Earth's most recent glacial period ended about _____ years ago. The Great Oxygenation Event began about ______ years ago. About ______ years ago carbon dioxide began increasing exponentially to unprecedented levels.

2.3 billion

160

11,500

Earth's most recent glacial period ended about 11,500 years ago. The Great Oxygenation Event began about 2.3 billion years ago. About 160 years ago, carbon dioxide began increasing exponentially to unprecedented levels.