Climate change since the Quaternary

Climate Change since the Quaternary

• A History of Earth's Climate (Enclavar)
• A History of Earth's Climate (Enclavar)

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.