India will overtake China as the world’s most populous country around 2022, several years earlier than previously predicted, according to a United Nations report released Wednesday.

The report also projects that the world’s population will reach 8.5 billion — up from its current 7.3 billion — by 2030, and 9.7 billion in 2050. By the year 2100, the U.N. projects, there will be 11.2 billion people on Earth.

The population estimates factor into decision making on issues from how to combat global warming to ways to eradicate poverty and hunger. Already, China and India combined 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 enrollment and health systems,” John Wilmoth, director of the population division of the U.N. Department of Economic and Social Affairs, told the AP in an email.

The next half-century of population growth, as well as greenhouse gas emissions growth, will be dominated by Asia and Africa, with nine countries expected to comprise half of the total growth between now and 2050. These countries include India, Nigeria, Pakistan, Congo, Ethiopia, Tanzania, the U.S., Indonesia and Ghana.

By about 2050, Nigeria, which is currently the most populous country in Africa, 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.

By contrast, almost 50 countries are expected to see their population contract over the next several decades, particularly in Europe, where fertility rates are slowing.

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% 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.

Additional reporting by the Associated Press.