{]mno\ Imem-h-ÿm hyxn-bm-\-߃ 102 tum. ]n. lcn-\m-cm-b-w ticf kwÿm\ imkv{x kmt -XnI ]cn-ÿnxn Iu kn 4600 Zi-e w ]g- -ap `qan-bn 4 henb lna-bp-k-߃ AYhm {]] w apgph a p-]mfn aqsn-in-s- p km ]ni bpkw D m-b-xmbn `ua-imkv{x ]T-\- ߃ hy -am- p- p. CXn BZy-tØXv 850 Zi-e w h jw apx 635 Zi-e wh jw hsc-bp (Proterozic) bpk-øn-emwv G hpw henb lna-bpkw D m-bn- p- -Xv. Hmtcm lna-bp-k-øn\pw XWp-Øp-d = {]]- hpw, ]n osv AXypjvW-Imem-h-ÿbpw D m-b-xmbn ]T-\-߃ kqnn- n- -p- p. `ua-imkv{x ]T-\-߃ hy - am- p- Xv G hpw HSp-hn-embn 10000-15-000 h j߃ v ap ]mwv lna-kwlxn (glaciation) D m-b-xv F mwv. Ct mƒ `qan-bn Interglacial Period AYhm c v lna-kw-lxn-iƒ n-s-bn-ep DjvWIm-em-h-ÿ-bpsS Ime-am-Wv. ASpØ Hcp lnakw-lxn (glaciation) D m-ti- Xv 50,000 h j-߃ v tij-amwv F v IW- m- s - n-cn- p p. {]mno\ Imem-hÿ imkv{xw `ua-imkv{xøns Hcp ]T-\-imJ AYhm `qan-bnse {]mno\ Imem-ÿ-sb- p-dn v ine-i-fpw, t^mkn-ep-i-fpw, AXp-t]mse Xs _mly-am w F n-h-bn \n v sxfn-hp-iƒ tij-cn v ]T-\-߃ \S-Øp- p. `qan-bn D m-b-xmbn IW- m- p ag-bp-ssbpw a n-s bpw Afhv AXp-ambn Xmc-X-ay-s -SpØn D m-ip Poh-Pm-e-ß-fp-sSbpw Imb- cn-i-in-e-i-fp-ssbpw cq]o-i-cww, `qan-bpss ]pdw ]mfn-bn (Crust) D m-ip am - ߃ F nh ]T-\-hn-t[-b-am- n-bmwv {]mno\ Imem-h-ÿ-sb- p-dn v a\-kn-em- p- -Xv. {]mno\ Imemÿm hnz-kv CØcw Imem-hÿm hyxn-bm-\-߃
]Tn v `mhn-bn D m-tb- m-hp Imem-hÿm hyxn-bm-\-tøbpw AXp-aqew D m- Im-hp am -ß-sf- p-dn pw P\-߃ v ap -dn-bn v \ In-bn-cp- p. 20000 h jw ap ]p hsc-bp Imem-h-ÿ-sb- p-dn v IrXy-amb Adnhv e`n- p-tºmƒ AXn\p ap ]p ImesØ Imem-h-ÿ-sb- p-dn- p ]T-\-߃ hfsc hnc-f-am-sw- nepw Ign 150000 h jsø Imem-h-ÿ-sb- p-dn- p GI-tZi Imcy-߃ e`y-am-wv. AXn\p ap ]p Imem-h-ÿsb pdn v A\p-am-\-߃ am{xta e`n-bv p- p- p. {]mno\ Imem-hÿm kqn-\-iƒ {]mno\ Imem-h-ÿsb a\-kn-em- p- -Xn-\mbn Poh-Pm-e-ßsf Hcp kqnn-ibmbn Icp-Xm-hp- -Xm-Wv. ]hn-g p- p-iƒ (Coral), antxmjvw-im-e-sø-bmwv kqnn- n- p- -Xv. AXp-t]mse Xs ac-ß-fpss heb߃ Imem-h-ÿ-bpsS hyxn-bm- \sø kqnn- n- p- p. I -cn-iƒ D mb Ime-L w Cu -ap (Humid) ImesØ kqnn- n- p- p. lna-]m-x-ß-fpss _m n ]{X-amb Snsse vkv XWpØ Imem-h-ÿsb kqnn- n- p- p. AXp-t]mse Xs kap{z \nc- nse Ipdhv lna-kwl-xn-iƒ D mb Ime-sØbpw kqnn- n- p- p. kqcys civan-iƒ `qan-bn ]Xn-bv p- -Xnse hyxn-bm-\-ßsf p-dn- p ]T- \-߃ hy -am- n-bn-cn- p- Xv Hcp \n nx Ime-b-fhn Xs D m-ip p F -Xm- Wv. 100000, 40000, 