GEOGRAPHY FORM 1: TOPIC 5 - CLIMATE

CLIMATE

What is climate?

Climate: is the average of weather conditions (atmospheric condition) which recorded over long period of time which usually over thirty (30) to fourty (40) years in the specific geographical area.

Parameters of climate

Climate has two major parameters which are:-

i. Temperature

ii. Rainfall/precipitation 

CLIMATOLOGY

Climatology: is the scientific study of climate for a long period of time which usually over thirty (30) to fourty (40) years in the specific geographical area.

Climatologist: is a person who deal with study of climate for a long period of time which usually over thirty (30) to fourty (40) years in the specific geographical area.

THE MAIN DIFFERENCES OF WEATHER AND CLIMATE

WEATHER	CLIMATE
1. Is the condition of the atmosphere in a particular time and place.	-Is the average weather conditions of a region.
2. Weather varies from one place to another within a region	-Climate remains uniform over the region.
3. Weather changes rapidily.	-Climate change gradually/slowly.
4. There are instruments used t measure and record elements of weather.	-Elements of climate are not measured.

5. Weather cover small area.	-Climate cover large area.
6. Weather is recorded for short period of time. Normally from 24 up to 48 hours.	-Climate is recorded over long period of time. Normally over thirty (30) years.

FACTORS INFLUENCING CLIMATE OF THE PLACE

The characteristics of various type of climate are a result of the following factors:-

1. Latitude: Influences temperatures on the surface of the earth whereby the areas nearer to the Equator experience higher temperature than those far away. Shifting of the overhead position of the sun is determined by latitudes and has an influence on climate.

2. Altitude: Influences temperature and pressure of a region. Low altitude regions are warmer and experience high atmospheric pressure while high altitude areas are cooler and have low pressure.

3. Distance from the sea: Has an influence in both temperature and rainfall of a region. During summer onshore winds have cooling effect on the land which is warm. During winter the sea is warmer than the land.

4. Aspect: Aspect refers to the direction in which a slope faces e.g in The Northern Hemisphere, the Southern ward slopes are warmer than the North ward facing slopes. This is because the North slopes never receive direct sunshine as the sun in this region never gets over head. Windward slopes of highlands receive much higher rainfall than the Leeward slopes.

5. Ocean Currents: Current flowing along the Coasts tend to modify the climate of the Coastal regions. Where onshore wind blow over a cold ocean current are cooled from the below and the moisture they are carrying is condensed and dropped over the sea as rain.

6. Prevailing Winds: Wind is a medium of transfer of heat and moisture over the land. If wind is blowing from a warm region, it has the warming effects over the region it is blowing across and if wind will blow from cold region it will be cold and will cool the land over which it is blowing.

7. Human Activities: Like development of settlements, agriculture and construction of dams and creation of man made lakes have influence on climate. In recent times we are realizing the effects of human activities in causing climate change, caused by clearing of forests , draining and cultivating swamp areas, emission of Chlorofluorocarbons and other gases from factories and motor vehicles.

 

NATURAL REGIONS IN THE WORLD

Natural Regions: are geographical areas with uniform physical characteristics that differ between one and another natural regions.

CHARACTERISTICS OF NATURAL REGIONS

1. They experience similar environmental problems.

2. They characterized by having the same geographical back ground.

3. They are connected by the same latitude positions.

4. They characterized by having uniform soil and vegetation characteristics.

5. They have the same occupation such as a mining, agriculture and animal husbandry.

TYPES/ CLASSIFICATIONS OF NATURAL REGIONS

1. Equatorial Regions.

2. Tropical/savannah Region.

3. Mediterranean.

4. Hot Desert.

5. Warm Temperate Interior Region.

6. Cold Temperate Continental Region (SIBERIAN TYPE).

7. Cool Temperate West margin Region (BRITISH TYPE).

8. Cool Temperate Eastern margin Region (LAURENTIAN TYPE).

9. Warm Temperate Eastern coast margin Region (CHINA TYPE).

10. Monsoon Region.

11. Mountain Region.

12. Tundra and Polar Region.

1. EQUATORIAL REGIONS

lt located to the latitude position between 0° - 5° North and South of the equator. Example of equatorial regions include:-

i. West coastal Nigeria.

ii. Congo basin.

iii. Amazon basin.

iv. Indonesia basin.

v. Singapore basin.

 

CHARACTERISTICS OF EQUATORIAL CLIMATIC REGIONS

1. High temperature of about 27°c throughout the year.

2. Annual temperature range is up to 2°c.

3. Rainfall is heavy throughout the year.

4. The Annual rainfall is about 2000mm.

5. There is no remarkable season of the year.

6. Type of rainfall is convectional.

7. Crops grown in Equatorial region are cassava, groundnuts, maize, millet, beans, bananas, coffee, cotton, etc.

Human activities

The types of human activities found in Equatorial region are:

i. plantation agriculture.

ii. fishing.

iii. cultivation.

