After wilfully and pointedly ignoring and obstructing the global climate treaty under George Bush, the United States of America will be part of renewing the Kyoto protocol in Copenhagen in December next year.
"My presidency will mark a new chapter in America's leadership on climate change that will strengthen our security and create millions of new jobs in the process." said Obama.
This is huge and - although expected - should be celebrated.
With the right world leadership in place change has a chance of happening as fast as we need it to.
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