摘要:Twenty years since Eco 92, Rio de Janeiro will be the 2012 host of the conference Rio+20, which will have two main points on the agenda: green economy and institutional structure for sustainable development and the eradication of poverty. However, critical voices have risen which maintain that the green economy goes astray due to an excess of scientific positivism, as it trusts resolving problems arising from climate change by applying science above political debate. According to its detractors, it is betting on technologies whose risks are unpredictable, such as nanotechnology, synthetic biology and geo engineering, areas in which States and businesses have already invested billions of dollars.