Mr. Croll believes that the last great glacial period occurred about 240,000 years ago, and endured, with slight alterations of climate, for about 160,000 years.
Crollek uste du azken glaziaraldi handia duela 240.000 urte inguru izan zela, eta, klima-aldaketa txikiekin, 160.000 urte inguru iraun zuela.