World climates and effects on human activity

Unit 3.3 & 3.4

Content Layout

• Weather and climate

• Measuring weather

• Major climate zones

• Effects of climate on human activities

Measuring weatherElement of weather Instrument Unit

Temperature Thermometer *C or *F

Precipitation Rain guage Mm

Humidity hygrometer %

Air Pressure Barometer Mb

Wind speed Anemometer Km/h

Wind direction Wind vane Vector (wind rose diagram)

Sunshine Sunshine recorded Watt/ hr

Stevenson screen

• Why we use Stevenson screen?

Weather station

Identify the input/ source of weather data and output

Weather Forecast

Using Climograph

• Interpretition of climographs helps understand the charecterstics of climate.

• Temperature is shown on a line graph, with the figures being shown on the left side of the graph.

• Rainfall is shown by a bar graph, with the figures being shown down the right side of the graph.

Temperature• Describing temperature:

• Is the temperature the same all year round ?

• Which season is the warmest?

• Is this warm (10 - 20° C), hot (20- 30° C) or very hot (30° C)?

• Which season is the coolest?

• Is this mild ( 0 - 10° C), cold (-10 - 0° C) or very cold (below -10° C)?

• What is the range of temperature? (subtract the minimum temperature from the maximum temperature)

• Write down the temperature and state if it is warm, hot etc.

Precipitation

• Describing Rainfall

• Does rainfall occur all year round?

• What is the pattern of the rainfall (i.e. which season(s) is/are drier or wetter than others)?

• Is the rainfall high, moderate or low?

• What is the total annual rainfall? (add each month's total together)

• The seasons of the year are different in the Southern hemisphere i.e. Australia's summer is November - February!!

Climograph

Major world climatesUnit 3.4

Tropical climates• Includes: Equatorial, Savanna, Monsoon and desert

• All of these areas receives high insolation throughout the year (vertical or almost vertical sunrays).

• They are distinguished from one another by the amount and distribution of rainfalls.

Tropical climates- comparative analysisEquatorial Savanna Monsoon Desert

Temperature

About 27*C

Low ATR (1-3*C)

High temperature all

year around (25 *C-

35*C)

High temperature all

year around (20 *C)

Very hot temperature

(+40 *C)

Precipitation High annual rainfall

2000+mm/year

Wet all year

Moderate annual

rainfall (500-

1000mm)

Annual precipitation

1000-3000mm

Less than 250mm per

year

Characteristic No seasonal change.

Receives 12 hrs. of

day throughout the

year

Rainfall in summer

only and long dry

season in winters.

One very wet and one

dry season.

Located on the

western side of

continent, close to the

tropics and next to a

cold current

Cool Temperate and Tundra climate• Located only in northern hemisphere.

•

Cool temperate Tundra

Temperature Short Summers temperature 14 0C and very

cold Winters below -200C.

Avg. Summer temperature below 100C

and in Winters below -300C.

Precipitation Rainfalls in summer, Annual rainfall totals

under 500mm

Irregular precipitation.

Low annual rainfall 300mm

Irregular precipitation.

Characteristic Strong, cold wind and snow blizzards.

Slightly warmer summer, the growing

season is long enough to support coniferous.

Growing season is less than 3 months.

Even mid summers are not warm enough

to encourage plant growth

Human activities

• Climate of an area directly controls basic human needs; For water supply and shelter.

• It also affects on food habits, art and culture and most importantly on human occupation.

Climatic areas Water supply Shelter

Very hot /Deserts Low From scorching sun

Very cold/ Tundra Frozen From extreme cold

Human Occupations

• In wet and warm climate, farming is the most adopted activity.

• In cold climates, people tend to live on coast and adopt fishing as an activity.

Farming systemUnit 3.5

Farming

• the activity or business of growing crops and raising livestock.

• "land was enclosed for arable farming“

Farming system

Shifting cultivation• Shifting cultivation is an agricultural system in which plots of

land are cultivated temporarily, then abandoned and allowed to revert to their natural vegetation while the cultivator moves on to another plot.

Advantages Disadvantages

• A new forest with diverse forest layer

generates soon after the land is abounded.

• Simple growing method

• No need of power/ no mechanization

involved.

• Pest management

• Organic farming

• Low output per hectare.

• More effort is required

• Not long term

• Shifting cultivation has negative impacts on

environment, e.g., deforestation, soil erosion

and other downstream effects

• Forest clearance and declining land

productivity due to soil erosion from shifting

cultivation results in low income and poverty

Subsistence farmingform of farming in which nearly all of the crops or livestock raised

are used to maintain the farmer and the farmer’s family, leaving little, if any, surplus for sale or trade. Preindustrial agricultural peoples throughout the world have traditionally practiced subsistence farming. Some of these peoples moved from site to site as they exhausted the soil at each location. As urban centers grew, agricultural production became more specialized and commercial farming developed, with farmers producing a sizable surplus of certain crops, which they traded for manufactured goods or sold for cash.Subsistence farming persists today on a relatively wide scale in various areas of the world, including large parts of sub-Saharan Africa. Subsistence farms usually consist of no more than a few acres, and farm technology tends to be primitive and of low yield.

Commercial Farming

• the production of crops and farm animals for sale, usually with the use of modern technology.

