ane ▁would ▁have ▁been ▁broken ▁down ▁into ▁carbon ▁dio x ide ▁by ▁other ▁organ isms . ▁ ▁The ▁bu il dup ▁of ▁these ▁two ▁g ases ▁would ▁have ▁caused ▁o xygen ▁levels ▁in ▁the ▁ocean ▁to ▁decrease ▁dram atically , ▁while ▁also ▁increasing ▁acid ity . ▁Terr est rial ▁clim ates ▁would ▁simultaneously ▁have ▁experienced ▁rising ▁temper atures ▁and ▁significant ▁climate ▁change ▁from ▁the ▁release ▁of ▁these ▁green house ▁g ases ▁into ▁the ▁atmosphere . ▁ ▁It ▁is ▁possible ▁the ▁bu il dup ▁of ▁carbon ▁dio x ide ▁and ▁m eth ane ▁in ▁the ▁atmosphere ▁eventually ▁caused ▁the ▁release ▁of ▁hydro gen ▁sul f ide ▁gas , ▁further ▁stress ing ▁terrest rial ▁life . ▁ ▁The ▁team ' s ▁find ings ▁were ▁published ▁in ▁the ▁Pro ceed ings ▁of ▁the ▁National ▁Academy ▁of ▁Sciences ▁in ▁March ▁ 2 0 1 4 . ▁ ▁The ▁micro be ▁theory ' s ▁pro ponents ▁argue ▁that ▁it ▁would ▁better ▁explain ▁the ▁rapid , ▁but ▁contin ual , ▁rise ▁of ▁carbon ▁is ot ope ▁level ▁in ▁period ▁sed iment ▁depos its ▁than ▁vol can ic ▁er u ption , ▁which ▁causes ▁a ▁sp ike ▁in ▁carbon ▁levels ▁followed ▁by ▁a ▁slow ▁decl ine . ▁ ▁The ▁micro be ▁theory ▁suggests ▁that ▁vol can ic ▁activity ▁played ▁a ▁different ▁role ▁- ▁supp lying ▁the ▁nick el ▁which ▁M eth anos arc ina ▁required ▁as ▁a ▁c of actor . ▁ ▁Thus , ▁the ▁micro be ▁theory ▁holds ▁that ▁Si ber ian ▁vol can ic ▁activity ▁was ▁a ▁catal