Just before Christmas 2009, an old friend and I were discussing climate change. Because I am a scientist, he asked my opinion about an internet site claiming that global warming is a fallacy and that carbon dioxide is good for the planet. As a geologist I knew about climate changes of the distant past, such as the warm world when dinosaurs roamed and the more recent ice ages, but I could not answer some of the questions he asked, and that prompted me to look into climate science more deeply. My reply to him is this book.

Looking at the newspaper articles and websites on the topic, I found a remarkably wide range of views, running the gamut from ‘global warming is real, burning coal and oil caused it, we are doomed’ to ‘we need to address the reality that increasing amounts of greenhouse gases are causing climate change’ and on to ‘increased levels of carbon dioxide will grow bigger crops and stop the next ice age’.