![\"\"](\"https:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/2018\/09\/2-8-300x225.jpg\")
Daha serin bir D\u00fcnya\u2019da ya\u015f\u0131yor olabilirdik <\/b><\/p>\n
\u00c7evre Ara\u015ft\u0131rmalar\u0131 Enstit\u00fcs\u00fc\u2019n\u00fcn Wisconsin \u00dcniversitesi-Madison \u00dcniversitesi \u0130klim Ara\u015ft\u0131rma Merkezi\u2019nde k\u0131demli bir biliminsan\u0131 olan ba\u015fyazar Stephen Vavrus, tar\u0131m\u0131n eski k\u00f6klerinin \u00e7evreyi etkileyecek kadar karbondioksit ve metan gaz\u0131 \u00fcretti\u011fini s\u00f6yleyerek \u201cErken tar\u0131m faaliyetleri olmasayd\u0131 D\u00fcnya\u2019n\u0131n iklimi bug\u00fcn \u00e7ok daha serin olurdu\u201d tespitinde bulunuyor.<\/p>\n
Bulgular, Holosen olarak adland\u0131r\u0131lan ve mevcut jeolojik zaman dilimimizle; 800 bin y\u0131l \u00f6nce benzer \u00f6zelliklere sahip jeolojik zaman diliminin kar\u015f\u0131la\u015ft\u0131r\u0131lmas\u0131na dayan\u0131yor. MIS19 olarak adland\u0131r\u0131lan \u00f6nceki d\u00f6nemin, 1850 y\u0131l\u0131 civar\u0131nda Holosen\u2019deki e\u015fde\u011fer s\u00fcreden daha \u00f6nce 2,3 derece Fahrenhayt (1,3 C) daha so\u011fuk oldu\u011fu ifade ediliyor. Bu etki, s\u0131cakl\u0131klar\u0131n 9 ila 11 derece\/Fahrenhayt daha so\u011fuk oldu\u011fu Kuzey Kutbu\u2019nda daha belirgin.<\/p>\n
Buz \u00e7ekirde\u011fi \u00f6rnekleriyle iklim modellemesi<\/b><\/p>\n
Buz\u00a0tabakas\u0131ndan veya y\u00fcksek bir da\u011f buzulundan \u00e7\u0131kan bir\u00a0\u00e7ekirdek\u00a0\u00f6rne\u011fi olan buz \u00e7ekirde\u011fi verilerine dayanan iklim rekonstr\u00fcksiyonlar\u0131n\u0131 kullanan model; MIS19 ve Holosen\u2019in benzer karbondioksit ve metan konsantrasyonlar\u0131 ile ba\u015flad\u0131\u011f\u0131n\u0131 g\u00f6sterirken; MIS19\u2019un her iki sera gaz\u0131nda da sabit bir d\u00fc\u015f\u00fc\u015f oldu\u011funu, Holosen\u2019in ise 5 bin y\u0131l \u00f6nce ters y\u00f6nde d\u00f6nd\u00fc\u011f\u00fcn\u00fc ve en y\u00fcksek konsantrasyona ula\u015ft\u0131\u011f\u0131n\u0131 g\u00f6sterdi.<\/p>\n
Milankovitch d\u00f6ng\u00fcleri<\/b><\/p>\n
D\u00fcnyan\u0131n 4,5 milyar y\u0131ll\u0131k tarihinin \u00e7o\u011fu i\u00e7in iklim, b\u00fcy\u00fck \u00f6l\u00e7\u00fcde D\u00fcnya\u2019n\u0131n G\u00fcne\u015f etraf\u0131ndaki y\u00f6r\u00fcngesinin \u015feklindeki daha d\u00f6ng\u00fcselden daha eliptik olana do\u011fru dalgalanan periyodik de\u011fi\u015fimler anlam\u0131na gelen Milankovitch d\u00f6ng\u00fcleri ile belirlendi.<\/p>\n
