Climates of the World

    Climate is an essential aspect to understanding the world around us. It is the long term summation of weather patterns for a region.  It affects the region physically (i.e. vegetation and soil patterns) and culturally (i.e. agriculture and population).  Can you think of a few things in your own life that are affected by climate?  Try the inverse: can you think of anything in your life that is completely unaffected by climate?  Climate is the single most important physical component of our world that shapes human lifestyles and behaviors.
     The study of climates or "climatology" is one of the most important branches of physical geography.  Two key factors are crucial in defining climate.  Weather refers to the day-to-day changes in the atmosphere of a place. Climate, on the other hand, refers to the annual pattern of atmospheric conditions in a place. Different climate classifications are primarily based upon (1) the seasonal variations in temperature, and (2) the annual rainfall amount and seasonality--that is,what time of the year the rain comes.  Temperature is determined by the length of time the sun's most intense rays are focused on a area. Precipitation is the amount of rain and snow a region receives.   The major factors which influence temperature and precipitation, and therefore shape climate, are (1) Latitude, (2) Air Masses & Ocean Currents, (3)Continentality , and (4) Topography.

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Based on latitudinal variation you just read about above, there are 3 major subdivisions of climate; the tropics, mid latitudes and polar.  Each has distinctive characteristics which make it unique.  Vegetation, animal life and people all exist in each. Please link to these pages to learn more in depth about the climate of each subregion.

In tropical latitudes(those near the equator), there is little difference in the amount of solar heating between summer and winter. Average monthly temperatures therefore do not change much during the year. However, amount and seasonality of precipitation vary greatly, and is the reason that  we further subdivide the tropics into Tropical Rainforests, Monsoon, and Savanna.

 In mid-latitudes, from the Tropic of Cancer to the Arctic Circle and from the Tropic of Capricorn to the Antarctic Circle, solar heating is considerably greater in summer than in winter. Mid-lats experience seasonal shifts between warm summers and cool winters.

In polar latitudes, north of the Arctic Circle and south of the Antarctic Circle, the sun never rises during large portions of the year. Therefore, the contrast in solar heating between summer and winter is extreme. Summers are cool to mild, and winters are bitterly cold. In addition, daylight hours  in the summer are close to 24 hours and in the winter there are times when the sun does not rise; short, cool summers; long, frigid winters.

VEGETATION The subdivisions of climate that you read about above are based on differences in climate, but also differences in vegetation, making them more of a climate/biome division.  A biome is characterized by particular plant and animal types, usually named for a region's climate or dominant vegetation type.  As you might have gathered, climate is the most important factor in determining type of vegetation that an area can support--which in turn affect animal life it can support.

To grow, plants depend on the two most important elements of a climate: heat and water.  Thus, the differences in availability of heat and water account for the great diversity of plant life and biomes around the world--forests, savannas, woodlands, deserts, swamps, tundras, grasslands, etc.  The figure above is an excellent matrix showing some of the associations among temperature, water availability, and vegetation characteristics.  The distribution of animal species is strongly influenced by the distribution of vegetation.  And let's not forget humans--vegetation, especially the edible kind,  has affected human settlement in terms of availability of food and other resources that vegetation supplies us.