page_title: Late Cenozoic Ice Age
section_title: Glaciation of the southern hemisphere
hierarchical_section_title: Late Cenozoic Ice Age / Glaciation of the southern hemisphere
caption_attribution_description: English: Collection: NASA Scientific Visualization Studio Collection.Compilation of NASA stills, film and video, created in partnership with Internet Archive.Image n.a003402. This image shows a view of the Earth on September 21, 2005 with the full Antarctic region visible. Description: This matching pair of images showing a global view of the Arctic and Antarctic . The images also show the sea ice in the date at which it was at its minimum extent in the northern hemisphere.
context_page_description: The Late Cenozoic Ice Age, or Antarctic Glaciation began 33.9 million years ago at the Eocene-Oligocene Boundary and is ongoing. It is Earth's current ice age or icehouse period. Its beginning is marked by the formation of the Antarctic ice sheets. The Late Cenozoic Ice Age gets its name due to the fact that it covers roughly the last half of Cenozoic era so far.
  Six million years after the start of the Late Cenozoic Ice Age, the East Antarctic Ice Sheet had formed, and 14 million years ago it had reached its current extent. It has persisted to the current time.
  In the last three million years, glaciations have spread to the northern hemisphere. It commenced with Greenland becoming increasingly covered by an ice sheet in late Pliocene During the Pleistocene Epoch, the Quaternary glaciation developed with decreasing mean temperatures and increasing amplitudes between glacials and interglacials. During the glacial periods of the Pleistocene, large areas of northern North America and northern Eurasia have been covered by ice sheets.
context_section_description: Australia drifted away from Antarctica forming the Tasmanian Passage, and South America drifted away from Antarctica forming the Drake Passage.  This caused the formation of the Antarctic Circumpolar Current, a current of cold water surrounding Antarctica. This current still exists today, and is a major reason for why Antarctica has such an exceptionally cold climate.
  The Eocene-Oligocene Boundary 33.9 million years ago was the transition from the last greenhouse period to the present icehouse climate. At this point CO₂ levels had dropped to 750 ppm. This was the beginning of the Late Cenozoic Ice Age. This was when the ice sheets reached the ocean, the defining point.
  33 million years ago was the evolution of the thylacinid marsupial (Badjcinus).
  The first balanids, cats, eucalypts, and pigs came about 30 million years ago.  The brontothere and embrithopod mammals went extinct at this time.
  At 29.2 million years ago, there were three ice caps in the high elevations of Antarctica.  One ice cap formed in the Dronning Maud Land.  Another ice cap formed in the Gamburtsev Mountain Range.  Another ice cap formed in the Transantarctic Mountains.  At this point, the ice caps weren't very big yet. Most of Antarctica wasn't covered by ice.
  By 28.7 million years ago, the Gamburtsev ice cap was now much larger due to the colder climate.
  CO₂ continued to fall and the climate continued to get colder. At 28.1 million years ago, the Gamburtsev and Transantarctic ice caps merged into a main central ice cap. At this point, ice was now covering a majority of the continent.
  28 million years ago was the time period in which the largest land mammal existed, the Paraceratherium.
  The Dronning Maud ice cap merged with the main ice cap 27.9 million years ago. This was the formation of the East Antarctic Ice Sheet.
  25 million years ago brought about the first deer. It also was the time period in which the largest flying bird existed, the Pelagornis sandersi.
  Global refrigeration set in 22 million years ago.
  20 million years ago brought about the first bears, giraffes, giant anteaters, and hyenas. There was also an increase in the diversity of birds.
  The first bovids, kangaroos, and mastodons came about 15 million years ago. This was the warmest part of the Late Cenozoic Ice Age, with average global temperatures around 18.4 °C (65.1 °F). This is about 3.4 °C (6.2 °F) warmer than the 2013-2017 average. Atmospheric CO₂ levels were around 700 ppm. This time period was called the Mid-Miocene Climatic Optimum (MMCO).
  By 14 million years ago, the Antarctic ice sheets were similar in size and volume to present times. Glaciers were starting to form in the mountains of the Northern Hemisphere.
  The Great American Interchange began 9.5 million years ago (with the highest rate of species crossing occurring around 2.7 million years ago). This was the migration of different land and freshwater animals between North and South America.  During this time, armadillos, glyptodonts, ground sloths, hummingbirds, meridiungulates, opossums, and phorusrhacids migrated from South America to North America. Also, bears, deer, coaties, ferrets, horses, jaguars, otters, saber-toothed cats, skunks, and tapirs migrated from North America to South America.
  Around 7 million years ago, the first potential hominin,Sahelanthropus is estimated to have lived.
  The australopithecines first appear in the fossil record around 4 million years ago, and diversified vastly over the next 2 million years. The Mediterranean Sea was dry between 6 and 5 million years ago.
  Five million years ago brought about the first hippopotami and tree sloths. Elephants, zebras, and other grazing herbivores became more diverse. Lions, members of the genus Canis, and other large carnivores became more diverse. The burrowing rodents, birds, kangaroos, small carnivores, and vultures increase in size. There was a decrease in the number of perissodactyl mammals, and the nimravid carnivores went extinct.
  The first mammoths came about 4.8 million years ago.
  The evolution of the ''Australopithecus'' occurred four milli
caption: Antarctica from space on 21 September 2005
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