I do not know Chris Packham, the BBC nature broadcaster, personally, but he wrote me a letter last month, enclosing a book called Manifesto, The Battle for Green Britain by Dale Vince which, he tells me, ‘has something very important to say at this most important time’. In his letter, Chris says that ‘irrespective of any party politics’, ‘The coming election will be the most important of our lifetimes’ because we are ‘halfway through the last decade’ left to avoid ‘the worst of climate breakdown’.