Box 2.2 summarises the main features for each of the 3 scenarios, which could be considered as relatively optimistic. The overall conclusion of UNEP (2011) was that without significant improvements in resource productivity, it will not be possible to meet the needs of a global population of 9 billion people (including the eradication of poverty) by 2050, while protecting the environment and providing for future generations. Key assumptions were that all countries would have a similar resource use per capita by 2050, and that there would be no negative feedback on the economy from resource constraints. Annual global resource extraction would increase three-fold.