US unequivocal about climate change in UNFCCC report

That quote from President Barack Obama is how the US opens its latest report to the United Nations Framework Convention on Climate Change, underscoring a major shift in approach of the world’s largest economy.

The US Climate Action Report 2010 is unequivocal on the fact and cause of climate change: “Global temperature has increased over the past 50 years. This observed increase is due primarily to human-induced emissions of heat-trapping gases.”

But