We saved the whale. The same vision can save the planet | Susanna Rustin

Hope alone won’t halt climate change but Al Gore’s latest film highlights the role optimism can play“Hope is essential – despair is just another form of denial,” Al Gore said last week, in an interview to promote the sequel to his 2006 climate change documentary An Inconvenient Truth. As well as the very bad news of Donald Trump’s science-denying presidency, An Inconvenient Sequel: Truth to Power, which opens in the UK today, brings good news: the plummeting c