Last December, Donald Trump reacted furiously when the climate activist Greta Thunberg was named Time magazine’s Person of the Year. He was still griping about it in January, when he complained to reporters at a press conference in Davos that ‘she beat me out on Time magazine’. Trump’s bitterness about being ‘beaten’ by a seventeen-year-old girl says more about his narcissism than anything else, and his attacks haven’t done her any harm. Thunberg embodies everything the president hates, being the antithesis of the image of young women favoured by the former promoter of the Miss Teen USA ‘beauty’ contest.

Much of the hostile commentary around Thunberg has focused on her appearance. In a culture where teenage girls are under pressure to wear make-up and overtly sexy clothes, she challenges a great deal more than the complacency of climate change deniers. Among her critics there’s an undertone of disbelief that a young woman who so resolutely fails to play the game of sexual attraction is taken seriously, invited to speak at international gatherings and listened to by world leaders. Trump’s sarcastic tweet after her speech at the UN General Assembly last autumn – ‘she seems like a very happy young girl looking forward to a bright and wonderful future’ – backfired when Thunberg promptly added it to her Twitter bio.

Thunberg’s back story is fascinating. Before she changed it in response to Trump’s tweet, her Twitter profile read ‘16-year-old climate activist with Asperger’s’. Her condition has elicited mockery in some quarters. Her father, Svante Thunberg, has spoken about her anorexia, recalling a period when she didn’t eat for three months. At one point, Greta accused both parents of being hypocrites for campaigning for human rights while ignoring climate change, prompting Svante to become vegan and dramatically change his lifestyle. ‘I did all these things … but I didn’t do it to save the climate, I did it to save my child,’ he said in a revealing interview on BBC Radio 4’s Today programme.

There is plenty of material here for a biography, so much so that it isn’t hard to see why the idea of a book about Thunberg and her family would be attractive to publishers. Who is best placed to write it is another matter, not least because climate change is such an emotive subject, frequently discussed in apocalyptic terms. A degree of authorial distance might actually help the cause of environmentalism, allowing readers to think for themselves as they follow Thunberg’s path out of depression and anorexia to climate activism. Our House is on Fire is emphatically not that kind of book, with whole pages of it reading like a flyer handed out at a climate change rally. Even worse is the sense of having plunged into someone’s teenage diary, where feelings spill onto the page in a howl of rage:

I should not have written a book about how I felt. I should not have written a book about how my family has felt for long periods during the past few years. But I had to. We had to. Because we felt like shit. I felt like shit. Svante felt like shit. The children felt like shit. The planet felt like shit. Even the dog felt like shit. And we had to write about it. Together.

By this point in the book I wasn’t feeling great either, not least because I had another two hundred pages to get through. I simply can’t imagine writing in such childish terms for public consumption – whatever happened to editing, I wonder?

The very personal nature of the text raises the question of who the author actually is. The book is credited to Thunberg’s parents and both their daughters, but it seems to have been written principally by Greta’s mother, an opera singer called Malena Ernman, who insists on the first page that she isn’t interested in autobiography. So what is the book about and why are we supposed to read it? Ernman says it’s about ‘the crisis that struck our family’ when both her daughters began to display behaviours that eventually led to diagnoses of Asperger’s, anorexia and selective mutism in the case of Greta and Asperger’s and ADHD in Beata’s. Four years ago, Ernman was herself diagnosed with ADHD, depression and chronic fatigue, adding to the extraordinary pressure her family has been under.

The book is also about the climate crisis, however, and Ernman gives the impression of believing that the two things are linked. In Sweden, she writes, mental health issues in children aged ten to seventeen have more than doubled in a decade, while the number of unreported cases is ‘huge’. Elsewhere she asserts that a great many people are feeling ‘worse and worse’, adding that ‘burn-out and mental illness are no longer a global ticking health bomb – the bomb has already exploded’. It’s certainly possible that aspects of modern life are affecting people’s mental health, but it’s also hard to resist the sense that there’s quite a bit of projection going on here. Are the problems within Ernman’s family related to the state of the planet? I don’t know, but there’s an awful lot of this stuff to wade through before we reach her account of Thunberg’s school strike and her protest outside the Swedish Parliament House, which is a riveting story.

At an age when many other young people don’t know what they want to do with their lives, Thunberg has undeniably become a force in the world. Her public persona is unusual and inspiring, and it offers an alternative to the pornified images of teenage girls that dominate popular culture. She also, I’m afraid, deserves a better book than this messy melange of painful self-exposure and naive exhortation. ‘Perhaps some of the things that Svante and I, along with the children, decided to share here, after considerable deliberation, should have been saved for later,’ Ernman admits. It’s a sentiment that this battered, exhausted reader can’t help agreeing with.