25000 anem timhn v ssk nƒ (Milankovitch cycles) h j-ßfpss Ime-{I-a-Øn hyxn-bm-\- ߃ D m-b-xmbn ]T-\-߃ hy -am- p- p. Cu Ime-b-f-hn `uam- -co- -Øn am -߃ D m-b-xns ^e-ambn lna-kwl-xn-iƒ pw, kap-{z-\n-c- nepw, ag-bpss txmxnepw Imcy-ambn hyxn-bm\w D m-b-xmbn ImWmw. AXp-t]mse Xs tπ v ssivtsm-wniv Ne-\-߃ Imemhÿm hyxn-bm-\-øn\v hgn h - anem timhn v ssk nƒ Xmbn ]T-\-߃ sxfn-bn- p- p. A -co- -Ønse hmx-i-ß-fmb HmIvkn-P, Hmtkm, Im _ ssu HmIvsskUv F n-h-bpss txmxn-ep- mb am w Imem-hÿm hyxn-bm-\-øn\v klmb-i-am-bn. Im _ ssuhmivssk-uns Db txmxn-ep h -\hpw lcn-x- Krlmhÿ D m- n-b-xmbn Nne ]T-\-߃ kqnn- n- n- p- v. 103
104 A n ] -X-߃, D -I-fpsS ]X-\w XpS-ßn-b-hbpw `qan-bn Imem-hÿm hyxn-bm-\øn\v Imc-W-am-bn- p- v. Znt\m-k-dp-Iƒ AS- -ap Nne kky P p Poh-Pm-e-߃ \mam-h-ti-j-am-ip- -Xn\v CØcw hyxn-bm-\-߃ Imc-W-hpam-bn- p v. Imem-hÿm Ncn{Xw 4600 Zi-e w h jw apx 542 Zi-e w hsc-bp {]oiymw-{ºn-b (Pre cambrian) bpk-øn Imem-h-ÿ-sb- p-dn v Imcy-amb ]T\ dnt m p-iƒ e`y-a-. CXn\p ImcWw Cu bpk-øn P p Pme-I-ß-tfm, Imb- -cni ine-itfm e`y-a- m-ø-xm-wv. F m Cu Ime-b-f-hn Nne lna-kw-l-xn-iƒ D m-b-xmbn A\pam-\n- -s -Sp- p. {]oiymw-{ºn-b bpkøns XpS -bmb ]mentbmtkmbniv (Paleozoic) bpk- Øn (590 240 Zi-e w h jw hsc) c v lna-kw-l-xn-iƒ D m-b-xmbpw [mcmfw ssph-ssh-hn[yw D m-b-xmbpw ImWp- p. Ic-bn kky-k-ºøv hym]n- -Xns ^e-ambn Imem-hÿm hyxn-bm-\-øn\v B w Iq n-b-xmbpw ]T-\-ßfn \n v A\p-am-\n- mw. ]men-tbm-tkm-bniv bpk-øn-emwv C y-bnse 98% Iev cnbpw D m-ip- -Xn-\p \nt ]w D m-b-xv F p- Xp Xs [mcmfw kky-k- ºØv `qan-bn Cu Ime-b-f-hn D m-b-xns sxfn-hm-wv. antkm-tkm-bniv bpk-øn (Mesozoic Era - 240-65 Zi-e w hsc) Znt\m-kdp-Iƒ AS- -ap Poh-Pm-e-߃ [mcm-f-ambn D m-bn-cp- p. antkm-tkm-bniv bpk- Øns BZy-Im-e-L- -Øn AXm-bXv ss{sbm-kniv (Triassic) ]nco-un hc DjvW-Im-em-h-ÿ-bmWv D m-bn-cp- Xv F n ]n osv Imem-h-ÿ-bn Imcy-amb hyxn-bm-\-߃ D m-b-xmbn ]T-\-߃ hy -am- p- p. ss{sbm-kniv ]nco-un kap-{z-ønse Pe-\n-c v Xmc-X-tay\ hfsc Ipd-hm-bn-cp- p. F m Ppdm-knIv (Jurassic) ]nco-un kap-{z-øn\sn-bn-ep A n-] -X-ß-fn \n p emhm-{]-hmlw aqew kap-{z-ønse Pe-\n-c v Db-cp-Ibpw AXp-hgn ISpØ {]f-b-øn-te v hgn-sh- -Xmbn `ua-imkv{x ]T-\-߃ hy -am- p- p. C m-eøv acp-`q-an-bnepw a p Xmgv {]tz-i-ß-fnepw {]f-b-sø-xp-s v Imem-h-ÿ-bn k p-en-xm-hÿ D m-b-xmbpw ImWmw. s{it jykv (Cretaceous) ]nco-uns Ah-km\ Ime-L- -ß-fn