According to the Biodiversity Synthesis of the Millennium Ecosystem Assessment
, unprecedented additional efforts would be needed to achieve, by 2010, a significant reduction in the rate of biodiversity loss at all levels
The magnitude of the challenge of slowing the rate of biodiversity loss is demonstrated by the fact that most of the direct drivers of biodiversity loss are projected to either remain constant or to increase in the near future
. Moreover, inertia in natural and human institutional systems results in time lags—of years, decades, or even centuries—between actions being taken and their impact on biodiversity and ecosystems becoming apparent.
Several of the 2010 Biodiversity sub-targets adopted by the Convention on Biological Diversity could be met for some components of biodiversity, or some indicators, in some regions. For example, the overall rate of habitat loss, which is the main driver of species loss in terrestrial ecosystems, is now slowing in certain regions. This may not necessarily translate, however, into lower rates of species loss for all taxa because of the nature of the relationship between numbers of species and area of habitat, because decades or centuries may pass before species extinctions reach equilibrium with habitat loss, and because other drivers of loss, such as climate change, nutrient loading, and invasive species, are projected to increase.
While rates of habitat loss are decreasing in temperate areas, they are projected to continue to increase in tropical areas. At the same time, if areas of particular importance for biodiversity are maintained within protected areas or by other conservation mechanisms, and if proactive measures are taken to protect threatened species, then the rate of biodiversity loss of targeted habitats and species could be reduced.