 

iv. Sedentary farming.

Common animals found in tropical region are: Monkey, gorillas, crocodiles, and hippopotamus. 

Example of Equatorial climate

Month	J	F	M	A	M	J	J	A	S	O	N	D	Yearl y
Temperatu re 0C	25. 5	25	25	25.5	25.5	25.5	25. 5	25. 5	26. 1	26. 1	26. 7	26. 1	25.5
Rainfall mm	19 8	337. 8	431. 8	352. 1	279. 7	231. 1	58. 4	71. 1	15. 2	12. 7	15. 2	66	2275. 8

2. TROPICAL REGION /GRASSLAND/SAVANNAH

It is found to the latitude position between 5° - 20°North and South of the equator. Example of tropical regions are:

i. East and Central Africa.

ii. Brazilian plateau,

iii. Venezuela,.

iv. North Australia.

CHARACTERISTICS OF TROPICAL REGION

1. High temperature of about 20°c - 32°c.

2. Temperature range is 8°c.

3. Total rainfal varies from 500mm to 1500mm.

4. Vegetation: tall grasses which lie dormant in dry season e.g Miombo, palm, acacia, gum tree.

3. HOT DESERT CLIMATE

Desert: is an area which receives low amount of rainfall of less than 250mm per year. It is located between 15° - 30° latitudes North and south of the equator. Hot Desert in the world are: Sahara, Kalahari, Attacama and Namibia desert.

CHARACTERISTICS OF HOT DESERT

1. Very high temperature of about 40°c during day time.

2. There is very little rainfall usually less than 250 mm per year.

3. It characterized by poor Vegetation such as scrubs, bow bow, cactus, etc.

4. The temperature range is more than 20c.

5. The daily mean temperature is up to 30c.

Crops grown are dates, palm oil, sisal, cotton, fruit trees, etc. Economic activities

Trading, mining, low agriculture over irrigation around coastal areas.

Example of hot desert climate

 

Mont h	J	F	M	A	M	J	J	A	S	O	N	D	Yearl y
Temp	21.	22.	22.	21	18.	16.	16	16	16	16.	18.	21	18.9
0C	7	8	8		9	7				7	9
Rainf all mm	0	0	0	0	0	5	7.6	12. 7	12. 7	2.5	0	0	45.7

4. MEDITERRANEAN REGION

It is found between 30° - 45° North and south of the equator around Mediterranean ocean only.

Areas found in mediterranean region include

i. South Eastern Australia.

ii. Central Chile.

iii. Central California.

iv. North and South America.

CHARACTERISTICS OF MEDITERRANEAN REGION

1. Mean temperature is about 20°c - 25°c.

2. Annual rainfall is about 500mm to 760mm.

3. Has two (2) types of climatic conditions (season) per annual.

4. They face problems like TSUNAMI.

5. Type of rainfall is cyclonic rainfall.

6. The climatic condition is dry in summer and cool wet in winter.

 

7. It is a coastal belt region.

8. Rain has 2 seasons, not throughout the year.

9. Animal found include,

Elephant, rhino, zebra, lion, buffalo.

10. Human activities found in mediterranean region are:

Tourism, agriculture, fishing and navigation.

Crops grown in mediterranean region are:

are wheat potatoes, vegetable, maize and fruit cultivation, as orange, lemon and grape fruits.

Example of Mediterranean climate

Mont h	J	F	M	A	M	J	J	A	S	O	N	D	Yearl y
Temp	21.	21.	20	17.	15	13.3	12.	13.	14.	16.	17.	20	16.7
0C	1	1		2			8	3	4	1	8
Rainf all mm	17. 8	15. 2	22. 9	48. 3	96. 5	114. 3	94	86. 4	58. 4	40. 6	27. 9	20. 3	642. 6

CLIMATE CHANGE

Climate change: refers to the slow changing in element of weather fora long period of time in a given area. It has been noted that a certain area experience a certain climatic condition. Therefore any deviation from the expected condition denotes for a climatic change. There are several evidences of climatic change. These include; rocks are found today in areas which seems to have a different climatic condition under which they formed, fossil landscape, sea level changes, shifting of vegetation belts Sahara, etc.

CAUSES OF CLIMATE CHANGE

For the factors or causes of historical climatic change, refer to the theories which explain the ice ages.

Note: However today the world is experiencing the so called “Global warming” Scientists

 

have reached a consensus on this point of global warming as a published by the International Panel on climate change (IPCC).

