Climate Change and Glacial Budgets Flashcards
What period are we living in currently. How did it begin?
The Quaternary Ice Age - began around 2 million years ago with the onset of global cooling and ice-house conditions. Plate tectonics created suitable conditions to kick start the ice age by positioning Antarctica as an isolated continent.
What is the Quaternary Period divided into
The Pleistocene - 2 million years ago -> 11,500 years ago
The Holocene - 11,500 years ago -> Current
What are glacials/interglacials, and what are stadials/interstadials?
Glacials and Interglacials are periods of warm and cool within an epoch, and stadials/interstadials are periods of warm and cool within a glacial/interglacial.
What are the 3 factors in the Milankovitch Theory
Eccentricity, axis tilt, and axial precession
What is Eccentricity
Changes in orbit - going from more elliptical to more circular every 100,000 years, changing amount of SR received from sun
What is Axis Tilt
Axis Tilt is where the tilt of Earth’s axis varies from 21.8-24.4 every 41,000 years. Affects seasonality.
What is Axial Precession
The earth wobbling, changing the point of the year at which the Earth is closest to the sun over a 21,000 year cycle.
What is a supporting point of the Milankovitch Theory
Glacials seem to have occurred every 100,000 years, in line with his Eccentricity timeline.
Limitation of the Milankovitch Theory
Impact of orbital changes on solar radiation is small, only enough to change global temps by 0.5 - 1 degree.
Explain the solar forcing explanation for shorter-term fluctuations
Solar energy varies depending on the number and density of sunspots. Records indicate the Maunder Minimum aligned with the height of the Little Ice Age. However, variations in SR due to sunspot variation is 0.1%.
Explain the volcanic causes explanation for shorter-term fluctuations
Can alter global climate as a result of global dimming. VEI 4+ eruptions eject huge volumes of gas into the atmosphere. In 1815, Tambora (Indonesia) erupted with 200 million tonnes of sulphur, cooling the Earth by 0.7 degrees.
