T\u1eeb kh\u00f3a t\u00ecm ki\u1ebfm: H\u00e3y Tr\u1ea3 L\u1eddi Em T\u1ea1i Sao? \u2013 T\u1eadp 10 – Arkady Leokum<\/p>\n\n\n\n
D\u00e2n s\u1ed1 c\u1ee7a tr\u00e1i \u0111\u1ea5t hi\u1ec7n nay l\u00e0 kho\u1ea3ng 6,2 t\u1ec9 v\u00e0 \u0111\u00fang r\u1eb1ng \u0111\u00e2y l\u00e0 con s\u1ed1 l\u1edbn nh\u1ea5t t\u1eeb x\u01b0a t\u1edbi gi\u1edd: g\u1ea5p \u0111\u00f4i d\u00e2n s\u1ed1 c\u1ee7a nh\u1eefng n\u0103m 1960 v\u00e0 g\u1ea5p 6 l\u1ea7n con s\u1ed1 c\u1ee7a n\u0103m 1800. V\u1ea5n \u0111\u1ec1 l\u00e0, m\u1eb7c d\u00f9 d\u00e2n s\u1ed1 th\u1ebf gi\u1edbi \u0111\u00e3 b\u00f9ng n\u1ed5 trong nh\u1eefng th\u1eadp k\u1ec9 g\u1ea7n \u0111\u00e2y, n\u00f3 \u0111\u00e3 t\u0103ng tr\u01b0\u1edfng \u1edf m\u1ed9t t\u1ed1c \u0111\u1ed9 kh\u00e1 l\u1edbn trong nhi\u1ec1u th\u1ebf k\u1ec9 v\u00e0 khi c\u1ed9ng l\u1ea1i n\u00f3 s\u1ebd th\u00e0nh m\u1ed9t con s\u1ed1 r\u1ea5t l\u1edbn. \u0110\u1ec3 \u01b0\u1edbc l\u01b0\u1ee3ng xem n\u00f3 l\u1edbn t\u1edbi m\u1ee9c n\u00e0o, c\u00e1c nh\u00e0 nh\u00e2n ch\u1ee7ng h\u1ecdc ph\u1ea3i s\u1eed d\u1ee5ng c\u00e1c d\u1eef li\u1ec7u l\u1ecbch s\u1eed \u0111\u1ec3 t\u1ea1o ra c\u00e1c bi\u1ec3u \u0111\u1ed3 m\u00f4 t\u1ea3 d\u00e2n s\u1ed1 th\u1ebf gi\u1edbi \u1edf c\u00e1c th\u1eddi \u0111i\u1ec3m kh\u00e1c nhau. C\u00e1c bi\u1ec3u \u0111\u1ed3 n\u00e0y th\u01b0\u1eddng cho th\u1ea5y m\u1ed9t \u0111\u01b0\u1eddng th\u1eb3ng kh\u00e1 \u1ed5n \u0111\u1ecbnh v\u00e0 d\u1ed1c l\u00ean d\u1ea7n d\u1ea7n cho t\u1edbi gi\u1eefa th\u1ebf k\u1ec9 18 th\u00ec \u0111\u01b0\u1eddng th\u1eb3ng \u0111\u00f3 b\u1eaft \u0111\u1ea7u v\u00fat th\u1eb3ng l\u00ean. Vi\u1ec7c chuy\u1ec3n c\u00e1c bi\u1ec3u \u0111\u1ed3 n\u00e0y th\u00e0nh m\u1ed9t \u01b0\u1edbc \u0111o\u00e1n v\u1ec1 t\u1ed5ng s\u1ed1 ng\u01b0\u1eddi \u0111\u00e3 t\u1eebng s\u1ed1ng th\u00ec c\u1ea7n ph\u1ea3i \u0111\u01b0a ra m\u1ed9t s\u1ed1 gi\u1ea3 \u0111\u1ecbnh, \u0111\u01b0\u01a1ng nhi\u00ean bao g\u1ed3m c\u1ea3 th\u1eddi \u0111i\u1ec3m b\u1eaft \u0111\u1ea7u c\u1ee7a nh\u00e2n lo\u1ea1i. V\u00ed d\u1ee5, gi\u00e1o s\u01b0 nh\u00e2n ch\u1ee7ng h\u1ecdc n\u1ed5i ti\u1ebfng c\u1ee7a Canada Nathan Keyfitz \u0111\u00e3 ch\u1ecdn th\u1eddi \u0111i\u1ec3m m\u1ed9t tri\u1ec7u n\u0103m TCN l\u00e0 th\u1eddi \u0111i\u1ec3m m\u00e0 ch\u1ec9 c\u00f3 hai ng\u01b0\u1eddi tr\u00ean h\u00e0nh tinh n\u00e0y. M\u1eb7c d\u00f9 ch\u1eafc ch\u1eafn nhi\u1ec1u ng\u01b0\u1eddi s\u1ebd ph\u1ea3n \u0111\u1ed1i c\u00e1ch ch\u1ecdn n\u00e0y, \u0111i\u1ec1u \u0111\u00f3 c\u0169ng kh\u00f4ng th\u00e0nh v\u1ea5n \u0111\u1ec1: t\u1ed5ng s\u1ed1 ng\u01b0\u1eddi t\u1eebng \u0111i tr\u00ean tr\u00e1i \u0111\u1ea5t cu\u1ed1i c\u00f9ng \u0111\u00e3 tr\u1ed9i h\u01a1n d\u00e2n s\u1ed1 hi\u1ec7n nay r\u1ea5t nhi\u1ec1u l\u1ea7n, v\u1edbi kho\u1ea3ng 60 t\u1edbi 100 t\u1ec9 ng\u01b0\u1eddi. N\u00f3i c\u00e1ch kh\u00e1c, nh\u1eefng ng\u01b0\u1eddi \u0111ang s\u1ed1ng \u0111\u1ea1i di\u1ec7n cho kh\u00f4ng h\u01a1n 10% t\u1ed5ng s\u1ed1 ng\u01b0\u1eddi \u0111\u00e3 t\u1eebng s\u1ed1ng.<\/p>\n\n\n\n