Climate change since the Quaternary

Climate Change since the Quaternary

A History of Earth's Climate (Incorporar)

A History of Earth's Climate (Incorporar)

The Quaternary Period

The Quaternary is the most recent period in the geological timeline of the Earth.    The Quaternary stretched from 2.6 million years ago to the present day.   The Quaternary marks a global drop in temperature and the beginning of the most recent ice age.   This period is split into the Pleistocene epoch and the Holocene epoch. 

How has the climate changed?

The Quaternary is determined to be an ice age due to the presence of a permanent ice sheet on Antarctica.   During the pleistocene epoch there were fluctuations between cold glacial periods and warm interglacial periods. This brought the expansion and contraction of ice sheets.    The Holocene marks the beginning of the current interglacial period and the current period of relative climate stability.    Evidence for this can be seen in ice cores and ocean sediment; more recent changes are often described in historical records and tree rings.

What is the evidence for this change?

Ice cores Antarctic ice cores act as a time capsule to the Earth's history; the lack of inhabitants means that there is little to no damage to these records. The ice cores can be drilled and investigated in a lab.  Oxygen isotopes in the cores are used to estimate the global temperatures of the earth in the past.  When the cores are melted, trapped gasses like carbon dioxide and methane are released, and can be measured and compared to today's levels.

Ocean sediments The principle of ocean sediment drilling works similarly to that of ice core drilling. The amount and variation of shells in ocean sediment can determine the temperature and conditions of the planet.  Ocean sediments display the interglacial and glacial periods of the quaternary when graphed.