British researchers from Cardiff University said that the oceans could be to “blame for 100,000 year ice age” intervals, Daily Mail reported.

They mentioned that they could think of the oceans as inhaling and exhaling carbon dioxide, so when the ice sheets were larger, the oceans had inhaled carbon dioxide from the atmosphere, making the planet colder.

When the ice sheets were small, the oceans had exhaled carbon dioxide, so there was more in the atmosphere which made the planet warmer.