The Quaternary if the last period of the Cenozoic Era (2.6 Million years ago to Present). There are two Epochs in this period: Pleistocene epoch approximately 2.59 Ma (million of years ago) that marks the beginning of Ice Age, widespread glaciers and continuing orogeny and volcanism, and Recent or Holocene Epoch, major characteristic the end of Ice Age.
During the Pleistocene planet Earth is experiencing a time of tectonism and volcanism, and this process is still continuing to our present days; tectonic plates are still diverging and converging, slide passing one another at transform plate boundaries. Orogenic (the process of mountain formation) is present as well as its seismic activity and volcanic eruptions. Major geologic events during this period are the formation of the Himalayan Belt, Indian-Eurasian Plate collision, among other mountain formations. Pleistocene glaciers covered about 30 percent of the land surface mostly in the Northern Hemisphere continents.
Moreover, the temperature on Earth cool gradually during the Cenozoic Era, evidence found at deep sea cores reveal that in the last 2 million years planet Earth has had 20 major warm-cold cycles, temperatures fluctuated by as much as 10 degrees Fahrenheit. The period from about 1400 to 1900, also defined as "Little Ice Age" characterized the expansion of mountain glaciers and cooling of global temperatures, especially in the Alps, Scandinavia, Iceland, and Alaska. "...Plants and animals that sought warmth and comfort toward the Equator return to the higher latitudes. In fact, each shift alters global winds and ocean currents that in turn alter patterns of precipitation and aridity around the world...On land, the chilliest stretches of the Quaternary saw mammals like mammoths, rhinos, bison, and oxen grow massive and don shaggy coats of hair. They fed on small shrubs and grasses that grew at the ever moving edges of the ice sheets. About 10,000 years ago, the climate began to warm, and most of these so-called megafauna went extinct."
Scientists are uncertain whether the warming climate is to blame for the extinction at the end of the last ice age or is to blame humans? Modern humans were rapidly spreading around the planet during that time, in fact, the Quaternary is often considered the "Age of Humans." It is true that it is the Earth is going through a natural process of global warming, but for sure humans are 100% responsible for accelerating climate change due to the excessive burning of fuel, oil, waste, and for polluting the environment, and on top of that we are responsible for the extinction of prehistoric animals like mammoths, dire wolf, or the american Lion.
Sources: Book, Historical Geology Evolution of Earth and Life Through Time by Reed Wicander
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