.N. climate secretariat has urged the United States to participate in climate change negotiations "in a meaningful way, and a way that is commensurate with its responsibility on climate."

April 2009: Obama pledges US lead on climate change

PRAGUE (AFP) — President Barack Obama said Sunday the United States was ready to take the lead in tackling climate change, as EU leaders pushed him to follow their ambitious targets to combat global warming.
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"Together we must confront climate change by ending the world's dependency on fossil fuels by tapping the power from the sources of energy like the wind and the sun and calling upon all nations to do their part.

"And I pledge to you that in this global effort the US is now ready to lead."