Global warming may refer to the world wide increase in the lower atmospheric and terrestrial temperature. This may be as a result of increase in the concentration of one or more greenhouse gases (GHG) as well as the Ozone layer depletion. Global warming is mainly theory asserts that the increasing levels of GHG will progressively trap more of the Earth's heat, gradually warming the global climate as much as 3 to 9 degrees.

However the reasons which have been put forward to explain the scenario are related to those activities which pump the GHG into the atmosphere. Therefore man through different activities carried out for his triggers off climate change.

1. Choloro Frolocarbons (CFCs) and Halons: Scientists first suggested in 1974 that the worldwide use of CFC’s and halons could be destroying the Ozone layer. In 1982, British scientist for the first time documented the existence of a large hole in the ozone layer over the Antarctica that had been theoretically predicted earlier. In this case the emitted CFC’s and halon react with the ozone in the stratosphere to be depleted which formally absorbed some incoming radiation. CFC’s is emitted from coolants in air conditioners and refrigerators, propellants in aerosol spray cans, cleaners for electronic parts such as computer chips, production and burning of plastic foam products.

2. Burning of fossil fuel: Like coal burning in industries before the introduction of alternative energy source; this could emit large amounts of GHG such as carbon dioxide and methane into the atmosphere. The industrial revolution sparked off the extraction of the coal to run the machines or industries which had sprung up. The perpetual burning meant continuous emission of carbon dioxide and sulphur hence contributing through the greenhouse effect.

3. Deforestation: This involve the clearing of vegetation and burning of grassland for either establishment of settlement/industries or agricultural activities. This results into the accumulation of carbon dioxide which would have been taken up by plants.

4. Cultivation of rice: This crop tend to release methane gas into the atmosphere.

5. Livestock farming: Animals like cattle produce methane gas due to their microbial fermentative reaction. Therefore the dumping of cow dung will release too much methane as it decomposes. Animal husbandry is thought to be responsible for much of the increase.

6. Ozone layer depletion: The chemical reactions which take place between the GHG may break down or deplete the ozone layer. This makes it thinner or drill a hole making it easier for more insolation to pass through to reach surface. Therefore the more insolution reaching the Earth’s surface, the more the temperature will increase hence climate change.

7. Industrialization: Some industries emit GHG into the atmosphere to change the climate through the greenhouse effect as well as reacting with the ozone layer.

8. Transportation: Automobile emit carbon dioxide during the combustion of fuel in the engine which act as GHG to contribute the global warming.

EFFECTS OF CLIMATIC CHANGE

The effects we feel or observe are rarely, if ever, the effects of a single factor, they are combined impacts of the whole of factors (pollutants) acting over the total life span, and frequently the effects are synergistic. For instance both plant and animals may be so stressed by climatic change and become vulnerable to other environmental factors such as attack by parasites and diseases. Given the complexity of this situation, it is extremely difficult to determine the effect of any particular factor. Nevertheless some significant progress has been made to link climate change and some effects, these may include:-

1. It can led to decline of soil fertility: Higher temperatures could reduce the water holding capacities and increase soil moisture deficits. It should be noted that climate change will alter the chemical, biological and physical properties of the soils. The expected temperature raise and related prolonged droughts will increase the rate of soil organic matter decomposition thus accelerating land and soil degradation. This will escalate soil fertility depletion result into low productivity. On the other hand, the anticipated floods in highland areas will accelerate run off and soil erosion.

2. It contributes to the loss of biodiversity: Higher temperatures and increased water deficits could mean loss of several species. This is because the exiting flora and fauna cannot adjust drastically to acclimatize to the new climatic conditions. For instance the increasing temperature may affect the aquatic animals like fish which are used to cool/cold environment. In which addition to that, the change in climate will change in the quality of the different habitats and consequently all the flora and fauna in them. The habitats may include; wetlands, forests, etc.

3. It contribute to decline of agriculture production: Agricultural activities which entirely depend on rainfall will be hit by climate change such as prolonged drought, unreliable rainfall are evident in some areas. Droughts lower the productive capacity of rain –fed agriculture hence reducing the agro exports, increasing food prices, nutritional deficiencies and destabilize the macro economies. Cereals will be hit by dry seasons hence a reduction in the production of crops. For instance according to NAPA (2007), in the Lake Victoria basin in Tanzania, maize productivity is estimated to reduce by 17% due to the anticipated climate variability manifesting in form of temperature raise and reduction in rainfall. The increase in the number of pest and diseases due to climate change is a set-back in the agricultural activities.

4. It contribute to sea level change: Rise in sea level, increase in height of storms result into more flooding especially around estuaries. Flooding affects housing, industry,

 

farming, transport and wildlife. Flooding increases the susceptibility of water borne diseases along lake shores, coastlines, and other places liable to flooding. For instance in Uganda the outbreaks of malaria, bilharzia, and other water borne diseases were reported to as often occurring during and immediately after floods, (Ugandan NAPA 2007), According to the Tanzania NAPA (2007), Malaria prevalence has been reported tom occur in areas where it was not commonly found in the previous decade for example in some parts of Kagera, Musoma, Mwanza in Tanzania; Kisumu and Kiisi in Kenya. 

