Packed with fascinating facts, this is the astonishing story of the numbers that underpin everything we know about climate change. Earth's climate is changing - understanding how has become one of the biggest scientific projects ever undertaken. But the epic scale of this study has made it remote and difficult to understand; we're overwhelmed by a blizzard of information and no-one knows which bits to believe. This revelatory documentary looks at the incredible methods that allowed scientists to arrive at precise figures, and uses stories from around the world to present this previously obscure field in an accessible way. A timely take on an urgent issue, Climate Change by Numbers reveals why scientists are so certain they are right, where we have reached the limits of our knowledge, and what uncertainty really means.