If you've ever been stumped when someone tells you: "The climate has always changed"; if you can read in your favourite journal, "carbon dioxide is the highest it's been in 1,000 years", and "carbon dioxide is the highest in a million years"; if you can't figure out what "net zero 2050" actually means - then you're not alone. The climate problem has a strange presence in public talk. This short book is to help you sort out confusions like these, and give you the kind of understanding you can use as an advocate and concerned citizen. The very big body of knowledge that now tells us about the problem belongs to the specialists who created it. The book introduces you to what they know, so your concern can be properly and reliably informed. As much as anything, the world right now needs capable advocates. That's what the book is for