Climate change during the Quaternary period

Climate Change During the Quaternary Period

Understanding the Quaternary Period

  • The Quaternary period began around 2.6 million years ago and continues to the present day.
  • It is noted for being a period of recurring glacial and interglacial epochs.
  • The Quaternary period is divided into two epochs: the Pleistocene and the Holocene.
  • The Pleistocene epoch, often referred to as the Ice Age, was characterised by periods when large parts of the Northern Hemisphere were covered by ice sheets.
  • The Holocene epoch, which began around 11,700 years ago and continues to the present, is characterised by a warmer climate and the evolution and expansion of human populations.

Climate Change Throughout the Quaternary Period

  • During the Pleistocene epoch, there are evidences of at least 20 glacial periods interspersed with warmer interglacial periods.
  • These glacial periods were characterised by the growth of extensive ice sheets, especially in the Northern Hemisphere.
  • Interglacial periods were marked by warmer global temperatures and major retreats of these ice sheets.
  • The causes of these shifts between glacial and interglacial periods are thought to be related to changes in Earth’s orbit and tilt, solar radiation, ocean currents and concentrations of greenhouse gases.
  • The most recent glacial period ended around 11,700 years ago, marking the start of the Holocene epoch, a time of warmer and more stable climate.
  • However, even during the Holocene, there have been periodic fluctuations in temperature, such as the Medieval Warm Period (AD 950 to 1250) and the Little Ice Age (AD 1300 to 1850).

Impact of Quaternary Climate Change

  • The climate changes of the Quaternary period have had dramatic impacts on the world’s geography.
  • Ice sheets and glaciers have eroded landscapes, creating valleys, cliffs, and moraines.
  • The variation in temperature and precipitation patterns has also greatly influenced the distribution of ecosystems and species.
  • Sea levels have also fluctuated significantly during this period, leading to changes in coastlines and the formation of land bridges which have allowed species, including early human populations, to migrate across continents.

Quaternary Climate Change and Human Evolution

  • Human evolution and migration have been strongly influenced by the climate changes of the Quaternary period.
  • Homo sapiens has existed for approximately 300,000 years, therefore, humanity has lived entirely within the Quaternary period.
  • Climate changes, particularly the fluctuation between glacial and interglacial periods, have directed human evolution, forced migration, and shaped human societies and cultures.