A new analysis of several major global studies of future species shifts and losses foresees inevitable continuing decline of biodiversity during the 21st century but offers new hope that it could be slowed if emerging policy choices are pursued.

Fundamental changes needed

The authors found universal agreement across the studies that fundamental changes are needed in society to avoid high risk of extinctions, declining populations in many species, and large scale shifts in species distributions in the future. There is no question that business-as-usual development pathways will lead to catastrophic biodiversity loss. Even optimistic scenarios for this century consistently predict extinctions and shrinking populations of many species. The target of stopping biodiversity loss by 2020 appears not realistic.

Opportunities for interventions

Recent scenarios show that slowing climate change and deforestation can go hand-in-hand to reduce biodiversity loss. This is due to significant opportunities to intervene through better policies, such as those aimed at mitigating climate change without massive conversion of forests to biofuel plantations. But action must be taken quickly, as the study indicates the window of opportunity is closing rapidly, as differences in policy action taken now could either lead to an increase in global forest cover of about 15% in the best case or losses of more than 10% in the worst case by 2030.

Figure 1. Comparison of recent and distant past extinction rates with rates at which species are 'committed to extinction' during the 21st century. E/MSY is number of extinctions per million species years. “Fossil record” and “20th century” estimates are based on the Millennium Ecosystem Assessment. “21st century” refers to projections of species committed to extinction according to different global scenarios, estimates for vascular plants were based on IMAGE.

Plea for independent panel: IPBES 

The authors say the creation of an Intergovernmental Panel on Climate Change (IPCC)-like mechanism for biodiversity (to be called the Intergovernmental Platform on Biodiversity and Ecosystem Services -- IPBES) is “extremely important” for achieving commonly-agreed definitions and indicators for biodiversity and to inform decision making. The issues are so urgent and the stakes for humanity so important that scientists need to coalesce through the IPBES to inform policy-makers with a unified, authoritative voice.

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.

• To the publication