MAJOR WORLD CLIMATE

THE MAJOR WORLD CLIMATIC REGIONS

Different regions of the world experience different amount of temperature and rainfall. The differences in the amount of rainfall and temperature experienced in different regions of the world make them have different climatic characteristics. This gives rise to various climatic regions around the globe. Temperature and rainfall are the main elements that determine the type of climate. Both elements vary considerably from one region to another and form a basis for classifying climate.

The five broad types of climate are hot, warm, cool, cold and arctic (very cold) climates. Each of these climates is further subdivided into different subtypes as it will be explained in detail below:

HOT CLIMATES

These are the type of climates found within the tropics, mainly between 23C° north and 23C° south of the equator. Hot climates include the following climate sub types:

vEquatorial climate

vTropical marine climate

vTropical continental climate

vTropical monsoon climate

v  Desert climate

Equatorial climate

The region is found approximately between 0° and 5° north and south of the equator. It may extend up to 10° north or south of the equator in some regions. Examples of areas found within this region include the Amazon basin (South America), and the Congo basin, the southern Ivory Coast, south Ghana, western coastal Nigeria, and eastern coastal Malagasy Republic (all in Africa).

Climatic characteristics

There are no marked seasons.

 High temperature throughout the year.

The daily temperature range.

Rainfall is heavy and is usually convection rain.

Rainfalls usually occur in the afternoons and they are accompanied by lightning and thunder.

Total annual rainfall is about 200 mm with two maxima (peaks).

High humidity and intensive cloud cover throughout the year .This climate can generally be described as hot and wet throughout the year, with a small annual temperature range.

Variations on the basic type of climate occur in the highland regions of equatorial Africa. The climate of most of these regions has an equatorial rainfall pattern.

In areas such as the south-eastern Nigeria, Cameroon, the south-east Asian islands of Malaysia, Indonesia and the Philippines, the climate is equatorial monsoon because of the seasonal reversal of winds. This results in even heavier rainfall.

Human activities carried out in the equatorial climate region include shifting cultivation and plantation agriculture.

 Crops grown in this region include yams, cassava, maize, millet, sweet potatoes, sorghum, beans, water melons, bananas and groundnuts. Examples of this type of farming is practiced in some parts of West Africa and Asia.

In plantation agriculture, crops such as cocoa, rubber and oil palms are grown on large scale farms. Most rubber plantations are found in Malaysia, Indonesia, Thailand and Srilanka. They are also found in Liberia. Cocoa plantations are found in Brazil and West Africa (Ghana, Nigeria and Ivory Coast). Oil palms are grown in Nigeria, Malaysia and Indonesia.

Rainforests are also common in equatorial regions. In Africa, the equatorial forests are found in the Democratic Republic of Congo (RDC), Gabon and some parts of West Africa.

Tropical continental climate

This climate is also known as Sudan type or Savannah climate. In the interior of the continents it is referred to as tropical continental climate.

Location: This climatic region occurs between 5oN and 15oN and 5oS and 15oS though it extends to 25o north or south of the equator. It is best developed in most parts of Africa, and some parts of South America, India and Australia.

Climatic characteristics

Hot summers (32oC) and cooler winters (21oC).

The annual temperature range is about 11oC.

The highest temperatures occur just before the rainy season begins.

Heavy rains, mainly convection, occur in the summer.Total annual rainfall is around 765mm, though this increases in the areas lying close to the equatorial climate region. Similarly, rainfall decreases towards the tropical deserts.

Humidity is high during the hot, wet season.

This climate is characterized by tall grass and trees .The savannah region is suitable for herbivores animals such as giraffes, elephants, buffaloes, rhino, zebras, antelopes, wildebeests and many other animals. There are also carnivorous animals such as lions, leopards, hyenas, etc. The region also supports a variety of species of birds, reptiles and insects.

People living in this region mainly engage in livestock keeping, cultivation and tourism. Also lumbering is practised. Many tourists come from foreign countries to view the wildlife that live in the vast grassland. Numerous national parks have been established in this region. In Tanzania, for example, there are established national parks such as Serengeti, Mikumi, Selous, Tarangire, Ruaha, Saadani, Ngorongoro, Katavi and Manyara.

The major crops grown in this region are maize, millet, groundnuts, beans, onions, cotton, tobacco, sugarcane, sisal, rice and coffee.

