Past causes of climate change
If a volcanic eruption is large and explosive enough ash and gas can rise and spread around the earth, in the stratosphere, by high level winds.
The blanket of ash and gas stop some sunlight reaching the earths surface and reflects it back into space.
This means that the planet is cooled and the temperature is lowered. In general the climate will only be affected for a few years.
The earth's orbit changes very gradually over a long period of time, and can affect the amount of sunlight that reaches the earth and where the sunlight falls. The three way the orbit changes:
The earth's orbit is sometimes circular, and sometimes more of an eclipse.
The earth's axis tilt and means the earth can sometimes be more upright and sometimes be more on its side.
The earth's axis wobbles.
Little ice age
Impact on People:
- food ran out- livestock died and crops couldn't be harvested.
- New crops had to be grown- potato.
- Trade links were blocked by sea ice.
- Frozen rives were used as a new form of entertainment.
Impact on the enviroment
- Rivers and lakes froze
- Sea levels fell
- Animals and plants died
Asteroid collisions and solar output
If a large enough asteroid hits the earth is can cause a thick cload of ash and dust to be released into the atmosphere.
Effect on climate
The dust and ash would cool the climate as only a limited amount of sunlight would be able to pass through.
How long would it last?
It would be similar to a large volcanic eruption and could last between 5 and 10 years.
The activeness of the sun changes, and these changes can be measured through the amount of sun spots seen on the sun.
Effect on climate
cooler periods such as the little ice age and warmer periods such as the medieveal warm period could have been caused by sun spot activity.