This study develops a wide-ranging index to assess the many factors that contribute to the health and benefits of the oceans, and the scores for all costal nations are assessed.

The intergovernmental body for biodiversity must draw on a much broader range of knowledge and stakeholders than the IPCC, say Esther Turnhout and colleagues.

Now that the Rio+20 summit is over, experts and the public at large have got busy analysing its outcome document. The media has already declared the conclave on sustainable development, held in the Brazilian city of Rio de Janeiro between June 20 and 22, a failure. It is true that unlike the summit in 1992—where three conventions and the Global Environmental Facility (GEF) were born—Rio+20 did not provide the stuff media could chew for days. The summit, however, did make a signature statement on the pathway of sustainability.

Groundwater is a life-sustaining resource that supplies water to billions of people, plays a central part in irrigated agriculture and influences the health of many ecosystems. Most assessments of global water resources have focused on surface water but unsustainable depletion of groundwater has recently been documented on both regional and global scales. It remains unclear how the rate of global groundwater depletion compares to the rate of natural renewal and the supply needed to support ecosystems.