Greta Thunberg’s speeches shook the world. With The Climate Book, she has created an essential tool for everyone who wants to help save it.It seems like an impossible task: secure a safe future for life on Earth, at a scale and speed that the world has never seen, in the face of vast and powerful forces—not just oil tycoons and governments but also the changing climate system itself. The odds are against us, and we are running out of time. But it doesn’t have to be this way.Around the world, geophysicists and mathematicians, oceanographers and meteorologists, engineers, economists, psychologists, and philosophers have been using their expertise to develop a deep understanding of the crises we face. Greta Thunberg has created The Climate Book in partnership with more than one hundred of these experts in order to equip us all with this knowledge. Alongside them, Thunberg shares her own stories of learning, demonstrating, and uncovering greenwashing around the world, revealing the extent to which we have been kept in the dark. This is one of our biggest problems, she shows, but also our greatest source of hope. Once we are given the full picture, we will be able to act—and if a schoolchild’s strike could ignite a global protest, what could we do collectively if we tried? The Climate Book shows that we all have the responsibility of being alive at the most decisive time in the history of humanity, and that, together, we can do the seemingly impossible. But it has to be us, and it has to be now.