Tropical monsoon climate

The areas which mainly experience monsoon type of climate are South East Asia, Northern Australia, Southern China, and the Indian subcontinent. This type of climate is most marked in India.

Climatic characteristics

Seasonal reversal of winds (monsoon winds); onshore during one season and offshore during another season.

Onshore wind brings heavy rain to coastal regions while offshore winds bring little or no rain, except where they cross a wide stretch of the sea.

Temperatures range from 32ºC in the hot season to about 25ºC in the cool season, giving an annual range of about 7ºC.

Annual rainfall varies greatly, depending on relief and the angle at which onshore winds meet the highlands.

The main human activities carried out in areas experiencing this type of climate include rice growing and livestock husbandry. Apart from rice, the other crops grown are wheat, millet, maize, and sorghum.Sugarcane, cotton and juice are important lowland crops grown in India, Pakistan and Bangladesh. The other crops grown are tea (Sri-lanka, Bangladesh and India) and rubber in Malaysia. Animals kept in this climatic region include pigs, cattle, buffalos, sheep, goats, and poultry.

Tropical marine climate

Regions with this type of climate are located on the east coasts of regions lying between 10oN and 25oN and 10o S and 25oS. These areas are under the influence of onshore trade winds. The main areas are the east coasts of Brail and Malagasy, the lowlands of central American and the west indies the coast of Australia and the southern Islands of the Philippines.

Climatic characteristics

Temperature characteristics are similar to those of the equatorial climate.

Hot season temperature is 29ºC and cooler season temperature is 21ºC.

Total annual rainfall varies from 1000 mm to 200 mm depending on the location.

Rainfall is both convection and topographic (brought by onshore trade winds).

Maximum rainfall occurs in the hot season.

High humidity throughout the year.

This climate can generally be described as hot and humid throughout the year. However, the climate is cooled by the onshore winds blowing almost every day.

The main human activities carried out in this climatic region include crop cultivation, lumbering and animal rearing. The crops grown include sugarcane, rice, banana and wheat. The animals kept are such as cattle, pigs, sheep, goats and poultry.

Tropical desert climate

The tropical desert climate occurs on the western margins of landmasses between latitude 20o to 30o north and south of the equator. The climate is experienced in all the major tropical deserts of the world. The hot deserts occupy about one third of the earth’s surface. The principal tropical deserts occur on the continents as follows:

Africa: Sahara, Kalahari and Namib Deserts. Asia: the desert of Jordan, Syria, Iran, Iraq, Saudi Arabia and Israel, and the desert of India. North America: Mohave, Colorado and Mexican Deserts. South America: Atacama Desert. Australia: Great Australian Desert.

Climatic characteristics

Very little total annual rainfall (less than 120 mm in any one year)

Mean monthly temperatures range from 29ºC in the hot season to 10ºC in the cool season.

 In most deserts, daytime temperature can rise to as high as 47ºC or more.

 Night temperatures can fall to as low as 16ºC in summer and 5ºC in winter.

Very high diurnal temperature range (due to very hot days and very old nights).

The annual temperature range is large. It is about 16ºC. Humidity is always low and therefore evaporation is high.

Desert environments support very minimal human activities. Wherever water is available as in oases and along rivers, agriculture is practiced. The crops grown include date palms, cotton, rice, sugarcane, vines, millet, tomatoes, tobacco and fruits. Apart from the people who live permanently in oases, there are nomads who move from one place to another in search of pasture. They keep camels, donkeys, goats and sheep. The camel is an animal that has adapted to desert conditions. It can survive for many days without drinking water. It is mainly used for transport in the desert. Other desert people are good hunters and also collect food from the bushes.

The other activities that can be done by desert dwellers include weaving mats, making ropes, and trading.

WARM CLIMATES

Warm climates border the hot tropical deserts. They occur between 30o and 40o north and south of the equator. There are four broad types of warm climates:

Warm temperature western margin;

Warm temperature continental;

Warm temperature eastern margin; and

Warm temperature desert.

Warm temperate western margin.

This is also known as the Mediterranean climate. This type of climate occurs between 30oN and 45oN and 30oS and 40oS on the western sides of the continents. Places experiencing the Mediterranean climate are on the coastal lands around the Mediterranean Sea (the Maghreb, Spain, Italy, Greece, Egypt and Israel), the western sides of north and South America (central California and central Chile), South Australia (Perth and Adelaide) and South Africa (Cape Province).

