By Ben Tavener, Senior Contributing Reporter
RIO DE JANEIRO, BRAZIL – Brazilian President Dilma Rousseff has used her speech at the opening ceremony of the Rio+20 Earth Summit - the UN Conference on Sustainable Development - to call on developed nations to contribute more funds to finance sustainable development. Current pledges have not yet reached the levels deemed necessary for the work required in funding change and helping developing nations to reach their own targets.
As she . . .