Research by the University of Birmingham has provided evidence that a warm atmosphere rich in carbon dioxide was present in an ancient ice age. This could only have happened if the planet was nearly all covered in ice and snow. Scientists from the University’s School of Geography, Earth and Environmental Sciences, say that, whereas today, we associate more greenhouse gases with a warm world, in a very severe ice age, even plenty of greenhouse gas cannot stop the world being covered in reflective ice and snow. This type of glaciation could occur again in the future if the Earth’s atmosphere...