From Greta Thunberg, the world's leading climate activist, comes the essential guide to making it happen. You might think it's an impossible task: securing a safe future for life on Earth at a scale and speed you've never seen, against all odds. There is hope—but only if we listen to the science before it's too late. In a book about climate Greta Thunberg has gathered the wisdom of over a hundred experts – geophysicists, oceanographers and meteorologists; engineers, economists and mathematicians; historians, philosophers and indigenous leaders – to equip us all with the knowledge we need to fight climate catastrophe. Along with them, she shares her own stories of demonstrating and exposing greenwashing around the world, revealing how much we have been kept in the dark. She shows that this is one of our greatest challenges, but also our greatest source of hope. When we get the full picture, how can we not act? And if a school strike could inspire a global protest, what could we do together if we tried? We are living in the most crucial time in human history. Together we can do the seemingly impossible. But it has to be us, and it has to be now.