Polar forests of the Cretaceous Polar forests of the Cretaceous Cretaceous polar forests were temperate forests that grew at polar latitudes during the final period of the Mesozoic Era, known as the Cretaceous Period 145–66 Ma. During this period, global average temperature was about higher and carbon dioxide (CO) levels were approximately 1000 parts per million (ppm), 2.5 times the current concentration in Earth's atmosphere. The abundance of atmospheric carbon dioxide had a very significant impact on global climate and Earth's natural systems as its concentration is considered one of the main factors in the development of a pronounced greenhouse Earth during the Cretaceous with
Million Years Ago (song) of my youth"". Musically, the song is an acoustic tune accompanied only by guitar. "Million Years Ago" received positive reviews from critics, with many comparing it to the music of Madonna. The song charted in Australia, Belgium, Canada, France, Finland, Germany, Hungary, Ireland, Spain, the United Kingdom and the United States. Adele performed the song during "Adele at the BBC" and on "Today". "Million Years Ago" is an acoustic tune accompanied only by guitar, finds Adele pining "for the normality of her not-so-distant childhood. Entwined with Middle Eastern twists of background hums that suggest Madonna's 'Frozen'". The song's lyrics touch