The UN conference to be held in Brazil next week should act as a catalyst for a sustainable development agenda, says Carlos Nobre.

Debates surrounding new sustainable development goals should pay attention to lessons learned from the MDGs, argues Jeffrey D. Sachs.

Sustainable development targets will work only if they engage with the realities of national politics, says policy expert Matthew Lockwood.

The concept of environmental thresholds could weaken progress on sustainability at Rio+20, says global change scientist Simon L. Lewis.

Rio+20 must launch SDGs to guide countries through complex development challenges, argues Colombian ministry official Paula Caballero Gómez.

Next month's meeting in Brazil needs send the right signals to encourage progress on sustainability, says ODI's Claire Melamed.

World leaders must promote effective land use methods to mitigate drought, says Luc Gnacadja of the UN Convention to Combat Desertification.

Reforms in the Arab region should focus on transitioning to a green economy, argues award-winning environmental advocate Najib Saab.

Durable food security and agricultural growth depend on development strategies with resilience built in from the start, says Gordon Conway.

The proposed Sustainable Development Goals need more focus on health to continue the progress achieved with MDGs, argues Priya Shetty.

Rio+20 should set up a scientific cooperation mechanism drawing on capabilities in both North and South, say Gisbert Glaser and Alice Abreu.

The proposed UN World Environment Organisation is badly needed to give poor countries a strong voice in green policy, says Zakri Abdul Hamid.