L2 - Natural Change Flashcards
What are natural processes which affects how much radiation we receive from the sun?
Milankovitch cycles - eccentricity, axial tilt, precession
How does axial tilt affect climate change?
The Earth is tilted at 23 degrees, every 40,000 years the tilt changes, sometimes closer to the sun, sometimes further, the further the tilt the more pronounced the seasons are.
If there is less tilt the difference between the seasons is less.
How does eccentricity affect climate change?
The shape of the Earth’s orbit changes every 100,000 years
The orbit may be circular (warmer, inter-glacial period) or very elliptical (cooler, glacial period)
How does precession affect climate change?
The Earth wobbles on its axis, the direction the axis changes is affected, this changes every 24,000 years.
How does volcanism affect global climate change?
When volcanoes erupt, large amounts of ash and dust are released into the atmosphere blocking solar radiation, this causes a short period of global cooling.
How does surface impact, impact global climate change?
Cosmic material such as asteroids and comets will eject large volumes of dust into the atmosphere, this blocks solar radiation making the Earth’s temperature drop fast (glacial periods). E.g. the major climate change knocked out dinosaurs.
How does solar variation affect global climate change?
Sunspots are magnetic storms of the sun’s surface, they vary every 11 years with the strongest every 22 years.
When sunspots are present, solar radiation is intense, causing interglacial periods, when the sunspots disappear there are glacial periods.
