ROYaL Bank of Scotland has come under fire after it emerged the bank - a main sponsor of a climate-change initiative - is a major investor in the coal sector.  Friends of the Earth Scotland said a report, put together with a consortium including Platform and People & Planet, reveals RBS was involved in providing finance worth nearly ???8 billion to the world's biggest coal mining and coal power generating companies over three years.  The Edinburgh-based bank is a sponsor of Climate Week, which begins today. Mary Church, of Friends of the Earth Scotland, said: "Instead of using initiatives like Climate Week as greenwash, RBS should put its money where its mouth is and start financing the urgently needed transition to a green economy."  Entitled Dirty Money, Corporate Greenwash and RBS Coal Finance, the report claims RBS provides more financing to coal mining and power companies than any other UK bank.  a spokesman for RBS said: "We are committed to supporting the economy through the transition to more sustainable forms of energy generation."