Im _ ssu HmIvssk-Uns txmxv {Iam-[o-X-ambn h n- -Xns ^e-ambn Xm]-\ne Db -Xmbn Nne ]T\ dnt m p-iƒ hy -am- p- p. Cu Ime-b-f-hnse ]T-\-cnt m piƒ ]expw hyxy-ÿ-amb coxn-bn-emwv Imem-h-ÿ-sb- p-dn v {]Xn-_m-[n- p- -Xv. F m henb D -I-fpsS ]X\w Imem-hÿm hyxn-bm-\-øn\v hgn Xpd- p-ibpw Znt\m-k-dp-I-f-S w A\-h[n Poh-Pm-e-ß-fpsS \mi-øn\p hgn h Xmbpw ImWmw. Cu Dev m-{]-hmlw A -co- -Øn kqcys\ ad-bv p- -X-c- Øn s]msn-]-s-e-߃ Db Øp-Ibpw [mcmfw Im _ AS-ßn-bn- p ]md-iƒ Dcp-Ip-Ibpw AXp-hgn Im _ ssuhmivsskuv ]pd- - -s - -Xmbpw dnt m p-ifn ImWmw. F m knt\m-tkm-bniv (Cenozoic) bpk-øn (65 Zi-e w apx CXp-h-sc) [mcmfw lnakwl-xn-i- -fpw DjvW-Im-em-ÿbpw D m-b-xmbn \ap p ImWmw. Cu bpk-øn-emwv `qan-bpss C sø cq]m- cw D m-bn- p- -Xv. `qan-
bn kkvx-\-po-hn-i-fpss Ime-L- -am-bmwv knt\m-tkm-bniv bpkw Adn-b-s -Sp- Xv. knt\m-tkm-bniv bpk-ønse BZy-`m-K-amb ]mentbmpo (Paleogene) ImeØv antxmjvw Imem-h-ÿ-bmWv IqSp-X-embn A\p-`-h-s - n- p- -Xv. F m CXns XpS -bmb \ntbm-po Ime-L- -Øn IqSp-X ssixy-im-em-h-ÿ-bmwv D mbn-cp- -Xv. CXns XpS -bmbn lna-kw-lxn (Ice Age) cq]-s -Sp-I-bp- m-bn. CØc-Øn-ep Ah-km-\sØ lna-kw-lxn D m-bxv GXm v ]Xn-s\m- m-bncw h j߃ v ap ]m-wv. Hcp lnakw-l-xn-bp-ssbpw DjvW-Im-em-h-ÿ-bp-sSbpw Imem-h[n 100000 h jambn IW- m- n-bn- p- v. knt\m-tkm-bniv bpk-øn Ah-km-\-ambn 10700 h j߃ v ap ]mwv lna-kw-lxn D m-b-xv. AXm-bXv, Ct mƒ DjvW-Im-em-h-ÿbpsS Ime-am-bmWv IW- m- -s -Sp- -Xv. XpS p hcp 50,000 h jhpw DjvW- Im-em-hÿ BIpsa v ]T-\-߃ hy -am- p- p. 19- mw \q m- n Bcw-`n hyhm-k-mbh-xv -c-whpw t^mkn C -\-߃ AYhm sslt{um Im _-Wp-I-fmb I -cn, {]Ir-Xn-hm-X-Iw, s]t{sm-fnbw XpSßn-b-h-bpsS Pze\w, h\-\io-i-cww F nh Aan-X-ambn Im _ Dƒs -ssbp lcn-x Krlhm-X-I-ß-fpsS ]pd- - -en\v hgn h p. IPCC bpss Imem-h-ÿsb- p-dn- p 1900- -sebpw 1992- -sebpw imkv{x dnt m p-iƒ kqnn- n- p- Xv Ct mgp Imem-hÿm hyxn-bm-\hpw {]mno\ Imem-hÿm hyxn-bm-\hpw Xmc-X-ay-s - Sp-Øn-bm a\p-jys CS-s]-S aqe-ap- mb am hpw, \mw Ct mƒ Pohn- p- Xv c v lna-kw-l-xn-iƒ n-s-bn-ep Ime-L- -Øn-em-b-Xn-\mepw (Interglacial Period) Bb-Xn-\mepw BtKmf Xm]-Øn-ep- mb h -\hv as mcp lna-kw-lxn C m-xm- p- -txm-ssm w kap{z \nc- n Imcy-amb h -\hpw D mipw F mwv. CXv Xmgv {]tz-i-ß-fn Pohn-bv p P\-߃ pw Poh-Pm-e-߃ pw h `oj-wnbm-wp-b Øp- -Xv. Imem-hÿ hyxn-bm-\hpw `ua-im-kv{xhpw ine-ifn (]m-d-ifn ) {]mno\ Imem-h-ÿ-bp-tS-bpw, hyxn-bm-\-ß-fp-tsbpw