EXPLORE: Natural Causes for Climate Change

1. Introduction

Several natural processes may affect Earth's temerature. In fact, natural processes are responsible for climate changes throughout most of Earth's past. Here are several natural causes for climate change:

1. Sunspots. Sunspots are storms on the sun. When the number of sunsspots is high, the sun gives off more energy than usual. There is little evidence that links significant climate changes to sunspot activity, but it is an area of active research.
2. Plate movements. Continents drift closer to the poles or the equator over time. Ocean currents also shift when continents drift. All these changes can affect Earth's global temperature.  Also, plate movement triggers volcanic activity. A huge eruption could spew so much gas and ash into the air that little sunlight would reach the surface for months or years. This could lower Earth's temperature.
3. Asteroid. A large asteroid hitting Earth would throw a lot of dust into the air. This could block sunlight and cool the planet.
4. Earth's rotation on its axis. Earth goes through regular changes in its position relative to the sun. Its orbit changes slightly. Earth also wobbles on its axis of rotation. The planet also changes the angle it is tilted on its axis. These changes can cause alterations to Earth's global temperature.
5. Natural greenhouse gas concentrations fluctuate. This (in addition to human caused greenhouse gas emissions) can raise global temperatures. 

Source: Climate Change. Retrieved from http://www.ck12.org/section/Climate-Change-%253A%253Aof%253A%253A-MS-Climate/ on August 27, 2013.