Post Carbon Fellow Bill McKibben told Bill Maher that "we broke the Arctic".
From the article at Huffington Post:
While on the show, McKibben expressed his frustration with those who perpetuate the idea that scientists remain divided about the existence or human origin of climate change. He says, "Scientists figured it out. That's why we have scientists."
McKibben cites 2012's record temperatures and severe drought as confirmation of what NASA climate scientist James Hansen has called a "planetary emergency."