Did a modern-day scourge save ancient Earth?

A gas blamed for global warming may once have helped Earth escape a deep freeze, some scientists propose.

The re­search­ers claim Earth nev­er froze over com­pletely dur­ing the so-called Cryo­ge­nian per­i­od. This view con­tra­dicts the “Snow­ball Earth” hy­poth­e­sis, which claims Earth was locked in ice ow­ing to a run­away, plan­et-cooling chain re­ac­tion.

What might have let the plan­et es­cape this fate is un­clear, but the sci­en­tists point to re­cent re­search from the Uni­ver­s­ity of To­ron­to. This spec­u­lates that ad­vanc­ing ice was stalled by the in­ter­ac­tion of the cli­mate sys­tem and the car­bon cy­cle of the ocean, with car­bon di­ox­ide play­ing a key role in in­su­lat­ing the plan­et.

Car­bon di­ox­ide is by the same to­ken to­day blamed for glob­al warm­ing.

The To­ron­to sci­en­tists say that as Earth’s tem­per­a­tures cooled, ox­y­gen was drawn in­to the ocean, where it re­acted chem­ic­ally with or­gan­ic mat­ter, re­leas­ing car­bon di­ox­ide in­to the at­mos­phere.


Source: http://www.world-science.net/othernews/081130_snowball