In his remarks today at COP21, the former U.S. vice-president, Al Gore, placed the climate crisis in a historical context. “When a choice becomes clear, the outcome is inevitable,” said Gore. “The climate crisis is the latest in a long string of social struggles, from abolition, to women’s rights, anti-apartheid; I could go on. But the world is increasingly recognizing that it is immoral to put 110 million tons of greenhouse gases into the atmosphere every day as if it were an open sewer.”