General characteristics

Temperatures range from 21ºC in the summer to 10ºC (or below) in the winter.

 Mean annual temperature is about 15ºC.

Annual total rainfall varies from 500 to 900 mm.

 Hot, dry summers and cold, wet winters. This is because westerly winds blow off shore in the summer and on shore in the winter.

The Mediterranean climate can generally be described as having hot, dry summers and middy, rainy winters. The climate permits a wide range of crops to be grown, which include fruits and cereals. It is in this region that much of the world’s citrus fruits are grown. Citrus fruits include oranges, lemons, grapes and limes. Other fruits grown here are peaches, apricots, plums, cherries, olives, almonds and pears. The cereals include maize, wheat, rice and barley. Agriculture has given rise to specialized industries such as wine-making, flour-milling, fruit canning and food processing industries.

Warm temperate continental.

This type of climate is also known as warm temperate interior region.

Location: It occurs in the interior of the continents, between 20o and 35o north and south of the equator. The best examples of the areas having this climate are Murray-Darling lowlands of Australia; The high Veldt of South Africa; and the central Paraguay and central Argentina (South America); central lowlands of North America (Oklahoma and Texas in northern Mexico); central European lowlands, and the plains of Manchuria.

Climatic characteristics

Temperatures range from 26ºC in the summer to 10ºC in the winter.

The annual rainfall varies from 380 to 700 mm, depending on the distance from the sea.

Rainfall is convectional type and falls mainly in spring and early summer. The main economic activities carried out in this region are cattle rearing and crop growing. Tourism is also practiced.

Warm temperate eastern margin.

Location: It occurs in the eastern sides of the continents between latitudes 23o and 35o north and south of the equator. The countries having this type of climate are central China, south eastern USA, Southern Brazil, eastern part of Argentina, South Africa, southern Brazil, Eastern part of Argentina, South Africa, southern Japan, and south eastern Australia.

Climatic characteristics

Temperatures are about 26oC in summer and 13oC in the winter. The total annual rainfall varies is about 1000 mm. The rain is convectional and torrential type and it mostly falls in the summer.

Temperatures and rainfall in this type of climate make it possible to grow crops and keep animals. Lumbering is also practiced in the forested areas. The crops grown include rice, maize, cotton, sugarcane and tobacco. Animals are extensively kept in Argentina and Australia. The animals produce products such as meat, milk, butter and cheese for consumption and export.

Warm temperate desert

This type of climate is also called mid-latitude desert climate. The areas having this type of climate include Nevada and Utah states of North America and Pentagonia in South America. It is also found in regions that extend from Turkey, northern Iran, across the Caspian Sea and Aral areas into former USSR. It is also experienced in the Gobi desert of Mongolia.

COOL CLIMATES

These climates are experienced in regions between 35o north and 60o south of the equator. They are characterized by definite seasonal variations in temperature. There are four types of cool climates:

·      Cool temperate continental (British type);

·      Cool temperate continental (Siberian type);

·      Cool temperate eastern margin (Laurentian type); and

·      Temperate desert.

Cool temperate western margin.

It occurs on the western sides of the continents between 45o and 60o north and south of the equator. Areas with this type of climate include North West Europe, British Columbia in western Canada, Southern Chile, Tasmania, and the south Island of New Zealand.

Climatic characteristics.

Winter temperatures range between 2ºC and 7ºC, while summer temperatures range from 13ºC to 15ºC.

The annual temperature range is between 8ºC and 11ºC.

Rain falls throughout the year, with maxima in winter.

The total annual rainfall is about 760 mm.

The rain is both conventional and cyclonic in nature.

People living in this region engage in a myriad of economic activities which include agriculture, mining, lumbering, manufacturing and commerce. Agriculture is extensive and includes keeping of beef and dairy cattle and sheep and the growing of wheat, barley oats, vegetables and fruit farming.

Cool temperate continental.

This type of climate is found extensively in the northern hemisphere. It occurs in the interiors of North America and Eurasia between 35º and 60ºN.

Climatic characteristics

Moderately warm summers (18º) and very cold winters (-19ºC).

The annual temperature range is very high (37ºC).

Most of the rain falls in the summer.

The rain is convectional type and is often accompanied with thunder.

