What Russia's green snow reveals about the rise of pollution

Incidents of snow turning green and black are causing increasing alarm. So just how worried should we be about the world's increasingly colourful snow?Don't eat yellow snow has always been good advice. To that we can now add warnings against green, pink, orange and black snow, as new evidence of our trashing of the planet is now being etched out on the most pristine of environments - our dwindling snow caps.A spate of incidents in Russia has grabbed internet attention. Residents of Siberian towns watched with dismay as the snow around them turned green and black, with toxic emissions forcing some to wear masks. These seem to be connected to local factories, with a chrome plant in particular behind the green snow, and, as protests gather pace, the Putin government has come under pressure. Continue reading...