Move over: The world's population is expected to reach 8.5 billion by 2030 and 9.7 billion in 2050, a new United Nations report says. And there should be 11.2 billion people on Earth by the end of this century.

Meanwhile, India's population is set to pass China's in size around 2022, according to the report released Wednesday.

The population estimates play a huge role as the international community tries to figure out how to slow the danger of global warming, while pursuing the ambitious goals of eliminating both poverty and hunger.

The current world population is 7.3 billion. China and India each have more than one billion people.

"While the global projections should not be cause for alarm, we must recognize that the concentration of population growth in the poorest countries presents a distinct set of challenges, making it more difficult to eradicate poverty and inequality, to combat hunger and malnutrition, and to expand educational enrolment and health systems," John Wilmoth, director of the population division of the U.N. Department of Economic and Social Affairs, said in an email.

Nine countries are expected to make up half of the world's population growth between now and 2050: India, Nigeria, Pakistan, Congo, Ethiopia, Tanzania, the U.S., Indonesia and Ghana.

The report says that by 2050 or so, Nigeria will pass the U.S. to have the world's third-largest population, behind India and China. Africa has the world's highest rate of population growth.

Global aging is also noted. The report says the number of people age 60 and above should more than double by 2050. The report says Europe will lead the way, with more than 34 per cent of people there expected to be over 60 years old by 2050.

The U.N. report updates previous population estimates with new data from national censuses in 2010 as well as recent health and demographic surveys.