Long term climate change causes

Question 1

Volcanic activity

Answer 1

large scale eruptions lead to lots of ash in atmoshere - block sunlight, reducing global temperatures

Question 2

sunspot activity

Answer 2

areas on the suns surface that send more solar radiation - less sunspot activity likely to lead to glacials

Question 3

Milankovitch cycle

Answer 3

natural changes to the earths orbit and position, effecting how much solar radiation we receive
-eccentricity (100,000) = orbit becomes elliptical (more oval) - glacials occur when orbit almost circular
-axial tilt (41,000)= angle of earths tilt changes, more tilt = interglacials as seasons more extreme
precession (21,000) = earth wobbles on its axis, altering distance from earth and sun

Question 4

Variations in composition of atmospheric gases

Answer 4

increased composition of greenhouse gases