Fred Pearce uses strong words to criticize the United Nations' latest projected global population figures (Nature 473, 125; 2011). But the UN's projections of a continuing rise in the population (see http://go.nature.com/wj3br5) are in line with its previous projections and with those of other major sources, including the US Census Bureau (see http://go.nature.com/owcela) and the International Institute for Applied Systems Analysis (http://go.nature.com/cbg34l).

The new UN 'medium variant' projection expects 10.1 billion people by 2100, 3 billion more than now. This is a sobering prospect for those concerned with human and environmental poverty.

In his book The Coming Population Crash (Beacon Press, 2010), Pearce predicts a drastic population decline owing to falling fertility. But the birth rate worldwide still exceeds the replacement rate, so the young greatly outnumber the old. The number of young women coming into reproductive age can be three times the number becoming post-menopausal. So, although women are now having fewer children than they did previously, the number of children remains high. The US Census Bureau projects no decline in the global number of births to 2050.

The result is that the population has risen by a billion people in the past 13 years and the UN's medium variant expects about the same in the next 13 years.

None of the UN scenarios envisages a rise in fertility. If fertility stays at its present level, the UN projects 27 billion people in 2100. Only by assuming a continuing and rapid fall in fertility do projections come down to between 6 and 16 billion.

Globally, there are 2.5 births for each death (see http://go.nature.com/ows9ux). Population stability, let alone a decline, is therefore a long way off. For the foreseeable future, the world is going to be much more crowded than it is now.