The Köppen Climate
Classification System is the most widely used system for classifying the
world's climates. Its categories are based on the annual and monthly averages
of temperature and precipitation. The Köppen system recognizes five major
Tropical rainforest climate has no dry season – all years have an average precipitation
values of at least 250cm. Tropical rainforest climates have no pronounced
summer or winter; it is typically hot and wet throughout the year and rainfall
is both heavy and frequent. One day in an equatorial climate can be very
similar to the next, while the change in temperature between day and night may
be larger than the average change in temperature along the year. A tropical
rainforest climate is usually found at latitudes within five degrees North and
south of the equator, which are dominated by the Intertropical
Convergence Zone. In some eastern-coast areas, they may extend
to as much as 25° away from the equator. The climate is most commonly found in Southeast Asia, Central Africa and South America.
Tropical monsoon climate, occasionally
also known as a tropical wet climate is a relatively rare type of climate This type of climate results
from the monsoon winds which change direction
according to the seasons. These climates have monthly mean temperatures above
18°C in every month of the year and feature wet and dry seasons. The tropical monsoon
climate experiences abundant rainfall like that of the tropical rain forest
climate, but it is concentrated in the high-sun season. This climate has driest
months with less than 60 mm of precipitation (which nearly always occurs
at or soon after the "winter" solstice for that side of the equator)
Tropical monsoon climates are most commonly found in South Asia, Southeast Asia, Africa (particularly West and Central Africa), the Caribbean.
The tropical wet and dry or savanna has an extended dry season
during winter. Precipitation during the wet season is usually less than 1000
millimeters. A seasonal change occurs between wet tropical air masses and dry
tropical air masses. As a result, there is a very wet season and a very dry
season. Trade winds dominate during the dry season. It gets a little cooler
during this dry season but will become very hot just before the wet season.
Very prominent difference of Savanna climate from Tropical Monsoon Climate is
that tropical monsoon climate has less variance in temperatures during the
course of the year than a tropical savanna climate. Global Range: West Africa, southern Africa, South America and the
north coast of Australia.
Dry Climates The most obvious climatic feature of this climate is that potential evaporation exceeds precipitation. These climates extend
from 20 - 35° North and South of the equator and in large continental regions
of the mid-latitudes often surrounded by mountains. Minor types of this climate
Dry arid (desert) is a true desert climate. It covers 12 % of the Earth's
land surface. These latitude belts are centered on sub tropical high pressure
belt, also called as horse latitudes.
Winds are light, which allows for the evaporation of moisture in the
intense heat. They generally flow downward so the area is seldom penetrated by
air masses that produce rain. This makes for a very dry. Global Range:
southwestern United States and northern Mexico; Argentina; North Africa; South
Africa; central part of Australia.
Dry semiarid (steppe) is a grassland
climate that covers 14% of the Earth's land surface. It receives more precipitation
than the Dry arid. It can
be found between the desert climate and more humid climates. If it received
less rain, the steppe would be classified as an arid desert. With more rain, it
would be classified as a tall grass prairie (An extensive area of flat or
rolling, predominantly treeless grassland, especially the large tract or plain
of central North America). The majority
of the plants are xerophytic. This is characterised by small, spindly leaves,
with waxy layers to reduce evaporation. Trees have gnarled trunks to reduce water
loss. Extremes can be recorded in the summer of up to 40 °C and in winter, –40
°C. Besides this huge difference between summer and winter, the differences
between day and night are also very great. In the highlands of Mongolia, 30 °C
(86 °F) can be reached during the day with sub-zero °C (sub 32 °F) readings at
night. Global Range: Western North
America (Great Basin, Columbia Plateau, Great Plains); Eurasian interior, from
steppes of Eastern Europe to the Gobi Desert and North China.
Since both the above climates
are obtained in the interiors of the continents, they are also known as Dry mid-latitude Climates.
Mid-Latitude Climates This climate generally has
warm and humid summers with mild winters. Its extent is from 30 to 50° of latitude
mainly on western borders of most continents. Therefore this climate is also
referred to as Oceanic climate or Marine west coast climate. During the winter, the main weather feature is
the mid-latitude cyclone. Convective thunderstorms dominate summer months.
