The Eruption Theory
Large volcanic eruptions can change the earth's climate. However, they have to be very large and explosive to actually affect the climate. Volanic eruption emit ash and sulphur dioxide gas. If the ash and gas rises up into the statosphere, it could be spread by high winds. This acts like a blanket, reflecting the sunlight before it hits the earth's surface. As a result of the sunlight being reflected, it cools the planet, lowering the average temperature.
The Sunspot Theory
Chinese astronomers started to record over 2000 years ago. Sunspots are black areas on the surface of the Sun. Occiasionally, the Sun has lots of these spots. At other times they disappear. More…