Guardian: Countries could protect nature, help halt climate change, and provide food and clean water for a billion people for little more than has been pledged to bail out the world’s banks in the last week, according to a series of authoritative economic reports from the UN, world bodies, major charities and banks. Estimates of the sum committed this week by governments to rescue the world’s financial system range between $2-4 trillion. Investment on this scale to reduce greenhouse gas …