The annual precipitation (rain plus snow) ranges from 400 to 500 mm.The main human activities in this region include lumbering fishing, mining and some agriculture.

Cool temperate western margin.

It occurs on the eastern sides of the continents between 35oN and 5oN, and south of 40oS. It is experienced mainly on the eastern sides of North America and Asia.

Climatic characteristics

Winter temperatures range from -10ºC to 4ºC.

Summer temperatures range from 12ºC to 24ºC.

The annual temperature range is large and averages 24ºC.

Precipitation (in the form of rain and snow) is distributed throughout the year.

Annual precipitation varies between 700 and 1000 mm. Rainfall is both conventional and cyclonic.

The main economic activities in this region are farming, mining, and manufacturing. The crops grown include wheat, maize, millet and soya beans. Sheep farming.  Mining and manufacturing are practiced where minerals are found.

Temperate desert.

This climate occurs in the interiors of Eurasia and North America, and in Patagonia (South America).

Climatic characteristics

 Winters are very cold with temperatures often below -7ºC.

Summer temperatures vary between 25ºC and 37º

 Precipitation is very low, it averages about 250 mm.

 Most of the rain falls in late winter and early spring.

The human activities carried out in this region include mining, animal rearing and some agriculture. The animals reared are such as camels, donkeys, sheep and goats. The main crops grown in this region are date palms, oil palms, and millet. Agriculture is mostly practiced in oases and along river valleys.

COLD CLIMATES

Cold climates are mainly experienced in regions between latitudes 60ºN and 68ºN.There are three types of cold climates:

§  Cold temperate western margin;

§  Cold temperate continental; and

§  Cold temperate eastern margin.

Cold temperate western margin

This climate is confined to coastal areas of Scandinavia and Alaska.

Climatic characteristic

 Short, cold summers with temperatures of about 12ºC.

 Long winters with temperatures ranging from -2ºC to 4ºC.

Annual rainfall is about 750 mm.

Rain falls in most months except the winter when show falls.

The main economic activities practiced in this region include agriculture, mining and manufacturing. Dairy cattle farming is mainly practiced in the Scandinavian countries such as Norway Denmark and Sweden.

Cold temperate Continental.

This climate occurs between 55oN and 68oN in the interior of America and Eurasia.

Climatic characteristics

Cold and long winters with temperatures ranging between -34ºC and -45ºC.

Warm and short summers with average temperatures up to 21ºC.

Annual precipitation is very low, about 380 mm. (d) Most of the rainfalls in summer, but in winter, precipitation is in the form of snow.

Cold temperate eastern margin.

This climate occurs in the north east pacific of Russia.

Climatic characteristics.

Long, cold winters with an average temperature as low as -20ºC or below.

Short, hot summers with an average temperature up to 21ºC or higher.

 Total annual rainfall varies between 500 and 1000 mm.

ARCTIC CLIMATES

These types of climates are experienced in regions beyond the Arctic Circle (661/2oN) and around Arctic Ocean. They are also known as polar deserts. The main features of these climates are low amounts of precipitation (rain), mild summers and very cold winters. Arctic climates comprises of Tundra and Polar climates.

Tundra climate

This region occurs in the northern coast of North America, southern coast Greenland and the Arctic coast of Europe and Asia.

Climatic characteristics

Very long, cold winters with temperatures ranging between -29ºC and - 40ºC.

Short, cool summers with temperatures of about 10ºC.

Annual precipitation is 250 mm; some of it falls as snow in winter and as rain in summer.

Polar climate

It occurs in the interiors of Iceland, Greenland and Antarctica.

Climatic characteristics

Temperatures are permanently below 0ºC.

Precipitation is in the form of blizzards (now storms).

The winters consist of continuous night, and summers of continuous day. Because temperatures are very low, most these regions are uninhabited and hence limited human activities take place here. The natural occupations are hunting, fishing and herding of reindeer.

Mountain climate

This type of climate occurs in the main mountain areas of the world.

The areas that experience such climates include the East Africa Mountains, the Ethiopian highlands, the mountains and plateaus of central Asia, the Alps of Europe, the Andes of South America and the Rockes of North America.

Climatic characteristics.

 Pressure and temperature generally decrease with increase in altitude. Precipitation increases with altitude. In areas around mountains within the tropic, temperatures may range from high at the foot of a mountain to very cold at the peak, e.g. Mount Kilimanjaro.