"The issues are so urgent and the stakes for humanity so important, scientists need to coalesce through the IPBES to inform policy-makers with a unified, authoritative voice," states Dr. Pereira, of the Universidade de Lisboa, Portugal.
IPBES could also play an important role in organizing the scientific co-operation to reduce uncertainty in biodiversity scenarios. Models foresee extinction rates ranging from less than 1% per century (close to the current rate of extinctions) to more than 50%.
"The degree of both land use and climate change explains a substantial fraction of the range of projected extinctions, but incomplete understanding of species ecology is also an important source of uncertainty," says Dr. Leadley.
Among the key issues is the lack of consensus defining the length of time involved in species' extinction - which may be decades or millennia - leading to "considerable uncertainty in models and substantial disagreement within scientific community concerning the likelihood of massive extinctions over the coming century."
Furthermore, the researchers note that changes in species distributions and population sizes should receive more attention because they are likely more critical to human well-being and better short-term indicators of the pressures of humans on ecosystems.
For example the continuing overall decline in populations of large-bodied fish species due to over-fishing, the poleward migration of marine species at a rate of more than 40 km per decade due to climate change, and the 10 to 20% decline in the abundance of terrestrial species by mid-century primarily due to land-use chang
|Contact: Terry Collins|