This book offers a vital new perspective on where we are headed, how we can prepare, and what’s at stake if we fail to act. The world is waking up to a new reality: wildfires are now seasonal in California, the Northeast is getting less and less snow each winter, and the ice sheets in the Arctic and Antarctica are melting fast. Heat is the first order threat that drives all other impacts of the climate crisis. And as the temperature rises, it is revealing fault lines in our governments, our politics, our economy, and our values. The basic science is not complicated: Stop burning fossil fuels tomorrow, and the global temperature will stop rising tomorrow. Stop burning fossil fuels in 50 years, and the temperature will keep rising for 50 years, making parts of our planet virtually uninhabitable. It’s up to us.