I just finished "Field Notes from a Catastrophe" by Elizabeth Kolbert. The author describes some of the actual evidence of global warming : the melting of glaciers, the extinction of species, the actual warming of the climate (it was warmer this year than it has been since 420,000 years ago) and explains why the changes are irreversible and are increasing in momentum with every passing year. Even if you already understand the "greenhouse effect" and believe that climate change is occurring, this book will shock you. "Field Notes" is a compact book, well written, compelling. I wish everyone would read it because the kind of initiatives required even to slightly slow the progress of global warming will require massive grass roots support. If you have any free time to do some reading of your own choice, I hope you will have a look at this.