Organic vs. Commercial Agriculture• Commercial farms consume or release synthetic pesticides into the

environment — some of which have the potential to harm soil, water and local terrestrial and aquatic wildlife.

• Organic farms are better at sustaining diverse ecosystems,

• Organic food is healthier to its lack of synthetic pesticides and organic foods are minimally processed without artificial ingredients, preservatives, or irradiation to maintain the integrity of the food.

• Organic food tends to be more expensive than commercial due to the fact that organic products typically cost 10 to 40% more than similar conventionally produced products. Processed organic foods vary in price when compared to their conventional counterparts Prices may be higher because organic produce is produced on a smaller scale, and may need to be milled or processed separately. Furthermore, there is an increase in shipping costs from more centralized production in otherwise regional markets

Commercial/ Modern farming

• After the Green revolution, the entire farming world changed.

• Farmers now use the HYV seed, modern machineries, fertilizers and pesticides to increase crop yield.

Green Revolution• The term Green Revolution refers to the renovation of

agricultural practices beginning in Mexico in the 1940s. Because of its success in producing more agricultural products there, Green Revolution technologies spread worldwide in the 1950s and 1960s, significantly increasing the amount of calories produced per acre of agriculture.

• The crops developed during the Green Revolution were high yield varieties - meaning they were domesticated plants bred specifically to respond to fertilizers and produce an increased amount of grain per acre planted.

Impacts of Green Revolution

• Since fertilizers are largely what made the Green Revolution possible, they forever changed agricultural practices because the high yield varieties developed during this time cannot grow successfully without the help of fertilizers.

• Irrigation also played a large role in the Green Revolution and this forever changed the areas where various crops can be grown. For instance before the Green Revolution, agriculture was severely limited to areas with a significant amount of rainfall, but by using irrigation, water can be stored and sent to drier areas, putting more land into agricultural production - thus increasing nationwide crop yields.

• In addition, the development of high yield varieties meant that only a few species of say, rice started being grown. In India for example there were about 30,000 rice varieties prior to the Green Revolution, today there are around ten - all the most productive types. By having this increased crop homogeneity though the types were more prone to disease and pests because there were not enough varieties to fight them off. In order to protect these few varieties then, pesticide use grew as well.

• Finally, the use of Green Revolution technologies exponentially increased the amount of food production worldwide. Places like India and China that once feared famine have not experienced it since implementing the use of IR8 rice and other food varieties.

Criticism of the Green Revolution• Along with the benefits gained from the Green Revolution,

there have been several criticisms. The first is that the increased amount of food production has led to overpopulation worldwide.

• The second major criticism is that places like Africa have not significantly benefited from the Green Revolution. The major problems surrounding the use of these technologies here though are a lack of infrastructure, governmental corruption, and insecurity in nations.

• Despite these criticisms though, the Green Revolution has forever changed the way agriculture is conducted worldwide, benefiting the people of many nations in need of increased food production.

Adverse effect of modern farming practices

• Source of problem:• Overuse of chemicals, pesticides and fertilizers

• Improper irrigation plans

• Overcultivation and overgrazing

• Increasing wealth gap between rich and poor farmers

Overuse of chemicals, pesticides and fertilizers

• Contaminates soil, air and water.

• Biodiversity loss, along with the target specie many background species could be killed by pesticides.

• Can cause eutrophication.

• Can enter the food chain

• Effects human health

• May contain carcinogenic elements

Effects on human health• Certain environmental chemicals, including pesticides termed

as endocrine disruptors, are known to elicit their adverse effects by mimicking or antagonizing natural hormones in the body and it has been postulated that their long-term, low-dose exposure is increasingly linked to human health effects such as immune suppression, hormone disruption, diminished intelligence, reproductive abnormalities and cancer

• Source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984095/

Irrigation

• Salinization

• Improper management of large dams

Overgrazing and Overcultivation

• Can exhaust soil nutrients

• Results in soil erosion and degradation

• Desertification

Desertification

• Desertification: the reduction in the fertility of the land as a result of human or natural processes. Causes include overgrazing, over-cropping, gradual destruction of trees for fuel, the use of cattle dung as a fuel, deforestation and climate change.

Sustainable agricultureNext lesson

References• http://www.bbc.co.uk/bitesize/standard/geography/weather_climate/climate_zones/revision/3/

• http://oceanservice.noaa.gov/education/pd/oceans_weather_climate/media/climate_zones.swf

• http://www.yourarticlelibrary.com/essay/effect-of-climate-on-human-life/32105/.

• http://terrysunderland.com/_asset/berkas/Causes_and_consequences_of_shifting_cultivation_and_its_alternative_in_the_hill_tracts_of_eastern_Bangladesh-220811.pdf

• http://www.slideshare.net/AbhishekRaj77/shifting-final-50286856

• http://www.bbc.co.uk/bitesize/standard/geography/farming/farming_system/revision/2/

• http://www.britannica.com/topic/subsistence-farming

• http://www.lewishistoricalsociety.com/wiki/tiki-read_article.php?articleId=20#

• http://geographyfieldwork.com/GeographyVocabularyGCSEFarming.htm

• http://revisionworld.com/gcse-revision/geography/agriculture/different-types-agricultural-activity