Last week's summit has confirmed that sustainable development will only be achieved through the political leadership of developing countries.

The message from Rio+20 is for practical action to deliver existing targets. Scientists must identify and overcome barriers to change.

The launch of a discussion website about the Rio+20 agenda raises questions about effective management for a successful outcome.

Efforts to promote sustainable development must tap into technologies developed locally, driven by community needs and priorities.

The shortage of credible and diverse voices in science undermines the capacity of journalists to respond to development challenges.

Management of marine resources for sustainable development needs local capacity for science, particularly in the Pacific region.

A new intergovernmental panel would not be the best way of tackling the multifaceted challenges of sustainable development.

Yet more failure to make much progress on climate change in Durban means that developing countries must exert stronger political pressure.