In this seasonal Question of the Week we explore how removing the lovely white reflective stuff might cause the whole world to warm up. Plus, we ask how wet T-shirt competitions work (the science behind it, that is)!

• I've read that painting rooftops white can help to cool cities. So does ploughing away the snow warm... - Questions
• International Polar Year 2007-9 - Features
• The Wrong Sort of Snow? - Podcasts
• The International Meteorite Market - Features
• John Snow and Cholera - Podcasts
• Does it snow in the sea? - Interviews