Seven billion people will call planet Earth home from this Monday.

That is the projected date at which the number of people alive will pass the seven-billion milestone, according to a landmark study of global population pressures released overnight by the UN Population Fund.

It charts a steadily growing population ballooning to more than 10 billion people by the end of the century. The vast bulk of the growth, to 9.3 billion, is expected to occur within 40 years.

But it said only a small variation in fertility would see population reach more than 15 billion in 2100. The crush of humanity will place enormous pressures on water reserves, food production and the environment.