A new report says that Tokyo's population will be 7.13 million in 2100, about half of what it is today.
The study by a group including seven academics and 10 metro government and municipal bureaucrats, revealed that Tokyo's population, which stood at 13.16 million in 2010, will peak at 13.35 million in 2020 before dropping by 45.8 percent from the 2010 census figure 88 years from now.
According to the Japan Times, this means the 2100 population will be resemble that of 1940's Japan.
"So it will be crucial to take measures to turn around the falling birthrate and enhance social security measures for the elderly," the group said.
The group said that the number of Tokyoites 65 or over, estimated at 2.68 million in 2010, will peak at 4.41 million in 2050 before falling to 3.27 million in 2100, while their presence in the overall population will rise to 37.6 percent in 2050 and 45.9 percent in 2100 compared with 20.4 percent in 2010.
Those aged in their productive years between 15 and 64 will represent 46.5 percent of the population in 2100, the group added.