Jim Hansen is the person most responsible for the 350 movement–he's the NASA scientist whose team demonstrated in 2008 that 350 was the most important number in the world, and that's only the latest of his accomplishments. In 1988 he was the first to warn the US Congress that global warming was real and dangerous. 

Now he's written a remarkable book, Storms of My Grandchildren, that summarizes the latest data in readable and understandable form. If you know people who still doubt the facts about climate change, then this is the book they need. There will soon be Chinese, Malaysian and Italian editions, but for now the book is available most easily in the US, where it has been receiving excellent reviews.  

Ask at your local bookstore or Amazon or Barnes and Noble.  And take a look at this interview with David Letterman.