The global total fertility rate will be 1.66 in 2100, well below the replacement rate of 2.1. Pretty much every advanced country’s fertility rate in 2017 was below replacement. By 2050, 151 countries are forecasted to have a fertility rate below 2.1, and 183 by 2100. 23 countries including Japan, Thailand, and Spain, will have population declines greater than 50% from 2017 to 2100; China’s population is forecasted to decline by 48% in 2100 due to the extraordinarily low ratio of young to old because of the one child policy of the past. China’s 2017 fertility rate was 1.53.
The authors of this forecast say that “continued trends in female educational attainment and access to contraception will hasten declines in fertility and slow population growth.” And, “Our findings show that some countries with fertility lower than replacement level, such as the USA (now: 1.81), Australia, and Canada, will probably maintain their working-age populations through net immigration. Our forecasts for a shrinking global population have positive implications for the environment, climate change, and food production, but possible negative implications for labour forces, economic growth, and social support systems in parts of the world with the greatest fertility declines.”
The world’s population today is 7.6 billion. The world’s population will peak in 2068. In 2100 it will be 8.8 billion, but if female education and contraception goals that have been articulated are met, the 2100 popularion will be less then 7 billion.
From The Lancet, and as reported here.