Climate change natural causes

Question 1

Volcanic eruption theory

Answer 1

• major volcanic eruptions lead to a brief period of global cooling, due to ash and dust high in the atmosphere blanketing the earth.
• eg. 1883: Krakatoa, reduced world temperatures by 1.2C for at least a year afterwards

Question 2

Sunspot theory

Answer 2

• Sunspots is when uneven temperatures develop on the suns surface
• they can reduce or increase the amount of solar energy put out, and therefore the temperature of the earth.
• the sunspots seem to come and go in an irregular cycle that lasts about 11 years.
• temperatures are greatest when there are plenty of spots.

Question 3

Orbital theory

Answer 3

• Changes in how the earth moves around the sun are believed to cause ice ages
• Every 100,00 years the Earth’s orbit changes from circular to elliptical (egg shaped) pattern. It is when the orbit is in the circular pattern that the ice ages are most likely to occur, because it changes how much sunlight we receive.