Chapter 3.3 Climates of the Earth

Iceland’s climate belies the country’s name Iceland’s climate belies the country’s name. Because Iceland sits along the rift where the North American and European plates are pulling apart, it has numerous geysers and volcanoes and a ready supply of geothermal energy. In addition, Iceland is affected by the Gulf Stream. Consequently, Iceland’s winters are relatively mild and its summers are cool and sunny.

Climate Regions Tropical Climates Tropical climates are found in or near the low latitudes. The two types of tropical climates are tropical rain forest and tropical savanna. Tropical rain forests are densely wooded areas that are hot and wet year-round. Tropical savannas are grasslands that are hot year-round, dry in winter, and wet in summer.

Dry Climates Dry climates include deserts and steppes. Deserts are always dry with sparse vegetation; temperatures vary greatly from day to night and season to season, and rainfall is 10 inches (about 25 cm) or less per year. Steppes are dry grasslands that receive from 10 to 20 inches (25 to 51 cm) of rain annually.

Mid-latitude Climates Earth’s mid-latitude climates include four temperate climate regions. Regions with a marine west coast climate are cool in summer, damp in winter, and forested. Mediterranean climate regions have mild, rainy winters and hot, sunny summers.

Humid subtropical climate regions have short, mild winters and year-round rain. Those areas with humid continental climates are inland; ocean currents do not moderate their climates. Winters in these areas are generally cool to very cold; summers are hot.

High Latitude Climates The surfaces of ice cap regions are constantly covered with snow and ice. Tundra climate regions are slightly warmer than ice cap regions and can support short grasses. Subarctic climate regions, experiencing bitterly cold winters, have a long enough growing season for needled evergreens.

Highlands Climates At high altitudes, climates vary with elevation. The higher the altitude, the cooler the temperatures. The natural vegetation of these areas also varies with elevation.

Human Influence on Climate We have been affecting the climate since we appeared on this earth millions of years ago.  In those times, the affect on the climate was small.  Trees were cut down to provide wood for fires.  Trees take in carbon dioxide and produce oxygen.  A reduction in trees will therefore have increased the amount of carbon dioxide in the atmosphere. 

The Industrial Revolution, starting at the end of the 19th Century, has had a huge effect on climate.  The invention of the motor engine and the increased burning of fossil fuels have increased the amount of carbon dioxide in the atmosphere.  The number of trees being cut down has also increased, meaning that the extra carbon dioxide produced cannot be changed into oxygen.