The climate is determined by a number of factors, including how the atmosphere, oceans and continents react to the solar radiation that heats the planet. The oceans play a major role in determining long-term climate, as they transport and release stored heat slowly over hundreds of years.
Earth's climate is a very complex system involving different types of land masses, atmospheric conditions and even living organisms. The planet's climate evolved slowly over millions of years in response to both its own internal dynamics and changes brought about by external factors. Events, such as volcanic eruptions, variations in solar output and even the changes in atmospheric composition caused by industry, have all had an impact on the climate.
The climate is powered by heat from the sun. The atmosphere is able to transport heat energy very rapidly, whereas ocean currents have a much more long-term effect on the climate. Snow and ice on the planet's surface also play an important role by reflecting heat energy back into space. Even human industry has served to shape the climate of Earth, as greater amounts of heat have been trapped in the atmosphere by carbon dioxide and other greenhouse gases produced from the combustion of fossil fuels.