The world population will reach 10.1 billion in the next ninety years, reaching 9.3 billion by the middle of this century.

United Nations : scientists
According to the medium variant of the 2010 Revision of World Population Prospects, the official United Nations population projections, much of this increase is to come from the high-fertility countries, which comprise 39 countries in Africa, nine in Asia, six in Oceania and four in Latin America. Population increases will be notable also in the US, Denmark, UK and other developed nations. Globally, life expectancy is projected to increase from 68 years in 2005-2010 to 81 in 2095-2100.

United Nations (2010) "World Population Prospects, the 2010 Revision"