The OECD reported (2002) that, on current trends, by 2025 15% of all forest species will be extinct.
The Earth may need 10 million years to recover from the significant reduction in species diversity caused by humans, regardless of the scale of extinctions. This could be because new species cannot simply evolve to fill empty niches. Instead, completely new niches must develop. The long delay is a measure of the time it takes to recreate a diverse ecosystem with a wide variety of niches.