Minor groups are:
climate has coldest month's mean temperature to be between -3 °C and
18 °C, and the warmest month to be above 22 °C It is either
accompanied with a dry winter or has no distinguished dry season. Winter
rainfall (and sometimes snowfall) is
associated with large storms that the westerlies steer from west to east.
Most summer rainfall occurs during thunderstorms
and an occasional tropical storm,
hurricane or cyclone. These climates
normally lie on the southeast side of all continents, generally between latitudes 25° and 40° north and tend to
be located at coastal or near coastal locations. However in some cases the
climate extends well inland, most notably in China and the United States.
A Mediterranean climate is a climate that resembles those of the
lands bordering the Sea. This climate is characterized by warm to hot, dry
summers and mild to cool, wet winters. These regions receive rain primarily
during winter season from the mid-latitude cyclone. Extreme summer aridity is
caused by the sinking air of the subtropical highs and may exist for up
to 5 months. Areas with this climate receive almost all of their precipitation
during their winter, autumn and spring seasons, and may go anywhere from 4 to 6
months during the summer without having any significant precipitation. Fires occur frequently in due to dry
weather in summers. Most of the region being closer to large water bodies,
temperature range is moderate. Global
Position: central and southern California; coastal zones bordering the
Mediterranean Sea; coastal Western Australia and South Australia; Chilean
coast; Cape Town region of South Africa.
Mid-latitude Climates Moist continental
mid-latitude climates have warm to cool summers and cold winters. The location
of these climates is pole ward of the moist subtropical climates. The average
temperature of the warmest month is greater than 10° Celsius, while the coldest
month is less than -3° Celsius. Winters are severe with snowstorms, strong
winds, and bitter cold from Continental Polar or Arctic air masses. Global Position: eastern parts of the United States and southern
Canada; northern China; Korea; Japan; central and eastern Europe.
Climates Polar and arctic air masses dominate these
regions. Canada and Siberia are two air-mass sources, which fall into this
group. A southern hemisphere counterpart to these continental centers does not
exist. Polar climates have year-round cold temperatures with the warmest month
less than 10° Celsius. Polar climates are found on the northern coastal areas
of North America, Europe, Asia, and on the landmasses of Greenland and
Antarctica. Two minor climate types exist.
Polar tundra is a climate
where the soil is permanently frozen to depths of hundreds of meters, a
condition known as permafrost. Mosses, lichens, dwarf trees and scattered woody
shrubs, dominate vegetation. The winter season is long and severe. A short,
mild season exists, but not a true summer season. Global Position: arctic zone
of North America; Hudson Bay region; Greenland coast; northern Siberia
bordering the Arctic Ocean.
ice caps have a surface that is permanently
covered with snow and ice.
Global warming has more damaging effects. Increasing global temperatures are
causing a broad range of changes. Sea levels are rising due to thermal
expansion of the ocean, in addition to melting of land ice. Amounts and
patterns of precipitation are changing. The total annual power of hurricanes
has already increased markedly since 1975 because their average intensity and
average duration have increased (in addition, there has been a high correlation
of hurricane power with tropical sea-surface temperature).
Changes in temperature and precipitation
patterns increase the frequency, duration, and intensity of other extreme
weather events, such as floods, droughts, heat waves, and tornadoes. Other
effects of global warming include higher or lower agricultural yields, further
glacial retreat, reduced summer stream flows, species extinctions. As a further
effect of global warming, diseases like malaria are returning into areas where
they have been extinguished earlier.
Africa is the continent that will suffer most
under climate change. Temperature rise will trigger "sharp declines in
crop yield in tropical regions", estimated at 5 to 10 % in Africa with an
associated increase in undernourishment, malnutrition, malaria and related
deaths. Globally, Africa and Western Asia will suffer the largest crop losses,
while these regions are highly dependent on agriculture and have the largest
limits in purchasing power. Conflict and violence triggered by scarce resources
and famine will likely bring West Africa to socio-political instability.
But there are certain benefits of Global warming as well
In Greenland, where the ice is melting,
fishermen are thrilled by the return of cod and farmers are reporting higher
Higher yields of soybeans on farms in Argentina are reported. Many researchers
say if the world warms up, the sweet spots for growing crops will migrate
toward the poles.
The gross domestic product of Russia and much of northern Europe would likely
increase along with temperatures.