The two factors that play the biggest role in determining climate are the amount of heat energy the sun provides and how this energy is stored and transmitted. The Earth's climate is a complex system powered by solar radiation that heats the surface of the planet.
The degree of solar radiation that reaches the Earth varies depending on the position of the Earth's orbit or changes within the Sun itself. Solar radiation that does reach the planet reacts differently depending on the nature of the surface it reaches. While heat energy typically passes through the atmosphere with little resistance, snow and ice can serve to reflect it back into space, while bodies of water such as the oceans can store and transfer this energy over a period of hundreds or years.
Other factors that play a role in determining the global climate include volcanic eruptions, the impact of living organisms and the effects of human-created industry. Global weather patterns, the proximity to ocean currents, the amount of cloud cover and humidity present also play an important role in determining climate on a regional scale. The release of man-made greenhouse gases that trap heat within the atmosphere is another factor that shapes the global climate.