AS-bm-f-߃ tcj-s -Sp-Øn-bn- p- v. Imbm- -cni ine-i-fn-emwv Imem-h-ÿ-bp-ambn _ -s Hmtcm hyxn-bm-\hpw tcj-s -Sp-Øn-bn- p- -Xv. 4600 Zi-e w h jw {]mb-amb `qan-bn lna-]m-xhpw DjvWhpw amdn amdn h -Xns tcj hy -ambn Xs ine-i-fn tcj-s -Sp-Øn-bn- p- v. Ign c v ix-h j-߃ n-s-bn D mb am -߃ Imb- c ine-i-fn \S-Ønb ]T-\-߃ dnt m v snbvxn- p- v. Cu ]T-\-ß-fn \n v a\-kn-em-ip- Xv 21000 h j-߃ v ap ]v `qan-bn G hpw henb lna-]m-x-߃ D m-bn F- mwv. Hmtcm lna-]m-x- Øn\pw XpS -bmbn A -co- -Øn Im _-Wns Afhv h n- -Xns ^eambn NqSv IqSp-Ibpw lna-]m-x-߃ C m-xm-ip-ibpw (Deglaciation) snbvx-xmbn ]T-\-߃ hy -am- p- p. 105
F m Hcp Ime-b-f-hn am{xw D m-ti Im _-Wns txmxnse am w a\p-jys {]hrønaqew hfsc s]s v h n- Xv h hn]-øn-te v hnc Nq p- p. Hcp lna-]m-xhpw XpS p- mb DjvWhpw `ua-{]-{in-b-bp-ambn _ -s p InS- p {]Xn-`m-k-am-bn-cp- p-sh- nepw CXp- m- n-bn- p am -߃ \mw a\-knem-t - -Xp- v. AXn-\mbn `qan-bpss Ncn-{XsØ Ipdn v ]Tn- p-ibpw Hmtcm Ime- L- -Øn-ep- mb hn]-øp-iƒ a\-kn-em n Ct mƒ a\p-jys CS-s]-S-ep-Iƒ sim p- m-ip Imem-hÿ hyxn-bm-\-hp-ambn Xmc-X-ay-s -Sp-tØ- -Xm-Wv. {]mno\ime- Øp- mb Imem-hÿ hyxn-bm-\-øn kap{z \nc- n-ep- mb hyxn-bm-\w, Poh-Pme-߃ p- mb \mi-\jvsw F nh ]T-\-hn-t[-b-am n Imem-hÿ hyxn-bm\w sim p- m-ip B]-Øp-Isf Xncn- -dn-b-ww. 2008 `ua-{klsø ASp-Ø-dn-bm-\p h jw `qansb ASp-Ø-dn-bpI F e y-hp-ambn 2008 `ua-{k-l-øns h j-ambn U.N P\-d Akwªn {]Jym-]n- n-cn- p-i-bm-wv. temi-sø-ºmspw D m-bn-s m- n-cn- p B]-Øp-Iƒ Ipd-bv p- -Xn-\mbn {]txy-in v {]IrXn Zpc- -߃, a\pjys {]h Øn aqe-ap- m-ip Zpc- -ß-sf- p-dn v a\- n-em n Chsb t\cn-sp- -Xn-\p Xøm-sd-Sp- p-iƒ \S-ØpI F p- -XmWv `ua-h j-øns e yw. temiøv Imem-h-ÿ-bn D m-bn-s m- n-cn- p hyxn-bm-\-߃ a\p-jys {]h Øn-tbm-sSm w AX- mø taj-e-i-sf- p-dn v IqSp-X Adn-bp-Ibpw Imemhÿm hyxn-bm-\-sø- p-dn- p bym ]T-\-߃ pw `ua-h jm-n-cww Dt in- p- p. Imem-h-ÿm- hy-xn-bm\w aqew D m-im-hp B]-Øp-Iƒ Xncn- -dn-bm-\mbn `ua-im-kv{xsø IqSp-X-embn P\-ß-fn-te v FØn- p- -Xn\pw Cu hnjbw ]Tn- p- -Xn-\mbn IqSp-X hnzym n-isf BI jn- p- Xpw `ua-h jw 2008 ] XnIƒ hn`m-h\w snøp- p. Imem-h-ÿ-bn D m-bn-s m- n-cn- p hyxnbm-\-hpw, AXp-sIm v `qan v D m-tb- m-hp am hpw \mw a\- n-em- p-hm `ua-h j-øn \ap v km[n- -Ww. lna-kw-l-xn, acp-h -c-ww, kap-{z-\n-c- nse hyxn-bm\w F n-h-sb- p-dn v IqSp-X Adn-bp- -Xn\v `ua-h jw 2008 IqSp-X Ah-kcw Hcp- pw. 106