A region's climate refers to the average weather conditions. Because of the varied quantities of heat received from the sun, different places of the Earth have distinct climates. Some climates have distinct seasons, with little or no change in precipitation and temperature. Other climates vary only slightly throughout the year. Still other climates are very stable; it rarely gets cold there, for example.
The main cause of difference in climates around the world is the distance from the equator. Near the equator, the sun is directly overhead at noon during the summer months, so there is no shadowing to prevent heat from escaping. At the same time, there is hardly any difference between day and night temperatures because the sunlight is strong enough to keep things warm even after sunset.
As one moves away from the equator, there is more hour of darkness each day, which allows for heat to be lost from the atmosphere and land surfaces. At the same time, the strength of the sunlight decreases as you move away from the equator, so that by the time you reach a latitude of about 45 degrees north or south, there is barely any direct sunlight during most of the year. It gets dark at midday due to the absence of sunlight, but not completely black like at the poles. The reason for this is that much of the planet is covered in water, which reflects some of the sunlight back toward space.
Other climates have relatively stable temperatures throughout the year, but they can be cold or hot. Still other climates have highly variable temperatures, with day-to-day and season-to-season changes that can be large enough to cause problems for humans who lack protection from the weather.
Geographic location is the main factor determining a region's climate. The angle at which a land mass intercepts the rays of the sun determines how much heat it receives, and thus what type of climate it has. If two regions have similar distances from the equator, but one faces the sun more directly than the other, then this will also affect their climate patterns.
Other factors include the amount of moisture in the air, the altitude of the land, and the configuration of the surface rocks and soil.
Many elements influence a region's climate, including the quantity of sunshine it receives, its elevation above sea level, the form of the terrain, and its proximity to the oceans. Because the equator receives more sunshine than the poles, climate changes with distance from the equator. At the top of Earth's atmosphere, near space, there is no sun around which planets orbit so Earth's climate is completely controlled by its gravity. The only place on Earth where you could have a planet-sized ice rink in the summer is near the North Pole where the sun is out for many months at a time.
Below Earth's surface, heat flows from the hot interior toward the cold exterior. As this process occurs, different layers of the earth's crust cool and contract differently, causing large scale movement called tectonics. These movements result in mountain ranges, earthquakes, and volcanic activity.
At the surface, sunlight is one of the most important factors controlling the distribution of heat within Earth. Plants use the energy from the sun's light particles, known as photons, to make their food. Most of these plants are green because chlorophyll uses light energy to break down carbon dioxide and water into carbohydrates and oxygen. Some plants such as cacti don't contain chlorophyll and thus are colorless or white. Where there aren't any plants to absorb light energy from the sun, the land becomes arid.
Climate varies across the world due to changes in the quantity of radiation received from the Sun at different places of the Earth at different times of the year. The equator receives more heat from the sun than the north and south poles, where the angle of the sun's beams is lower. This means that the atmosphere at the equator is heated up faster than it is at the poles, which causes it to expand and move away from the earth.
The amount of solar energy that reaches each region also affects how much climate varies from place to place within those regions. For example, if all else were equal, then a region would have the same average temperature as another one that received less solar energy. This is because the amount of energy that reaches the ground averages out over time.
But what happens when something interferes with this balance? If the amount of energy received by a region increases or decreases, then it can have significant effects on its climate. For example, if a region experiences an increase in solar energy but no corresponding increase in the amount of energy retained by the atmosphere (for example, if there was no change in the amount of greenhouse gases in the atmosphere), then the region would eventually reach the same average temperature as other regions that receive less solar energy.