Scenarios for Global Biodiversity in the 21st Century

date: 2010-10-27


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.

Led by experts Henrique Miguel Pereira and Paul Leadley, the 23-member scientific team from nine countries, under the auspices of DIVERSITAS, UNEP-WCMC and the secretariat of the CBD compared results from five recent global environmental assessments and a wide range of peer-reviewed literature examining likely future changes in biodiversity. 

Published today in the journal Science, the analysis 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.

Action needed

Among the brightest spots of hope: recent scenarios show that slowing climate change and deforestation can go hand-in-hand to reduce biodiversity loss thanks to “significant opportunities to intervene through better policies, such as those aimed at mitigating climate change without massive conversion of forests to biofuel plantations” says Dr. Leadley.  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.

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 environmental assessments included in this study are all based on scenarios. Quantitative scenarios are coming of age as a tool for evaluating the impact of future socio-economic development pathways on biodiversity and ecosystem services. The scientists analyzed global terrestrial, freshwater and marine biodiversity scenarios using a range of measures including extinctions, changes in species abundance, habitat loss, and distribution shifts, as well as comparing model projections to observations. 


Scenarios developed using GLOBIO were used to estimate changes in species abundance in terrestrial ecosystems. In these scenarios a decline is projected of 9-17% in Mean Species Abundance by 2050 relative to 2000.

More information:


News archive