Biodiversity Scenarios: projections of 21st century change in biodiversity and associated ecosystem services
Convention on Biological Diversity
This study focuses on projected estimates of biodiversity change for the 21st century. Results were used for the third Global Biodiversity Outlook.
Scientists from a wide range of disciplines came together as part of the preparation of GBO-3 to identify possible future outcomes for biodiversity during the current century, based on observed trends, models and experiments.
The principal conclusions on biodiversity futures for the 21st century:
- Projections of the impact of global change on biodiversity show continuing and often accelerating species extinctions, loss of natural habitat, and changes in the distribution and abundance of species, species groups and biomes over the 21st century.
- There is a high risk of dramatic biodiversity loss and accompanying degradation of a broad range of ecosystem services if the Earth system is pushed beyond certain thresholds or tipping points.
- Earlier assessments have underestimated the potential severity of biodiversity loss based on plausible scenarios, because the impacts of passing tipping points or thresholds of ecosystem change have not previously been taken into account.
- There are greater opportunities than identified in earlier assessments to address the biodiversity crisis while contributing to other social objectives; for example, by reducing the scale of climate change without large-scale deployment of biofuels and accompanying loss of natural habitats.
- Biodiversity and ecosystem changes could be prevented, significantly reduced or even reversed if strong action is applied urgently, comprehensively and appropriately, at international, national and local levels.
The GLOBIO contribution consisted of a synthesis of results from earlier analyses for GEO4 and GBO2. As an example the figure below shows the modelled global change in the biodiversity indicator Mean Species Abundance (MSA) in four scenarios from 1970 - 2050. The modelled changes are presented together with the observed changes in terrestrial vertebrate populations according to the Living Planet Index.
An example from the GLOBIO contribution to GBO3