Conservation International

Reports quoting documents leaked ahead of the summit suggest that countries will be asked to sign up to 10 separate goals. These could include a deal on protecting oceans, the establishment of a powerful global agency for the environment, financial support to encourage sustainability for poorer nations and the appointment of an ecological high commissioner.

Realistically, the best that can be hoped for is that Rio +20 will be the start of a process that leads to some or all of these goals being met. Few expect hard and fast policies to be put in place after three days of discussion and the likelihood is that participants will sign up to a document committing themselves to further action in the future.

There are also numerous sticking points. Wealthy and poorer nations are likely to argue over sharing the burden of cutting carbon emissions. There have been concerns over the exclusion of references to basic human rights, such as access to water. Environmental monitoring methods are also expected to spark dissent.