Grist: Even by the standards of Mitt Romney, Mitt Romney has had a lot of positions on climate change. In 2008, when Republicans were allowed to accept the enormous evidence of anthropogenic climate change, he did. In 2011, when Rush Limbaugh declared Romney ineligible for the Republican nomination unless he recanted his climate heresy, Romney obediently shifted from saying that climate change is caused by humans to minimizing its human causes, and then to denying that we know anything about the causes...