In addition to the even the ice caps for instance on the Kilimanjaro Mountain has tremendously reduced as a result of accelerated ice melt. It is also anticipated to accelerate the popular ice cap melt too. During the century, sea level rose about 15 cm (6 inches) due to melting of ice and expansion of warmer waters. Models predict that sea level may rise as much as 59 cm (23 inches) during the Century, threatening coastal communities, wetlands, and coral fees. Arctic sea ice is melting. 

The summer thickness of sea ice is about half of what it was is 1950. Glacier and permafrost are melting for instance over the past 100 years, mountain glacier in all areas of the world have decreased in size and so has the amount of permafrost in the Arctic.

5. It can led to disappearance of water sources: Water is most likely to become scarce due to the increased rates of evaporation as well as the variation in the rainfall pattern in some areas. The anticipated climate variability in form of long droughts will worsen the availability of and accessibility to clean water particularly the poor or those who depend on rivers, streams, boreholes. 

This is because such source may be dried out or lowering of water levels, in springs, rivers, underground aquifers. Communities will veer to any available water irrespective of its quality hence pausing a danger for water borne diseases, harden the production of hydroelectric power, limit water transport. 

For instance the declining water levels of lake Victoria in 2002 to 2004 left many boat landing sites and harbours high and dry thus affecting water transport negatively; the extension of the Owen falls dam (Kiira and Nalubaale) opened in 2000 appears to have been designed to operate with conditions of high average water levels seen between 1960 1990 basing on the inability of the power plant to operate at full capacity during the low water levels of 2002. In Tanzania, the power cut off was extreme also as the mega like Kidatu could not operate at full capacity. This was portrayed through a more than 12 hours cut off.

6. It can led to decline of tourism industry: Normally the development of tourism industry depends on the beautiful glamorous natural features like mountains, habitats and associated flora and fauna. Climate change will distort the natural environment to as well affect the tourism sector negatively. To make matters worse, floods may destroy the roads to access the distant tourist sites. This is because most of the tourists attraction sites are located in the remote areas of which their roads are impassable during the rainy season. 

Since the rainfall pattern is unreliable and unpredictable, this will impede the movement of the tourists to such sites. The scenario will ultimately slump the economies which depend on tourism. Climate change will affect all the different sectors of a country and ultimately the micro economical status of the greatly affected areas or countries more so the developing countries. This is because they may not be robust enough to cope up with the changes hence rendering them variability and change.

7. It can led to eruption of different diseases: Due to global warming resulted in to occurrence of many health problems to people like respiratory problem, blood pressure and skin cancer.

STRATEGIES TO OVERCOME THE CLIMATE CHANGE

Strategies to address Climate change: It is responsibility for all people at a household or community level, NGO’s, government, regional groupings, and the international community at large to strive to reverse the situation. This is because everyone contributes to the existence of the problem though the magnitude of contribution differs. To make matters worse, the effects cut across i.e affects all. However it may be difficult to reverse the situation but the efforts should revolve around strategies to adapt to the climate changes as well as reducing the emission of GHG. Some of the avenues to fight climate change may include:-

1. To encourage the use of renewable energy sources: Countries should adopt the use of renewable energy resources such as solar, nuclear, biogas, geothermal, etc which are environmentally benign. In this case they should advocate against the use of fossil fuel such as coal, petroleum and natural gas which emit the GHG.

2. To apply afforestation: people should indulge in the policies which encourage the plantation of trees such as agro-forestry. This is because they act as carbon sink to minimize the amount of the carbon dioxide in the atmosphere.

3. Ambient standards: The International community should agree on the maximum amount of GHG to be emitted by a source point like an industry. In the extreme cases where the GHG can’t be curtailed, the strategy may be inevitable.

4. Use of ethanol or gasohol: The vehicles and other automobiles may replace petroleum with the use of ethanol and gasohol Biomass from sugar cane can be used for the production of ethanol which replace the usage of fossil fuel (petroleum inclusive) this will minimize the GHG which could be emitted the combustion.

5. Formulation good environmental policies: Countries should be stringent on those who emit more than the ambient standards. Abatement policies my involve the pay or cost to cater for the damage caused by the extra emissions the cost as disincentives to pollution.

6. Conducting relevant Conventions: signatories should implement accordingly. For instance the 1985 Vienna Convention on the protection of the ozone layer Depletion. The convention requires parties to take concern to the assessment of the cause, effects of ozone layer depletion as well as transmission of information and exchange of information and Technology to reduce ozone layer depletion.