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La sfarsitul anului 2007, numarul populatiei mondiale se afla la 6,7 miliarde. O estimare aproximativa arata ca pana in 2050 numarul locuitorilor planetei va ajunge la 9 miliarde. Aceasta veste nu a fost bine primita de catre tabara pesimistilor, care deja anunta o criza grava a resurselor cauzata de suprapopularea planetei.
Insa un nou raport elaborat de catre institutul non-guvernamental Worldwatch anunta ca situatia nu este chiar atat de grava. Rezultatele studiului se bazeaza pe variabilitatea ratelor de fertilitate inregistrate in toata lumea. Intre numeroasele rapoarte care au vizat aceasta problema, exista contradictii. Spre exemplu, numarul obisnuit al membrilor unei familii a inceput sa se micsoreze, cu toate acestea populatia globala a crescut.
Cercetatorii de la Institutul Worldwatch explica acest fenomen prin faptul ca varsta la care femeile devin mame s-a modificat, iar in acest moment sunt mai multe femei care se afla la aceasta varsta decat inainte. In 1970 existau doar 856 milioane de femei cu varste cuprinse intre 15 si 49 de ani, in vreme ce in 2007 numarul acestora se ridica la 1,7 miliarde, ceea ce ar putea explica cresterea natalitatii. Insa dupa aceasta perioada, este probabil sa urmeze una in care rata natalitatii mondiale sa scada, urmand modelul unui grafic oscilator, cu perioade de scaderi, urmate de perioade de crestere.
O serie de factori necunsocuti in prezent fac greu de prevazut ritmul exact de crestere al populatiei, insa pot fi aproximate perioadele de fertilitate in randul populatiei feminine. Alte rapoarte optimiste anunta ca Pamantul are destule resurse pentru a-si sustine in viitor locuitorii, insa problema vine din alta directie: tarile bogate abuzeaza de ele, in timp ce tarile sarace inregistreaaza cele mai numeroase familii.
Sursa: Daily Galaxy
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