is there any such nation which was once a part of it but later withdrew?
Yes, Canada
Kyoto Protocol
In 2011, Canada, Japan and Russia stated that they would not take on further Kyoto targets. The Canadian government announced its withdrawal—possible at any time three years after ratification—from the Kyoto Protocol on 12 December 2011, effective 15 December 2012. 
what was a major contributor to the collapse of enron in 2001 Enron scandal who were associated with this scandal? Jeffrey Skilling and his staff of executives, Andrew Fastow and Arthur Andersen were any steps taken against them? Enron shareholders filed a $40 billion lawsuit after the company's stock price plummeted to less than $1 by the end of November 2001 was the government criticized for this as well? Yes, critics of Bush and his administration attempted to link them to the scandal what is the full name of the aforementioned person? George W. Bush who was he? American politician and businessman who served as the 43rd president of the United States what policies did he adopt regarding environment? He opposed the Kyoto Protocol, signed an executive order to create an interagency task force to streamline energy projects, and announced the Clear Skies Act of 2003 what was this protocol about? It is an international treaty which extends the 1992 UNFCCC, that commits state parties to reduce greenhouse gas emissions
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Kyoto Protocol [SEP] Withdrawal of Canada
In 2011, Canada, Japan and Russia stated that they would not take on further Kyoto targets. The Canadian government announced its withdrawal—possible at any time three years after ratification—from the Kyoto Protocol on 12 December 2011, effective 15 December 2012. Canada was committed to cutting its greenhouse emissions to 6% below 1990 levels by 2012, but in 2009 emissions were 17% higher than in 1990. The Harper government prioritized oil sands development in Alberta, and deprioritized the reduction of greenhouse emissions. Environment minister Peter Kent cited Canada's liability to "enormous financial penalties" under the treaty unless it withdrew. He also suggested that the recently signed Durban agreement may provide an alternative way forward.