Is flying dangerous? How much do the world's cows weigh? And what makes people happy? From Earth's nations and inhabitants, through the fuels and foods that energize them, to the transportation and inventions of our modern world - and how all of this affects the planet itself - in Numbers Don't Lie, Professor Vaclav Smil takes us on a fact-finding adventure, using surprising statistics and illuminating graphs to challenge lazy thinking. Smil is on a mission to make facts matter, because after all, numbers may not lie, but which truth do they convey?