G\u00f6kbilimciler bu \u00e7evrimleri hassasiyetle hesaplayabilir; jeolojik ve paleoekolojik kay\u0131tlarda da g\u00f6zlemleyebilirler. D\u00f6ng\u00fc, g\u00fcne\u015f \u0131\u015f\u0131\u011f\u0131n\u0131n gezegende da\u011f\u0131ld\u0131\u011f\u0131, so\u011fuk buzul d\u00f6nemlerine ya da buzul d\u00f6nemleri ile daha s\u0131cak buzul \u00e7a\u011flar\u0131 aras\u0131 d\u00f6nemlere n\u00fcfuz eder. Son buzul d\u00f6nemi yakla\u015f\u0131k 12 bin y\u0131l \u00f6nce sona ermi\u015fti ve D\u00fcnya o zamandan beri bir ara d\u00f6nem olan Holosen\u2019de bulunuyor. Holosen ve MIS19, benzer Milankovitch d\u00f6ng\u00fcs\u00fc \u00f6zelliklerini payla\u015f\u0131r.<\/p>\n On be\u015f y\u0131l \u00f6nce, Virginia \u00dcniversitesi\u2019nde emekli paleoklimatolog olan e\u015f-yazar William Ruddiman, G\u00fcney Kutbu\u2019na yak\u0131n buzda tutulan metan ve karbondioksitin, al\u0131\u015f\u0131lmad\u0131k bir \u015fekilde on binlerce y\u0131l \u00f6ncesine dayand\u0131\u011f\u0131n\u0131 ifade etti.<\/p>\n Ruddiman, \u201cMetan konsantrasyonlar\u0131n\u0131n yakla\u015f\u0131k 10 bin y\u0131l \u00f6nce azalmaya ba\u015flad\u0131\u011f\u0131n\u0131 ve daha sonra 5 bin y\u0131l \u00f6nce y\u00f6n de\u011fi\u015ftirdi\u011fini; ayr\u0131ca karbondioksitin de yakla\u015f\u0131k 10 bin y\u0131l \u00f6nce azalmaya ba\u015flad\u0131\u011f\u0131n\u0131 ve sonra yakla\u015f\u0131k 7 bin y\u0131l \u00f6nce y\u00f6n\u00fcn\u00fc tersine \u00e7evirdi\u011fini fark ettim\u201d diyor ve ekliyor: \u201cBuna y\u00f6nelik yapaca\u011f\u0131m tek a\u00e7\u0131klama sera gazlar\u0131n\u0131 atmosfere sokan ve bunun ba\u015flang\u0131c\u0131 olan erken tar\u0131md\u0131r\u201d.<\/p>\n Ruddiman buna \u201cErken Antropojenik Hipotez\u201d ad\u0131n\u0131 veriyor ve yak\u0131n zamanda buna uygun olan bir dizi \u00e7al\u0131\u015fma ortaya \u00e7\u0131km\u0131\u015f. Yakla\u015f\u0131k 6 bin y\u0131l \u00f6nce Avrupa\u2019da ve yakla\u015f\u0131k 700 y\u0131l \u00f6nce \u00c7in\u2019de b\u00fcy\u00fck tar\u0131m alanlar\u0131n\u0131n ortaya \u00e7\u0131kmas\u0131yla birlikte, yayg\u0131n ormanlar yok olmu\u015f; Kuzeydo\u011fu Asya\u2019da sa\u011flam metan kaynaklar\u0131n\u0131n yay\u0131lmas\u0131 sa\u011flanm\u0131\u015f.<\/p>\n \u0130klim modellemesi sim\u00fcle edildi<\/b><\/p>\n Hipotezi test etmek isteyen Ruddiman, di\u011ferleri ile birlikte, iklim modellemesi konusunda uzman olan Vavrus ile i\u015fbirli\u011fi yaparak insan tar\u0131m\u0131nda olmasa da Holosen\u2019de neler olup bitti\u011fini sim\u00fcle etmek i\u00e7in Topluluk \u0130klim Sistemi Modeli 4\u2019\u00fc kulland\u0131. Ekip daha \u00f6nce kulland\u0131\u011f\u0131 iklim modellerinden daha y\u00fcksek \u00e7\u00f6z\u00fcn\u00fcrl\u00fck sundu ve buzulla\u015fman\u0131n alt\u0131nda yatan fiziksel s\u00fcre\u00e7ler hakk\u0131nda yeni bilgiler sa\u011flad\u0131.