Lots of oxygen does not necessarily lead to the evolution of advanced life

“Such ups and downs in oxygen contents have always taken place on Earth. However, we shall not expect any dramatic fluctuations in the future, assures Emma Hammarlund. Today there is so much of the planet’s carbon stored in underground rocks that cannot be released and react with oxygen. Only a gigantic disaster, for example if another planet crashed into Earth, could release this hard-bound carbon.”