<\/p>\n \u00d6rne\u011fin, MIS19\u2019un bir sim\u00fclasyonunda, buzulla\u015fma, Kuzey Kutbu\u2019ndaki g\u00fc\u00e7l\u00fc so\u011futma ve ard\u0131ndan deniz buzunun ve y\u0131l boyunca kar \u00f6rt\u00fcs\u00fcn\u00fcn geni\u015flemesi ile ba\u015flad\u0131. Model, bu yaz ba\u015flang\u0131c\u0131n\u0131, yaz s\u0131cakl\u0131klar\u0131n\u0131n 5 dereceden fazla d\u00fc\u015ft\u00fc\u011f\u00fc Baffin Adas\u0131\u2019n\u0131 da i\u00e7eren Kanada tak\u0131madalar\u0131 olarak bilinen bir b\u00f6lgede g\u00f6sterdi. Vavrus, \u201cBu, jeolojik kan\u0131tlarla tutarl\u0131d\u0131r\u201d a\u00e7\u0131klamas\u0131nda bulundu.<\/p>\n \u2018\u0130leride ne olaca\u011f\u0131n\u0131 bilmiyoruz\u2019<\/b><\/p>\n Bug\u00fcn, Kuzey Kutup b\u00f6lgesi \u0131s\u0131n\u0131yor. Vavrus ve Ruddiman ise k\u00fcresel iklim d\u00f6ng\u00fcs\u00fcnde ya\u015fanan bu temel de\u011fi\u015fikli\u011fin as\u0131l nedeninin bilinmedi\u011fini s\u00f6yl\u00fcyor: Ger\u00e7ek \u015fu ki ileride ne olaca\u011f\u0131n\u0131 bilmiyoruz ve buzullar, D\u00fcnya\u2019n\u0131n bask\u0131n tatl\u0131 su kayna\u011f\u0131 olarak uzun s\u00fcredir \u2018hizmet veriyor\u2019. <\/span><\/p>\n Ruddiman, \u201c\u0130klim bilimcileri toplulu\u011fu i\u00e7in uzun ve \u00f6ng\u00f6r\u00fclebilir bir gelecekte bir sonraki buzullamay\u0131 durdurmam\u0131z olduk\u00e7a iyi; \u00e7\u00fcnk\u00fc karbondioksiti atmosfere sokmay\u0131 b\u0131raksak bile \u015fimdi ne yapaca\u011f\u0131z?\u201d diye soruyor ve ekliyor: \u201cOla\u011fan\u00fcst\u00fc ger\u00e7ek \u015fu ki belki de D\u00fcnya\u2019n\u0131n ikliminin b\u00fcy\u00fck d\u00f6ng\u00fcs\u00fcn\u00fc durdurabildik ve daha s\u0131cak, daha s\u0131cak ve daha s\u0131cak havalarda kalabildik.\u201d<\/p>\n Kaynak<\/strong><\/p>\n https:\/\/www.sciencedaily.com\/releases\/2018\/09\/180906141507.htm<\/p>\n","protected":false},"excerpt":{"rendered":" Eski tar\u0131m uygulamalar\u0131n\u0131n, \u0131s\u0131y\u0131 kesme \u00f6zelli\u011fine sahip karbondioksit ve metan gaz\u0131n\u0131n atmosferdeki yay\u0131lmas\u0131nda bir art\u0131\u015fa yol a\u00e7t\u0131\u011f\u0131 g\u00f6zlemleniyor. Binlerce y\u0131l \u00f6nce, eski \u00e7ift\u00e7iler, tar\u0131m alanlar\u0131n\u0131 bu\u011fday, m\u0131s\u0131r, patates ve kabak ekimi i\u00e7in temizlediler; pirin\u00e7 yeti\u015ftirmek i\u00e7in tarlalar olu\u015fturdular. Ayr\u0131ca bu alanlarda hayvanc\u0131l\u0131k yapmaya ba\u015flad\u0131lar. Bu faaliyetlerle, bilmeden d\u00fcnya iklimini temelden de\u011fi\u015ftirmi\u015f olabilirler. Journal of Scientific […]<\/p>\n","protected":false},"author":1576,"featured_media":29240,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19],"tags":[4050,3585,4052,4051],"class_list":["post-29239","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","tag-antik-tarim","tag-holosen","tag-kutup-bolgeleri","tag-milankovitch-dongusu"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t![\"\"](\"https:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/2018\/09\/3-6-300x225.jpg\")